Sanofi and Swedish Orphan Biovitrum AB (Sobi®) recently shared positive results from the XTEND-1 pivotal phase 3 study of efanesoctocog alfa (BIVV001).

BIVV001 is an investigational recombinant factor VIII therapy (rFVIII) developed for the prevention of bleeding episodes in hemophilia A patients via once weekly prophylactic intravenous infusions. The results were presented at the 2022 International Society on Thrombosis and Haemostasis Congress, held July 9-13th in London.

BIVV001 is manufactured through proprietary Fc fusion technologies to extend the half-life of the rFVIII, resulting in more sustained protection from bleeds per infusion. In contrast to other FVIII replacement therapies, it is independent of von Willebrand factor. The therapy was granted Breakthrough Therapy designation by the U.S. Food and Drug Administration this past spring. 

The XTEND-1 clinical trials are designed to evaluate the safety, efficacy, and pharmacokinetics of BIVV001 in previously treated adults and adolescents with hemophilia A, who are 12 years of age and older. According to a new Sanofi press release, the study met the primary efficacy endpoint, whereby one infusion per week of BIVV001 in people with severe hemophilia A led to “clinically meaningful” protection from bleeding. Median and mean annualized bleeding rates (ABR) were 0.00 and 0.71, respectively. “Superior” bleed protection over prior factor VIII prophylaxis was demonstrated via an intra-patient comparison, with an estimated ABR reduction of 77% and a mean ABR of 0.69, in contrast to 2.96 on prior prophylaxis.

“The phase 3 data demonstrate once-weekly efanesoctocog alfa’s potential to provide superior bleed protection, leading to substantial improvements in physical health, pain, and joint health, by sustaining high factor levels for the majority of the week, reported Annette von Drygalski, MD, PharmD, study Investigator and Director, Hemophilia and Thrombosis Treatment Center, UC San Diego. “These unprecedented results may offer people with hemophilia A the possibility to redefine their treatment expectations.”

Source: Sanofi press release dated July 10, 2022