Results showed a clinically meaningful prevention of bleeds in people with severe haemophilia A

Sanofi and Swedish Orphan Biovitrum AB have announced positive results from the pivotal XTEND-1 phase 3 study into efanesoctocog alfa (BIVV001). The research involved patients previously treated with severe haemophilia A.

The primary endpoint was met, and the results showed a clinically meaningful prevention of bleeds in people with severe haemophilia A, who were receiving weekly prophylaxis with efanesoctocog alfa over a period of 52 weeks.

The study also met the key secondary endpoint, demonstrating that once-weekly efanesoctocog alfa was more effective than prior prophylactic replacement therapy. The treatment was well tolerated.

Haemophilia A is a rare genetic disorder in clotting factor VIII, which causes increased bleeding. It occurs in about one in 5,000 males births annually, and more rarely in females. Patients suffering from haemophilia can experience bleeding episodes that can cause pain, irreversible joint damage and life-threatening haemorrhages.

BIVV001 is a novel and investigational recombinant factor VIII therapy, designed to extend protection from bleeds with once-weekly prophylactic dosing for people with haemophilia A. It is still under clinical investigation, and has not yet been evaluated by regulatory authorities.

Dietmar Berger, Global Head of Development and CMO, Sanofi, commented on the results: “While advances have been made in the treatment of haemophilia, unmet medical needs still exist. These positive top-line data, showing a very low annualised bleeding rate, enhance efanesoctocog alfa’s potential to transform hemophilia A therapy.

“We believe efanesoctocog alfa provides higher protection for longer duration with reduced treatment burden of once-weekly dosing, and we look forward to working with regulators to bring this therapy to patients as soon as possible.”

Anders Ullman, Head of R&D and CMO, Sobi, added: “We believe once-weekly efanesoctocog alfa has the potential to represent a new class of factor VIII therapy designed to provide high sustained factor VIII levels near normal for the majority of the week. We look forward to sharing these phase 3 results, including data on physical health, pain and joint health, at future medical meetings.”