UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2023

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO

Commission File Number 001-37746

APTEVO THERAPEUTICS INC.

(Exact name of Registrant as specified in its Charter)

Registrant’s telephone number, including area code: (206) 838-0500

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ No ☒

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes ☐ No ☒

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or emerging growth company. See the definition of “large accelerated filer”, “accelerated filer”, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒

The aggregate market value of common stock held by non-affiliates of the Registrant as of June 30, 2023, the last business day of the Registrant’s most recently completed second fiscal quarter, was $11 million, based upon the closing price of the Registrant’s common stock on the Nasdaq Stock Market LLC on June 30, 2023, the last trading day of the fiscal quarter.

Excludes an aggregate of 79,986 shares of the Registrant’s common stock held as of such date by officers, directors, and stockholders that the registrant has concluded are or were affiliates of the Registrant. Exclusion of such shares should not be construed to indicate that the holder of any such shares possesses the power, direct or indirect, to direct or cause the direction of the management or policies of the Registrant or that such person is controlled by or under common control with the Registrant.

As of March 5, 2024, the number of shares of Registrant’s common stock outstanding was 23,472,436.

DOCUMENTS INCORPORATED BY REFERENCE

Table of Contents

In this Annual Report on Form 10-K, “we,” “our,” “us,” “Aptevo,” and the “Company” refer to Aptevo Therapeutics Inc. and, where appropriate, its consolidated subsidiaries.

PART I

Cautionary Note Regarding Forward-Looking Information

This Annual Report on Form 10-K includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended (the Exchange Act). Statements in this Annual Report on Form 10-K, other than statements of historical facts, including statements regarding our strategy, future operations, including the timing of future clinical trials, future financial position, future revenues, projected costs, prospects, plans, intentions, expectations, and objectives could be forward-looking statements. The words “anticipates,” “believes,” “could,” “designed,” “estimates,” “expects,” “goal,” “intends,” “may,” “plans,” “projects,” “pursuing,” “will,” “would” and similar expressions (including the negatives thereof) are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements are based upon management’s assumptions, expectations, projections, intentions, objectives and/or beliefs about future events or occurrences and are subject to a number of risks and uncertainties. The timing of certain events and circumstances and known and unknown risks and uncertainties could cause actual results to differ materially from the plans, intentions, expectations and objectives underlying or disclosed in the forward-looking statements that we make. Therefore, you should not place undue reliance on our forward-looking statements. Some factors that we believe could cause actual results or events to differ materially from our forward-looking statements include, but are not limited to, those discussed in “Risk Factors”, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and elsewhere in this Annual Report on Form 10-K. Our forward-looking statements in this Annual Report on Form 10-K are based on current information and we do not assume any obligation to update any forward-looking statements except as required by the federal securities laws.

You should read the following discussion and analysis together with the financial statements and the related notes to those statements included elsewhere in this Annual Report on Form 10-K.

Item 1. Business.

OVERVIEW

We are a clinical-stage, research and development biotechnology company focused on developing novel immunotherapy candidates for the treatment of different forms of cancer. We have developed two versatile and enabling platform technologies for rational design of precision immune modulatory drugs and have two clinical candidates and three preclinical candidates currently in development. Clinical candidate APVO436 is a CD3xCD123 T-cell engager currently being clinically evaluated for the treatment of acute myelogenous leukemia (AML). Clinical candidate ALG.APV-527 targets 4-1BB (co-stimulatory receptor) and 5T4 (tumor antigen). The compound is designed to reactivate antigen-primed T-cells to specifically kill tumor cells and is currently being evaluated for the treatment of multiple solid tumor types.

Preclinical candidates, APVO603 and APVO711, were also developed using our ADAPTIR™ modular protein technology platform. Our preclinical candidate APVO442 was developed using our ADAPTIR-FLEX™ modular protein technology platform.

Our ADAPTIR and ADAPTIR-FLEX platforms are designed to generate monospecific, bispecific, and multi-specific antibody candidates capable of enhancing the human immune system against cancer cells. ADAPTIR and ADAPTIR-FLEX are both modular platforms, which gives us the flexibility to potentially generate immunotherapeutic candidates with a variety of mechanisms of action. This flexibility in design allows us to generate novel therapeutic candidates that may provide effective strategies against difficult to treat, as well as advanced forms of cancer. We have successfully designed and constructed numerous investigational-stage product candidates based on our ADAPTIR platform. The ADAPTIR platform technology is designed to generate monospecific and bispecific immunotherapeutic proteins that specifically bind to one or more targets, for example, bispecific therapeutic molecules, which may have structural and functional advantages over monoclonal antibodies. The structural differences of ADAPTIR molecules over monoclonal antibodies allow for the development of ADAPTIR immunotherapies that are designed to engage immune effector cells and disease targets to produce signaling responses that modulate the immune system to kill tumor cells.

We believe we are skilled at candidate generation, validation, and subsequent preclinical and clinical development using the ADAPTIR platform and the ADAPTIR-FLEX platform to generate bispecific and

multi-specific candidates or other candidates to our platform capabilities. We have developed a preclinical candidate based on the ADAPTIR-FLEX platform which is advancing in our pipeline. We are developing our ADAPTIR and ADAPTIR-FLEX molecules using our protein engineering, preclinical development, process development, and clinical development capabilities.

STRATEGY

We seek to grow our business by, among other things:

Advancing our lead clinical blood cancer candidate, APVO436, through clinical development to evaluate its therapeutic potential alone and in combination with other therapies. Based on the positive results from our Phase 1 dose escalation and dose expansion studies, we plan to initiate a dose optimization Phase 1b/2 trial in the first half of 2024, in frontline AML patients who will receive a combination of APVO436 + Venetoclax + Azacitidine to assess safety and efficacy of APVO436 and to determine an optimal dose.

Advancing our lead solid tumor candidate, ALG.APV-527, developed in partnership with Alligator Bioscience AB (Alligator), further in the clinic. Aptevo and Alligator continue to investigate ALG.APV-527 for the treatment of multiple solid tumor types with 5T4-tumor expressing antigens. This drug candidate is in an ongoing first-in-human Phase I clinical trial that started in the first quarter of 2023. We are currently enrolling new patients. ALG.APV-527 targets the 4-1BB co-stimulatory receptor (on T lymphocytes and NK cells) and 5T4 (solid tumor antigen) and is designed to promote anti-tumor immunity. Aptevo believes this compound has the potential to be clinically important because 4-1BB can stimulate the immune cells (tumor-specific T-cells and NK cells) involved in tumor control, making 4-1BB a particularly compelling target for cancer immunotherapy.

Continued development and advancement of our preclinical candidates, APVO603 (targeting 4-1BB (CD137) and OX40 (CD134), both members of the TNF-receptor family), APVO442 (targeting Prostate Specific Membrane Antigen (PSMA), a tumor antigen that is highly expressed on prostate cancer cells and CD3), and APVO711 (an anti-PD-L1 x anti-CD40 compound). We continue to advance APVO603 and APVO442 through preclinical and IND-enabling studies. In January 2023, we filed a provisional patent with the U.S. Patent and Trademark Office (USPTO) pertaining to APVO711. In January 2024, the provisional patent was amended to include new preclinical data and a patent application under the Patent Cooperation Treaty ("PCT") was filed pertaining to APVO711, which has the potential to treat a range of solid malignancies such as head and neck cancer. APVO711 is a dual mechanism bispecific antibody candidate that is designed to provide synergistic stimulation of CD40 on antigen presenting cells while simultaneously blocking the PD-1/PD-L1 inhibitory pathway to potentially promote a robust anti-tumor response. Preclinical studies are planned to further evaluate the mechanism of action and efficacy of APVO711.

Development of novel bispecific and multi-specific proteins for the treatment of cancer using our ADAPTIR and ADAPTIR-FLEX platforms. We have expertise in molecular and cellular biology, immunology, oncology, pharmacology, translational sciences, antibody engineering and the development of protein therapeutics. This includes target validation, preclinical proof of concept, cell line development, protein purification, bioassay and process development and analytical characterization. We focus on product development using our ADAPTIR and ADAPTIR-FLEX platforms. We plan to generate additional monospecific, bispecific, and multi-specific protein immunotherapies for development, potentially with other collaborative partners, to exploit the potential of the ADAPTIR and ADAPTIR-FLEX platforms. We will select novel candidates that have the potential to demonstrate proof of concept early in development. We expect to continue to expand the ADAPTIR and ADAPTIR-FLEX product pipelines to address areas of unmet medical need. Bispecific therapeutics are increasingly recognized as potent anti-cancer agents. Nine new bispecific agents have been approved for use by the FDA in the last three years and there is a total of 125 bispecific drug candidates currently in development. We believe our candidates in development and our future molecules derived from our ADAPTIR and ADAPTIR-FLEX platforms will be highly competitive in the market as they are rationally designed for safety and tolerability as well as efficacy.

Establishing collaborative partnerships to broaden our pipeline and provide funding for research and development. We intend to pursue collaborations with other biotechnology and pharmaceutical companies, academia, and non-governmental organizations to advance our product portfolio.

PRODUCT CANDIDATES AND PLATFORM TECHNOLOGY

PIPELINE

Product Portfolio

Our current product candidate pipeline is summarized in the table below:

Product Candidates

Our pipeline includes investigational clinical and preclinical stage anti-cancer drug candidates with clinical impact potential for treating both hematologic malignancies, also known as “liquid” tumors, and solid tumor malignancies.

APVO436. APVO436 is a bispecific ADAPTIR that is designed to engage CD3 and CD123 to redirect T-cells to destroy leukemia cells expressing the target CD123 molecule on their surface. We have completed a multi-center, multi-cohort Phase 1b dose expansion clinical trial to evaluate APVO436 in adult patients with AML both as monotherapy and in combination with current standard-of-care therapies (APVO436-5001). This antibody-like recombinant protein therapeutic candidate is designed to engage both leukemia cells and T-cells of the immune system and activate T cells via CD3 only when engaging CD123 to trigger the destruction of leukemia cells as well as leukemic stem cells. Importantly, CD123 is not only expressed on the leukemic blast cells but is also expressed on leukemic stem cells. APVO436 has been engineered using our proprietary ADAPTIR platform technology and is uniquely designed to reduce the likelihood and severity of cytokine release syndrome (CRS). APVO436 has received orphan drug designation ("orphan status") for the treatment of acute myelogenous leukemia from the U.S. Food and Drug Administration (FDA). In the first half of 2024, we plan to initiate a Phase 1b/2 trial, beginning with a dose optimization study, in patients who will receive APVO436 in combination with Venetoclax and Azacitidine.

The Company observed positive clinical data from its Phase 1b dose expansion trial, which was completed in 2023. The safety profile and efficacy data in a heavily pretreated population is summarized in the table below.

APVO436 was generally well tolerated, with the highest response rate of 82% composite clinical remission (Composite CR) and 73% complete remission/complete remission with incomplete hematologic recovery (CR/CRi) observed in Cohort 2 in Venetoclax naïve patients, where we saw 91% clinical benefit.

The table below shows the final patient response rate to APVO436 treatment for patients enrolled in Cohorts 1, 2, and 3:

There were 44 patients enrolled in the expansion cohorts 1, 2, 3, and 5 who are part of the safety population and received at least one dose of APVO436. The median number (range) of administered APVO436 cycles were 1.0 (1–4), 2.0 (1–4), 2.0 (1–4), and 3.0 (3–3) for Cohorts 1, 2, 3, and 5, respectively. The most common TEAEs (reported in ≥20%) were pyrexia (48%), fatigue (39%), chills (32%), hypokalemia (32%), anemia (29%), nausea (27%), thrombocytopenia (27%), neutropenia (25%), febrile neutropenia (23%), oedema peripheral (23%), constipation (23%), hypocalcemia (21%), hypomagnesemia (21%), and diarrhea (21%). Twelve of the 44 patients treated developed Cytokine Release Syndrome (CRS). The majority of cases were mild to moderate (grade 1 or 2). However, one patient experienced a treatment related grade 5 CRS event, although this case was highly confounded by sepsis and pneumonia which made a causality assessment difficult.

A potential complication associated with treatment using bispecific, T cell engaging antibodies is a systemic inflammatory syndrome known as CRS. CRS may occur within minutes to hours after infusion of the bispecific T cell engaging antibody or emerge as a delayed onset complication after several days. Clinical manifestations of CRS may range from mild to severe including hypotension, hypoxia, and uncontrolled systemic inflammatory response with circulatory collapse, vascular leakage, peripheral and/or pulmonary edema, renal failure, cardiac dysfunction, and fatal multiorgan system failure. Heart failure can also be a consequence of the systemic inflammatory syndrome of CRS. Another form of systemic inflammation a bispecific T cell engaging antibody can cause is Hemophagocytic Lymphohistiocytosis (HLH)/Macrophage Activation Syndrome (MAS) which shares many clinical and laboratory features with CRS. HLH/MAS is considered a form of CRS when it occurs after treatment with a bispecific T cell engaging antibody.

CRS cases occurred in some APVO436 patients in both the dose escalation as well as the dose expansion phases. These patients were effectively treated using the generally recommended standard CRS treatment, which includes the use of tocilizumab and dexamethasone, combined with standard supportive care. This has been confirmed to be generally effective in the APVO436 patients that have experienced CRS.

On November 26, 2019, the FDA granted Orphan Drug Designation for the treatment of acute myelogenous leukemia to APVO436, which grants us potential exclusive marketing and development rights, as well as eligibility for market exclusivity upon FDA approval of APVO436.

ALG.APV-527. ALG.APV-527 is a novel investigational bispecific ADAPTIR candidate, developed in partnership with Alligator Bioscience AB (Alligator), featuring a mechanism of action designed to simultaneously target 4-1BB (CD137) and 5T4, a tumor antigen overexpressed in several different types of cancer. 4-1BB, a co-stimulatory receptor on T cells, is known to enhance the immune response to cancer through activation of tumor-specific T cells and is believed to be a promising target for new immunotherapeutic approaches. ALG.APV-527 could potentially have utility in the treatment of a broad spectrum of cancers over-expressing the 5T4 tumor antigen, including malignant pleural mesothelioma, non-small cell lung, gastric/gastro-esophageal, head and neck squamous cell carcinoma, pancreatic, renal, ovarian, prostate, breast, cervical, colorectal, endometrial, and bladder cancers.

ALG.APV-527 Phase 1 Clinical Trial Overview:

Multi-Center, Multi-Cohort Phase 1 Open-Label Clinical Trial

4-1BB is a particularly compelling target for cancer immunotherapy. We designed ALG.APV-527 to overcome limitations of the 1st generation 4-1BB monospecific mAbs by improving the efficacy as 5T4-dependent 4-1BB signaling confers T-cell and NK cell stimulation at the tumor site.

ALG.APV-527 is as potent as urelumab but demonstrates 5T4-dependent 4-1BB signaling. In vitro, this is demonstrated in assays with primary T cells and NK cells that secrete inflammatory cytokines, proliferate, produce cytotoxic granules only when 5T4-expressing tumor is present. In vivo, our molecule can induce a robust, long-term antitumor response and does not induce a systemic T cell stimulation like urelumab.

Aptevo and Alligator continue to advance ALG.APV-527 for the treatment of solid tumors and commenced a first-in-human study started in the first quarter of 2023. We continue to enroll additional patients across the United States.

APVO603. APVO603 is a preclinical dual agonist bispecific ADAPTIR candidate designed to simultaneously target 4-1BB (CD137) and OX40 (CD134), both members of the TNF-receptor family. Dual targeting of 4-1BB and OX40 provides synergistic co-stimulation of T cells with the potential to amplify the cytotoxic function of activated T cells and NK cells, potentially leading to robust anti-tumor responses. APVO603’s combined activation of both the 4-1BB and OX40 TNF receptors represents an attractive approach in potentially overcoming the immunosuppressive tumor microenvironment. The targeted co-stimulation of 4-1BB and OX40 has the potential to promote an important immunological cascade, enhancing T cell activation, prolonging T cell survival, and improving tumor cell killing. Of note, this product candidate is not dependent on any one tumor antigen and has the potential to treat multiple solid tumors. IND-enabling studies continue for APVO603.

APVO442. APVO442 is a novel bispecific candidate based on the ADAPTIR-FLEX platform technology that binds to PSMA with two identical binding domains and with one binding domain to CD3 with reduced binding affinity. This candidate was designed to increase biodistribution of drugs to PSMA positive tumors for treatment of prostate cancer. The low-affinity single binding domain to CD3 has the potential to allow for increased concentrations at the tumor due to reduced binding of the drug by circulating peripheral T cells. Preclinical studies are being concluded and demonstrate in vitro RTCC that is directed to PSMA bearing tumor cell lines in vitro and in animal tumor models. IND-enabling studies are beginning.

APVO711. APVO711 is a preclinical dual mechanism bispecific ADAPTIR candidate that is designed to provide synergistic stimulation of CD40 on antigen presenting cells while simultaneously blocking the PD-1/PD-L1 inhibitory pathway to potentially promote a more robust anti-tumor response. Preclinical studies both in vitro and in vivo will continue to provide us a better understanding of the mechanism of action and the efficacy of APVO711.

PLATFORM TECHNOLOGIES

Platform Technology

ADAPTIR and ADAPTIR-FLEX Platform Technologies. The ADAPTIR and ADAPTIR-FLEX platform technologies can be used to produce monospecific, bispecific, and multi-specific immunotherapeutic proteins. These protein candidates bind to one or more targets on tumor cells, immune cells, or other cells in circulation to either amplify, suppress, or otherwise regulate the body’s defense mechanisms to treat cancer. We focus on developing drugs for treatment of oncology indications, but also may pursue other indications, including inflammatory diseases. We believe we are well positioned for the development of monospecific, bispecific, and multi-specific therapeutics, which are antibody-based molecules that can bind one or more targets of therapeutic interest, utilizing our innovative ADAPTIR (modular protein technology) and ADAPTIR-FLEX platform technologies. This allows us to take an innovative approach to cancer immunotherapy or treatment of other diseases.

ADAPTIR and ADAPTIR-FLEX molecules are similar to antibodies; they can exhibit similar therapeutic properties to an antibody but can be easily modified to either eliminate or incorporate activities, while maintaining a similar size, stability, half-life and manufacturing advantages of a monoclonal antibody. The ADAPTIR molecules are single-chain polypeptides comprising customized elements, including a protein domain that binds to one or more targets connected to the hinge domain and a set of antibody constant domains known as the fragment crystallizable region, or Fc region of a human antibody. A second protein binding domain can be connected to the Fc region using a linker. The antibody Fc region can elicit an immune response by binding to the corresponding Fc receptors found on various immune cells such as natural killer (NK) cells, and other cells bearing Fc receptors to mediate antibody-dependent cell cytotoxicity resulting in killing the target. With the ADAPTIR platform, the Fc region can be modified to enhance or eliminate these functions. Incorporation of the Fc region into the ADAPTIR platform also provides for an extended serum half-life by engaging recycling via the neonatal Fc receptor or FcRn. A longer serum half-life could potentially reduce dosing frequency and dose quantity. The ADAPTIR-FLEX molecules are comprised of at least two polypeptides that are comprised of customized elements similar to ADAPTIR candidates. The Fc region of these molecules can be modified to enable formation of a stable heterodimer. These candidates have similar mutations in the Fc region as ADAPTIR candidates to enable or eliminate binding to Fc receptors but retaining binding to FcRn to provide for an extended serum half-life.

The ADAPTIR platform technology enables the design of both monospecific and bispecific bi-valent protein therapeutics.

Bispecific ADAPTIR molecules are similar in structure to monospecific ADAPTIR molecules, with the exception that they have two customized target binding domains on the ends of the Fc region. We have created several bispecific molecules that are able to redirect T cell cytotoxicity (RTCC). T cells are white blood cells that fight infections and tumor cells. RTCC ADAPTIR molecules are designed to activate T cells to specifically kill tumor cells. The RTCC ADAPTIR does so by binding to a common T cell component CD3, a receptor complex that activates T cells, when engaging a specific tumor antigen on a specific tumor via the second binding domain, thereby activating the T cell to kill the tumor cell.

Our ADAPTIR-FLEX platform technology extends advantages of ADAPTIR technology to create protein therapeutics with varied specificity and valency and potentially new modes of action.

ADAPTIR-FLEX molecules are composed of two different polypeptides that form a hetero-dimer through modifying specific sequences in the Fc region of each polypeptide. Each end of the polypeptide may contain one or two different binding domains, enabling the ADAPTIR-FLEX molecules to bind up to four targets. In addition, the ADAPTIR-FLEX platform can be used to modify the valency of binding to each target, which means it can bind a target, through one binding domain or through multiple binding domains, to a specific target to enable modifying the strength of binding to a specific target.

We believe that ADAPTIR and ADAPTIR-FLEX are promising platform technologies within the rapidly growing field of immuno-oncology therapeutics. The structural differences between ADAPTIR and ADAPTIR-FLEX molecules and monoclonal antibodies allow for the development of new immunotherapies that engage disease targets in a novel manner and produce a unique signaling response. By customizing the binding domains of our molecules, we can select the desired potency, half-life, toxicity and stability/manufacturability. We have the potential to develop products with mechanisms of action including, but not limited to, redirected T cell cytotoxicity (RTCC), modulating signals through immunostimulatory or immunoinhibitory receptors and targeted cytokine delivery. We believe we can expand our ADAPTIR and ADAPTIR-FLEX platforms to generate monospecifics, bispecifics, or multi-specifics that target tumor antigens in combination with co-stimulatory molecules, including TNF-Receptor family members and other activating or inhibitory signaling receptors. We believe the ADAPTIR and ADAPTIR-FLEX platform technologies may prove to have advantages over other immunotherapies and other bispecific T cell engaging technologies. In preclinical studies, our data indicates that APVO436, a RTCC ADAPTIR bispecific that binds CD123, may have high potency and activity at low doses with reduced cytokine release compared to other bispecifics targeting the same tumor antigen and CD3. The ADAPTIR and ADAPTIR-FLEX monospecifics, bispecifics, and multi-specifics can be produced using standard manufacturing practices. Further clinical and preclinical studies may not confirm the anticipated benefits of this platform.

Our ADAPTIR and ADAPTIR-FLEX platform intellectual property (IP) portfolio consists of IP that we solely own and control, with the exception of non-exclusive licenses to Chinese hamster ovary (CHO) cell lines and related expression systems, and a non-exclusive license to certain transgenic rodents of Open Monoclonal Technology, Inc.’s (OMT) OmniAb platform, which we non-exclusively license from various third parties. See “Intellectual Property” for additional information about the ownership rights to ADAPTIR and ADAPTIR-FLEX platform intellectual property.

Competition

We face, and will continue to face, intense competition from both U.S.-based and foreign producers of both large and small molecule immune oncology products, some of which have lower cost structures, greater access to capital, greater resources for research and development, and sophisticated marketing capabilities. Any product candidate that we successfully develop and commercialize is likely to compete with currently marketed products, as well as other novel product candidates that are in development for the same indications.

APVO436: We anticipate that APVO436 would compete with other agents targeting both CD123 and non-CD123 that are in development if they are also approved. Competitors developing antibody therapies targeting CD123 include: Affirmed, Arcellx, AvenCell, Cellectis, Macrogenics, Inc. / Gilead, ImmunoGen, Menarini Group and Sanofi. Competitors developing non-CD123 antibody therapies include Novartis, Bio-Path, Shattuck Labs, Syros Pharma, Faron Pharma and ALX Oncology. Additionally, there are companies and institutions developing gene and CAR-T therapies that may potentially be competitive with APVO436.

ALG.APV-527: This asset targets 4-1BB in a bispecific format when cross-linked with the tumor antigen 5T4. We anticipate that ALG.APV-527 would compete with bispecifics targeting 5T4 and 4-1BB, which are currently in preclinical development such as by Crescendo Biologics. Companies developing bispecifics in the clinic targeting 5T4 include GenMab and Abbvie. In addition, other competitors include bispecifics targeting 4-1BB in combination with other targets such as 4-1BB x FAP (FAP is expressed on tumor associated stromal fibroblasts). 4-1BB x FAP is currently in Phase 1 clinical development by Molecular Partners and Amgen and Hoffmann-La Roche (RO7122290). PD-L1 x 4-1BB is currently in Phase 1/2 clinical development by BioNTech / Genmab and Pieris / Servier. Another bispecific targets 4-1BB x HER2, which is in phase 2 clinical development by Pieris for treatment of HER2+ solid tumors.

Furthermore, we face significant competition in the oncology market in general, including from the following: Affimed, AstraZeneca, Bristol Myers Squib, F-Star Biotechnology Ltd., Genentech Inc., (a subsidiary of F. Hoffmann-La Roche Ltd.), Genmab A/S, Gilead Sciences Inc., GlaxoSmithKline plc, ImmunoGen, Inc., Johnson & Johnson, Macrogenics, Inc., Sanofi-Aventis US LLC, Regeneron Pharma, Xencor, Inc. and Zymeworks Biopharmaceuticals, Inc. Additionally, there may be other potential competitors or companies developing competitive products such as ADCs that may not be known to us at this time.

