Sanofi recently announced results from their phase 1/2a EXTEN-A trial for their investigational therapy BIVV001, which were published in the New England Journal of Medicine (NEJM).

BIVV001 is a novel recombinant factor VIII therapy (rFVIII) designed for the prevention of bleeding episodes in hemophilia A patients via once weekly prophylactic infusions. It is developed through proprietary Fc fusion technologies to extend the half-life of the rFVIII, resulting in more sustained protection from bleeds per intravenous infusion. According to a new Sanofi press release, it is also the first FVIII therapy independent of von Willebrand factor.

EXTEN-A is a multicenter trial designed to evaluate the safety, tolerability, and pharmacokinetics of BIVV001 in two different size doses in severe hemophilia A patients between ages 19-63 years. Enrolled individuals were placed in one of two groups, depending on the size dose they received.

After a single infusion of BIVV001, the larger dose group reached a FVIII half-life of 43 hours, representing a greater than three-fold increase from the 13-hour half-life observed with a conventional rFVIII therapy. In addition, mean FVIII activity level was ≥51% and in the normal range for four days, and 17% at seven days post infusion.

While in the smaller dose group, a single infusion of BIVV001 achieved a FVIII half-life of 38 hours, a four-fold increase from the 9-hour half-life observed with conventional rFVIII therapy, plus a mean factor activity level of 5% at seven days post infusion.  

In addition, BIVV001 was “generally well tolerated” with no detection of inhibitor development through 28 days post-dose. Investigators also reported no adverse events of allergic reaction, anaphylaxis, or clinically meaningful treatment-related adverse events during the study period.  

“BIVV001 represents a potential new class of factor VIII replacement therapies. The sustained factor activity levels and three- to four-fold increase in half-life observed underscore its potential to provide near-normal bleed protection while reducing the dosing frequency of a prophylactic treatment to once a week,” said Barbara A. Konkle, MD, lead investigator and Chief Scientific Officer, Bloodworks Northwest and Professor of Medicine/Hematology, University of Washington. “These results support the conclusion that BIVV001 may be a significant advancement for patients and we look forward to exploring this further in the ongoing Phase 3 study.”

“As part of our overall commitment to the hemophilia community, we are excited by the clinical potential of BIVV001 to overcome the limitations of current factor VIII therapies,” said Dietmar Berger, Global Head of Development and Chief Medical Officer at Sanofi. “The New England Journal of Medicine’s publication of these early results support the possibility of BIVV001 to provide people with hemophilia A with higher protection for longer, which could allow them to lead a more active life. We look forward to providing future updates as we continue to evaluate BIVV001 in Phase 3 development.”

The article “BIVV001 Fusion Protein as Factor VIII Replacement Therapy for Hemophilia A,” was published September 10, 2020 in NEJM.

Source: Sanofi press release dated September 10, 2020