Aptevo Therapeutics Reports First Complete Remission, Providing Clinical Update for Its Phase 1b Multi Center, Multi Cohort Expansion Trial in the Treatment of Acute Myeloid Leukemia
A high-risk AML patient treated in Cohort 1 with a combination of chemotherapy plus APVO436 achieved a complete remission (CR) after one cycle of therapy. The chemotherapy regimen included the standard leukemia drugs Mitoxantrone, Etoposide, and Cytarabine. The patient tolerated treatment without evidence of overt toxicity.
The overarching goal of the Phase 1b expansion phase study is to determine if APVO436 treatments can improve the quality of remission in high-risk AML patients by reducing the residual chemotherapy-resistant measurable residual disease (MRD) burden. The quality of remission will be assessed using state-of-the art multiparameter flow cytometry methods for quantitative MRD assessment in a centralized laboratory.
MRD, previously known as minimal residual disease, in AML refers to leukemia cells that are present at very low numbers but can be detected using highly sensitive flow cytometric or genomic methods. A recent systematic review of the clinical significance of MRD in over 10,000 AML patients has demonstrated that achievement of MRD negativity is associated with superior leukemia-free survival and overall survival. Therefore, MRD status has emerged as an attractive and clinically meaningful end point that may allow for accelerated evaluation of novel therapies in AML (reference: Short et al.,
Aptevo believes that APVO436 has the potential to help AML patients achieve complete remissions without MRD and thereby reduce their risk of leukemic relapses. Aptevo also believes that the use of APVO436 for targeting MRD in AML may be associated with a very low risk of cytokine release syndrome (CRS) as well as an increased likelihood of responses as both CRS as well as responses are inversely correlated with the leukemia burden of the patients. If successful, deepening the remission to an MRD-negative remission using this strategy could translate into an improved overall survival in AML.
The Company recently published information about the compound's favorable safety profile, characterized by a low incidence of CRS, and promising single agent activity of APVO436 in two back-to-back peer-reviewed publications in the prestigious oncology journal Cancers (
1. Uckun, F.M.; Lin, T.L.; Mims, A.; Patel, P.; Lee, C.; Shahidzadeh, A.; Shami, P.; Cull, E.; Cogle, C.R.; Watts, J. A Clinical Phase 1B Study of the CD3xCD123 Bispecific Antibody APVO436 in Patients with Relapsed/Refractory Acute Myeloid Leukemia or Myelodysplasia. Cancers (
2. Uckun FM, Watts J, Mims AS, Patel P, Wang E, Shami PJ, Cull E, Lee C, Cogle CR,
Overexpression of CD123 is the hallmark of many forms of leukemia. Aptevo's lead proprietary drug candidate, APVO436 is a bispecific CD3xCD123 ADAPTIR that is designed to redirect the immune system of the patient to destroy leukemia cells expressing the target CD123 molecule on their surface. This antibody-like recombinant protein therapeutic is designed to engage both leukemia cells and T-cells of the immune system and bring them closely together to trigger the destruction of leukemia cells. APVO436 has been engineered using Aptevo's proprietary and enabling bioengineering methods and is designed to reduce the likelihood and severity of CRS. APVO436 has received orphan drug designation ("orphan status") for AML according to the Orphan Drug Act.
Safe Harbor Statement
This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, including, without limitation, Aptevo's expectations about the activity, efficacy and safety of its therapeutic candidates and potential use of any such candidates as therapeutics for treatment of disease, advancement of its clinical trials and its expectations regarding the effectiveness of its ADAPTIR and ADAPTIR-FLEX platforms, whether APVO436 treatments can improve the quality of remission in high-risk AML patients, whether APVO436 helps AML patients achieve complete remissions without MRD, whether the use of APVO436 for targeting MRD in AML will be associated with a very low risk of CRS as well as an increased likelihood of responses, whether Aptevo's strategy will translate into an improved overall survival in AML, and any other statements containing the words "may," "believes," "expects," "anticipates," "hopes," "intends," "optimism," "potential," "designed," "engineered," "breakthrough," "innovative," "innovation," "promising," "plans," "forecasts," "estimates," "will" and similar expressions are intended to identify 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.
There are several important factors that could cause Aptevo's actual results to differ materially from those indicated by such forward-looking statements, including a deterioration in Aptevo's business or prospects; adverse developments in clinical development, including unexpected safety issues observed during a clinical trial; adverse developments in the