COLLABORATIONS WITH ALLIGATOR BIOSCIENCE

On July 20, 2017, our wholly owned subsidiary Aptevo Research and Development LLC (Aptevo R&D), entered into a collaboration and option agreement (the Collaboration Agreement) with Alligator Bioscience AB, (Alligator), pursuant to which Aptevo R&D and Alligator are collaboratively developing ALG.APV-527, a lead bispecific antibody candidate simultaneously targeting 4-1BB (CD137), a member of the TNFR superfamily of a co-stimulatory receptor found on activated T cells, and 5T4 a tumor antigen overexpressed in a number of different types of cancer. This product candidate is built on our novel ADAPTIR platform. A first-in-human clinical study of ALG.APV-527 started in the first quarter of 2023. We continue to enroll new patients across the United States. ALG.APV-527 targets 4-1BB (T lymphocyte co-stimulatory receptor) and 5TA (tumor antigen) and is designed to reactivate antigen-primed T cells.

Subject to certain exceptions for Aptevo R&D’s manufacturing and platform technologies, the parties jointly own intellectual property generated in the performance of the development activities under the Collaboration Agreement. Under the terms of the Collaboration Agreement, the parties intend to share revenue received from a third-party commercialization partner equally, or, if the development costs are not equally shared under the Collaboration Agreement, in proportion to the development costs borne by each party.

The Collaboration Agreement also contains several points in development at which either party may elect to “opt-out” (i.e., terminate without cause) and, following a termination notice period, cease paying development costs for this product candidate, which would be borne fully by the continuing party. Following an opt-out by a party, the continuing party will be granted exclusive rights to continue the development and commercialization of this product candidate, subject to a requirement to pay a percentage of revenue received from any future commercialization partner for this product, or, if the continuing party elects to self-commercialize, tiered royalties on the net sales of this product by the continuing party ranging from the low to mid-single digits, based on the point in development at which the opt-out occurs. The parties have also agreed on certain technical criteria or “stage gates” related to the development of

this product that, if not met, will cause an automatic termination and wind-down of the Collaboration Agreement and the activities thereunder, provided that the parties do not agree to continue.

The Collaboration Agreement contains industry standard termination rights, including for material breach following a specified cure period, and in the case of a party’s insolvency.

INTELLECTUAL PROPERTY

We rely on a combination of patents, trademarks, trade secrets, and nondisclosure and non-competition agreements to protect our proprietary intellectual property and will continue to do so. We own or exclusively license the patents and patent applications in our patent portfolio that support the ADAPTIR-FLEX platform, ADAPTIR platform and pipeline products with the exception of certain cell line rights and other research tools, which we license on a non-exclusive basis. We practice patent life cycle management by filing patent applications to protect new inventions relating to meaningful improvements to our products and related methods. We primarily seek patent protection for inventions that support our products and product candidates, but from time to time, we may seek patent protection for inventions that could, for instance, support a potential business opportunity or block a competitor from designing around our existing patents.

In general, and where possible, we pursue patent protection in countries where we believe there will be a significant market for the corresponding product or product candidate. We generally do not seek patent protection in countries where we have reason to believe we would not be able to enforce patents. For instance, we tend to not file in countries that are frequently listed on the Priority Watch List of the Special 301 Report prepared by the Office of the United States Trade Representative, with the exception that we typically file patent applications in China. We may also decide to take a narrower filing approach for secondary and improvement type inventions as compared to inventions that are more foundational to our products. We do not seek patent protection in countries that are on the United Nations, or U.N., list of Least Developed Countries.

The term of protection for various patents associated with, and expected to be associated with, our marketed product and product candidates is typically twenty years from the filing date, but may vary depending on a variety of factors, including the date of filing of the patent application or the date of patent issuance and the legal term of patents in the countries in which they are obtained. The protection afforded by a patent varies on a product-by-product basis and country-to-country basis and depends upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory-related extensions, the necessity for terminal disclaimers, the availability of legal remedies in a particular country, and the validity and enforceability of the patents.

In some cases, we may decide that the best way to protect our intellectual property is to retain proprietary information as trade secrets and confidential information, rather than to apply for patents, which would involve disclosure of proprietary information to the public. When determining whether to protect intellectual property as a trade secret, we consider many factors including, for instance, our ability to maintain the trade secret, the likelihood that a competitor will independently develop the information, our ability to patent protect the intellectual property and the likelihood we would be able to enforce a resulting patent.

We are a party to a number of license agreements under which we license patents, patent applications, and other intellectual property. These agreements impose various commercial diligence and financial payment obligations on us. We expect to continue to enter into these types of license agreements in the future.

ADAPTIR and ADAPTIR-FLEX Platforms. We protect the ADAPTIR platform technology through a combination of patents and trade secrets. We own all ADAPTIR and ADAPTIR-FLEX platform intellectual property, with the exception that we have licenses to certain intellectual property related to third-party research tools that we use in conjunction with our ADAPTIR platform technology such as cell lines, vectors, expression systems, and transgenic rodents. For instance, we have a non-exclusive commercial license and research license with Lonza Group AG (Lonza) related to its CHO cell lines and vectors. Under our Lonza research license, we have an option to take a license to use the GS System to develop and manufacture therapeutic proteins for our commercial purposes. We also have a non-exclusive license to certain transgenic rodents of OMT’s OmniAb platform.

The initial version of the ADAPTIR platform technology was originally developed by Trubion Pharmaceuticals, Inc. (Trubion) prior to its acquisition by Emergent BioSolutions Inc. (Emergent). A patent family supporting use of unique linkers in the homodimer (a molecule consisting of two identical halves) version of the ADAPTIR platform was invented jointly by Trubion and Wyeth Pharmaceuticals, Inc. (Wyeth) as part of a collaboration between the two

companies. Wyeth assigned the rights it had in that platform patent family to Trubion. We subsequently received the rights to the platform patent family upon our spinoff from Emergent.

In order to differentiate our platform inventions from antibodies and other antibody-like constructs that have been publicly disclosed, many of our patents and patent applications are directed to unique aspects or components of our platform such as linkers, targets, or binding domains.

We have patents relating to the ADAPTIR platform issued in the United States, Australia, Canada, Hong Kong, Israel, Japan, Mexico, New Zealand, Russia, Singapore, South Africa and South Korea. We also have applications pending in various territories including Brazil, Canada, and Norway. We plan to continue to improve our ADAPTIR platform and to file patent applications on those improvements. Our decision as to where to file any new ADAPTIR improvement inventions will be based in part on the significance of the improvement. If patents issue on the pending ADAPTIR patent applications, the patent term for those patents are estimated to expire between 2027 and 2039. As our ADAPTIR platform technology evolves, we may decide to allow patent applications and patents to expire if they contain claims that are limited to aspects of the platform that are no longer of value to Aptevo.

ADAPTIR-FLEX, our heterodimer platform, is covered by patent application under the Patent Cooperation Treaty (PCT) that we filed in 2021, which was nationalized in 2023 in various countries and territories including the United States, Europe, Japan, China, Australia, and Canada. If patents claiming priority to the pending ADAPTIR-FLEX patent application are issued, the resulting patents are estimated to expire in 2041.

We own patent families directed to use of particular binding domains in the ADAPTIR and ADAPTIR-FLEX platforms. For instance, we have some patents that cover the use of an ADAPTIR therapeutic to target CD3. We also have pending patent applications that cover ADAPTIR therapeutics containing our preferred humanized CD3 binding domain polypeptide sequences.

APVO436. We nationalized our core patent family, which covers the APVO436 product candidate in various countries and territories including the United States, Australia, Brazil, Canada, China, Colombia, Eurasia, Europe, Hong Kong, India, Indonesia, Israel, Japan, Malaysia, Mexico, New Zealand, Philippines, Singapore, South Africa, South Korea, Ukraine, and Vietnam.

ALG.APV-527. We co-own with Alligator a patent family corresponding to PCT application PCT/EP2018/069850, which covers the ALG.APV-527 product candidate. In January and February of 2020, this patent family was nationalized in various countries. Aptevo and Alligator also co-own U.S. patent 10,239,949, which relates to protein molecules that specifically bind to 5T4 and/or 4-1BB and U.S. patent 11,312,786, which relates to the 4-1BB binding domain.

In addition to the co-owned assets, Alligator owns a patent family corresponding to PCT application PCT/EP2017/059656, which also covers ALG.APV-527. Aptevo has an exclusive license from Alligator to this patent family for the development of the ALG.APV-527 product candidate.

Preclinical Therapeutic Candidates. We routinely file United States provisional patent applications and/or Patent Cooperation Treaty (PCT) patent applications on our preclinical therapeutic assets when we believe we have sufficient data to support a patent application filing. Aptevo owns pending patent applications for its APVO603 therapeutic candidate, which was nationalized in various countries and territories, as well as APVO442 and APVO711 therapeutic candidates.

Trademarks owned by Aptevo Therapeutics Inc. and its subsidiaries. Where possible, we pursue registered trademarks for our marketed products in significant markets. We own trademark registrations and pending applications for the marks: APTEVO THERAPEUTICS, APTEVO BIOTHERAPEUTICS, APTEVO RESEARCH AND DEVELOPMENT, the Aptevo logo, ADAPTIR, and ADAPTIR-FLEX in relevant jurisdictions.

REGULATION

Regulations in the United States and other countries have a significant impact on our product development, manufacturing, and marketing activities. Government authorities in the United States, at the federal, state, and local level, and in other countries, extensively regulate, among other things, the research, development, testing, approval, manufacture, packaging, storage, recordkeeping, labeling, advertising, promotion, distribution, marketing, import, and export of biopharmaceutical products. In addition, sponsors of biopharmaceutical products participating in Medicaid and Medicare are required to comply with mandatory price reporting, discount, and rebate requirements. The processes for obtaining regulatory approvals in the United States and in foreign countries, along with compliance with applicable statutes and regulations, require the expenditure of substantial time and financial resources. In the United States, the FDA regulates biopharmaceutical products under the Federal Food, Drug, and Cosmetic Act, or FDCA, the Public Health Services Act, or PHSA, and their implementing regulations. FDA’s requirements and expectations with respect to product development are constantly evolving.

U.S. Product Development for Therapeutics

The process required by the FDA before a biologic may be marketed in the United States generally involves the following:

Preclinical Testing. Before beginning testing of any compounds with potential therapeutic value in human subjects in the United States, stringent government requirements for preclinical data must be satisfied. Preclinical testing includes both in vitro, or in an artificial environment outside of a living organism, and in vivo, or within a living organism, laboratory evaluation and characterization of the safety and efficacy of a drug and its formulation, as well as its chemistry, pharmacology, and toxicity. We perform preclinical testing on all of our product candidates before we initiate any human trials.

Investigational New Drug Application. Before clinical testing may begin, the results of preclinical testing, together with manufacturing information, analytical data and any other available clinical data or literature, must be submitted to the FDA, as part of an IND. The sponsor must also include an initial protocol detailing the first phase of the proposed clinical investigation, together with information regarding the qualifications of the clinical investigators. The provided data must provide an adequate basis for evaluating both the safety and the scientific rationale for the initial clinical studies in human volunteers. The IND automatically becomes effective 30 days after receipt by the FDA unless the FDA imposes a clinical hold within that 30-day time period. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. Clinical holds also may be imposed by

the FDA at any time before or during trials due to safety concerns or non-compliance. As a result, submission of an IND may not result in FDA authorization to commence a clinical trial.

Clinical Trials. Clinical trials involve the administration of the drug to healthy human volunteers, or to patients with the target disease or disorder under the supervision of a qualified physician (also called an investigator) pursuant to an FDA-reviewed protocol. Human clinical trials typically are conducted in three sequential phases, although the phases may overlap with one another. Clinical trials must be conducted under protocols that detail the objectives of the study, the parameters to be used to monitor safety and the efficacy criteria, if any, to be evaluated. Each protocol, and any subsequent amendments, must be submitted to the FDA, as part of the IND, or comparable foreign regulatory authorities.

In March 2022, the FDA released a final guidance entitled “Expansion Cohorts: Use in First-In-Human Clinical Trials to Expedite Development of Oncology Drugs and Biologics,” which outlines how drug developers can utilize an adaptive trial design commonly referred to as a seamless trial design in early stages of oncology drug development (i.e., the first-in-human clinical trial) to compress the traditional three phases of trials into one continuous trial called an expansion cohort trial. Information to support the design of individual expansion cohorts are included in IND applications and assessed by FDA. Expansion cohort trials can potentially bring efficiency to drug development and reduce developmental costs and time.

Additional kinds of data may also help to support a BLA or product development, such as patient experience and real-world evidence. For appropriate indications sought through supplemental BLAs, data summaries may provide marketing application support. For genetically targeted products and variant protein targeted products intended to address an unmet medical need in one or more patient subgroups with a serious or life threatening rare disease or condition, the FDA may allow a sponsor to rely upon data and information previously developed by the sponsor or for which the sponsor has a right of reference, that was submitted previously to support an approved application for a product that incorporates or utilizes the same or similar genetically targeted technology or a product that is the same or utilizes the same variant protein targeted drug as the product that is the subject of the application.

In addition, under the Pediatric Research Equity Act of 2003, or PREA, BLAs and supplements for a new active ingredient, indication, dosage form, dosage regimen, or route of administration must contain data to assess the safety and efficacy of the product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDA may grant deferrals for submission of data or full or partial waivers. Unless otherwise required by regulation, PREA does not apply to any drug or biologic for an indication for which orphan designation has been granted for the relevant indication except that PREA will apply to an original BLA for a new active ingredient that is orphan-designated if the biologic is a molecularly targeted cancer product intended for the treatment of an adult cancer and is directed at a molecular target that FDA determines to be substantially relevant to the growth or progression of a pediatric cancer.

Good Clinical Practice. All of the phases of clinical studies must be conducted in conformance with the FDA’s GCP or equivalent standards from comparable foreign regulatory authorities, which are ethical and scientific quality standards for conducting, recording and reporting clinical trials to assure that the data and reported results are credible and accurate and that the rights, safety and well-being of trial participants are protected. GCP include requirements that all research subjects provide their informed consent in writing for their participation in any clinical trial. Investigators must also provide certain information to the clinical trial sponsors to allow the sponsors to make certain financial disclosures to the FDA. In addition, an Institutional Review Board, or IRB, at each study site participating in the clinical trial or a central IRB must review and approve the plan for any clinical trial, informed consent forms, and communications to study subjects before a study commences at that site. An IRB considers, among other things, whether the risks to individuals participating in the trials are minimized and are reasonable in relation to anticipated benefits, and whether the planned human subject protections are adequate. The IRB must continue to oversee the clinical trial while it is being conducted. Once an IND is in effect, each new clinical protocol and any amendments to the protocol must be submitted to FDA for review, and to the IRB for approval. If a product candidate is being investigated for multiple intended indications, separate INDs may also be required. Progress reports detailing the results of the clinical trials must also be submitted at least annually to the FDA and the IRB and more frequently if serious and unexpected suspected adverse events are observed or other significant safety information is found, such as any findings from other studies or animal or in vitro testing that suggest a significant risk in humans exposed to the product. The sponsor must submit an IND safety report within 15 calendar days after the sponsor determines that the information qualifies for reporting. The sponsor also must notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction within seven calendar days after the sponsor's initial receipt of the information.

Information about certain clinical trials, including a description of the study and study results, must be submitted within specific timeframes to the National Institutes of Health, or NIH, for public dissemination on their clinicaltrials.gov website. Sponsors or distributors of investigational products for the diagnosis, monitoring, or treatment of one or more serious diseases or conditions must also have a publicly available policy on evaluating and responding to requests for expanded access requests.

The manufacture of investigational biologics for the conduct of human clinical trials is subject to FDA’s current Good Manufacturing Practice, or cGMP requirements. Investigational biologics and therapeutic substances imported into the United States are also subject to regulation by the FDA. Further, the export of investigational products outside of the United States is subject to regulatory requirements of the receiving country as well as U.S. export requirements under the FDCA.

Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the product candidate as well as finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, manufacturers must develop methods for testing the identity, strength, quality, potency, and purity of the final product. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.

The FDA may order the temporary, or permanent, discontinuation of a clinical trial at any time, or impose other sanctions, if it believes that the clinical trial either is not being conducted in accordance with FDA requirements or presents an unacceptable risk to the clinical trial patients. An IRB may also require the clinical trial at the site to be halted, either temporarily or permanently, for failure to comply with the IRB’s requirements or if the trial poses an unexpected serious harm to subjects. The FDA or an IRB may also impose conditions on the conduct of a clinical trial. Clinical trial sponsors may also choose to discontinue clinical trials as a result of risks to subjects, a lack of favorable results, or changing business priorities.

Marketing Approval - Biologics

Biologics License Application. All data obtained from a comprehensive development program, including research and product development, manufacturing, preclinical and clinical trials, labeling and related information are submitted in a biologics license application, or BLA, to the FDA and in similar regulatory filings with the corresponding agencies in other countries for review and approval. In most cases, the submission of a marketing application is subject to a substantial application user fee. These user fees must be paid at the time of the first submission of the application, even if the application is being submitted on a rolling basis. Fee waivers or reductions are available in certain circumstances. By example, product candidates that are designated as orphan products, which are further described below, are not subject to application user fees unless the application includes an indication other than the orphan indication.

The submission of an application is not a guarantee that the FDA will find the application complete and accept it for filing. The FDA may refuse to file the application and request additional information rather than accept the application for filing, in which case the application must be resubmitted with the supplemental information. The resubmitted application is also subject to review before the FDA accepts it for filing. The FDA has two months to review an application for its acceptability for filing.

Once an application is accepted for filing, the FDA begins an in-depth substantive review. The Prescription Drug User Fee Act, or PDUFA, establishes a two-tiered review system: Standard Review and Priority Review. When conducting Priority Review, the FDA has a goal to review and act on BLA submissions within six months from the date of the FDA’s acceptance for filing of the application, rather than the ten-month goal under a Standard Review. The FDA gives Priority Review status to product candidates that provide safe and effective therapies where no satisfactory alternative exists or to a product candidate that are intended to treat serious conditions and, if approved, would provide significant improvements in the safety or effectiveness of the treatment, diagnosis, or prevention of the serious condition. The PDUFA date is only a goal, thus, the FDA does not always meet its PDUFA dates. The review process and the PDUFA date may also be extended if the FDA requests or the sponsor otherwise provides substantial additional information or clarification regarding the submission.

The FDA may refer certain applications to an advisory committee. Before approving a product candidate for which no active ingredient (including any ester or salt of active ingredients) has previously been approved by the FDA, the FDA must either refer that product candidate to an external advisory committee or provide in an action letter, a summary of the reasons why the FDA did not refer the product candidate to an advisory committee. The FDA may also refer other product candidates to an advisory committee if FDA believes that the advisory committee’s expertise would be beneficial. An advisory committee is typically a panel that includes clinicians and other experts, which review, evaluate, and make a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

The FDA reviews applications to determine, among other things, whether a product candidate meets the agency’s approval standards and whether the manufacturing methods and controls are adequate to assure and preserve the product’s identity, strength, quality, potency, and purity. Before approving a marketing application, the FDA typically will inspect the facility or facilities where the product is manufactured, referred to as a Pre-Approval Inspection. The FDA will not approve an application unless it determines that the manufacturing processes and facilities, including contract manufacturers and subcontractors, are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving a marketing application the FDA will inspect one or more clinical trial sites to assure compliance with GCP.

In reviewing a BLA, the FDA may grant approval or deny the application through a complete response letter, or CRL, if it determines the application does not provide an adequate basis for approval requesting additional information. A CRL indicates that the review cycle of the application is complete and the application is not ready for approval and describes all of the specific deficiencies that the FDA identified. A CRL generally contains a statement of specific conditions that must be met in order to secure final approval of the marketing application, and may require additional clinical or preclinical testing in order for the FDA to reconsider the application. The deficiencies identified may be minor, for example, requiring labeling changes; or major, for example, requiring additional clinical trials. If a CRL is issued, the applicant may either: resubmit the marketing application, addressing all of the deficiencies identified in the letter; withdraw the application; or request an opportunity for a hearing. Even if additional information outlined in a CRL is submitted, the FDA may ultimately decide that the BLA does not satisfy the criteria for approval.

The receipt of regulatory approval often takes many years, involving the expenditure of substantial financial resources. The speed with which approval is granted often depends on a number of factors, including the severity of the disease in question, the availability of alternative treatments and the risks and benefits demonstrated in clinical trials. The FDA may also impose conditions upon approval. For example, it may require a Risk Evaluation and Mitigation Strategy, or REMS, for a product. This can include various required elements, such as publication of a medication guide, patient package insert, a communication plan to educate health care providers of the drug’s risks and/or restrictions on distribution and use, such as limitations on who may prescribe or dispense the drug. Following product approval, a REMS may also be required by the FDA if new safety information is discovered and the FDA determines that a REMS is necessary to ensure that the benefits of the product outweigh the risks.

The FDA may also significantly limit the indications or populations approved for a given product, require that contraindications, warnings, or precautions be included in the product labeling, including a boxed warning, and/or require, as a condition of approval, enhanced labeling, special packaging or labeling, post-approval clinical trials, distribution or other risk management mechanisms, expedited reporting of certain adverse events, pre-approval of promotional materials or restrictions on direct-to-consumer advertising, any of which could negatively impact the commercial success of a drug. The FDA may also not approve label statements that are necessary for successful commercialization and marketing.

After approval, some types of changes to the approved product, such as adding new indications, manufacturing changes, and additional labeling claims, are subject to further testing requirements and FDA review and approval. The FDA may also withdraw the product approval if compliance with the pre- and post-marketing regulatory standards are not maintained or if problems occur after the product reaches the marketplace. Further, should new safety information arise, additional testing, product labeling, or FDA notification may be required.

Designated Platform Technology. Under the Food and Drug Omnibus Reform Act of 2022, or FDORA, a platform technology incorporated within or utilized by a biologic is eligible for designation as a designated platform technology if (1) the platform technology is incorporated in, or utilized by, a product approved under a BLA; (2) preliminary evidence submitted by the sponsor of the approved or licensed product, or a sponsor that has been granted a right of reference to data submitted in the application for such product, demonstrates that the platform technology has the potential to be incorporated in, or utilized by, more than one product without an adverse effect on quality, manufacturing, or safety; and (3) data or information submitted by the applicable person indicates that incorporation or utilization of the platform technology has a reasonable likelihood to bring significant efficiencies to the drug development or manufacturing process and to the review process. A sponsor may request the FDA to designate a platform technology as a designated platform technology concurrently with, or at any time after, submission of an IND application for a product that incorporates or utilizes the platform technology that is the subject of the request. If so designated, the FDA may expedite the development and review of any subsequent original BLA for a product that uses or incorporates the platform technology. Designated platform technology status does not ensure that a product will be developed or reviewed by the FDA more quickly or receive FDA approval. In addition, the FDA may revoke a designation if the FDA determines that a designated platform technology no longer meets the criteria for such designation.

Breakthrough Therapy. Under the provisions of the Food and Drug Administration Safety and Innovation Act, or FDASIA, the FDA may designate a product as a breakthrough therapy if the product is intended, alone or in combination with one or more other products, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the product may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. Products designated as breakthrough therapies are also eligible for accelerated approval. A sponsor may request that a product candidate be designated as a breakthrough therapy concurrently with, or at any time after, the submission of an IND, and the FDA must determine if the candidate qualifies for breakthrough therapy designation within 60 days of receipt of the sponsor’s request. If so designated, the FDA must take certain actions, such as holding timely meetings and providing advice, intended to expedite the development and review of an application for approval of a breakthrough therapy. The FDA may rescind breakthrough therapy designation if the product candidate does not continue to meet the criteria for such designation.

Orphan Drugs. Under the Orphan Drug Act, an applicant can request the FDA to designate a product as an “orphan drug” in the United States if the drug is intended to treat an orphan, or rare, disease or condition. A disease or condition is considered orphan if it affects fewer than 200,000 people in the United States, or affecting more than 200,000 in the United States and for which there is no reasonable expectation that the cost of developing and making the product available in the United States will be recovered from United States sales. Additionally, sponsors must present a plausible hypothesis for clinical superiority to obtain orphan drug designation if there is a product already approved by the FDA that that is considered by the FDA to be the same as the already approved product and is intended for the same indication. This hypothesis must be demonstrated to obtain orphan exclusivity. Orphan drug designation must be requested before submitting a BLA. Products designated as orphan drugs are eligible for special grant funding for research and development, potential tax credits for research, waived user fees for marketing applications and a seven-year period of market exclusivity after marketing approval. The tax advantages, however, were limited in the 2017 Tax Cuts and Jobs Act.

Orphan drug exclusivity (afforded to the first applicant to receive approval for an orphan designated drug) prevents FDA approval of applications by others for the same drug for the designated orphan disease or condition. The FDA may approve a subsequent application from another applicant if the FDA determines that the application is for a different drug or different use, or if the FDA determines that the subsequent product is clinically superior, or that the holder of the initial orphan drug approval cannot assure the availability of sufficient quantities of the drug to meet the public’s need. A grant of an orphan designation is not a guarantee that a product will be approved. On November 26, 2019 FDA granted Orphan Drug Designation to APVO436, a bispecific antibody candidate, for the treatment of acute myelogenous leukemia.

