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Aptevo Therapeutics Presents New Clinical Data Evaluating the Safety and Efficacy of IXINITY in Children With Hemophilia B

Data Presented at the Hemostasis and Thrombosis Research Society 2017 Scientific Symposium

SEATTLE, April 10, 2017 (GLOBE NEWSWIRE) -- Aptevo Therapeutics Inc. (Nasdaq:APVO), a biotechnology company focused on developing novel oncology and hematology therapeutics, today announced the presentation of new clinical data evaluating the safety and efficacy of IXINITY® [Coagulation Factor IX (Recombinant)] in previously treated patients under 12 years of age with Hemophilia B.  The data suggest that IXINITY appears to be safe and well tolerated in this subject population, and is comparable to the results from the overall patient population studied in the pivotal clinical trial of IXINITY.

“We’re encouraged to see data in a pediatric setting demonstrating the safety and efficacy of IXINITY in this important population,” said Scott Stromatt, Senior Vice President and Chief Medical Officer.  “The key efficacy outcomes from this study are comparable to what has previously been demonstrated in our pivotal study of IXINITY, which formed the basis for our licensure in the United States in patients 12 years of age or older.  In this pooled analysis, IXINITY was well tolerated and effective in preventing and controlling bleeding episodes in previously treated patients under the age of 12 with Hemophilia B.  According to the Centers for Disease Control and Prevention Community Counts public health monitoring program, approximately 22% of people treated for Hemophilia B are under the age of 10 years, representing a sizeable new addressable market for IXINITY, should we be successful in expanding the labeled indication for IXINITY to include this patient population.”

Launched in the United States in 2015 and wholly-owned by Aptevo, IXINITY is an intravenous recombinant factor IX therapeutic for use in people 12 years of age or older with Hemophilia B -- a hereditary bleeding disorder characterized by a deficiency of clotting factor IX in the blood, which is necessary to control bleeding.

Study Design

The data presented at the Hemostasis and Thrombosis Research Society 2017 Scientific Symposium represent a pooled analysis of 2 prospective, multi-center, non-randomized, open-label studies of 12 children with Hemophilia B under the age of 12 years.  Patients were treated with either a prophylactic or on demand regimen based on investigator discretion.  Bleed control efficacy was evaluated using: annualized bleeding rate; subject’s rating of efficacy for the degree of bleed control; and the number of infusions required to treat a bleeding episode.  Subjects were monitored for adverse events and regularly assessed for the development of factor IX inhibitors.


Among the 11 subjects receiving a prophylactic regimen of IXINITY, the median number of bleeding episodes was 1.0 (range 0-11) and the median annualized bleeding rate was 0.3 (range 0-4.0).  Of the 61 bleeding episodes experienced by all subjects in this study, 6 (10%) resolved with no infusions of IXINITY, 44 (72%) resolved after one infusion of IXINITY, 5 (8%) required two infusions, and 6 (10%) required three, four, or five infusions of IXINITY.  Of the 34 bleeding episodes rated, subjects rated bleed control as “excellent” for 22 (65%) of the bleeding episodes; “good” for 11 (32%) of the bleeding episodes; “fair” for 1 (3%) of the bleeding episodes; and “poor” for no episodes.

Adverse events reported in this study which were believed to be related to IXINITY were hyperhidrosis (excessive sweating) and fever in one patient, and hyperhidrosis in another patient. None of the subjects developed factor IX inhibitors during the study.

“As patients are known to respond to different factor IX options differently, IXINITY offers people with Hemophilia B another option to dose strategically to prevent and control bleeding episodes.  We see value in having a variety of options available for patients and look forward to building on the data set in a pediatric setting to support a label expansion for IXINITY in patients under 12 years of age,” said Dr. Stromatt.

About Hemophilia B

Hemophilia B is a congenital bleeding disorder caused by a deficiency of coagulation factor IX. It affects approximately 1:25,000 male births, with approximately 4,000 persons affected in the U.S. The clinical spectrum may include spontaneous or trauma-induced bleeding into joints, muscles, and soft tissues, resulting in joint damage, reduction in mobility, and severe arthritis, all of which negatively impact health-related quality of life. The primary aim of care is to prevent and treat bleeding by replacing the deficient clotting factor.


