Study Underway to Investigate Efficacy, Safety of New Hemophilia A Treatment

BIVV001 (rFVIIIFc-VWF-XTEN) is currently being investigated as recombinant factor VIII (FVIII) treatment for hemophilia A, according to a presentation at the 62^nd American Society of Hematology (ASH) Annual Meeting and Exposition.

Hemophilia A is a genetic disorder in which blood does not clot properly. FVIII replacement enables management of the disease. However, there is a need for new therapies that provide high sustained activity with longer dosing intervals. The half-life extension of current FVIII replacement products is 15 to 19 hours by the chaperone effect of endogenous von Willebrand factor (VWF) on FVIII, according to the study.

BIVV001 is an investigational FVIII therapy consisting of a single-chain FVIII, the Fc domain of human immunoglobulin G1, 2 XTEN polypeptides, which are registered trademark of Amunix Pharmaceuticals, Inc, and the FVIII-binding D’D3 domain of VWF. In a phase 1 repeat-dose study, the drug sustained FVIII activity. The mean steady-state FVIII activity at 3 days was 46% and 10% at 7 days. No safety concerns were identified.

The phase 3 XTEND-1 is multicenter, open-label, and nonrandomized trial. Study participants are aged 12 years or less and have been previously treated. The study will evaluate bleed events and factor usage as well as patient-reported outcome measurements, such as physical activity monitoring.

XTEND-1 will test the efficacy, safety, and pharmacokinetics of 50 IU/kg once-weekly prophylactic dosing of BIVV001 in severe hemophilia A. The study is currently recruiting participants.

REFERENCE

Konkle, Barbara A. et al. 856 Evaluating BIVV001, a New Class of Factor VIII Replacement Therapy: A Phase 3 Study (XTEND-1) Design [Abstract] December 5, 2020. ASH. Accessed December 8, 2020. https://ash.confex.com/ash/2020/webprogram/Paper138820.html.