Post-Approval Requirements. Any biologic for which we receive FDA approval will be subject to continuing regulation by the FDA, including, among other things, record keeping requirements, reporting of adverse experiences, reporting of deviations and shortages, providing the FDA with updated safety and efficacy information, product sampling and distribution requirements, cGMP, and restrictions on advertising and promotion. Adverse events that are reported after marketing approval can result in additional limitations being placed on the product’s distribution or use and, potentially, withdrawal or suspension of the product from the market. In addition, the FDA authority to require post-approval clinical trials and/or safety labeling changes if warranted. In certain circumstances, the FDA may impose a REMS after a product has been approved.

Facilities involved in the manufacture and distribution of approved products are required to register their establishments with the FDA and certain state agencies, list their manufactured products, and are subject to periodic unannounced inspections by the FDA for compliance with cGMP and other laws. Manufacturers and other parties involved in the supply chain for prescription drug products must also comply with product tracking and tracing requirements and for notifying the FDA of counterfeit, diverted, stolen and intentionally adulterated products or products that are otherwise unfit for distribution in the United States. Recently, the information that must be submitted to FDA regarding manufactured products was expanded through the Coronavirus Aid, Relief, and Economic Security, or CARES, Act to include the volume of drugs produced during the prior year. Manufacturers must continue to expend time, money, and effort in the areas of production and quality-control to maintain compliance with cGMP. Regulatory authorities may withdraw product approvals, require label modifications, or request product recalls, among other actions, if a company fails to comply with regulatory standards, if it encounters problems following initial marketing, or if previously unrecognized problems are subsequently discovered.

The FDA also closely monitors advertising and promotional materials we may disseminate for our products for compliance with restrictions on off-label promotion and other laws. We may not promote our products for conditions of use that are not included in the approved package inserts for our products. Physicians, in their independent professional medical judgment, however, may prescribe legally available products for unapproved indications that are not described in the product’s labeling and that differ from those tested and approved by the FDA. Certain additional restrictions on advertising and promotion exist for products that have boxed warnings in their approved package inserts. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significant liability, including, but not limited to, criminal and civil penalties under the FDCA and False Claims Act, exclusion from participation in federal healthcare programs, mandatory compliance programs under corporate integrity agreements, suspension and debarment from government contracts, and refusal of orders under existing government contracts.

Biosimilars and Exclusivity. The Biologics Price Competition and Innovation Act of 2009, or BPCIA, creates an abbreviated approval pathway for biological products shown to be highly similar to or interchangeable with an

FDA-licensed reference biological product. Biosimilarity sufficient to reference a prior FDA-approved product requires a high similarity to the reference product notwithstanding minor differences in clinically inactive components, and no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency. Biosimilarity must be shown through analytical studies, animal studies, and at least one clinical trial, absent a waiver by the FDA. There must be no difference between the reference product and a biosimilar in mechanism of action, conditions of use, route of administration, dosage form, and strength. A biosimilar product may be deemed interchangeable with a prior approved product if it meets the higher hurdle of demonstrating that it can be expected to produce the same clinical results as the reference product and, for products administered multiple times, the biologic and the reference biologic may be switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic.

A reference biologic is granted 12 years of exclusivity from the time of first licensure, and no application for a biosimilar can be submitted for four years from the date of licensure. However, certain changes and supplements to an approved BLA, and subsequent applications filed by the same sponsor, manufacturer, licensor, predecessor in interest, or other related entity do not qualify for the twelve-year exclusivity period. The first biologic product submitted under the abbreviated approval pathway that is determined to be interchangeable with the reference product is eligible for a period of exclusivity against other biologics submitted under the abbreviated approval pathway during which time the FDA may not determine that another product is interchangeable with the same reference product for any condition of use. The FDA may approve multiple “first” interchangeable products so long as they are all approved on the same first day of marketing. This exclusivity period, which may be shared amongst multiple first interchangeable products, lasts for the lesser of (i) one year after the first commercial marketing, (ii) 18 months after approval if there is no legal challenge, (iii) 18 months after the resolution in the applicant’s favor of a lawsuit challenging the biologic’s patents if an application has been submitted, or (iv) 42 months after the application has been approved if a lawsuit is ongoing within the 42-month period. The PHSA also includes provisions to protect reference products that have patent protection. The biosimilar product sponsor and reference product sponsor may exchange certain patent and product information for the purpose of determining whether there should be a legal patent challenge. Based on the outcome of negotiations surrounding the exchanged information, the reference product sponsor may bring a patent infringement suit and injunction proceedings against the biosimilar product sponsor. The biosimilar applicant may also be able to bring an action for declaratory judgment concerning the patent.

In an effort to increase competition in the biologic product marketplace, Congress, the executive branch, and the FDA have taken certain legislative and regulatory steps. For example, in 2020, FDA finalized a guidance to facilitate drug and biologic product importation. Moreover, the 2020 Further Consolidated Appropriations Act included provisions requiring that sponsors of approved biologic products, including those subject to REMS, provide samples of the approved products to persons developing biosimilar products within specified timeframes, in sufficient quantities, and on commercially reasonable market-based terms. Failure to do so can subject the approved product sponsor to civil actions, penalties, and responsibility for attorney’s fees and costs of the civil action. This same bill also includes provisions with respect to shared and separate REMS programs for reference and generic drug products.

Patent Term Restoration. If approved, biologic products may also be eligible for periods of U.S. patent term restoration. If granted, patent term restoration extends the patent life of a single unexpired patent that has not previously been extended, for a maximum of five years. The total patent life of the product with the extension also cannot exceed fourteen years from the product’ approval date. Subject to the prior limitations, the period of the extension is calculated by adding half of the time from the effective date of an IND to the initial submission of a marketing application, and all of the time between the submission of the marketing application and its approval. This period may also be reduced by any time that the applicant did not act with due diligence.

Regulation in the European Union. Product development, the regulatory approval process and safety monitoring of medicinal products and their manufacturers in the European Union proceed broadly in the same way as they do in the United States. Therefore, many of the issues discussed above apply similarly in the context of the European Union. In addition, drugs are subject to the extensive price and reimbursement regulations of the various EU member states. The Clinical Trial Regulation EU 536/2014 (CTR) repealed the Clinical Trials Directive 2001/20/EC, as amended (CTD) on January 31, 2022, subject to a three-year transition period. The CTR makes it possible within the EU for sponsors to submit a single harmonized electronic submission via a single online platform known as the Clinical Trials Information System (CTIS) for approval to conduct a clinical trial in several European countries and have a single assessment process for clinical trials conducted in multiple member states. Under the CTR, sponsors can use the CTIS from January 31, 2022 but are not obliged to use it immediately, in line with a three-year

transition period. Sponsors may use CTIS to apply to conduct a clinical trial under the CTR or may choose to apply to conduct a trial under the CTD until January 30, 2023. From January 31, 2023, sponsors will need to use CTIS to apply to start a new clinical trial in the EU/EEA. From January 31, 2025, any trials approved under the CTD that continue running will need to comply with the CTR and their sponsors must have recorded information on such trials in CTIS.

Healthcare Fraud and Abuse and Anti-Corruption Laws

Various federal and state laws pertaining to health care “fraud and abuse” exist, including state and federal anti-kickback laws false claims laws, and patent privacy and security laws. Anti-kickback laws make it illegal for a drug manufacturer to knowingly and willfully solicit, offer, receive or pay any remuneration in exchange for, to induce, or in return for, the referral of business that may be reimbursed by a third-party payor (including Medicare and Medicaid), including the purchase, prescribing or recommendation of a particular drug. Due to the breadth of the statutory provisions, it is possible that our practices might be challenged under anti-kickback or similar laws. Civil and criminal false claims laws, false statement laws and civil monetary penalty laws prohibit, among other things, anyone from knowingly presenting, or causing to be presented for payment, to third-party payors (including Medicare and Medicaid) claims for reimbursed drugs or services that are false or fraudulent, claims for items or services not provided as claimed or claims for medically unnecessary items or services. Our activities relating to the sale and marketing of our products may be subject to scrutiny under these laws. Privacy and security laws, such as the Health Insurance Portability and Accountability Act of 1996, or HIPAA, create federal criminal and civil liability for executing a scheme to defraud any healthcare benefit program or knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false statement in connection with the delivery of or payment for healthcare benefits, items or services. Additionally, HIPAA, as amended by the Health Information Technology for Economic and Clinical Health, or HITECH, and their respective implementing regulations, impose certain requirements relating to the privacy, security, and transmission of individually identifiable health information.

In addition, as part of the Affordable Care Act, the federal government enacted the Physician Payment Sunshine Act. Manufacturers of drugs biologics and devices that are reimbursed by Medicare, Medicaid or the Children’s Health Insurance Program are required to annually report to CMS payments and transfers of value made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors) and teaching hospitals, and ownership or investment interest held by physicians and their family members. Effective January 1, 2022, these reporting obligations extend to include transfers of value made to certain non-physician providers (physician assistants, nurse practitioners, clinical nurse specialists, certified registered nurse anesthetists and anesthesiologist assistants, and certified-nurse midwives).

Our operations are also subject to compliance with the U.S. Foreign Corrupt Practices Act, or FCPA, which prohibits corporations and individuals from directly or indirectly paying, offering to pay, or authorizing the payment of anything of value to any foreign government official or employee, or any foreign political party or political candidate in an attempt to obtain or retain business or to otherwise influence such official, employee, party or candidate in his or her or its official capacity. Our operations are also subject to compliance with the U.K. Bribery Act of 2010, which applies to activities both in the public and private sector, Canada’s Corruption of Foreign Public Officials Act and similar laws and industry codes in other countries where we do business.

Other Regulation

Our present and future business has been and will continue to be subject to various other laws and regulations. Various laws, regulations and recommendations relating to safe working conditions, laboratory practices, the experimental use of animals, and the purchase, storage, movement, import, export, use and disposal of hazardous or potentially hazardous substances, including radioactive compounds and infectious disease agents used in connection with our product development, are or may be applicable to our activities.

HUMAN CAPITAL

Employees and Office Location

Aptevo employed 40 full-time persons as of December 31, 2023. The team is comprised of a dedicated group of accomplished professionals who bring a broad range of academic achievements combined with significant industry experience. We believe that our future success will depend in part on our continued ability to attract, hire and retain

qualified personnel. To this end, we strive to maintain competitive base compensation structures and comprehensive benefits packages, and to engage our employees through ongoing development and training. None of our employees are represented by a labor union or covered by collective bargaining agreements. We believe our relationships with our employees are positive.

Our principal executive offices are located at 2401 4th Ave., Suite 1050, Seattle, Washington 98121. Our telephone number is (206) 838-0500.

Corporate Values

Leading by our core values unifies Aptevo and enables every employee to be an agent of positive culture. We believe that our success depends on creating an environment that is personally and professionally rewarding and creating opportunities for personal and professional development. These values, which are the foundation of our Company culture, are:

We consider these values to be an integral part of our corporate goal setting and review process. We believe in empowering our employees and consider them as owners of the business. We treat each other with respect and maintain a high level of professionalism and accountability. Our Board of Directors and executive team continues to monitor and focus on our human capital resources to ensure we live by our core values.

Diversity, Equity, and Inclusion

Diversity, equity, and inclusion (DEI) is of great importance to our culture, day-to-day operations, and future success. Aptevo is an equal opportunity employer, and we are committed to fostering DEI within our work environment and beyond. We believe DEI promotes our business growth, drives innovation in the therapeutic product candidates we develop, and in the way we solve problems. Our efforts are focused on hiring and retaining qualified candidates, and promoting a supportive and inclusive working environment for all of our employees. The Company is resolute on its commitment to the development and fair treatment of all candidates and employees, including equal opportunity hiring and advancement practices and policies, and anti-harassment and anti-retaliation policies. We believe that fostering diversity, equity, and inclusion is a key element to discovering, developing, and bringing transformative therapies to patients. As of December 31, 2023, 55% of our workforce and 50% of our leadership (at the Director level and above) were female. In addition, 40% of our workforce and 43% of our leadership (at the Director level and above) were racially or ethnically diverse. We strive to build a workforce representative of the people we serve and to nurture an inclusive culture where all voices are welcomed, heard, and respected.

Recruiting and Retention

We invest in resources to recruit, develop, and retain the talent needed to achieve our business goals. We believe in supporting our employees to reach their full potential and strive to promote internally. We have been successful in

attracting and retaining talented personnel to support our business, though competition for personnel in our industry is intense.

Compensation and Benefits

Our compensation packages are designed to attract and retain talent, drive Company performance and achieve business goals. In setting appropriate compensation levels, we look at the average base pay rate for each position based on market data. We also offer an annual cash incentive program and long-term equity incentive plans designed to assist in attracting, retaining, and motivating employees and promoting the creation of long-term value for stockholders. Further, all employees are eligible for health insurance and other health benefits, paid and unpaid leaves, retirement benefits with Company match, and life and disability coverage/insurance. We have an unlimited paid time off policy that provides employees with considerable flexibility in scheduling time away from work.

Health & Safety

Employee safety and well-being is of paramount importance to us and was of continued focus in 2023. The Company maintains a hybrid working environment. Our essential employees, which mainly include our research and development team, work onsite, and non-essential employees work remotely or hybrid. We equip our employees working remotely or hybrid with necessary equipment and tools to continue to collaborate and remain productive.

Additionally, we have an Environmental, Health and Safety program that focuses on implementing policies and training programs, as well as performing self-audits to enhance work safety.

ORGANIZATIONAL HISTORY

Aptevo was formed as a wholly-owned subsidiary of Emergent for the purpose of serving as the parent company for the development-based biotechnology business focused on novel oncology, hematology, and autoimmune and inflammatory therapeutics and was incorporated in Delaware in February 2016. On August 1, 2016, Emergent effectuated a spin-off of Aptevo into an independent publicly traded company and made a pro rata distribution of Aptevo common stock to Emergent’s stockholder base at that time. Accordingly, Aptevo has operated as an independent publicly traded company since August 1, 2016.

AVAILABLE INFORMATION

The Aptevo website is located at www.AptevoTherapeutics.com. Aptevo makes certain filings with the Securities and Exchange Commission (the SEC), including its Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and all amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act available free of charge through its website as soon as reasonably practicable after we electronically file those reports with, or furnish them to, the SEC.

In addition, all disclosures that are required to be posted by applicable law, the rules of the SEC or the Nasdaq listing standards regarding any amendment to, or waiver of, our code of business conduct and ethics are available free of charge on our website. We intend to use our website as a means of disclosing material non-public information and for complying with our disclosure obligations under Regulation FD. Accordingly, investors should monitor our website, in addition to following our press releases, investor deck, SEC filings and public conference calls and webcasts. We have included our website address as an inactive textual reference only. The information contained on, or that can be accessed through, our website is not a part of, or incorporated by reference into, this Annual Report on form 10-K.

Item 1A. Risk Factors.

We are subject to significant risks and uncertainties that could impact the Company’s businesses, results of operations and financial condition, including by causing our actual results to differ materially from those projected in any forward-looking statements. Additional risks and uncertainties that are not currently known to the Company or management or that are not currently believed by the Company or management to be material may also harm the Company’s business, financial condition and results of operation. You should carefully consider the following risks and other information in this Annual Report on Form 10-K in evaluating us and our common stock.

RISK FACTOR SUMMARY

The following is a summary of the material risks to our business, operations, and ownership of our common stock:

RISKS RELATED TO OUR BUSINESS

Financial Risks

We have a history of losses and may not be profitable in the future.

We have experienced significant operating losses in the past and may not be profitable in the future. For the year ended December 31, 2023, we had net loss of $17.4 million compared to $8.0 million net income for the same period in 2022. The net income for the year ended December 31, 2022 was due to a one-time $37.2 million gain recognized as a result of Amendment to Royalty Purchase Agreement with HCR. As of December 31, 2023, we had an accumulated deficit of $223.4 million. We expect to continue to incur annual net operating losses for the foreseeable future, and will require substantial resources over the next several years as we expand our efforts to discover, develop and commercialize immunotherapeutic candidates. Our future success and ability to attain profitability will depend upon our ability to develop and commercialize our product candidates.

Our management and board of directors have concluded that a substantial doubt is deemed to exist concerning our ability to continue as a going concern.

Accounting Standards Update, or ASU 2014-15, requires management to assess our ability to continue as a going concern for one year after the date the financial statements are issued. As further discussed in Note 1, Nature of Business and Significant Accounting Policies to our condensed consolidated financial statements in this Form 10-K, substantial doubt is deemed to exist about the company’s ability to continue as a going concern through March 2025. Our financial statements do not include any adjustment relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might be necessary should we be unable to continue as a going concern. Our ability to continue as a going concern will require us to generate positive cash flow from operations, obtain additional financing, enter into strategic alliances and/or sell assets in addition to our existing cash and cash equivalents and the funding provided by our Purchase Agreement with XOMA, potential future milestone payments from Medexus under our LLC Purchase Agreement, our ability to issue securities under our Purchase Agreement with Lincoln Park Capital, and exercise of warrants. The reaction of investors to the inclusion of a going concern statement in this report on Form 10-K, our current lack of cash resources and our potential inability to continue as a going concern may materially adversely affect our share price and our ability to raise new capital and enter into strategic alliances. If we become unable to continue as a going concern, we may have to liquidate our assets and the values we receive for our assets in liquidation or dissolution could be significantly lower than the values reflected in our financial statements.

We will require additional capital and may be unable to raise capital when needed or on acceptable terms.

As of December 31, 2023, we had cash and cash equivalents in the amount of $16.9 million. We will require additional funding to continue our business including to support the ongoing clinical development of APVO436 and ALG.APV-527, develop additional products, support commercial marketing activities or otherwise provide additional financial flexibility. If we are not able to secure adequate additional funding, we may need to make reductions in spending. This may include extending payment terms with suppliers, liquidating assets, and suspending or curtailing planned programs. We may also have to delay, reduce the scope of, suspend or eliminate one or more research and development programs. We may also be forced to grant rights to develop and market our product candidates that we would otherwise prefer to develop or market ourselves or we may be unable to take advantage of future business opportunities. A failure to raise the additional funding or to effectively implement cost reductions would harm our

business, results of operations and future prospects. Our future capital requirements will depend on many factors, including:

Further, changing circumstances, some of which may be beyond our control, such as macroeconomic conditions, could cause us to consume capital significantly faster than we currently anticipate, and we may need to seek additional funds sooner than planned.

We cannot guarantee that future financing will be available in sufficient amounts, or on commercially reasonable terms, or at all. If our capital resources are insufficient to meet our future capital requirements, we will need to finance our cash needs through bank loans, public or private equity or debt offerings, collaboration and licensing arrangements, or other strategic transactions. Our ability to raise future capital on acceptable terms or at all will be impacted by the macroeconomic environment, including rising and fluctuating interest rates, economic uncertainty and volatility in the capital market, geopolitical tensions, including the ongoing war between Ukraine and Russia and the rising conflict in the Middle East, reoccurrences of COVID-19 or other pandemics, or other future widespread public health epidemics, or other factors could also adversely impact our ability to access capital as and when needed or increase our costs in order to raise capital. Current capital market conditions, including the impact of inflation, have increased borrowing rates and can be expected to significantly increase our cost of capital as compared to prior periods. On August 4, 2023, we completed a public offering related to the issuance and sale of 8,064,517 shares of our common stock (or pre-funded warrant in lieu thereof) at a purchase price of $0.62. We received $5 million in gross proceeds from issuance of these shares. Our net proceeds from the offering amounted to $4.3 million after placement agent and other fees. On November 9, 2023, we entered into a warrant inducement agreement with certain Holders of existing common warrants ("Existing Warrants") issued to Holders on August 4, 2023, to exercise for cash their Existing Warrants to purchase shares of our common stock at a purchase price of $0.233. In consideration of the Holders' agreement to exercise their Existing Warrants, we agreed to issue new common warrants ("New Warrants") to purchase a number of shares of common stock equal to 200% of the number of shares of common stock issued upon exercise of the Existing Warrants. We received $3.3 million in gross proceeds from the exercise of 14,198,518 common warrants and issued 28,397,036 New Warrants. Our net proceeds from the offering amounted to $3.0 million after placement agent and other fees. Future issuances of common stock may include, but not be limited to, (i) the issuance of 581,826 remaining shares of common stock pursuant to our Purchase Agreement with Lincoln Park, (ii) the issuance of up to 350,589 remaining outstanding shares of common stock upon the exercise of warrants issued in connection with our March 2019 public offering of common stock and warrants, (iii) the issuance of the remaining outstanding shares of common stock upon the exercise of warrants issued in connection with our August 2023 public offering of common stock and warrants that would result in gross proceeds of $1.2 million, (iv) the issuance of the remaining shares of common stock upon the exercise of warrants issued in connection with our November 2023 Warrant Inducement Agreement with certain Holders of our Series A and Series B common warrants issued in connection with our August 2023 public offering that would result in gross proceeds of $6.6 million, or (v) the issuance of common stock in a firm commitment offering or private placement. Public or bank debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, pursuing acquisition opportunities, declaring dividends, our ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact our ability to conduct our

business. If we raise funds by issuing equity securities, our stockholders will experience dilution. If we raise funds through collaboration and licensing arrangements with third parties or enter into other strategic transactions, it may be necessary to relinquish valuable rights to our technologies or product candidates or grant licenses on terms that may not be favorable to us. If financing is unavailable or lost, our business, results of operations, financial condition and financial prospects would be adversely affected and we could be forced to delay, reduce the scope of or eliminate many of our planned activities.

Our shelf registration statement on Form S-3 expired on December 18, 2023. SEC regulations limit the amount of funds we can raise during any 12-month period pursuant to a shelf registration statement on Form S-3. Prior to expiration of our shelf registration statement, on March 29, 2022, we filed an amendment to the prospectus related to the Registration Statement on Form S-3 filed on December 14, 2020 pursuant to General Instruction I.B.6 of Form S-3 (General Instruction I.B.6), which updated the amount of registered shares that we were eligible to sell. So long as the aggregate market value of our common stock held by non-affiliates was less than $75 million, we would not be permitted to sell any registered shares under such Form S-3 with a value of more than one-third of the aggregate market value of our common stock held by non-affiliates in any 12-month period due to the limitations of General Instruction I.B.6 of Form S-3 and the then-current public float of our common stock. In the year ended December 31, 2023, we sold $1.6 million worth of shares of our common stock pursuant to our Equity Distribution Agreement with Piper Sandler, which expired in December 2023. The limitations of General Instruction I.B.6 do not apply to sales of our shares under our Purchase Agreement with Lincoln Park Financial LLC as those sales were committed prior to us being subject to the limitations of General Instruction I.B.6. If we are required to file a new registration statement on another form, we may incur additional costs and be subject to delays in raising capital due to review by SEC staff.

Our business is affected by macroeconomic conditions, including rising and fluctuating inflation, interest rates, market volatility, economic uncertainty, and supply chain constraints.

Various macroeconomic factors have in the past and could adversely affect in the future our business and the results of our operations and financial condition, including changes in inflation, interest rates and overall economic conditions and uncertainties such as those resulting from the current and future conditions in the global financial markets. For instance, inflation has negatively impacted the Company by increasing our labor costs, through higher wages and higher interest rates, and operating costs. Supply chain constraints have led to higher inflation, which if sustained could have a negative impact on the Company's product development and operations. If inflation or other factors were to significantly increase our business costs, our ability to develop our current pipeline and new therapeutic products may be negatively affected. Interest rates, the liquidity of the credit markets and the volatility of the capital markets could also affect the operation of our business and our ability to raise capital on favorable terms, or at all, in order to fund our operations.

We are susceptible to changes in the U.S. economy. The U.S. economy has been affected from time to time by economic downturns or recessions, supply chain constraints, rising and fluctuating inflation and interest rates, restricted credit, poor liquidity, reduced corporate profitability, volatility in credit, equity and foreign exchange markets, bankruptcies and overall uncertainty with respect to the economy.

In addition, any further deterioration in the U.S. economy would likely affect the operation of our business and ability to raise capital. In addition, U.S. debt ceiling and budget deficit concerns have increased the possibility of additional credit-rating downgrades and economic slowdowns, or a recession in the United States. Although U.S. lawmakers passed legislation to raise the federal debt ceiling on multiple occasions, ratings agencies have lowered or threatened to lower the long-term sovereign credit rating on the United States. The impact of this or any further downgrades to the U.S. government’s sovereign credit rating or its perceived creditworthiness could adversely affect the U.S. and global financial markets and economic conditions. Similarly, these macroeconomic factors could affect the ability of our third-party suppliers and manufacturers to manufacture clinical trial materials for our product candidates.

Actions of activist stockholders against us have been and could be disruptive and costly and may cause uncertainty about the strategic direction of our business.

Stockholders have in the past and may, from time to time, engage in proxy solicitations or advance stockholder proposals, or otherwise attempt to effect changes and assert influence on our board of directors and management. Activist campaigns that contest or conflict with our strategic direction or seek changes in the composition of our board of directors or management could have an adverse effect on our operating results and financial condition. A proxy

contest would require us to incur significant legal and advisory fees, proxy solicitation expenses and administrative and associated costs and require significant time and attention by our board of directors and management, diverting their attention from the pursuit of our business strategy. Any perceived uncertainties as to our future direction and control, our ability to execute on our strategy, or changes to the composition of our board of directors or senior management team arising from a proxy contest could lead to the perception of a change in the direction of our business or instability which may result in the loss of potential business opportunities, make it more difficult to pursue our strategic initiatives, or limit our ability to attract and retain qualified personnel and business partners, any of which could adversely affect our business and operating results. If individuals are ultimately elected to our board of directors with a specific agenda, it may adversely affect our ability to effectively implement our business strategy and create value for our stockholders. We may choose to initiate, or may become subject to, litigation as a result of a proxy contest or matters arising from the proxy contest, which would serve as a further distraction to our board of directors and management and would require us to incur significant additional costs. In addition, actions such as those described above could cause significant fluctuations in our stock price based upon temporary or speculative market perceptions or other factors that do not necessarily reflect the underlying fundamentals and prospects of our business.