IXINITY is indicated for the control and prevention of bleeding episodes and for perioperative management for adults and children ≥12 years of age with Hemophilia B. IXINITY is not indicated for induction of immune tolerance in patients with Hemophilia B. IXINITY contains recombinant coagulation factor IX (trenonacog alfa). Trenonacog alfa is a purified single chain glycoprotein derived from Chinese hamster ovary (CHO) cells and has an amino acid sequence that is comparable to the Thr148 allelic form of plasma-derived factor IX. No human or animal proteins are added during any stage of manufacturing or formulation of IXINITY. The recombinant factor IX is purified by a chromatography purification process. The process includes three validated steps for virus inactivation and removal. The process also includes a validated manufacturing step to reduce the presence of CHO proteins in the final drug product.

Indications and Important Risk Information

IXINITY [Coagulation Factor IX (Recombinant)] Lyophilized Powder for Solution for Intravenous Injection is a coagulation factor IX (recombinant) indicated in adults and children ≥ 12 years of age with Hemophilia B for control and prevention of bleeding episodes, and for perioperative management. IXINITY is not indicated for induction of immune tolerance in patients with Hemophilia B. IXINITY is contraindicated in patients who have known hypersensitivity to IXINITY or its excipients, including hamster protein.

Hypersensitivity reactions, including anaphylaxis, may occur following IXINITY administration. Discontinue use of IXINITY if hypersensitivity symptoms occur, and initiate appropriate treatment. Regularly evaluate patients for the development of factor IX inhibitors by appropriate clinical observations and laboratory tests. If expected factor IX activity plasma levels are not attained, or, if bleeding is not controlled as expected with a certain dose, perform an assay that measures factor IX inhibitor concentration. An association between the occurrence of a factor IX inhibitor and allergic reactions has been reported. Individuals with factor IX inhibitors may be at increased risk of severe hypersensitivity reactions or anaphylaxis if re-challenged.

Nephrotic syndrome may occur with IXINITY. Nephrotic syndrome has been reported following attempted immune tolerance induction in Hemophilia B patients with factor IX inhibitors and a history of allergic reactions. Thromboembolism may occur when using IXINITY (e.g., pulmonary embolism, venous thrombosis, and arterial thrombosis). Patients may develop hypersensitivity to hamster (CHO) protein as IXINITY contains trace amounts. The most common adverse drug reaction observed in >2% of patients in clinical trials was headache.

Please see full Prescribing Information at www.IXINITY.com.

About Aptevo Therapeutics Inc.

Aptevo Therapeutics Inc. is a biotechnology company focused on novel oncology and hematology therapeutics to meaningfully improve patients’ lives. Our core technology is the ADAPTIR™ (modular protein technology) platform. Aptevo has four commercial products in the areas of hematology and infectious diseases, as well as various investigational stage product candidates in immuno-oncology.

Safe Harbor Statement

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Any statements, other than statements of historical fact, including, without limitation, statements regarding IXINITY, our technology and related pipeline, the potential for regulatory approvals, collaboration and partnership opportunities, commercial portfolio, Aptevo’s future growth rates, Aptevo’s ability to timely manufacture its products, and any other statements containing the words “believes,” “expects,” “anticipates,” “intends,” “plans,” “forecasts,” “estimates,” “will” and similar expressions are forward-looking statements. These forward-looking statements are based on Aptevo’s current intentions, beliefs and expectations regarding future events. Aptevo cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from Aptevo’s expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement. Any forward-looking statement speaks only as of the date of this press release, and, except as required by law, Aptevo does not undertake to update any forward-looking statement to reflect new information, events or circumstances.

There are a number of important factors that could cause our actual results to differ materially from those indicated by such forward-looking statements, including possible negative effects on our business operations, assets or financial results as a result of the separation; a deterioration in our business or prospects; the ability to obtain regulatory approvals; the ability of our contractors and suppliers to supply product and materials;  our ability and the ability of our contractors and suppliers to maintain compliance with cGCP and other regulatory obligations; the results of regulatory inspections; adverse developments in our customer-base or markets and our ability to retain patients; adverse developments in the U.S. or global capital markets, credit markets or economies generally; and changes in regulatory, social and political conditions. Additional risks and factors that may affect results are set forth in our filings with the Securities and Exchange Commission, including Aptevo’s most recent Annual Report on Form 10-K, as filed on March 31, 2017. The foregoing sets forth many, but not all, of the factors that could cause actual results to differ from our expectations in any forward-looking statement.


Aptevo TherapeuticsStacey Jurchison
Senior Director, Investor Relations and Corporate Communications

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