Our future income will depend, in part, on the ability of Medexus to successfully further develop, market and commercialize IXINITY, resulting in milestone payments to the Company by Medexus.

On February 28, 2020, we entered into a Purchase Agreement with Medexus, pursuant to which we sold all of the issued and outstanding limited liability company interests of Aptevo BioTherapeutics, a subsidiary of Aptevo that wholly owns the IXINITY and related Hemophilia B business. We are entitled to receive future potential payments to the extent of the achievement of certain regulatory and commercial milestones and through deferred payments based on net sales of IXINITY. Royalties were earned at the rate of 2% of net revenue through June 2022. As of June 30, 2022, the royalty rate on net revenue of IXINITY increased to 5%. On March 29, 2023, we entered into and closed a Purchase Agreement with XOMA pursuant to which we sold to XOMA our right, title, and interest to all future deferred payments from Medexus and a portion of potential milestones. As consideration, we received $9.6 million at closing from XOMA and an additional $0.05 million post-closing payment. We accounted for the $9.6 million Closing Payment and the $0.05 million post-closing payment from XOMA as other income in accordance with ASC 610-20 Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets in the first quarter of 2023.

We no longer control the development, marketing, and commercialization of IXINITY and are dependent on Medexus to successfully do so. Although Medexus has agreed to use commercially reasonable efforts to commercialize IXINITY in the ordinary course of business in good faith, Medexus may not commit adequate resources to the further development, marketing, and commercialization of IXINITY, may experience financial difficulties, may face competition, or may prioritize other products or initiatives. Medexus’ ability to continue to successfully commercialize the IXINITY business may be affected, and we may experience potential impacts on our future milestone payments from Medexus due to the macroeconomic and geopolitical environment. The failure of Medexus to successfully market and commercialize IXINITY, including because of factors outside of Medexus’ control, could result in lower than expected milestone payments to us and negatively impact our future financial and operating results.

Our operating results are unpredictable and may fluctuate.

Our operating results are difficult to predict and will likely fluctuate from quarter to quarter and year to year, as a result of a variety of factors, including:

Due to the macroeconomic and geopolitical environment, we may experience delays in opportunities to partner our product candidates, due to financial and other impacts on potential partners. Additionally, we may experience potential impacts on our future milestone payments from Medexus, which may impact Medexus’ ability to continue

to successfully commercialize the IXINITY businesses. These and other factors may have a material adverse effect on our business, results of operations and financial condition.

We face product liability exposure, which could cause us to incur substantial liabilities and negatively affect our business, financial condition, and results of operations.

The nature of our business exposes us to potential liability inherent in pharmaceutical products, including with respect to the testing of our product candidates in clinical trials and any product candidates that we successfully develop. Product liability claims might be made by patients in clinical trials, consumers, health care providers or pharmaceutical companies or others that sell any products that we successfully develop. These claims may be made even with respect to those products that are manufactured in licensed and regulated facilities or otherwise receive regulatory approval for study or commercial sale. We cannot predict the frequency, outcome or cost to defend any such claims.

If we cannot successfully defend ourselves against future claims that our product candidates caused injuries, we may incur substantial liabilities. Regardless of merit or eventual outcome, product liability claims may result in:

The amount of insurance that we currently hold may not be adequate to cover all liabilities that may occur. Further product liability insurance may be difficult and expensive to obtain. We may not be able to maintain insurance coverage at a reasonable cost and we may not be able to obtain insurance coverage that will be adequate to satisfy all potential liabilities. Claims or losses in excess of our product liability insurance coverage could have a material adverse effect on our business, financial condition, and results of operations. The cost of defending any product liability litigation or other proceeding, even if resolved in our favor, could be substantial. Uncertainties resulting from the initiation and continuation of product liability litigation or other proceedings could have a material adverse effect on our ability to compete in the marketplace. Product liability claims, regardless of merit or eventual outcome, may absorb significant management time and result in reputational harm, potential loss of revenue from decreased demand for any product candidates we successfully develop, withdrawal of clinical trial participants and potential termination of clinical trial sites or entire clinical programs, and could cause our stock price to fall.

Our success is dependent on our continued ability to attract, motivate and retain key personnel, and any failure to attract or retain key personnel may negatively affect our business.

Because of the specialized scientific nature of our business, our ability to develop products and to compete with our current and future competitors largely depends upon our ability to attract, retain and motivate highly qualified managerial and key scientific and technical personnel. If we are unable to retain the services of one or more of the principal members of senior management, including our Chief Executive Officer, Marvin L. White, our Chief Operating Officer, Jeffrey G. Lamothe, our Chief Financial Officer, Daphne Taylor, our General Counsel, SoYoung Kwon, or other key employees, our ability to implement our business strategy could be materially harmed. We face intense competition for qualified employees from biotechnology and pharmaceutical companies, research organizations and academic institutions. Attracting, retaining or replacing these personnel on acceptable terms may be difficult and time-consuming given the high demand in our industry for similar personnel. We believe part of being able to attract, motivate and retain personnel is our ability to offer a competitive compensation package, including equity incentive awards. If we cannot offer a competitive compensation package or otherwise attract and retain the qualified personnel necessary for the continued development of our business, we may not be able to maintain our operations or grow our business.

We do not currently have enough shares available under our 2018 Stock Incentive Plan to grant awards to senior management and future awards to our employees, which could result in our inability to attract, retain, and motivate our key personnel.

We completed a Section 382 study and have concluded that we experienced an “ownership change” as defined in Section 382 of the U.S. Internal Revenue Code of 1986, as amended (the "Code"), and thus the tax benefits of our pre-“ownership change” net operating loss carryforwards and certain other tax attributes will be subject to an annual limitation under Sections 382 and 383 of the Code.

In general, a corporation undergoes an “ownership change” under Section 382 of the Code if, among other things, the stockholders who own, directly or indirectly, 5% or more of the corporation’s stock (by value), or are otherwise treated as “5% stockholders” under Section 382 of the Code and the Treasury regulations promulgated thereunder, increase their aggregate percentage ownership (by value) of the corporation’s stock by more than 50 percentage points over the lowest percentage of stock owned by the 5% stockholders at any time during the applicable testing period, which is generally the rolling three-year period preceding the date of the potential ownership change testing event. Such potential ownership change testing events include changes involving a stockholder becoming a 5% stockholder or arising from a new issuance of capital stock or share repurchases by the corporation, subject to certain exceptions.

In the event of an “ownership change,” Sections 382 and 383 of the Code impose an annual limitation on the amount of taxable income a corporation may offset with pre-change net operating loss carryforwards and certain other tax attributes. The annual limitation is generally equal to the value of the outstanding stock of the corporation immediately before the ownership change (excluding certain capital contributions), multiplied by the long-term tax-exempt rate as published by the IRS for the month in which the ownership change occurs (the long-term tax-exempt rate for November 2020 is 0.89%). Any unused annual limitation may generally be carried over to subsequent years until the pre-ownership change net operating loss carryforwards and certain other tax attributes expire or are fully utilized by the corporation. Similar provisions of state tax law may also apply to limit the use of state net operating loss carryforwards and certain other tax attributes.

Additionally, Section 382 of the Code includes special rules that apply to a corporation with a significant amount of net unrealized built-in gains or net unrealized built-in losses in its assets immediately prior to ownership change under Section 382 of the Code. In general, certain built-in gains recognized during the five-year period beginning on the date of the ownership change increases the corporation’s annual limitation under Sections 382 and 383 of the Code in the taxable year that such built-in gains are recognized or deemed recognized (but only up to the amount of the net unrealized built-in gain), while certain built-in losses recognized during such five-year period are subject to the annual limitation under Section 382 of the Code (but only up to the amount of the net unrealized built-in loss).

As of December 31, 2023, we had approximately $168.2 million and $70.5 million of federal and state net operating loss carryforwards, respectively, available to reduce future taxable income that will begin to expire in 2037 for federal income tax purposes. We completed an IRC Section 382 study through December 31, 2021. The study concluded that we have experienced an ownership change in November of 2020 and December of 2020 and $162.6 of our NOL carry forwards are subject to an annual limitation. It is not expected that the annual limitations will result in the expiration of NOL carryforwards prior to utilization assuming sufficient income.

We cannot predict or control the occurrence or timing of another ownership change under Section 382 of the Code in the future. In addition, it is possible that any offering of securities by us could result in an ownership change. If another ownership change were to occur, future limitations could apply to our net operating losses and certain other tax attributes, which could result in a material amount of our net operating loss carryforwards and certain other tax attributes becoming unavailable to offset future income tax liabilities.

The realization of all or a portion of our deferred income tax assets (including net operating loss carryforwards) is dependent upon the generation of future income during the statutory carryforward periods. Our inability to utilize our limited pre-ownership change net operating loss carryforwards and certain other tax attributes, or the occurrence of a future ownership change and resulting additional limitations to these tax attributes, could have a material adverse effect on our financial condition, results of operations and cash flows.

The change to the deductibility of our research and development expenditures enacted under the Tax Cuts and Jobs Act ("TCJA") could increase the amount of taxes to which we are subject and our effective tax rate.

Beginning in 2022, the TCJA eliminates the option to deduct research and development expenditures currently and requires taxpayers to capitalize and amortize these expenditures over five or fifteen years depending on the type of research and development expenditure pursuant to Section 174 of the Code. Such change to the deductibility of our research and development expenditures could increase the amount of taxes to which we are subject and our effective tax rate.

Our investments are subject to market and credit risks that could diminish their value and these risks could be greater during periods of extreme volatility or disruption in the financial and credit markets, which could adversely impact our business, financial condition, results of operations, liquidity and cash flows.

Our investments are subject to risks of credit defaults and changes in market values. Periods of macroeconomic weakness or recession, heightened volatility or disruption in the financial and credit markets, such as the current macroeconomic environment, increase these risks, potentially resulting in other-than-temporary impairment of assets in our investment portfolio. The impact of geopolitical tension, such as a deterioration in the bilateral relationship between the US and China, the rising conflict in the Middle East, or Russia’s invasion of Ukraine, including any additional sanctions, export controls or other restrictive actions that may be imposed by the United States and/or other countries against governmental or other entities in, for example, Russia, also could lead to disruption, instability and volatility in the global markets, which may have an impact on our investments across negatively impacted sectors or geographies. Severe global economic and societal disruptions and uncertainties, such as reoccurrences of COVID-19 or other pandemics, or other future widespread public health epidemics may cause disruptions that could severely impact our business, such as delays or difficulties to the financing environment and raising capital due to economic uncertainty or volatility.

Product Development Risks

The results of our current and planned preclinical studies and clinical trials may not satisfy the requirements of the FDA or non-U.S. regulatory authorities. Results from early preclinical studies and clinical trials may not be predictive of results from later-stage or other trials and interim or top line data may be subject to change or qualification based on the complete analysis of data.

We completed our Phase 1b dose expansion clinical trial with APVO436 in 2023 and plan to initiate a dose optimization Phase 1b/2 study in the first half of 2024 to assess safety and efficacy of APVO436 and to determine an optimal dose in front line patients. Additionally, we initiated a first-in-human Phase 1 clinical study of ALG.APV-527 in the first quarter of 2023 and we are currently enrolling new patients. None of our other product candidates have entered clinical development. Clinical failure can occur at any stage of preclinical or clinical development. Preclinical studies and clinical trials may produce inconsistent, negative or inconclusive results. The FDA or a non-US regulatory authority may require us to conduct additional clinical or preclinical testing. Success in early preliminary data, preclinical studies and clinical trials does not mean that future larger registration clinical trials will be successful and interim results of a clinical trial do not necessarily predict final results. Product candidates in later-stage clinical trials may fail to demonstrate sufficient safety and efficacy to the satisfaction of the FDA and non-U.S. regulatory authorities despite having progressed through initial clinical trials. In some instances, there can be significant variability in safety or efficacy results between different clinical trials of the same product candidate due to numerous factors, including changes in trial procedures set forth in protocols, differences in the size and type of the patient populations, changes in adherence to the dosing regimen and other clinical trial protocols and the rate of dropout among clinical trial participants. In addition, preclinical and clinical data are often susceptible to various interpretations and analyses, and many companies whose product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy profile despite having progressed through preclinical studies and initial clinical trials. A number of companies in the pharmaceutical and biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to lack of efficacy or adverse safety profiles, notwithstanding promising results in earlier studies, and we cannot be certain that we will not face similar setbacks. Even if early-stage clinical trials are promising, we may need to conduct additional clinical trials of our product candidates in additional patient populations or under different treatment conditions before we are able to seek approvals from the FDA and regulatory authorities outside the United States to market and sell these product candidates. Any of these events could limit the commercial potential of our product candidates and have a material adverse effect on our business, prospects, financial condition and results of operations. A number of companies in the pharmaceutical industry, including those with greater resources and

experience than us, have suffered significant setbacks in advanced clinical trials, even after obtaining promising results in earlier clinical trials.

In addition, our APVO436 clinical trial is an open-label study and is conducted at a limited number of clinical sites on a limited number of patients. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational product candidate or an existing approved drug. Most typically, open-label clinical trials test only the investigational product candidate and sometimes may do so at different dose levels or in combination with other drugs. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. The results from these clinical trials may not be predictive of future clinical trial results with APVO436 or other product candidates. In addition, although the FDA issued a “may proceed” notification which allowed us and Alligator to initiate our Phase 1 clinical trial of ALG.APV-527, we cannot guarantee that this trial or future trials of ALG.APV-527 will show the desired safety and efficacy.

We may publicly disclose top line or interim data from time to time, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. The top line or interim results that we report may differ from future results of the same studies, or different conclusions or considerations may qualify such results once additional data have been received and fully evaluated. Even in situations where a clinical stage candidate appears to be benefiting a patient that benefit may not be of a permanent nature. Top line and interim data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. In addition, the achievement of one primary endpoint for a trial does not guarantee that additional co-primary endpoints or secondary endpoints will be achieved. Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our company in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is based on what is typically extensive information, and you or others may not agree with what we determine is material or otherwise appropriate information to include in our disclosure.

Our future clinical trials may not be successful. Moreover, should there be a flaw in a clinical trial, it may not become apparent until the clinical trial is well advanced. We may also experience numerous unforeseen events during, or as a result of, clinical trials that could delay or prevent our ability to receive marketing approval or commercialize our product candidates, including:

Further, our product candidates may not be approved even if they achieve their primary endpoints in Phase 3 clinical trials or registration trials. Regardless of any advisory committee recommendation, the FDA may decline to approve the BLA for a number of reasons including, if the clinical benefit, safety profile or effectiveness of the drug is not deemed by the FDA to warrant approval. The FDA or other non-U.S. regulatory authorities may disagree with our trial design, and our interpretation of data from non-clinical studies and clinical trials. In particular, the FDA may not view our data as being clinically meaningful or statistically persuasive. The regulatory authorities and policies governing the development of our product candidates may also change at any time. In addition, any of these regulatory authorities may change requirements for the approval of a product candidate even after reviewing and providing comments or advice on a protocol for a pivotal Phase 3 clinical trial. Any of these regulatory authorities may also approve a product candidate for fewer or more limited indications than we request or may grant approval contingent on the performance of costly post-marketing clinical trials. The FDA or other non-U.S. regulatory authorities may not approve the labeling claims that we believe would be necessary or desirable for the successful commercialization of our product candidates.

We may not be able to file INDs, or IND amendments to commence additional clinical trials on the timelines we expect, and even if we are able to, the FDA may not permit us to proceed.

We have submitted INDs and received approvals to proceed into clinical trials for multiple product candidates, including ALG.APV-527 and APVO436, however, we may not be able to file future INDs for our product candidates on the timelines we expect. For example, we may experience manufacturing delays or other delays with IND-enabling studies. Moreover, we cannot be sure that submission of future INDs will result in the FDA allowing clinical trials to begin, or that, once begun, issues will not arise that suspend or terminate clinical trials. Additionally, even if such regulatory authorities agree with the design and implementation of the clinical trials set forth in an IND, we cannot guarantee that such regulatory authorities will not change their requirements in the future. These considerations also apply to new clinical trials we may submit as amendments to existing INDs or to a new IND. Any failure to file INDs on the timelines we expect or to obtain regulatory approvals for our trials may prevent us from completing our clinical trials or commercializing our products on a timely basis, if at all.

If we experience delays or difficulties in the commencement, site initiation, enrollment of patients or completion of our clinical trials, the time to reach critical trial data and receipt of any necessary regulatory approvals could be delayed.

We may not be able to initiate or continue clinical trials for our product candidates if we are unable to locate, enroll and maintain a sufficient number of eligible patients to participate in these trials as required by the FDA or similar regulatory authorities outside the United States. In addition, some of our competitors have ongoing clinical trials for product candidates that treat the same indications as our product candidates, and patients who would otherwise be eligible for our clinical trials may instead enroll in clinical trials of our competitors’ product candidates. Furthermore, APVO436 has received orphan drug designation for acute myelogenous leukemia and thus has a relatively small patient population. Also, the eligibility criteria of our clinical trials may further limit the pool of available study participants as we require that patients have specific characteristics that we can measure to assure their disease is either severe enough or not too advanced to include them in a study.

Patient enrollment is affected by other factors including:

Our inability to enroll a sufficient number of patients for clinical trials could result in significant delays and could require us to abandon one or more clinical trials altogether. Site initiation and enrollment delays in our clinical trials may result in increased development costs for our product candidates, delays in the availability of preliminary or final results, and delays to commercially launching our product candidates, if approved, which may cause the value of our company to decline and limit our ability to obtain additional financing.

Serious adverse events, undesirable side effects or other unexpected properties of our product candidates may be identified that could delay, prevent, or cause the withdrawal of regulatory approval, limit the commercial potential, or result in significant negative consequences following marketing approval.

Serious adverse events or undesirable side effects caused by, or other unexpected properties of any of our product candidates, either when used alone or in combination with other approved or investigational therapies, could cause us or regulatory authorities to interrupt, delay or halt our development activities and manufacturing and distribution operations and could result in a more restrictive label, the imposition of a clinical hold, suspension, distribution or use restrictions or the delay or denial of regulatory approval by the FDA or comparable foreign regulatory authorities. If any of our product candidates are associated with serious adverse events or undesirable side effects or have properties that are unexpected, we may need to abandon their development or limit development to certain uses or subpopulations in which the undesirable side effects or other characteristics are less prevalent, less severe or more acceptable from a risk-benefit perspective. Many compounds that initially showed promise in clinical or earlier stage testing have later been found to cause undesirable or unexpected side effects that prevented further development of the compound.

As we continue developing our product candidates and conduct clinical trials of our product candidates, serious adverse events, or SAEs, undesirable side effects, relapse of disease or unexpected characteristics may emerge causing us to abandon these product candidates or limit their development to more narrow uses or subpopulations in which the SAEs or undesirable side effects or other characteristics are less prevalent, less severe or more acceptable from a risk-benefit perspective or in which efficacy is more pronounced or durable. Undesirable side effects, or other unexpected adverse events or properties of any of our product candidates, could arise or become known either during clinical development or, if approved, after the approved product has been marketed. If such an event occurs during development, the FDA or comparable foreign regulatory authorities could suspend or terminate a clinical trial or deny

approval of our product candidates. Furthermore, we are currently and may in the future evaluate our product candidates in combination with approved and/or experimental therapies. These combinations may have additional or more severe side effects than caused by our product candidate as monotherapies. The uncertainty resulting from the use of our product candidate in combination with other therapies may make it difficult to accurately predict side effects or efficacy in potential future clinical trials. If our product candidates receive marketing approval and we or others later identify undesirable side effects caused by such products, a number of potentially significant negative consequences may result, including:

Any of these events could prevent us from achieving or maintaining market approval and acceptance of the affected product candidate, or could substantially increase commercialization costs and expenses, which could delay or prevent us from generating revenue from the sale of our products and materially harm our business and results of operations.

We depend on third parties to conduct our clinical and non-clinical trials. If these third parties do not effectively carry out their contractual duties, comply with regulatory requirements or meet expected deadlines, we may not be able to obtain regulatory approval for or commercialize our product candidates and our business could be substantially harmed.

We do not have the ability to independently conduct the clinical and preclinical trials required to obtain regulatory approval for our product candidates. We depend on third parties, such as independent clinical investigators, research sites, contract research organizations, or CROs, and other third-party service providers to conduct the clinical and preclinical trials of our product candidates, and we expect to continue to do so. For example, Dr. Dirk Huebner, Chief Medical Officer, is providing clinical trial and medical affairs oversight duties as an independent consultant. We rely heavily on Dr. Huebner and these other third parties for successful execution and oversight of our clinical and non-clinical trials, but we do not exercise day to day control over their activities.

While we have agreements governing the activities of third parties, we have limited influence and control over their actual performance and activities. For instance, our third-party service providers are not our employees, and except for remedies available to us under our agreements with such third parties we cannot control whether or not they devote sufficient time and resources to our ongoing clinical, and non-clinical programs. Our third-party service providers may also have relationships with other entities, some of which may be our competitors, for whom they may also be conducting trials or other therapeutic development activities that could harm our competitive position. If these third parties do not successfully carry out their contractual duties, meet expected deadlines or conduct our non-clinical studies or clinical trials in accordance with regulatory requirements or our stated protocols, if they need to be replaced or if the quality or accuracy of the data they obtain is compromised due to the failure to adhere to our protocols, regulatory requirements or for other reasons, our trials may be repeated, extended, delayed, or terminated, we may not be able to obtain, or may be delayed in obtaining, marketing approvals for our product candidates, we may not be able to, or may be delayed in our efforts to, successfully commercialize our product candidates, or we or they may be subject to regulatory enforcement actions.

Our reliance on third-party service providers does not relieve us of our regulatory responsibilities, including ensuring that our trials are conducted in accordance with the FDA-approved good clinical practices, or GCPs, and the plans and protocols contained in the relevant regulatory application. In addition, these organizations and individuals may not complete these activities on our anticipated or desired timeframe. We also may experience unexpected cost increases that are beyond our control. Problems with the timeliness or quality of the work of a contract research organization may lead us to seek to terminate the relationship and use an alternative service provider, which may prove difficult and/or costly and result in a delay of our trials. In addition, business disruptions arising from circumstances out of our control, could negatively affect the ability of some of the independent clinical investigators, contract research organizations and other third-party service providers that conduct our clinical and preclinical trials of our product candidates. Any delay in or inability to complete our trials could delay or prevent the development, approval, and commercialization of our product candidates.

If CROs or other third parties assisting us or our study sites fail to comply with applicable GCPs, the clinical data generated in our clinical trials may be deemed unreliable and the FDA or its non-U.S. counterparts may require us to perform additional clinical trials before approving our marketing applications. We or they may also face regulatory enforcement action. We cannot assure you that, upon inspection, the FDA or non-U.S. regulatory agencies will determine that any of our clinical trials comply with GCP. In addition, our clinical trials must be conducted with product produced under GMP and similar regulations outside of the United States. Our failure, or the failure of our product candidate manufacturers, to comply with these regulations may require us to repeat or redesign clinical trials, or conduct additional trials, which would increase our development costs and delay or impact the conduct of our preclinical studies, clinical trials, and the likelihood of regulatory approval.

If third parties do not carry out their duties under their agreements with us, if the quality or accuracy of the data they obtain is compromised due to the failure to adhere to our clinical protocols, including dosing requirements, or regulatory requirements, or if they otherwise fail to comply with clinical trial protocols or meet expected deadlines, our clinical trials may not meet regulatory requirements. If our clinical trials do not meet regulatory requirements or if these third parties need to be replaced, our clinical trials may be extended, delayed, suspended or terminated.

Agreements with third parties conducting or otherwise assisting with our clinical or non-clinical studies might terminate for a variety of reasons, including a failure to perform by the third parties. If any of our relationships with these third parties terminate, we may not be able to enter into arrangements with alternative providers or to do so on commercially reasonable terms. Switching or adding additional third parties involves additional cost and requires management time and focus. In addition, there is a natural transition period when a new third-party commences work. As a result, if we need to enter into alternative arrangements, it could delay our product development activities and adversely affect our business. Though we carefully manage our relationships with our third parties, there can be no assurance that we will not encounter challenges or delays in the future or that these delays or challenges will not have a material adverse impact on our business, financial condition and prospects, and results of operations.

If any of these events occur, we may not be able to obtain regulatory approval of our product candidates or succeed in our efforts to create approved line extensions for certain of our existing products or generate additional useful clinical data in support of these products. Moreover, if we are unable to obtain any necessary third-party services on acceptable terms or if these service providers do not successfully carry out their contractual duties or meet expected deadlines, our efforts to obtain regulatory approvals for our product candidates may be delayed or prevented.

Manufacture of our product candidates, especially in large quantities, is complex and time consuming. The loss of any of our third-party manufacturers, or delays or problems in the manufacture of our product candidates, could result in product shortages and/or delays in clinical development.

We do not have manufacturing capabilities and do not plan to develop such capacity in the foreseeable future. We depend on a limited number of third-party suppliers for the production of our product candidates. Accordingly, our ability to develop and deliver product candidates in a timely and competitive manner and to enable us to conduct our development programs depends on our third-party manufacturers being able to continue to meet our ongoing clinical trial needs and perform their contractual obligations. In order to successfully develop and commercialize our product candidates in a timely manner, we and our third-party manufacturers must be able to develop and execute on manufacturing processes and reach agreement on contract terms.

Our current and anticipated future dependence upon others for the manufacture of our product candidates or any product that we develop may adversely affect our future profit margins and our ability to commercialize any products that receive marketing approval on a timely and competitive basis. In addition, any performance failure on the part of our existing or future manufacturers could delay clinical development or marketing approval.

If these third-party manufacturers do not successfully carry out their contractual duties, meet expected deadlines or manufacture and/or store our product candidates in accordance with regulatory requirements, if there are disagreements between us and such parties, or if such parties are unable to expand capacities to support commercialization of any of our product candidates for which we obtain marketing approval, we may not be able to produce, or may be delayed in producing sufficient product candidates to meet our supply requirements. Any delays in obtaining adequate supplies with respect to our product candidates and components may delay the development or commercialization of our product candidates.

We may not succeed in our efforts to establish manufacturing relationships or other alternative arrangements for any of our product candidates, components, and programs. Our product candidates may compete with other products and product candidates for access to manufacturing facilities. There are a limited number of manufacturers that operate under cGMP regulations and that are both capable of manufacturing for us and willing to do so.

If our existing third-party manufacturers, or the third parties that we engage in the future to manufacture a product or component for commercial sale or for our clinical trials should cease to continue to do so for any reason, we likely would experience delays in obtaining sufficient quantities of our product candidates for us to meet commercial demand or to advance our clinical trials while we identify and qualify replacement suppliers. These third-party facilities may also be affected by natural disasters, such as floods or fire, or such facilities could face manufacturing issues, such as contamination or regulatory findings following a regulatory inspection of such facility. In such instances, we may need to locate an appropriate replacement third-party relationship, which may not be readily available or on acceptable terms, which would cause additional delay and increased expense. In some cases, the technical skills required to manufacture our products or product candidates may be unique or proprietary to the original manufacturer and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills to an alternate supplier in a timely fashion if at all. The addition of a new or alternative manufacturer may also require FDA approvals and may have a material adverse effect on our business.

If for any reason we are unable to obtain adequate supplies of our product candidates or the components used to manufacture them, it will be more difficult for us to develop our product candidates and compete effectively. Further, even if we do establish such collaborations or arrangements, our third-party manufacturers may breach, terminate, or not renew these agreements.

We or our third-party manufacturers may also encounter shortages in the raw materials or therapeutic substances necessary to produce our product candidates in the quantities needed for our clinical trials or, if our product candidates are approved, in sufficient quantities for commercialization or to meet an increase in demand. Such shortages may occur for a variety of reasons, including capacity constraints, delays or disruptions in the market, and shortages caused by the purchase of such materials by our competitors or others. We may also not be able to obtain such materials on favorable terms as a result of global trade policies. Our third-party manufacturers’ failure to obtain the raw materials, therapeutic substances, or active pharmaceutical ingredients necessary to manufacture sufficient quantities of our product candidates may have a material adverse effect on our business.

All of our current product candidates are biologics. Our product candidates must be made consistently and in compliance with a clearly defined manufacturing process. Problems may arise during manufacturing for a variety of reasons, including problems with raw materials, equipment malfunction or replacement and failure to follow specific protocols and procedures. Slight deviations anywhere in the manufacturing process, including obtaining materials, maintaining master seed or cell banks and preventing genetic drift, seed or cell growth, fermentation and contamination including from, among other things, particulates, filtration, filling, labeling, packaging, storage and shipping, and quality control testing, may result in lot failures or manufacturing shut-down, delays in the release of lots, product recalls, spoilage or regulatory action.

Additionally, our development and commercialization strategy involves entering into arrangements with corporate and academic collaborators, contract research organizations, distributors, third-party manufacturers, licensors, licensees and others to conduct development work, manage or conduct our clinical trials, manufacture our product candidates and market and sell our products outside of the United States and maintain our existing arrangements with respect to the commercialization or manufacture of our products. We may not have the expertise

or the resources to conduct all of these activities for all products and product candidates on our own and, as a result, are particularly dependent on third parties in many areas. Any current or future arrangements for development and commercialization may not be successful, as the amount and timing of resources that third parties devote to developing, manufacturing, and commercializing our products candidates are not within our control. If we are not able to establish or maintain agreements relating to our product candidates in development, our results of operations and prospects would be materially and adversely affected.

Any loss of a third-party manufacturer, any delays, or problems in the manufacture of our products, or termination of any arrangements for development and commercialization of our products could have a material adverse effect on our business, operations, results of operations and financial condition. We may be required to replace our manufacturer and if this were to occur, we may incur added costs and delays in identifying and qualifying any such replacements. We may also not be able to enter into such arrangements on favorable commercial terms.

Changes in product candidate manufacturing or formulation may result in additional costs or delay.

As product candidates are developed through preclinical studies to late-stage clinical trials toward approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods, manufacturing sites, and formulation, are altered along the way in an effort to optimize processes and results. Any of these changes could cause our product candidates to perform differently and affect the results of planned clinical trials or other future clinical trials conducted with the altered materials. Such changes may also require additional testing, clinical trials, FDA notification, or FDA approval. Any of the foregoing could limit our future revenues and growth.

Failure of our third-party manufacturers to successfully manufacture material that conforms to our specifications and the FDA’s or foreign regulatory authorities’ strict regulatory requirements, may prevent regulatory approval of those manufacturing facilities.

We rely on third parties to manufacture all clinical trial materials for our product candidates, and we will rely on third parties to manufacture commercial supplies, if any such product candidates are ultimately approved for commercial sale. Manufacturers of our product candidates and therapeutic substances must comply with GMP requirements enforced by the FDA that are applicable to both finished products and their active components used both for clinical and commercial supply. The FDA enforces these requirements through its facilities inspection program. Our product candidates, including APVO436 and ALG.APV-527, will not be approved for marketing by the FDA or other foreign regulatory authorities unless the FDA or their foreign equivalents also approve the facilities used by our third-party manufacturers to produce them for commercialization. If our third-party manufacturers cannot successfully manufacture material that conforms to our specifications and the FDA’s or foreign regulatory authorities’ strict regulatory requirements, the FDA or their foreign counterparts will not approve their manufacturing facilities, which would result in significant delays in obtaining FDA or foreign marketing approvals for our product candidates. If this were to occur, we may also never receive marketing approval, we may need to repeat clinical trials, we may need to undertake costly corrective actions, including product recalls, we may risk harm to subjects or patients, and we may face enforcement actions.

While we are ultimately responsible for the manufacture of our product candidates, other than through our contractual arrangements, we have little control over our manufacturers’ compliance with these regulations and standards. If the FDA or a comparable foreign regulatory authority does not approve these facilities for the manufacture of our product candidates or if it withdraws any such approval in the future, we may need to find alternative manufacturing facilities, which would significantly impact our ability to develop, obtain and maintain regulatory approval for or market our product candidates, if approved. Additionally, we may be unable to contract with alternative manufacturers on favorable or reasonable terms. Any new manufacturers would need to either obtain or develop the necessary manufacturing know-how, and obtain the necessary equipment and materials, which may take substantial time and investment. In some cases, the technical skills required to manufacture our products or product candidates may be unique or proprietary to the original manufacturer and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills to a back-up or alternate supplier, or we may be unable to transfer such skills at all. In addition, if we are required to change manufacturers for any reason, we will be required to verify that the new manufacturer maintains facilities and procedures that comply with quality standards and with all applicable regulations. We will also need to verify, such as through a manufacturing comparability study, that any new manufacturing process will produce our product candidate according to the specifications previously submitted to the FDA or any other regulatory authority. The delays associated with the verification of a new manufacturer could negatively affect our ability to develop product candidates or commercialize

our products in a timely manner or within budget. Furthermore, a manufacturer may possess technology related to the manufacture of our product candidate that such manufacturer owns independently. This would increase our reliance on such manufacturer or require us to obtain a license from such manufacturer in order to have another manufacturer produce our product candidates. In addition, changes in manufacturers often involve changes in manufacturing procedures and processes, which could require that we conduct bridging studies between our prior clinical supply used in our clinical trials and that of any new manufacturer. We may be unsuccessful in demonstrating the comparability of clinical supplies which could require the conduct of additional clinical trials. We must also receive FDA approval for the use of any new manufacturers for commercial supply.

We and our third-party manufacturers may not be able to meet these manufacturing process requirements for any of our current product candidates, all of which have complex manufacturing processes, which make meeting these requirements even more challenging. If we are unable to develop manufacturing processes for our clinical product candidates that satisfy these requirements, we will not be able to supply sufficient quantities of test material to conduct our clinical trials in a timely or cost-effective manner, and as a result, our development programs will be delayed, our financial performance will be adversely impacted and we will be unable to meet our long-term goals.

Certain of our product candidates have received orphan drug designation from the FDA. However, there is no guarantee that we will be able to maintain this designation, receive this designation for any of our other product candidates, or receive or maintain any corresponding benefits, including periods of exclusivity.

Certain of our product candidates have received orphan drug designation. We may also seek orphan drug designation for our other product candidates, as appropriate. While orphan drug designation does provide us with certain advantages, it neither shortens the development time or regulatory review time of a product candidate nor gives the product candidate any advantage in the regulatory review or approval process.

Generally, if a product candidate with orphan drug designation subsequently receives marketing approval before another product considered by the FDA to be the same for the same orphan indication, the product is entitled to a period of marketing exclusivity, which precludes the FDA from approving another marketing application for the same drug or biologic for the same indication for a period of seven years in the United States.

We may not be able to obtain any future orphan drug designations that we apply for. Orphan drug designations do not guarantee that we will be able to successfully develop our product candidates, and there is no guarantee that we will be able to maintain any orphan drug designations that we receive. For instance, orphan drug designations may be revoked if the FDA finds that the request for designation contained an untrue statement of material fact or omitted material information, or if the FDA finds that the product candidate was not eligible for designation at the time of the submission of the request.

Moreover, even if we are able to receive and maintain orphan drug designations, we may ultimately not receive any period of regulatory exclusivity if our product candidates are approved. For instance, we may not receive orphan product regulatory exclusivity if the indication for which we receive FDA approval is broader than the orphan drug designation. Orphan exclusivity may also be lost for the same reasons that orphan drug designation may be lost. Orphan exclusivity may further be lost if we are unable to assure a sufficient quantity of the product to meet the needs of patients with the rare disease or condition.

Even if we obtain orphan exclusivity for any of our current or future product candidates, that exclusivity may not effectively protect the product from competition as different products can be approved for the same condition or products that are the same as ours can be approved for different conditions. Even after an orphan product is approved, the FDA can also subsequently approve a product containing the same principal molecular features for the same condition if the FDA concludes that the later product is clinically superior. The FDA may further grant orphan drug designation to multiple sponsors for the same compound or active molecule and for the same indication. If another sponsor receives FDA approval for such product before we do, we would be prevented from launching our product in the United States for the orphan indication for a period of at least seven years, unless we can demonstrate clinical superiority. Moreover, third-party payors may reimburse for products off-label even if not indicated for the orphan condition.

We may seek Breakthrough Therapy designation by the FDA for a product candidate that we develop, and we may be unsuccessful. If we are successful, the designation may not lead to a faster development or regulatory review or

approval process, and it does not increase the likelihood that our product candidates will receive marketing approval.

We may seek Breakthrough Therapy designation for any product candidate that we develop. A breakthrough therapy is defined as a drug that is intended, alone or in combination with one or more other drugs, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over currently approved therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For drugs that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens. Drugs designated as breakthrough therapies by the FDA are also eligible for accelerated approval and priority review.

Even if we believe a product candidate we develop meets the criteria for designation as a breakthrough therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of Breakthrough Therapy designation for a product candidate may not result in a faster development process, review or approval compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if the product candidates we develop qualify as breakthrough therapies, the FDA may later decide that the drugs no longer meet the conditions for qualification and rescind the designation.

We may seek designation for our ADAPTIR and ADAPTIR-FLEX platform technologies as a designated platform technology, but we might not receive such designation, and even if we do, such designation may not lead to a faster development, regulatory review or approval process.

We may seek designation for our ADAPTIR and ADAPTIR-FLEX platform technologies as a designated platform technology. Under the FDORA, a platform technology incorporated within or utilized by a biologic is eligible for designation as a designated platform technology if (1) the platform technology is incorporated in, or utilized by, a product approved under a BLA; (2) preliminary evidence submitted by the sponsor of the approved or licensed product, or a sponsor that has been granted a right of reference to data submitted in the application for such product, demonstrates that the platform technology has the potential to be incorporated in, or utilized by, more than one product without an adverse effect on quality, manufacturing, or safety; and (3) data or information submitted by the applicable person indicates that incorporation or utilization of the platform technology has a reasonable likelihood to bring significant efficiencies to the drug development or manufacturing process and to the review process. A sponsor may request the FDA to designate a platform technology as a designated platform technology concurrently with, or at any time after, submission of an IND application for a product that incorporates or utilizes the platform technology that is the subject of the request. If so designated, the FDA may expedite the development and review of any subsequent original BLA for a product that uses or incorporates the platform technology. Even if we believe our platform technology meets the criteria for such designation, the FDA may disagree and instead determine not to grant such designation. In addition, the receipt of such designation for a platform technology does not ensure that a product will be developed more quickly or receive a faster FDA review process or ultimate FDA approval. Moreover, the FDA may revoke a designation if the FDA determines that a designated platform technology no longer meets the criteria for such designation.

We have in the past and may in the future conduct clinical trials for our product candidates outside the United States, and the FDA or non-U.S. regulatory authorities may not accept data from such trials in the development or approval of our product candidates in those jurisdictions.

We have in the past and may in the future conduct clinical trials outside the U.S. and the FDA and foreign regulatory authorities may not accept those data in support of the further development or approval of our product candidates. The acceptance of trial data from clinical trials conducted outside the United States by the FDA or applicable foreign regulatory authority may be subject to certain conditions. In cases where data from foreign clinical trials are intended to serve as the basis for marketing approval in the United States, the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the United States population and United States medical practice; (ii) the trials were performed by clinical investigators of recognized competence; and (iii) the data may be considered valid without the need for an on-site inspection by the FDA, or if the FDA considers such an inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other

appropriate means. Additionally, the FDA’s clinical trial requirements, including sufficient size of patient populations and statistical powering, must be met. Many foreign regulatory bodies have similar approval requirements.

In addition, such foreign trials will be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA or any applicable foreign regulatory authority will accept data from trials conducted outside of the United States. If the FDA or any applicable foreign regulatory authority does not accept such data, it would result in the need to conduct additional trials beyond those we have planned, which would be costly and time-consuming and delay aspects of our business plan, and which may result in our product candidates not receiving marketing approval for commercialization in the applicable jurisdiction.

Commercialization Risks

Our ability to grow revenues and execute on our long-term strategy depends heavily on our ability to discover, develop, and obtain marketing approval for our product candidates.

We currently have no products approved for commercial distribution. We have invested a significant portion of our efforts and financial resources in the development of our product candidates. Our business depends on the successful development and commercialization of our product candidates, which will require additional clinical and preclinical development, regulatory approval, commercial manufacturing arrangements, establishment of a commercial organization, significant marketing efforts, and further investment, which may never occur. Our ability to generate revenues is substantially dependent on our ability to develop, obtain regulatory approval for, and then successfully commercialize our product candidates. Except for the revenues from previously sold products, we currently generate no revenues from sales of any products, and we may never be able to develop or commercialize a marketable product.

In order for us to achieve our long-term business objectives, we will need to successfully discover and/or develop and commercialize our product candidates. Although we have made, and expect to continue to make, significant investments in research and development, we have had only a limited number of our internally-discovered product candidates reach the clinical development stage. We currently have two clinical-stage candidates, APVO436 and ALG.APV-527, which were built on the ADAPTIR platform. Drug discovery and development is a complex, time-consuming and expensive process that is fraught with risk and a high rate of failure. Our product candidates are susceptible to the risks of failure inherent at any stage of product development, including the appearance of unexpected or unacceptable adverse events or failure to demonstrate efficacy in clinical trials. Failure to successfully discover and/or develop, obtain marketing approval for and commercialize additional products and product candidates would likely have a material adverse effect on our ability to grow revenues and improve our financial condition. If we are required to conduct additional clinical trials or other testing of our product candidates that we develop beyond those that we currently expect, if we are unable to successfully complete clinical trials of our product candidates or other testing, if the results of these trials or tests are not positive or are only modestly positive, or if there are safety concerns, we may be delayed in obtaining marketing approval for our product candidates, not obtain marketing approval at all, obtain approval for limited indications or patient populations, with a label without claims necessary for us to successfully market our products, or with significant labeled warnings. We may also be subject to additional post-marketing testing requirements, surveillance requirements, or REMS. To the extent any of the foregoing should occur, our business may be materially harmed.

We may not be successful in our efforts to use and further develop our ADAPTIR or ADAPTIR-FLEX platforms.

A key element of our strategy is to expand our product pipeline of immuno-oncology candidates based on our ADAPTIR and ADAPTIR-FLEX platform technologies. We plan to select and create product candidates for early development, potentially with other collaborative partners. We expect to continue to develop the platform to address unmet medical needs through directed cytokine delivery via monospecifics and bispecifics in areas including oncology, and multi-specific molecules in oncology and other therapeutic areas. Our goal is to leverage this technology to make targeted investment in monospecific, bispecific, and multi-specific ADAPTIR and ADAPTIR-FLEX therapeutics. Even if we are successful in continuing to build our pipeline, the potential product candidates that we identify may not be suitable for clinical development, including as a result of being shown to have harmful side effects or other characteristics that indicate that they are unlikely to be products that will receive marketing approval and achieve market acceptance. If we do not successfully develop and commercialize product candidates based on our ADAPTIR and ADAPTIR-FLEX platform technologies, our ability to obtain product revenues in future periods may

be adversely affected, which likely would result in harm to our financial position and our financial prospects, and adversely affect our stock price.

We face and will continue to face substantial competition and our failure to effectively compete may prevent us from achieving significant market penetration for our product candidates, if approved.

The development and commercialization of new biotechnology products is highly competitive and subject to rapid technological advances. We may face future competition with respect to our current product candidates and any product candidates we may seek to develop or commercialize in the future obtained from other companies and governments, universities, and other non-profit research organizations. Our competitors may develop products that are safer, more effective, more convenient, or less costly than any products that we may develop or market, or may obtain marketing approval for their products from the FDA, or equivalent foreign regulatory bodies more rapidly than we may obtain approval for our product candidates. Our competitors may have greater resources and may devote greater resources to research and develop their products, research and development capabilities, adapt more quickly to new technologies, scientific advances or patient preferences and needs, initiate or withstand substantial price competition or macroeconomic impacts more successfully, or more effectively negotiate third-party licensing and collaborative arrangements.

We believe that our most significant competitors in the oncology market include: AbbVie Inc., Affimed, ALX Oncology Holdings Inc., Amgen Inc., Arcellx, AstraZeneca, AvenCell Therapeutics, Inc., BioNTech, Bio-Path, Bristol Myers Squibb, Cellectis, Faron Pharma, F-star Therapeutics, Genentech Inc. (a subsidiary of F. Hoffmann-La Roche Ltd.), Genmab A/S, Gilead Sciences, Inc., GlaxoSmithKline plc, ImmunoGen, Inc., Johnson & Johnson, Macrogenics, Inc., Menarini Group, Molecular Partners, Novartis, Pieris Pharmaceuticals, Inc., Regeneron Pharma, Sanofi-Aventis US LLC, Shattuck Labs, Syros Pharmaceuticals, Inc., Servier Laboratories, Xencor, Inc., and Zymeworks Biopharmaceuticals, Inc. We expect to compete on the basis of product efficacy, safety, ease of administration, price and economic value compared to drugs used in current practice or currently being developed. If we are not successful in demonstrating these attributes, physicians and other key healthcare decision makers may choose other products over any products we successfully develop, switch from our products to new products or choose to use our products only in limited circumstances, which could adversely affect our business, financial condition and results of operations.

Any of our product candidates, if approved, may become subject to unfavorable pricing regulations or third-party coverage and reimbursement policies, which would harm our business.

The success of our product candidates, if approved, will depend upon, among other things, their acceptance by physicians, patients, third-party payors, and other members of the medical community as a therapeutic and cost-effective alternative to competing products and treatments. If any of our product candidates do not achieve and maintain an adequate level of acceptance, we may not generate material revenues from sales of these products. The degree of market acceptance of our products will depend on a number of factors, including: our ability to provide acceptable evidence of safety and efficacy; the prevalence and severity of any side effects; availability, relative cost and relative efficacy of alternative and competing treatments; the ability to offer our products for sale at competitive prices; our ability to continuously supply the market without interruption; the relative convenience and ease of administration; the willingness of the target patient population to try new products and of physicians to prescribe these products; the strength of marketing and distribution support; publicity concerning our products or competing products and treatments; and the sufficiency of coverage or reimbursement by third parties.

Legislative or healthcare reform measures may have a material adverse effect on our business and results of operations.

In the United States, there have been and continue to be a number of legislative initiatives to contain healthcare costs. For example, in March 2010, the ACA was enacted, which substantially changed the way health care is financed by both governmental and private insurers, and significantly impacted the U.S. pharmaceutical industry. However, some provisions of the ACA have yet to be fully implemented and certain provisions have been subject to legal and political challenges, as well as efforts to repeal, replace delay, circumvent, or loosen certain aspects of the ACA or mandates required thereby. Additionally, Congress has considered legislation that would repeal or repeal and replace all or part of the ACA. While Congress has not passed comprehensive repeal legislation, it has enacted laws that modify certain provisions of the ACA, such as removing penalties as of January 1, 2019 for not complying with the ACA’s individual mandate to carry health insurance, delaying the implementation of certain ACA-mandated fees, and

increasing the point-of-sale discount that is owed by pharmaceutical manufacturers who participate in Medicare Part D. On June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the ACA. It is unclear how other healthcare reform measures of the Biden administration or other efforts, if any, to challenge, repeal or replace the ACA will impact our business. In addition, other legislative changes have been proposed and adopted in the United States since the ACA was enacted:

In addition, other legislative changes have been proposed and adopted in the United States since the ACA was enacted. On August 2, 2011, the Budget Control Act of 2011 among other things, created measures for spending reductions by Congress. A Joint Select Committee on Deficit Reduction, tasked with recommending a targeted deficit reduction of at least $1.2 trillion for the years 2013 through 2021, was unable to reach required goals, thereby triggering the legislation’s automatic reduction to several government programs. This includes aggregate reductions of Medicare payments to providers of 2 percent per fiscal year. These reductions went into effect on April 1, 2013 and, due to subsequent legislative amendments to the statute, will remain in effect through 2030 unless additional Congressional action is taken.

Additionally, there has been heightened governmental scrutiny recently over the manner in which manufacturers set prices for their marketed products. For example, there have been several recent Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drug products, including by tying reimbursement to the price of products in other developed countries. For example, proposals have been made to increase drug manufacturer competition, increase the negotiating power of certain federal healthcare programs, incentivize manufacturers to lower the list price of their products, and reduce the out-of-pocket costs of drug products paid by consumers. Individual states in the United States have also become increasingly active in passing legislation and implementing regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Legislative and regulatory agendas, as they relate to the healthcare and pharmaceutical industries and the economy as a whole, of the Biden administration and the U.S. Congress currently remain uncertain. One example of President Biden’s priorities came via an executive order that he issued on July 9, 2021 directing the FDA to, among other things, continue to clarify and improve the approval framework for biosimilars, including the standards for interchangeability of biological products, facilitate the development and approval of biosimilar and interchangeable products, clarify existing requirements and procedures related to the review and submission of BLAs, and identify and address any efforts to impede biosimilar competition. Any new laws and initiatives may result in additional reductions in Medicare and other healthcare funding or impose additional regulatory requirements on drug development or approval, which could have a material adverse effect on our future customers and accordingly, our financial operations.

We expect that additional state and federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that federal and state governments will pay for healthcare products and services, which could result in reduced demand for any product candidates we successfully develop or additional pricing pressures.

Regulatory and Compliance Risks

Our long-term success depends, in part, upon our ability to develop, receive regulatory approval for and commercialize our product candidates.

Our product candidates and the activities associated with their development, including testing, manufacture, recordkeeping, storage, and approval, are subject to comprehensive regulation by the FDA and other regulatory agencies in the United States and by comparable authorities in other countries. Failure to obtain regulatory approval for a product candidate will prevent us from commercializing the product candidate. We have limited resources for use in preparing, filing, and supporting the applications necessary to gain regulatory approvals and expect to rely on third-party contract research organizations and consultants to assist us in this process.

The FDA and other comparable regulatory agencies in foreign countries impose substantial and rigorous requirements for the development, production, marketing authorization and commercial introduction of drug products. These requirements include non-clinical, laboratory and clinical testing procedures, sampling activities, clinical trials, and other costly and time-consuming procedures. In addition, regulation is not static, and regulatory authorities, including the FDA evolve in their staff interpretations and practices and may impose more stringent or different requirements than currently in effect, which may adversely affect our planned and ongoing drug development and/or our sales and marketing efforts.

In the United States, to obtain approval from the FDA to market any of our future biologic products, we will be required to submit a BLA to the FDA. Ordinarily, the FDA requires a sponsor to support a BLA with substantial evidence of the product’s safety, purity, and potency in treating the targeted indication based on data derived from adequate and well-controlled clinical trials, including Phase 3 safety and efficacy trials conducted in patients with the disease or condition being targeted.

Developing and obtaining regulatory approval for product candidates is a lengthy process, often taking a number of years, is uncertain and expensive. All of the product candidates that we are developing, or may develop in the future, require research and development, non-clinical studies, non-clinical testing, and clinical trials prior to seeking regulatory approval, and commencing commercial sales. In addition, we may need to address a number of technological challenges in order to complete development of our product candidates. As a result, the development of product candidates may take longer than anticipated or not be successful at all.

Our product candidate development costs will also increase if we experience delays in testing or approvals, and we may not have sufficient funding to complete the testing and approval process for any of our product candidates. We may be required to obtain additional funds to complete clinical trials and prepare for possible commercialization of our product candidates. We do not know whether any non-clinical tests or clinical trials above what we currently have planned will be required, will begin as planned, will need to be restructured, or will be completed on schedule, or at all. Significant delays relating to any preclinical or clinical trials also could shorten any periods during which we may have the exclusive right to commercialize our product candidates or allow our competitors to bring products to market before we do. This may prevent us from receiving marketing approvals and impair our ability to successfully commercialize our product candidates and may harm our business and results of operations. In addition, many of the factors that cause, or lead to, delays in clinical trials may ultimately lead to the denial of marketing approval of any of our product candidates. If any of this occurs, our business, financial condition, results of operations, and prospects will be materially harmed.

Generally, no product can receive FDA approval, marketing authorization from the European Commission or the competent authorities of the EU Member States, or approval from comparable regulatory agencies in foreign countries unless data generated in human clinical trials demonstrates both safety and efficacy for each target indication in accordance with such authority’s standards.

The large majority of product candidates that begin human clinical trials fail to demonstrate the required safety and efficacy characteristics necessary for marketing approval. Failure to demonstrate the safety and efficacy of any of our product candidates for each target indication in clinical trials would prevent us from obtaining required approvals from regulatory authorities, which would prevent us from commercializing those product candidates. Negative or inconclusive results from the clinical trials or adverse medical events during the trials could lead to requirements that trials be repeated or extended, or that additional trials be conducted, any of which may not be clinically feasible or financially practicable, that the conduct of trials be suspended, or that a program be terminated.

Any regulatory approval we ultimately obtain may limit the indicated uses for the product or subject the product to restrictions or post-approval commitments that render the product commercially non-viable. Securing regulatory approval requires the submission of extensive non-clinical and clinical data, information about product manufacturing processes and inspection of facilities and supporting information to the regulatory authorities for each therapeutic indication to establish the product’s safety and efficacy. If we are unable to submit the necessary data and information, for example, because the results of clinical trials are not favorable, or if the applicable regulatory authority delays reviewing or does not approve our applications, we will be unable to obtain regulatory approval.

Delays in obtaining or failure to obtain regulatory approvals may delay or prevent the successful commercialization of any of the products or product candidates in the jurisdiction for which approval is sought; diminish our competitive advantage; and defer or decrease our receipt of revenue.

Some of our product candidates previously in development experienced regulatory and/or clinical setbacks. Clinical development has been discontinued for product candidates otlertuzumab, APVO414, and APVO210. Both APVO414 and APVO210 were discontinued after patients developed ADA. Most recently, in 2019, we elected to discontinue the APVO210 development program following the review of data from the Phase 1 multiple ascending dose (MAD) clinical study of APVO210 in healthy volunteers that suggests that APVO210 would not meet the desired target product profile for future commercialization. Specifically, the clinical data showed evidence of increasing titers of ADA with repeated doses of APVO210, which had varying impact on APVO210 drug levels in subjects’ blood. The cause of the ADA is uncertain; however, we believe that appearance of ADA is related to the mechanism of action of APVO210, and not due to the structure, or sequences characteristic of the ADAPTIR platform. Although we have re-designed certain components of the ADAPTIR platform based on what we have learned in prior clinical trials, there is no guarantee that the occurrence of ADA or other clinical setbacks will not occur in the development of our existing and future ADAPTIR product candidates.

The procedures to obtain marketing approvals vary among countries and can involve additional clinical trials or other pre-filing requirements. The time required to obtain foreign regulatory approval may differ from that required to obtain FDA approval. The foreign regulatory approval process may include all the risks associated with obtaining FDA approval, or different or additional risks. Regulatory agencies may have varying interpretations of the same data, and approval by one regulatory authority does not ensure approval by regulatory authorities in other jurisdictions. Accordingly, approval by the FDA does not ensure approval by the regulatory authorities in other countries, and approval by one foreign regulatory authority does not ensure approval by the FDA or regulatory authorities in other foreign countries. Failure to obtain regulatory approval in one jurisdiction, however, may impact the decision of other jurisdictions. We may not be able to file for regulatory approvals and may not receive necessary approvals to commercialize our products and products in development in any market on a timely basis, if at all.

Inadequate funding for the FDA, the SEC and other government agencies, including from government shutdowns, or other disruptions to these agencies’ operations, could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, the ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory and policy changes. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable.

Disruptions at the FDA and other agencies may also slow the time necessary for new product candidates to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. If a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, future

government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

Our product candidates are and will continue to be subject to ongoing obligations and continued regulatory review, which may result in significant additional expense. We may be subject to penalties if we fail to comply with regulatory requirements or experience unanticipated problems with our products.

We and our product candidates are subject to extensive and ongoing requirements of and review by the FDA and other regulatory authorities, including requirements related to the conduct of clinical and non-clinical studies, manufacturing processes, post-approval clinical data, labeling, packaging, distribution, adverse event reporting, storage, recordkeeping, export, import, advertising, marketing, and promotional activities for such products. These requirements further include submissions of safety and other post-marketing information, including manufacturing deviations and reports, registration and listing requirements, the payment of annual fees, continued compliance with GMP-requirements relating to manufacturing, quality control, quality assurance, and corresponding maintenance of records and documents, and requirements regarding the distribution of samples to physicians. Manufacturers and manufacturers’ facilities are required to comply with extensive FDA, and comparable foreign regulatory authority requirements, including ensuring that quality control and manufacturing procedures conform to GMP requirements and applicable product tracking and tracing requirements.

FDA and comparable foreign regulatory authorities will continue to closely monitor the safety profile of any product even after approval. If the FDA or comparable foreign regulatory authorities become aware of new safety information after approval of any of our product candidates, they may, among other actions, withdraw approval, require labeling changes or establishment of a REMS or similar strategy, impose significant restrictions on a product’s indicated uses or marketing, or impose ongoing requirements for potentially costly post-approval studies or post-market surveillance. Any such restrictions could limit sales of the product.

We and any of our collaborators could be subject to periodic unannounced inspections by the FDA to monitor and ensure compliance with GMPs and other FDA regulatory requirements. Application holders must further notify the FDA, and depending on the nature of the change, obtain FDA pre-approval for product and manufacturing changes. In addition, later discovery of previously unknown adverse events or that the product is less effective than previously thought or other problems with our products, manufacturers or manufacturing processes, or failure to comply with regulatory requirements both before and after approval, may yield various results, including:

Any of these events could prevent us from achieving or maintaining product approval and market acceptance of the particular product candidate, if approved, or could substantially increase the costs and expenses of developing and commercializing such product, which in turn could delay or prevent us from generating significant revenues from its sale. Any of these events could further have other material and adverse effects on our operations and business and could adversely impact our stock price and could significantly harm our business, financial condition, results of operations, and prospects.

The FDA’s policies may change and additional government laws and regulations may be enacted that could prevent, limit, or delay regulatory approval of our product candidates, that could limit the marketability of our product candidates, or that could impose additional regulatory obligations on us. For example, the current administration may implement new or revised laws, regulatory requirements, and associated compliance obligations, as well as postponed or frozen regulatory requirements. Changes in medical practice and standard of care may also impact the marketability of our product candidates. If we are slow or unable to adapt to changes in existing requirements, standards of care, or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and be subject to regulatory enforcement action.

Should any of the above actions take place, they could adversely affect our ability to achieve or sustain profitability. Further, the cost of compliance with post-approval regulations may have a negative effect on our operating results and financial condition.

If we fail to comply with foreign, federal, state, and local healthcare laws, including fraud and abuse and health information privacy and security laws, we could face substantial penalties and our business, results of operations, financial condition and prospects could be adversely affected.

As a biotechnology company, even though we do not provide healthcare services or receive payments directly from or bill directly to Medicare, Medicaid, or other third-party payors for our products, certain federal, state, local and foreign healthcare laws and regulations pertaining to fraud and abuse and patients’ rights are applicable to our business. We are subject to healthcare fraud and abuse and patient privacy regulation by both the federal government and the states in which we conduct our business. The laws that may affect our ability to operate include:

Because of the breadth of these laws and the narrowness of the statutory exceptions and safe harbors available under the U.S. federal Anti-Kickback Statute, it is possible that some of our business activities could be subject to challenge under one or more of such laws. Moreover, recent health care reform legislation has strengthened these laws. For example, the ACA, among other things, amends the intent requirement of the federal Anti-Kickback Statute and criminal health care fraud statutes, so that a person or entity no longer needs to have actual knowledge of the statute or specific intent to violate it. In addition, the ACA provides that the government may assert that a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the False Claims Act.

Recently, several pharmaceutical and other healthcare companies have been prosecuted under the federal false claims laws for allegedly inflating drug prices they report to pricing services, which in turn are used by the government to set Medicare and Medicaid reimbursement rates, and for allegedly providing free product to customers with the expectation that the customers would bill federal programs for the product. In addition, certain marketing practices, including off-label promotion, interactions with specialty pharmacies, and patient assistance programs may also violate fraud and abuse laws. To the extent that any product we make is sold in a foreign country, we may be subject to similar foreign laws and regulations.

In addition, certain state and local laws mandate that we comply with a state code of conduct, adopt a company code of conduct under state criteria, disclose marketing payments made to health care professionals and entities, disclose drug pricing information and/or report compliance information to the state authorities. The shifting compliance environment and the need to build and maintain robust and expandable systems to comply in multiple jurisdictions with different compliance and reporting requirements increase the possibility that a pharmaceutical company may violate one or more of the requirements. Any failure to comply with these reporting requirements could result in significant fines and penalties.

The risks of complying with these laws cannot be entirely eliminated. The risk of violation of such laws is also increased because many of them have not been fully interpreted by the regulatory authorities or the courts, and their provisions are open to a variety of interpretations. Any action against us for violation of these laws, even if we successfully defend against it, could cause us to incur significant legal expenses and divert our management’s attention from the operation of our business. Moreover, achieving and sustaining compliance with applicable federal, state, local and foreign privacy, security, fraud and transparency laws may prove costly. If our past or present operations, or those of our distributors are found to be in violation of any of the laws described above or any other governmental regulations that apply to us, we may be subject to sanctions, including civil and administrative penalties, criminal fines, damages, disgorgement, exclusion from participation in U.S. federal or state health care programs, individual imprisonment, integrity obligations, and the curtailment or restructuring of our operations, any of which could materially adversely affect our ability to operate our business and our financial results. Similarly, if healthcare providers, distributors or other entities with whom we do business are found to be out of compliance with applicable laws and regulations, they may be subject to sanctions, which could also have a negative impact on us.

Our employees, independent contractors, consultants, commercial partners, principal investigators, or CROs may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements, which could have a material adverse effect on our business.

We are exposed to the risk of employee fraud or other misconduct. Misconduct by employees, independent contractors, consultants, commercial partners, manufacturers, investigators, or CROs could include intentional, reckless, negligent, or unintentional failures to comply with FDA regulations or applicable fraud and abuse laws, provide accurate information to the FDA, properly calculate pricing information required by federal programs, comply with federal procurement rules or contract terms, report financial information or data accurately or disclose unauthorized activities to us. This misconduct could also involve the improper use or misrepresentation of information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation. It is not always possible to identify and deter this type of misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws or regulations. Moreover, it is possible for a whistleblower to pursue a False Claims Act case against us even if the government considers the claim unmeritorious and declines to intervene, which could require us to incur costs defending against such a claim. Further, due to the risk that a judgment in a False Claims Act case could result in exclusion from federal health programs or debarment from government contracts, whistleblower cases often result in large settlements. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, financial condition, and results of operations, including the imposition of significant fines or other sanctions.

Our operations, including our use of hazardous materials, chemicals, bacteria, and viruses, require us to comply with regulatory requirements and expose us to significant potential liabilities.

Our operations involve the use of hazardous materials, including chemicals, and may produce dangerous waste products. Accordingly, we, along with the third parties that conduct clinical trials and manufacture our products and product candidates on our behalf, are subject to federal, state, local and foreign laws and regulations that govern the use, manufacture, distribution, storage, handling, exposure, disposal and recordkeeping with respect to these materials. We are also subject to a variety of environmental and occupational health and safety laws. Compliance with current or future laws and regulations can require significant costs and we could be subject to substantial fines and penalties in the event of noncompliance. In addition, the risk of contamination or injury from these materials cannot be completely eliminated. In such event, we could be held liable for substantial civil damages or costs associated with the cleanup of hazardous materials.

Our failure to comply with data protection laws and regulations could lead to government enforcement actions and significant penalties against us, and adversely impact our operating results.

EU Member States, Switzerland and other countries have adopted data protection laws and regulations, which impose significant compliance obligations. For example, European Union, or EU, member states and other foreign jurisdictions, including Switzerland, have adopted data protection laws and regulations which impose significant compliance obligations. Moreover, the collection and use of personal health data in the EU is now governed under the EU General Data Protection Regulation, or the GDPR, effective in May 2018. The GDPR, which is wide-ranging in scope, imposed several requirements relating to the consent of the individuals to whom the personal data relates, the information provided to the individuals, the security and confidentiality of the personal data, data breach notification and the use of third-party processors in connection with the processing of personal data. The GDPR also imposes strict rules on the transfer of personal data out of the EU to the U.S., provides an enforcement authority and imposes large penalties for noncompliance, including the potential for fines of up to €20 million or 4% of the annual global revenues of the noncompliant company, whichever is greater. The GDPR requirements apply not only to third-party transactions, but also to transfers of information between us and our subsidiaries, including employee information. The GDPR increases our responsibility and liability in relation to personal data that we process, including in clinical trials, and we may be required to put in place additional mechanisms to ensure compliance with the GDPR, which could divert management’s attention and increase our cost of doing business. In addition, new regulation or legislative actions regarding data privacy and security (together with applicable industry standards) may increase our costs of doing business. However, despite our ongoing efforts, we may not be successful either due to various factors within our control, such as limited financial or human resources, or other factors outside our control. It is also possible that local data protection authorities may have different interpretations of the GDPR, leading to potential inconsistencies amongst various EU member states. Any failure or alleged failure (including as a result of deficiencies in our policies, procedures, or measures relating to privacy, data security, marketing, or communications) by us to comply with laws, regulations, policies, legal or contractual obligations, industry standards, or regulatory guidance relating to privacy or data security, may result in governmental investigations and enforcement actions, litigation, fines and penalties or adverse publicity. In addition, we expect that there will continue to be new proposed laws, regulations and industry standards relating to privacy and data protection in the United States, the EU and other jurisdictions, such as the California Consumer Privacy Act of 2018, which has been characterized as the first “GDPR-like” privacy statute to be enacted in the United States, and we cannot determine the impact such future laws, regulations and standards may have on our business.

If we experience a significant disruption in our information technology systems or breaches of data security, including due to a cybersecurity incident, our business could be adversely affected.

We rely on information technology systems to keep financial records, capture laboratory data, maintain clinical trial data and corporate records, communicate with staff and external parties and operate other critical functions. Our information technology systems are potentially vulnerable to disruption due to breakdown, malicious intrusion and computer viruses or other disruptive events including but not limited to natural disaster.

We also face the challenge of promptly detecting and remediating any cybersecurity breaches. Our information technology systems security measures are focused on the prevention, detection and remediation of damage from computer viruses, unauthorized access, cyber-attack and other similar disruptions. However, our information technology systems protection measures may not be successful in preventing unauthorized access, intrusion and damage. Threats to our systems can derive from human error, fraud or malice on the part of employees or third parties, including computer hackers, encryption by ransomware, or may result from technological failure.

If we were to experience a prolonged system disruption in our information technology systems or those of certain of our vendors, it could delay or negatively impact our development and commercialization of our product candidates, which could adversely impact our business. If operations at our facilities were disrupted, it may cause a material disruption in our business if we are not capable of restoring function on an acceptable timeframe.

In addition, as discussed above, our information technology systems are potentially vulnerable to data security breaches—whether by employees or others, intentionally or unintentionally—which may expose sensitive or personal data to unauthorized persons. Such data security breaches could lead to the loss of trade secrets or other intellectual property, or could lead to the public exposure of personal information (including sensitive personal information) of our employees, customers and others, any of which could have a material adverse effect on our business, financial condition and results of operations.

Moreover, a security breach or privacy violation that leads to destruction, loss, alteration, unauthorized use or access, disclosure or modification of, personally identifiable information or personal data, could harm our reputation, compel us to comply with federal, state and/or international breach notification laws, subject us to mandatory corrective or regulatory action, require us to verify the correctness of database contents and otherwise subject us to liability under laws and regulations that protect personal data, including the GDPR and the California Consumer Privacy Act of 2018, which could disrupt our business, result in increased costs or loss, and/or result in significant legal and financial exposure. In addition, a data security breach could result in loss of clinical trial data or damage to the integrity of that data.

If we are unable to implement and maintain adequate organizational and technical measures to prevent such security breaches or privacy violations, or to respond adequately in the event of a breach, our operations could be disrupted, and we may suffer loss of reputation, problems with regulatory authorities, financial loss and other negative consequences. In addition, these breaches and other inappropriate access can be difficult to detect, and any delay in identifying them may lead to increased harm of the type described above.

If a breach of our information technology systems or those of our key third-party vendors occurs, we may incur additional costs related to repairing or rebuilding our internal systems, complying with breach notification laws, defending legal claims or proceedings, responding to regulatory actions, incurring penalties, and paying damages. Moreover, it may be determined that as a result of such a breach there was a material weakness or significant deficiency in our internal controls or other failure of our control environment. If such a breach occurs, it may have a material adverse effect on our business, results of operations, and financial condition, and it may also negatively impact our reputation.

Intellectual Property Risks

If we are unable to protect our intellectual proprietary rights, our business could be harmed.

Our commercial success will depend, in large part, on our ability to obtain and maintain protection in the United States and other countries for the intellectual property covering or incorporated into our technology, products and product candidates. Obtaining and maintaining this protection is very costly. The patentability of technology in the biotechnology field generally is highly uncertain and involves complex legal and scientific questions. We cannot be certain that our patents and patent applications, including our own and those that we have rights through licenses from third parties, will adequately protect our intellectual property. Our success in protecting our intellectual property depends significantly on our ability to:

We may not be able to obtain issued patents relating to our technology or product candidates. Even if issued, patents may inadvertently lapse or be challenged, narrowed, invalidated, or circumvented, which could limit our ability to stop competitors from marketing similar products or limit the duration of patent protection we may have for our product candidates. Further, patents may lapse prior to the regulatory approval of the underlying product in one or more territories. In the past, we have abandoned the prosecution and/or maintenance of patent applications related to patent families in the ordinary course of business. In the future, we may choose to abandon such prosecution and/or maintenance in a similar fashion. If these patent rights are later determined to be valuable or necessary to our business, our competitive position may be adversely affected. Changes in patent laws or administrative patent office rules or changes in interpretations of patent laws in the United States and in other countries may diminish the value of our intellectual property or narrow the scope of our patent protection, or result in costly defensive measures.

Patent and other intellectual property laws outside the United States are even more uncertain than in the United States and are continually undergoing review and revisions in many countries. Further, the laws of some foreign countries may not protect our intellectual property rights to the same extent as the laws of the United States. For example, certain countries do not grant patent claims that are directed to business methods and processes. In addition,

we may have to participate in additional opposition proceedings, like the proceedings described above, to determine the validity of our foreign patents or our competitors’ foreign patents, which could result in substantial costs and diversion of our efforts.

Our collaborative partners and licensors may not adequately protect our intellectual property rights. These third parties may have the first right to maintain or defend intellectual property rights in which we have an interest and, although we may have the right to assume the maintenance and defense of such intellectual property rights if these third parties do not do so, our ability to maintain and defend such intellectual property rights may be compromised by the acts or omissions of these third parties.

The cost of litigation to uphold the validity of patents, once obtained, to prevent infringement or to otherwise protect or enforce our proprietary rights could be substantial and, from time to time, our patents are subject to patent office proceedings. Some of our competitors may be better able to sustain the costs of complex patent litigation because they may have substantially greater financial resources. Intellectual property lawsuits are expensive and unpredictable and would consume management’s time and attention and other resources, even if the outcome were successful. In addition, there is a risk that a court would decide that our patents are not valid and that we do not have the right to stop the other party from using the inventions covered by or incorporating them. There is also a risk that, even if the validity of a patent were upheld, a court would refuse to stop the other party from using the invention(s), including on the grounds that its activities do not infringe the patent. If any of these events were to occur, our business, financial condition and operating results could be materially and adversely affected.

In addition to patent litigation, we may be a party to adversarial proceedings before the Patent Trial and Appeal Board (PTAB) of the USPTO, or the Opposition Divisions of the European Patent Office (EPO). Potential proceedings before the PTAB include inter parties review proceedings, post-grant review proceedings and interference proceedings. Depending on our level of success at the PTAB and Opposition Divisions of the EPO, these proceedings could adversely impact our intellectual property rights with respect to our products and technology.

In addition, the U.S. Supreme Court has ruled on several patent cases in recent years, either narrowing the scope of patent protection available in certain circumstances or weakening the rights of patent owners in certain situations. This combination of events has created uncertainty with respect to the value of patents, once obtained, and with regard to our ability to obtain patents in the future. Depending on decisions by the U.S. Congress, the federal courts, and the USPTO, the laws and regulations governing patents could change in unpredictable ways that would weaken our ability to obtain new patents or to enforce our existing patents and patents that we might obtain in the future. Patent and intellectual property laws outside of the United States may also change and be uncertain.

Our patents, once obtained, also may not afford us protection against competitors with similar technology. Because patent applications in the United States and many foreign jurisdictions are typically not published until eighteen months after filing, or in some cases not at all, and because publications of discoveries in the scientific literature often lag behind actual discoveries, neither we nor our licensors can be certain that others have not filed or maintained patent applications for technology used by us or covered by our pending patent applications without our being aware of these applications.

We also will rely on current and future trademarks to establish and maintain recognized brands, including APTEVO THERAPEUTICS, APTEVO BIOTHERAPEUTICS, APTEVO RESEARCH AND DEVELOPMENT, the Aptevo logo, ADAPTIR, and ADAPTIR-FLEX in relevant jurisdictions. If we fail to acquire and protect such trademarks, our ability to market and sell our products, if approved for marketing, will be harmed. In addition, our current and future trademarks may be challenged, infringed, circumvented, declared generic, lapsed or determined to be infringing on or dilutive of other marks and we may not be able to protect our rights in these trademarks, which we need in order to build name recognition. Any of the foregoing could have a material and adverse effect on our business, financial condition and operating results.

If approved, our products regulated as biologics may face competition from biosimilars approved through an abbreviated regulatory pathway.

The Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively the ACA, includes a subtitle called the Biologics Price Competition and Innovation Act of 2009, or BPCIA, which created an abbreviated approval pathway for biological products that are biosimilar to or interchangeable with an FDA-licensed reference biological product. Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a BLA for the competing product containing the sponsor’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity, and potency of the other company’s product. The law is complex and is still being interpreted and implemented by the FDA. As a result, its ultimate impact, implementation, and meaning are subject to uncertainty. We believe that any of our product candidates approved as a biological product under a BLA should qualify for the 12-year period of exclusivity. However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider our investigational medicines to be reference products for competing products, potentially creating the opportunity for generic competition sooner than anticipated. Other aspects of the BPCIA, some of which may impact the BPCIA exclusivity provisions, have also been the subject of recent litigation.

There is a similar abbreviated pathway for the approval of biosimilar products in the EU. Reference products in the EU benefit from an eight-year data exclusivity period during which the data included in the dossier for the reference product may not be referenced for the purposes of an abbreviated biosimilar application. Following the expiration of the data exclusivity period, there is an additional two-year period of market exclusivity during which a biosimilar marketing authorization application can be submitted, and the innovator’s data may be referenced, but no product can be placed on the market until the expiration of such period. The overall 10-year period can be extended to a maximum of 11 years in certain circumstances. As in the U.S., there is no guarantee that a product will qualify for the prescribed period of exclusivity and, even if a product does qualify, another company may market a competing version of the reference product if such company obtained a marketing authorization with a complete independent data package of pharmaceutical tests, preclinical tests and clinical trials.

Moreover, the extent to which a biosimilar, once licensed, will be substituted for any one of our reference products in a way that is similar to traditional generic substitution for non-biological products, and will depend on a number of marketplace and regulatory factors that are still developing. If competitors are able to obtain marketing approval for biosimilars referencing any of our products, if approved, our products may become subject to competition from such biosimilars, which would impair our ability to successfully commercialize and generate revenues from sales of such products.

Third parties may choose to file patent infringement claims against us.

Our development and commercialization activities, as well as any product candidates or products resulting from these activities, may infringe or be claimed to infringe patents and other intellectual property rights of third parties under which we do not hold sufficient licenses or other rights. Third parties may be successful in obtaining patent protection for technologies that cover development and commercialization activities in which we are already engaged. These third parties may have substantially greater financial resources than us and could bring claims against us that could cause us to incur substantial expenses to defend against these claims and, if successful against us, could cause us to pay substantial damages. If a patent infringement or other similar suit were brought against us, we could be forced to stop or delay development, manufacturing or sales of the product or product candidate that is the subject of the suit. Intellectual property litigation in the biotechnology industry is common, and we expect this trend to continue.

As a result of patent infringement or other similar claims, or to avoid potential claims, we may choose or be required to seek a license from the third-party and be required to pay license fees or royalties or both. These licenses may not be available on acceptable terms, or at all. Even if we were able to obtain a license, the rights may be non-exclusive, which could result in our competitors gaining access to the same intellectual property. Ultimately, we could be prevented from commercializing a product, or be forced to cease some aspect of our business operations, if, as a result of actual or threatened patent infringement claims, we are unable to enter into licenses on acceptable terms, if at all, or if an injunction is granted against us, which could harm our business significantly.

There has been substantial litigation and other proceedings regarding patent and other intellectual property rights in the pharmaceutical and biotechnology industries. In addition to infringement claims against us, we may become a party to other patent litigation and other adversarial proceedings such as proceedings before the Patent Trial Appeals Board and opposition proceedings in the European Patent Office, regarding intellectual property rights that could impact our products and technology.

Patent litigation and other proceedings may also absorb significant management time. The cost to us of any patent litigation or other proceeding, even if resolved in our favor, could be substantial. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their substantially greater financial resources. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could have a material adverse effect on our ability to compete in the marketplace.

Our Aptevo trademarks may be opposed which could have a material and adverse effect on our business.

We have an application pending that covers the APTEVO THERAPEUTICS trademark and received a notice of allowance in September 2022 from the USPTO for the APTEVO BIOTHERAPEUTICS and APTEVO RESEARCH AND DEVELOPMENT trademarks. We refer to these trademarks as our house marks. If a third-party opposes any of these house marks and we are unable to reach settlement prior to the commencement of an opposition proceeding, we may incur significant expense in the course of participating in the opposition process, which can be expensive and lengthy. Any settlement with a third-party may result in our agreeing to be subject to restrictions on our use of the relevant house mark. In addition, if we are unsuccessful in an opposition against a house mark, we would lose the ability to obtain trademark registration for one or more uses of the relevant mark both in the United States and in other territories which could have a material and adverse effect on our business.

We may be subject to claims that our employees have wrongfully used or disclosed alleged trade secrets of their former employers.

As is common in the biotechnology and pharmaceutical industry, we employ individuals who were previously employed at other biotechnology or pharmaceutical companies, including our competitors or potential competitors. We may be subject to claims that these employees or we have inadvertently or otherwise used or disclosed trade secrets or other proprietary information of their former employers. Litigation may be necessary to defend against these claims. Even if we are successful in defending against these claims, litigation could result in substantial costs and be a distraction to management.

Failure to comply with our obligations in our intellectual property licenses with third parties, could result in loss of license rights or other damages.

We are a party to a number of license agreements and expect to enter into additional license agreements in the future. Our existing licenses impose, and we expect future licenses will impose, various diligence, milestone payment, royalty, insurance, and other obligations on us. If we fail to comply with these obligations, the licensor may have the right to terminate the license in whole or in part, terminate the exclusive nature of the license and/or sue us for breach, which could cause us to not be able to market any product that is covered by the licensed patents and may be subject to damages.

If we are unable to protect the confidentiality of our proprietary information and know-how, the value of our technology and product candidates could be adversely affected.

In addition to patented technology, we rely upon unpatented proprietary technology, information processes and know-how. These types of trade secrets can be difficult to protect. We seek to protect this confidential information, in part, through agreements with our employees, consultants and third parties as well as confidentiality policies and audits, although these may not be successful in protecting our trade secrets and confidential information. These agreements may be breached, and we may not have adequate remedies for any such breach. In addition, our trade secrets may otherwise become known, including through a potential cyber security breach, or may be independently developed by competitors. If we are unable to protect the confidentiality of our proprietary information and know-how, competitors may be able to use this information to develop products that compete with our products, which could adversely impact our business.

Risks Related to Collaborations and Other Transactions

We may not be successful in establishing and maintaining collaborations and entering into other transactions that leverage our capabilities in pursuit of developing and commercializing our product candidates and any such collaborations and transactions, if any, could result in financial results that differ from market expectations.

For each of our product candidates we plan to evaluate the merits of entering into collaboration arrangements with third parties, including leading biotechnology companies or non-governmental organizations. In July 2017, we entered into a collaboration agreement with Alligator pursuant to which Aptevo R&D and Alligator have been collaboratively developing ALG.APV-527, a lead bispecific antibody candidate simultaneously targeting 4-1BB (CD137), a member of the TNFR superfamily of a co-stimulatory receptor found on activated T-cells, and 5T4, a tumor antigen widely overexpressed in a number of different types of cancer. We intend to pursue collaboration arrangements with third parties that have particular technology, expertise or resources for the development or commercialization of our product candidates or for accessing particular markets. We face, and will continue to face, significant competition in seeking appropriate partners for our product candidates. If we are unable to identify partners whose capabilities complement and integrate well with ours and reach collaboration arrangements with such partners on a timely basis, on acceptable terms or at all, or if the arrangements we establish are unproductive for us, we may fail to meet our business objectives for the particular product candidate. Our ability to enter into such arrangements with respect to products in development that are subject to licenses may be limited by the terms of those licenses.

Our collaboration agreement with Alligator, or any collaboration agreement we may consider entering into, may not be successful and the success of our collaboration arrangements will depend heavily on the efforts and activities of our collaborative partners. It is likely that our collaborative partners will have significant discretion in determining the efforts and resources that they will apply to these collaborations.

The risks that we are subject to in any of our collaborations include, among others:

The failure of any of our current or future collaboration partners to perform as expected could place us at a competitive disadvantage and adversely affect us financially, including delay and increased costs of development, loss of market opportunities, lower than expected revenues and impairment of the value of the related product candidate. A loss of our collaboration agreement with Alligator would result in a burden of locating a replacement partner under potentially less favorable terms at an additional cost. Collaborations are a critical part of our business strategy, and any inability on our part to establish and successfully maintain such arrangements on terms favorable to us or to work successfully with our collaborative partners could have an adverse effect on our operations and financial performance. Due to the macroeconomic factors, we may experience delays in opportunities to develop our product candidates, due to financial and other impacts on potential partners.

In addition, in the normal course of business, the Company engages in discussions with third parties regarding possible strategic alliances, joint ventures, acquisitions, divestitures and business combinations to further develop or commercialize our product candidates. As a result of such transactions, our financial results may differ from our own or the investment community's expectations in a given fiscal quarter or over the long term. Furthermore, efforts to engage in such transactions require varying levels of management resources, which may divert the Company’s attention from other business operations. Any transactions we engage in could result in our financial results differing materially from market expectations.

Risks Related to Our Common Stock and General Risks

Our stock price is and may continue to be volatile.

Our stock price has fluctuated in the past and is likely to be volatile in the future. Between August 1, 2016 and December 31, 2023, the reported closing price of our common stock has fluctuated between $0.172 and $83.16 per share (as adjusted to reflect our 1-for-14 reverse stock split of our outstanding common stock that was effective on March 26, 2020). The stock market in general, and the market for biotechnology companies in particular, have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. In particular, the stock market has experienced extreme volatility in recent months as a result of the geopolitical climate, including the war in Ukraine and the rising conflict in the Middle East, and macroeconomic conditions, including rising and fluctuating inflation and interest rates and reduced consumer confidence. The market price of our common stock may fluctuate significantly due to a number of factors, some of which may be beyond our control or unrelated to our operations, including, among others:

Biotechnology company stock prices have declined significantly in certain instances where companies have failed to obtain FDA or foreign regulatory authority approval of a product candidate or if the timing of FDA or foreign regulatory authority approval is delayed. If the FDA’s or any foreign regulatory authority’s response to any application for approval is delayed or not favorable for any of our product candidates, our stock price could decline significantly.

In addition, when the market price of a company’s common stock drops significantly, stockholders often institute securities class action lawsuits against the company. A lawsuit against us could cause us to incur substantial costs and could divert the time and attention of our management and other resources.

In the event that coverage under our directors’ and officers’ liability insurance is reduced or terminated as a result of an ownership change or otherwise, our indemnification obligations and limitations of our directors’ and officers’

liability insurance may have a material adverse effect on our financial condition, results of operations and cash flows.

Under Delaware law, our certificate of incorporation, and our by-laws and certain indemnification agreements to which we are a party, we have an obligation to indemnify, or we have otherwise agreed to indemnify, certain of our current and former directors and officers with respect to past, current, and future investigations and litigation. In order to reduce the risk of expense of these obligations, we maintain directors’ and officers’ liability insurance. A significant change in the Company’s risk profile could increase the cost to us of our directors’ and officers’ liability insurance coverage or the coverage thereunder may be reduced or terminated in full. In the event that the coverage under our directors’ and officers’ liability insurance is reduced or terminated, we will be required to pay the expenses of indemnifying our current and former directors and officers in their defense of current and future investigations and litigation, which expenses may be significant. The increased costs to us of our directors’ and officers’ liability insurance coverage, or our indemnification obligations if our directors’ and officers’ liability insurance coverage is reduced or terminated, could result in the diversion of our financial resources, and may have a material adverse effect on our financial condition, results of operations and cash flows.

If we do not maintain effective internal controls, we may not be able to accurately report our financial results and our business could be harmed.

The Sarbanes-Oxley Act requires, among other things, that we assess the effectiveness of our internal control over financial reporting annually and the effectiveness of our disclosure controls and procedures quarterly. In particular, Section 404 of the Sarbanes-Oxley Act, or Section 404, requires us to perform system and process evaluation and testing of our internal control over financial reporting to allow management to report on, and our independent registered public accounting firm potentially to attest to, the effectiveness of our internal control over financial reporting. In the past, we were an emerging growth company and we currently are a non-accelerated filer and have availed ourselves of the exemption from the requirement that our independent registered public accounting firm attest to the effectiveness of our internal control over financial reporting under Section 404. If we cease to be a non-accelerated filer and our independent registered public accounting firm is required to undertake an assessment of our internal control over financial reporting, the cost of our compliance with Section 404 will correspondingly increase. Our compliance with applicable provisions of Section 404 will require that we incur substantial accounting expense and expend significant management time on compliance-related issues as we implement additional corporate governance practices and comply with reporting requirements. Moreover, if we are not able to comply with the requirements of Section 404 applicable to us in a timely manner, or if we or our independent registered public accounting firm identifies deficiencies in our internal control over financial reporting that are deemed to be material weaknesses, the market price of our stock could decline and we could be subject to sanctions or investigations by the SEC or other regulatory authorities, which would require additional financial and management resources.

Investor perceptions of our company may suffer if material weaknesses are found, and this could cause a decline in the market price of our common stock. Irrespective of compliance with Section 404, any failure of our internal control over financial reporting could harm our operating results and reputation. If we are unable to implement these requirements effectively or efficiently, it could harm our operations, financial reporting, or financial results and could result in an adverse opinion on our internal controls from our independent registered public accounting firm.

The public announcement of data from clinical trials or news of any developments related to our product pipeline may cause significant volatility in our stock price.

The announcement of data from clinical trials by us or our collaborative partners or news of any developments related to our key pipeline product candidates has in the past caused and may in the future cause significant volatility in our stock price. Furthermore, the announcement of any negative or unexpected data or the discontinuation of development of any of our key pipeline product candidates, or any delay in our anticipated timelines for filing for regulatory approval, could cause our stock price to decline significantly. There can be no assurance that data from clinical trials will support a filing for regulatory approval or even if approved, that any of our key pipeline products will become commercially successful.

Our common stock may be at risk for delisting from the Nasdaq Capital Market in the future if we do not maintain compliance with Nasdaq’s continued listing requirements. Delisting could adversely affect the liquidity of our common stock and the market price of our common stock could decrease.

Our common stock is currently listed on the Nasdaq Capital Market LLC (Nasdaq). Nasdaq has minimum requirements that a company must meet in order to remain listed on Nasdaq, including corporate governance standards and a requirement that we maintain a minimum closing bid price of $1.00 per share.

On September 13, 2023, the Company received a letter from Nasdaq notifying the Company that, for the last 30 consecutive business days, the bid price of the Company’s common stock had closed below $1.00 per share, the minimum closing bid price required by the continued listing requirements of Nasdaq Listing Rule 5550(a)(2) (the "Bid Price Requirement").

Nasdaq's letter has no immediate impact on the listing of the Company's common stock, which will continue to be listed and traded on Nasdaq subject to the Company’s compliance with the other continued listing requirements. Nasdaq’s letter provides the Company 180 calendar days, or until March 11, 2024 (the "Compliance Date"), to regain compliance with the Bid Price Requirement. To regain compliance with the Bid Price Requirement, the closing bid price of the Company’s common stock must be at least $1.00 per share for a minimum of ten consecutive business days before the Compliance Date. The Company may be eligible for an additional 180-day period to regain compliance if the Company meets all other listing standards of Nasdaq, with the exception of the bid price requirement, and provides written notice to Nasdaq of its intention to cure the deficiency during the second compliance period, by effecting a reverse stock split, if necessary. In the event the Company fails to regain compliance, the Company would have the right to a hearing before the Nasdaq Listing Qualifications Panel (the "Panel"). There can be no assurance that, if the Company receives a delisting notice and appeals the delisting determination by the Panel, such appeal would be successful.

The Company intends to take reasonable measures to regain compliance under the Nasdaq Listing Rules and remain listed on Nasdaq, including by effecting a reverse stock split.

In the future, if we fail to maintain such minimum requirements and a final determination is made by Nasdaq that our common stock must be delisted, the liquidity of our common stock would be adversely affected and the market price of our common stock could decrease. In addition, if delisted, we would no longer be subject to Nasdaq rules, including rules requiring us to have a certain number of independent directors and to meet other corporate governance standards. Our failure to be listed on Nasdaq or another established securities market would have a material adverse effect on the value of your investment in us.

If our common stock is not listed on Nasdaq or another national exchange, the trading price of our common stock is below $5.00 per share and we have net tangible assets of $6,000,000 or less, the open-market trading of our common stock will be subject to the “penny stock” rules promulgated under the Securities Exchange Act of 1934, as amended. If our shares become subject to the “penny stock” rules, broker-dealers may find it difficult to effectuate customer transactions and trading activity in our securities may be adversely affected.

Your percentage of ownership in Aptevo may be diluted in the future.

In the future, your percentage ownership in Aptevo may be diluted because of equity issuances or securities convertible into equity for acquisitions, capital market transactions or otherwise, including, but not limited to, equity issuances under our existing Purchase Agreement with Lincoln Park, under our Rights Plan with Broadridge Corporate Issuer Solutions, Inc., upon the exercise of warrants issued in connection with our March 2019 and August 2023 public offerings and November 2023 Warrant Inducement Agreement, and equity awards to our directors, officers and employees. Our employees have options to purchase shares of our common stock and from time to time, we expect to issue additional options, restricted stock units, or other stock-based awards to our employees under our employee benefits plans.

In addition, our restated certificate of incorporation authorizes us to issue, without the approval of our stockholders, one or more classes or series of preferred stock having such designation, powers, preferences and relative, participating, optional and other special rights, including preferences over our common stock respecting dividends and distributions, as our board of directors generally may determine. The terms of one or more classes or series of preferred stock could dilute the voting power or reduce the value of our common stock. For example, we could grant the holders of preferred stock the right to elect some number of our directors in all events or on the happening of specified events or the right to veto specified transactions. Similarly, the repurchase or redemption rights or liquidation preferences we could assign to holders of preferred stock could affect the residual value of the common stock.

Provisions under Delaware law and in our restated certificate of incorporation, amended and restated by-laws and rights agreement may discourage acquisition proposals, delay a change in control or prevent transactions that stockholders may consider favorable.

Certain provisions in our restated certificate of incorporation and amended and restated by-laws, and under Delaware law, may discourage, delay, or prevent a merger, acquisition or other changes in control that stockholders may consider favorable, including transactions in which stockholders might otherwise receive a premium for their shares. These provisions may also prevent or frustrate attempts by our stockholders to replace or remove our incumbent directors and management.

These provisions include:

The affirmative vote of holders of our capital stock representing at least 75% of the voting power of all outstanding stock entitled to vote is required to amend or repeal the above provisions of our certificate of incorporation. The affirmative vote of either a majority of the directors present at a meeting of our Board of Directors or holders of our capital stock representing at least 75% of the voting power of all outstanding stock entitled to vote is required to amend or repeal our by-laws.

In addition, Section 203 of the General Corporation Law of Delaware prohibits a corporation from engaging in a business combination with an interested stockholder, generally a person which, together with its affiliates, owns or within the last three years has owned 15% or more of the corporation’s voting stock, for a period of three years after the date of the transaction in which the person became an interested stockholder, unless the business combination is approved in a prescribed manner. Accordingly, Section 203 may discourage, delay or prevent a change in control of us.

Moreover, we currently have a short-term stockholder Rights Agreement in effect. On November 2, 2023, we entered into Amendment No. 3 to the Rights Agreement and extended the expiration of such agreement to November 4, 2024. This Rights Agreement could render more difficult, or discourage a merger, tender offer, or assumption of control of the Company that is not approved by our Board that some stockholders may consider favorable. The Rights Agreement, however, should not interfere with any merger, tender or exchange offer or other business combination approved by our Board. Nor does the rights agreement prevent our Board from considering any offer that it considers to be in the best interest of our stockholders.

Our by-laws include a forum selection clause, which may impact your ability to bring actions against us.

Subject to certain limitations, our bylaws provide that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery in the State of Delaware will be the sole and exclusive forum for any stockholder (including a beneficial owner) to bring: (a) any derivative action or proceeding brought on our behalf; (b) any action asserting a claim of breach of fiduciary duty owed by any of our directors, officers or other employees or our stockholders; (c) any action asserting a claim arising pursuant to any provision of the DGCL or our certificate of incorporation or by-laws; or (d) any action asserting a claim governed by the internal affairs doctrine. In addition, our bylaws provide that unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States will be the exclusive forum for resolving any complaint asserting a cause of action arising under the federal securities laws of the United States against us, our officers, directors, employees or underwriters. These limitations on the forum in which stockholders may initiate action against us could create costs, inconvenience or otherwise adversely affect your ability to seek legal redress.

Section 22 of the Securities Act creates concurrent jurisdiction for federal and state courts over all suits brought to enforce any duty or liability created by the Securities Act or the rules and regulations thereunder. As a result, a court may decline to enforce these exclusive forum provisions with respect to suits brought to enforce any duty or liability created by the Securities Act or any other claim for which the federal and state courts have concurrent jurisdiction, and our stockholders may not be deemed to have waived our compliance with the federal securities laws and the rules and regulations thereunder. If a court were to find the exclusive forum provisions to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions.

We may be subject to periodic litigation, which could result in losses or unexpected expenditure of time and resources.

From time to time, we may be called upon to defend ourselves against lawsuits relating to our business. Any litigation, regardless of its merits, could result in substantial costs and a diversion of management’s attention and resources that are needed to successfully run our business. Due to the inherent uncertainties of litigation, we cannot accurately predict the ultimate outcome of any such proceedings. An unfavorable outcome in any such proceedings could have an adverse impact on our business, financial condition and results of operations. If our stock price is volatile, we may become involved in securities class action lawsuits in the future.

A significant portion of our shares may be sold into the market at any time which could depress our stock price.

If our stockholders sell a substantial number of shares of our common stock in the public market, our market price could decline. In connection with the transaction with Lincoln Park, we registered under the Securities Act of 1933, as amended, the resale of shares of common stock that have been and may be issued under the Purchase Agreement with Lincoln Park. Any such sales or perception that such sales may occur, whether under the Lincoln Park Purchase Agreement or otherwise, could decrease the market price of our common stock.

Item 1B. Unresolved Staff Comments.

None.

Item 1C. Cybersecurity

The Company’s Board of Directors (the “Board”) is responsible for overseeing the Company’s risk management program and cybersecurity is a critical element of this program. Management is responsible for the day-to-day administration of the Company’s risk management program and its cybersecurity policies, processes, and practices. The Company’s cybersecurity policies, standards, processes, and practices are based on recognized frameworks established by the National Institute of Standards and Technology (“NIST”) and are included in the Company’s overall risk management system and processes. In general, the Company seeks to address material cybersecurity threats through a company-wide approach that addresses the confidentiality, integrity, and availability of the Company’s information systems or the information that the Company collects and stores, by assessing, identifying and managing cybersecurity issues as they occur.

Cybersecurity Risk Management and Strategy

The Company’s cybersecurity risk management strategy focuses on several areas:

In 2023, the Company engaged an independent assessor to assess the maturity of its cybersecurity program against the NIST Cybersecurity Framework (NIST CSF). The results of the NIST CSF maturity assessment laid the roadmap for the cyber initiatives conducted in 2023 and future. Further, a third-party conducted an external and internal penetration test, performed a dark web scan for any Aptevo private and confidential data and assessed Aptevo's cloud security configuration posture. All critical and high-risk findings from that assessment were addressed in 2023.

Governance

The Board has designated the Audit Committee as the governing committee for the oversight of the Company’s material IT cybersecurity risks. The Audit Committee reviews cybersecurity risks through quarterly updates, and the committee monitors the status of ongoing projects to strengthen existing information security controls and practices and mitigate the potential risk of cybersecurity incidents. Quarterly, the Company's Chief Financial Officer (CFO), with support from the expert firm providing Chief Information Officer (CIO) services, presents on material cybersecurity risks and their accompanying mitigation and remediation strategies to the Audit Committee.

The CIO and CFO are key management roles responsible for assessing and managing material risks from cybersecurity threats. The CIO reports to the CFO and is responsible for implementing and maintaining the enterprise cybersecurity organization. The CIO has over 20 years of experience in Information Security and Cybersecurity for public and private institutions in the pharmaceutical, insurance, manufacturing, healthcare, and non-profit industries. The CFO also brings over 20 years of experience with a focus on small to mid-size public companies in the life science and technology fields.

The CIO, in coordination with senior management including the CFO, works collaboratively across the Company to implement a program designed to protect the Company’s information systems from cybersecurity threats and to promptly respond to any material cybersecurity incidents in accordance with the Company’s incident response and recovery plans. The CIO and senior management are informed about and monitor the prevention, detection, mitigation and remediation of cybersecurity threats and incidents in real time, and report such threats and incidents to the Audit Committee when appropriate.

Material Effects of Cybersecurity Incidents

Risks from cybersecurity threats, including as a result of any previous cybersecurity incidents, have not materially affected and are not reasonably likely to materially affect the Company, including its business strategy, results of operations, or financial condition.

Item 2. Properties.

We lease our headquarters office and laboratory space in Seattle, Washington. The Seattle facility is approximately 48,000 square feet and the lease for the Seattle facility expires in April 2030.

Item 3. Legal Proceedings.

We may from time to time be named as a party to legal claims, actions and complaints, including matters involving employment claims, our intellectual property or other third-party claims. Our management believes that there are currently no claims or actions pending against us, the ultimate disposition of which could have a material adverse effect on our results of operations, financial condition, or cash flows.

Item 4. Mine Safety Disclosures.

Not applicable.

PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Our common stock has been listed on The Nasdaq Capital Market under the symbol “APVO” since October 18, 2019, and was listed on The Nasdaq Global Market from August 1, 2016 to October 17, 2019.

Holders of Common Stock

As of March 5, 2024, we had 23,472,436 shares of common stock outstanding held by 111 holders of record of our common stock. The number of record holders does not include stockholders who are beneficial owners but whose shares are held in “street name” by brokers and other nominees or persons, partnerships, associates, corporations, or other entities identified in security position listings maintained by depositories. We have never declared or paid any cash dividends and do not anticipate declaring or paying cash dividends for the foreseeable future.

Dividend Policy

We have never declared or paid any cash dividends on our common stock or any other securities. We anticipate that we will retain all available funds and any future earnings, if any, for use in the operation of our business and do not anticipate paying cash dividends in the foreseeable future. In addition, future debt instruments may materially restrict our ability to pay dividends on our common stock. Payment of future cash dividends, if any, will be at the discretion of the board of directors after taking into account various factors, including our financial condition, operating results, current and anticipated cash needs, the requirements of then-existing debt instruments and other factors the board of directors deems relevant.

Recent Sales of Unregistered Securities

We did not sell any unregistered securities during the year ended December 31, 2023.

Issuer Purchases of Equity Securities

We did not repurchase any shares of our common stock during the year ended December 31, 2023.

Item 6.

Not applicable.

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following Management’s Discussion and Analysis of Financial Condition and Results of Operations (this MD&A) together with the consolidated financial statements and the related notes thereto included in this Annual Report on Form 10-K. This MD&A contains forward-looking statements that are subject to risks and uncertainties, such as those set forth in the sections of this Annual Report on Form 10-K captioned “Cautionary Note Regarding Forward-Looking Statements,” “Risk Factors” and elsewhere. As a result, our actual results may differ materially from those anticipated in these forward-looking statements.

Overview

We are a clinical-stage, research and development biotechnology company focused on developing novel immunotherapy candidates for the treatment of different forms of cancer. We have developed two versatile and enabling platform technologies for rational design of precision immune modulatory drugs and have two clinical candidates and three preclinical candidates currently in development. Clinical candidate APVO436 is a CD3xCD123 T-cell engager currently being clinically evaluated for the treatment of acute myelogenous leukemia (AML). Clinical candidate ALG.APV-527 targets 4-1BB (co-stimulatory receptor) and 5T4 (tumor antigen). The compound is designed to reactivate antigen-primed T-cells to specifically kill tumor cells and is currently being evaluated for the treatment of multiple solid tumor types.

Preclinical candidates, APVO603 and APVO711, were also developed using our ADAPTIR™ modular protein technology platform. Our preclinical candidate APVO442 was developed using our ADAPTIR-FLEX™ modular protein technology platform.

Our ADAPTIR and ADAPTIR-FLEX platforms are designed to generate monospecific, bispecific, and multi-specific antibody candidates capable of enhancing the human immune system against cancer cells. ADAPTIR and ADAPTIR-FLEX are both modular platforms, which gives us the flexibility to potentially generate immunotherapeutic candidates with a variety of mechanisms of action. This flexibility in design allows us to generate novel therapeutic candidates that may provide effective strategies against difficult to treat, as well as advanced forms of cancer. We have successfully designed and constructed numerous investigational-stage product candidates based on our ADAPTIR platform. The ADAPTIR platform technology is designed to generate monospecific and bispecific immunotherapeutic proteins that specifically bind to one or more targets, for example, bispecific therapeutic molecules, which may have structural and functional advantages over monoclonal antibodies. The structural differences of ADAPTIR molecules over monoclonal antibodies allow for the development of ADAPTIR immunotherapies that are designed to engage immune effector cells and disease targets to produce signaling responses that modulate the immune system to kill tumor cells.

We believe we are skilled at candidate generation, validation, and subsequent preclinical and clinical development using the ADAPTIR platform and the ADAPTIR-FLEX platform to generate bispecific and multi-specific candidates or other candidates to our platform capabilities. We have developed a preclinical candidate based on the ADAPTIR-FLEX platform which is advancing in our pipeline. We are developing our ADAPTIR and ADAPTIR-FLEX molecules using our protein engineering, preclinical development, process development, and clinical development capabilities.

Results of Operations

Except as otherwise stated below, the following discussions of our results of operations reflect the results of our continuing operations, excluding the results related to Aptevo BioTherapeutics LLC (Aptevo BioTherapeutics), which was sold in February 2020 to Medexus and has been separated from continuing operations and reflected as a discontinued operation. See Note 2 – Discontinued Operations to the accompanying consolidated financial statements for additional information.

Year Ended December 31, 2023 Compared to Year Ended December 31, 2022

For the year ended December 31, 2023, we had net loss of $17.4 million compared to $8 million net income for the same period in 2022. As of December 31, 2023, we had $16.9 million in cash and cash equivalents.

Royalty Revenue

For the year ended December 31, 2023, we did not record royalty revenue compared to $3.1 million royalty revenue for the same period in 2022. We did not recognize royalty revenue in 2023 due to our Amendment to Royalty Purchase Agreement with HCR. As a result of the amendment, we ceased reporting as royalty revenue, and royalties were paid by Pfizer to HCR related to Pfizer’s sales of RUXIENCE beginning in the second quarter of 2022. The royalty revenue from Pfizer related to a Collaboration and License Agreement ("Definitive Agreement") acquired by Aptevo as part of our spin-off from Emergent in 2016. The Definitive Agreement was originally executed by Trubion Pharmaceuticals, which was subsequently acquired by Emergent, and Wyeth, a wholly owned subsidiary of Pfizer (see Note 9).

On March 30, 2021, we entered into and closed a Royalty Purchase Agreement with an entity managed by HCR pursuant to which we sold to HCR the right to receive royalty payments made by Pfizer in respect of net sales of RUXIENCE. Under the terms of the Royalty Purchase Agreement, the Company received $35 million at closing and we are eligible to receive additional payments in the aggregate of up to an additional $32.5 million based on the achievement of sales milestones in 2021, 2022 and 2023. We received the 2021 milestone payments in the collective amount of $10 million on March 8, 2022. The proceeds from these milestone payments, net of transaction costs, were recorded as an additional liability related to the sale of royalties on the consolidated balance sheet as of March 31, 2022.

Due to the nature of the transaction, which included a cap on HCR’s rate of return, constituting continuing involvement under the Collaboration and License Agreement originally between Trubion and Wyeth, we recorded a liability related to the proceeds received from HCR of $35.0 million, net of transaction costs of $1.1 million. Further, we received proceeds related to the 2021 milestone of $10.0 million, net of transaction costs of $0.5 million, and recorded additional liability related to sale of royalties. We recognized royalty revenue on net sales of RUXIENCE and recorded the royalty payments to HCR as a reduction of the liability when paid.

In order to non-dilutively address a Nasdaq listing compliance matter, on June 7, 2022, we entered into and closed an amendment to the Royalty Purchase Agreement (the Amendment to Royalty Purchase Agreement), pursuant to which we agreed to forego our right to receive 50% of incremental RUXIENCE royalty revenue after HCR received aggregate royalty payments totaling 190% of the Investment Amount plus Milestone Amounts to the extent paid by HCR. The Amendment to Royalty Purchase Agreement eliminated all of our continuing involvement with the cash generating activities related to the royalties and removed all restrictions related to HCR’s rate of return and therefore was accounted for under ASC 610-20, Gains and Losses from Derecognition of Nonfinancial Assets and ASC 405-20, Liabilities – Extinguishment of Liabilities, resulting in recognition of $37.2 million gain, which was the total balance of the liability related to the sale of royalties on the closing date.

We received 2022 milestone payment of $2.5 million on February 28, 2023. The proceeds from the 2022 milestone payment were recorded as other income in the consolidated statement of operations for the year ended December 31, 2022. We do not expect to receive any further milestone payments pursuant to our royalty purchase agreement.

Research and Development Expenses

We expense research and development costs as incurred. These expenses relate primarily to conducting non-clinical studies and clinical trials, fees to professional service providers for analytical testing, independent monitoring or other administration of our clinical trials and obtaining and evaluating data from our clinical trials and non-clinical studies. Our research and development expenses include:

We expect our research and development spending will be dependent upon such factors as the results from our clinical trials, the availability of reimbursement of research and development spending, the number of product candidates under development, the size, structure and duration of any clinical programs that we may initiate, and the costs associated with manufacturing our product candidates on a large-scale basis for later stage clinical trials. We may experience interruption of key clinical trial activities, such as site initiation, patient enrollment and clinical trial site monitoring, and key non-clinical activities due to a variety of risk factors, including macroeconomic conditions. While a number of our programs are still in the preclinical trial phase, we do not provide a breakdown of the initial associated expenses as we are often evaluating multiple product candidates simultaneously. Costs are reported in preclinical research and discovery until the program enters the clinic.

Our research and development expenses by program for the years ended December 31, 2023 and 2022 are shown in the following table:

Research and development expenses decreased by $0.8 million, to $17.1 million for the year ended December 31, 2023 from $17.9 million for the year ended December 31, 2022. The decrease was primarily due to lower APVO436 trial costs as we concluded our Phase 1b dose expansion study. The decrease was partially offset by higher expenses related to ALG.APV-527 trial costs as 2023 consisted of a full year of CRO and patient visit costs compared to preclinical and start-up activities in 2022.

General and Administrative Expenses

General and administrative expenses consist primarily of personnel-related costs and professional fees in support of our executive, business development, finance, accounting, information technology, legal and human resource functions. Other costs include facility costs not otherwise included in research and development expenses.

For the year ended December 31, 2023, general and administrative expenses decreased by $2.1 million, to $11.8 million from $13.9 million for the year ended December 31, 2022. The decrease is primarily due to lower employee and consulting costs.

Other Income (Expense), Net

Other income (expense), net consists primarily of gain on extinguishment of liabilities, milestone income related to sale of royalties, costs related to debt extinguishment, accrued exit fees on debt, non-cash interest on financing agreements, and interest on debt.

Other Income (Expense), Net

Other income, net was $0.6 million for the year ended December 31, 2023 and other expense, net was $4.0 million for the year ended December 31, 2022. The change in other income (expense), net is primarily due to higher interest income from our money market funds and not having interest expense related to our MidCap term loan due to principal paydown and full repayment of the outstanding balance in the first quarter of 2023. Additionally, we no

longer record non-cash interest expense due to our Amendment to the Royalty Purchase Agreement in the second quarter of 2022, which eliminated the liability related to the sale of royalties and the related non-cash interest expense.

Gain Related to Sale of Nonfinancial Asset

We recorded $9.7 million in other income for the year ended December 31, 2023, due to the sale of deferred payments and milestones to XOMA during the year (see Note 3).

Gain on Extinguishment of Liability Related to Sale of Royalties

We recorded $37.2 million in other income for the year ended December 31, 2022, due to our Amendment to Royalty Purchase Agreement (see Note 9).

Milestone Income Related to the Sale of Royalties

We recorded $2.5 million in other income for the year ended December 31, 2022, related to Pfizer's net sales of RUXIENCE in fiscal year 2022. Due to our Amendment to Royalty Purchase Agreement, we record Milestone Amounts from HCR when they are earned (see Note 9).

Discontinued Operations

For the year ended December 31, 2023 and 2022, we recorded $1.2 million and $1.0 million, respectively, of contingent gain consideration from previous discontinued operations.

Liquidity and Capital Resources

Cash Flows

The following table provides information regarding our cash flows for year ended December 31, 2023 and 2022:

Net cash used in operating activities for the year ended December 31, 2023, was primarily due to our net operating loss of $17.4 million and changes in our working capital accounts, and was partially offset by $2.5 million HCR 2022 royalty milestone payment. Net cash used in operating activities for the year ended December 31, 2022, was primarily due to changes in working capital accounts and our operating cash spend.

Net cash used in investing activities for the year ended December 31, 2023 was $0. Net cash used in investing activities for the year ended December 31, 2022 was primarily due to purchases of property and equipment.

Net cash provided by financing activities for the year ended December 31, 2023 was primarily due to the $3.3 million proceeds received from the issuance of common stock, $3.0 million proceeds received from the exercise of pre-funded warrants, and $3.3 million gross proceeds received from the exercise of common warrants. This was offset by $3.5 million of repayments of the MidCap term loan, which included the remaining outstanding principal balance and loan prepayment fees. Net cash used in financing activities for the year ended December 31, 2022 was primarily due to the $12.3 million of repayments of the MidCap Financial term loan, and $6.8 million royalties received from Pfizer by HCR pursuant to our Royalty Purchase Agreement. This was offset by the $10 million milestone received by Aptevo from HCR related to the sale of royalties, net of $0.5 million transaction costs, and $7.0 million of proceeds received from issuance of common stock pursuant to our Equity Distribution Agreement with Piper Sandler.

Sources of Liquidity

IXINITY Milestone Payments

On February 28, 2020, Aptevo entered into an LLC Purchase Agreement with Medexus, pursuant to which we sold all of the issued and outstanding limited liability company interests of Aptevo BioTherapeutics LLC, a wholly owned subsidiary of Aptevo. On March 29, 2023, we entered into and closed a Purchase Agreement with XOMA pursuant to which we sold to XOMA our right, title, and interest to all future deferred payments from Medexus and a portion of potential milestones. Aptevo continues to be eligible to receive up to $5.8 million in milestone payments from Medexus upon achievement of certain regulatory and IXINITY net sales threshold. For the year ended December 31, 2023, Aptevo received $0.5 million in deferred payments from Medexus related to IXINITY sales for the fourth quarter of 2022.

Lincoln Park Purchase Agreement

On February 16, 2022, we entered into a new Purchase Agreement and a Registration Rights Agreement with Lincoln Park (2022 Purchase Agreement and Registration Rights Agreement). The 2022 Purchase Agreement and Registration Rights Agreement replaced our Purchase Agreement and Registration Rights Agreement with Lincoln Park that we entered into with them in December 2018. Under the 2022 Purchase Agreement, Lincoln Park committed to purchase up to $35.0 million worth of our common stock over a 36-month period commencing after the satisfaction of certain conditions, which are within our control, as set forth in the Purchase Agreement. The purchase price per share will be based on the prevailing market price; provided, however, that the prevailing market price is not below $1.00. The Company issued 99,276 shares of our common stock to Lincoln Park for no cash consideration as an initial fee for its commitment to purchase shares of our common stock under the Purchase Agreement. The aggregate number of shares that we can sell to Lincoln Park under the Purchase Agreement may not exceed 981,103 shares, unless shareholder approval is obtained or the average price of all applicable sales of our common stock sold to Lincoln Park equals or exceeds $6.14 per share. For the year ended December 31, 2023, we issued 300,000 shares of our common stock for cash consideration to Lincoln Park under the 2022 Purchase Agreement. We received $0.5 million in proceeds from these shares. The Company did not issue any shares of common stock for cash consideration to Lincoln Park under the Purchase Agreement for the year ended December 31, 2022.

Actual sales of shares of our common stock to Lincoln Park under the Purchase Agreement will occur at our discretion from time to time and depend on a variety of factors, including, among others, market conditions, the trading price of our common stock and additional determinations as to the appropriate sources of funding for our operations. Lincoln Park has no right to require any sales, but is obligated to make purchases as we direct, in accordance with the Purchase Agreement.

Common Warrants - 2019

On March 11, 2019, in connection with the completion of a public offering of common stock, we issued warrants to purchase 1,571,429 shares of common stock at a price of $18.20. As of December 31, 2023 and 2022, there were warrants to purchase 350,589 shares of common stock outstanding. These warrants have a 5-year life and expire in March 2024.

Series A and Series B Common Warrants - August 2023

On August 4, 2023, in connection with the completion of a public offering, we issued Series A Common Warrants to purchase up to an aggregate of 8,064,517 shares of common stock and Series B Common Warrants to purchase up to an aggregate of 8,064,517 shares of common stock. The Series A and Series B Common Warrants have an exercise price of $0.62 per share, are exercisable immediately following the date of issuance and will expire on August 4, 2028 and February 4, 2025, respectively. As of December 31, 2023, we have 1,872,516 Series A and 58,000 Series B Common Warrants outstanding from our August 2023 public offering with an exercise price of $0.62 per

share. If the remaining August 2023 warrants are exercised, we may receive up to an additional $1.1 million in gross proceeds.

New Series A and Series B Common Warrants - November 2023

On November 9, 2023, we entered into a warrant Inducement Agreement with certain holders of our existing Series A common warrants and Series B common warrants (together, the "Existing Warrants") to purchase shares of common stock. Pursuant to the terms of the Inducement Agreement, the holders agreed to exercise for cash their Existing Warrants to purchase up to an aggregate of 16,013,034 shares of common stock at an exercise price of $0.233 during the period from the date of the Inducement Agreement until December 8, 2023. In consideration of the holder’s agreement to exercise the Existing Warrants, we agreed to issue new Series A and new Series B common warrants (together, the "New Warrants"), to purchase a number of shares of common stock equal to 200% of the number of shares of common stock issued upon exercise of the Existing Warrants. Holders exercised 6,192,001 Existing Series A and 8,006,517 Existing Series B Warrants and the Company received $3.3 million in gross proceeds. As of December 31, 2023, we have 12,384,002 New Series A and 16,013,034 New Series B Common Warrants outstanding from our November 2023 warrant inducement with an exercise price of $0.233 per share. If the New Warrants are exercised, we may receive up to an additional $6.6 million in gross proceeds.

Liquidity

We have financed our operations to date primarily through royalty and purchase agreements with various partners, sale of business products and segments, public offerings of our common stock, loan proceeds, milestone payments, research and development funding from strategic partners, revenue generated from our previously owned commercial products, and funds received at the date of our spin-off from Emergent. We had cash and cash equivalents of $16.9 million and an accumulated deficit of $223.4 million as of December 31, 2023.

For the year ended December 31, 2023, net cash used in our operating activities was $11.7 million.

Our future success is dependent on our ability to develop our product candidates. We anticipate that we will continue to incur significant operating losses for the next several years as we incur expenses to continue to execute on our development strategy to advance our preclinical and clinical stage assets. We will not generate revenues from our development stage product candidates unless and/or until we or our collaborators successfully complete development and obtain regulatory approval for such product candidates, which we expect will take a number of years and is subject to significant uncertainty. If we obtain regulatory approval for one of our development stage product candidates, we expect to incur significant commercialization expenses related to sales, marketing, manufacturing and distribution, to the extent that such costs are not paid by collaborators. We do not have sufficient cash to complete the clinical development of any of our development stage product candidates and will require additional funding in order to complete the development activities required for regulatory approval of such product candidates. We will require substantial additional funds to continue our development programs and to fulfill our planned operating goals.

We may experience delays in opportunities to partner our product candidates, due to financial and other impacts on potential partners. Additionally, we may experience potential impacts on our future milestones from Medexus due to effects of macroeconomic impacts, including, but not limited to, bank failure, and the rising and fluctuating inflation, which may impact Medexus’ ability to continue to successfully commercialize the IXINITY businesses.

There are numerous risks and uncertainties associated with research, development, and commercialization of pharmaceutical products. Accordingly, our future funding requirements may vary from our current expectations and will depend on many factors, including, but not limited to:

If we are unable to raise substantial additional capital in the next year, whether on terms that are acceptable to us or at all, then we may be required to:

The sale of additional equity or convertible debt securities may result in additional dilution to our stockholders. If we raise additional funds through the issuance of debt securities or preferred stock or through credit facilities, these securities and/or the loans under credit facilities could provide for rights senior to those of our common stock and could contain covenants that would restrict our operations. Additional funds may not be available when we need them, on terms that are acceptable to us, or at all. We also expect to seek additional funds through arrangements with collaborators, licensees or other third parties. These arrangements would generally require us to relinquish or encumber rights to some of our technologies or drug candidates, and we may not be able to enter into such arrangements on acceptable terms, if at all. Due to the macroeconomic factors, we may experience delays in clinical trials and non-clinical work, and opportunities to partner our product candidates, due to financial and other impacts on potential partners.

Our results of operations will be highly dependent on our research and development spending. When considered in aggregate, these factors raise substantial doubt about our ability to continue as a going concern for the one-year period from the date of issuance of these financial statements. We will need to raise additional funds to support our operating and capital needs in addition to our existing cash resources, cash to be generated from future milestones related to IXINITY sales and regulatory approvals achieved by Medexus, and exercise of warrants.

Our plans to address this condition include pursuing one or more of the following options to secure additional funding, none of which can be guaranteed or are entirely within our control:

There can be no assurance, however, that we will receive cash proceeds from any of these potential resources or to the extent cash proceeds are received such proceeds would be sufficient to support our current operating plan for at least the next twelve months from the date of filing this Annual Report on Form 10-K.

Contractual Obligations

We have an operating lease related to our office and laboratory space in Seattle, Washington. This lease was amended in March 2019 to extend the term of the amended lease is through April 2030 and provided two options to extend the lease term, each by five years, as well as a one-time option to terminate the lease in April 2023, with nine months’ notice, or by July 2022. On May 26, 2022, we further amended our office and laboratory lease to remove the one-time termination option in April 2023. In exchange for removing the termination option, we received six months of free rent. As a result, we recorded an additional $4.4 million of lease liability and right-of-use asset on the consolidated balance sheet in May 2022.

We have a non-exclusive Commercial Platform License Agreement with OMT ("OMT License Agreement") for certain transgenic rodents of OMT's OmniAb platform. Our OMT License Agreement obligates us to make milestone and royalty payments upon achievement of certain regulatory approvals and commercialization of our product candidates. APVO436 and APVO603 are the product candidates currently subject to this agreement. Pursuant to our agreement, we are required to make a $2.0 million milestone payment upon dosing the first patient in our Phase 2 clinical trial of APVO436.

Our principal commitments include obligations under vendor contracts to purchase research services and other purchase commitments with our vendors. In the normal course of business, we enter into services agreements with contract research organizations, contract manufacturing organizations and other third parties. Generally, these agreements provide for termination upon notice, with specified amounts due upon termination based on the timing of termination and the terms of the agreement. The actual amounts and timing of payments under these agreements are uncertain and contingent upon the initiation and completion of the services to be provided.

Critical Accounting Policies, and Significant Judgments, and Estimates

The preparation of our consolidated financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. We base our estimates on historical experience and on various other factors. Although we believe that our judgments and estimates are appropriate, actual results may differ materially from our estimates and changes in these estimates are recorded when known. An accounting policy is considered critical if it is important to a company’s financial condition and results of operations and if it requires the exercise of significant judgment and the use of estimates on the part of management in its application.

While our significant accounting policies are more fully described in Note 1 to our audited consolidated financial statements appearing elsewhere in this report, we believe the following accounting policies are the most critical to the judgments and estimates we use in the preparation of our consolidated financial statements.

Research and Development Expenses

Research and development expenses are expensed as incurred. Research and development costs primarily consist of internal labor costs, fees paid to outside service providers and the costs of materials used in clinical trials and research and development. Other research and development expenses include facility, maintenance, and related support expenses.

A substantial portion of our preclinical studies and all of our clinical studies have been performed by third-party contract research organizations (CRO). We review the activities performed by the CROs each period. For preclinical studies, the significant factors used in estimating accruals include the percentage of work completed to date and contract milestones achieved. For clinical study expenses, the significant factors used in estimating accruals include the number of enrolled patients visit at each site to date. Our estimates are highly dependent upon the timeliness and accuracy of the data provided by our CROs regarding the status of each program and total program spending and adjustments are made when deemed necessary.

Stock-Based Compensation

Under ASC 718, Compensation—Stock-based Compensation, we measure and recognize compensation expense for restricted stock units (RSUs), and stock options granted to our employees and directors based as of the fair value of the awards on the date of grant. The fair value of stock options is estimated at the date of grant using the Black-Scholes option pricing model that requires management to apply judgment and make estimates, including:

Stock-based compensation expense for RSUs, and stock options is recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the respective award. We are required to estimate a forfeiture rate to calculate the stock-based compensation expense for our awards. Our forfeiture rate is based on an analysis of our actual forfeitures since the adoption of our equity award plan. We routinely evaluate the appropriateness of the forfeiture rate based on actual forfeiture experience, analysis of employee turnover, and expectations of future option exercise behavior.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We are a smaller reporting company as defined by Rule 12b-2 of the Exchange Act, and are not required to provide the information required under this item.

Table of Contents

Index to Consolidated Financial Statements

Item 8. Financial Statements and Supplementary Data

APTEVO THERAPEUTICS INC.

Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of

Aptevo Therapeutics Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Aptevo Therapeutics Inc. (the “Company”) as of December 31, 2023 and 2022, the related consolidated statements of operations, cash flows, and changes in stockholders’ equity for the years then ended, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the consolidated financial position of the Company as of December 31, 2023 and 2022, and the consolidated results of its operations and its cash flows for the years then ended, in conformity with accounting principles generally accepted in the United States of America.

Going Concern Uncertainty

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern. As discussed in Note 1 to the consolidated financial statements, the Company has suffered recurring losses from operations and has a net capital deficiency that raise substantial doubt about its ability to continue as a going concern. Management’s plans in regard to these matters are also described in Note 1. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s consolidated financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures to respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Accounting for the Sale of Future Payments for IXINITY Sales

As described in Note 3, the Company sold to XOMA the right to receive all deferred payments and a portion of milestone payments related to global sales of IXINITY in exchange for total cash consideration of $9.65 million. The sale of deferred payments and certain milestone payments was recorded as a gain related to the sale of a non-financial asset in the Company’s consolidated statements of operations for the year ended December 31, 2023.

We identified the accounting for the sale of future payments for IXINITY sales as a critical audit matter because the transaction was highly complex and required management to interpret and apply complex accounting standards. This, in turn, led to a high degree of auditor judgment and increased audit effort, including the use of subject matter experts on technical accounting matters, in performing procedures to evaluate whether the transaction was properly accounted for in accordance with relevant accounting principles.

The primary procedures we performed to address this critical audit matter included:

/s/ Moss Adams LLP

Seattle, Washington

March 5, 2024

We have served as the Company’s auditor since 2020.

Aptevo Therapeutics Inc.

CONSOLIDATED BALANCE SHEETS

(in thousands, except share and per share amounts)

The accompanying notes are an integral part of these consolidated financial statements.

Aptevo Therapeutics Inc.

CONSOLIDATED STATEMENTS OF OPERATIONS

(in thousands, except share and per share amounts)

The accompanying notes are an integral part of these consolidated financial statements.

Aptevo Therapeutics Inc.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(in thousands)