Hemophilia A Treatment Earns Breakthrough Therapy Designation

The FDA granted breakthrough therapy designation to Sanofi and Sobi’s efanesoctocog alfa (BIVV001) for hemophilia A.

The designation is based on the pharmaceutical manufacturers’ XTEND-1 phase 3 study, which found that efanesoctocog alfa demonstrated a clinically meaningful prevention of bleeds in people with severe hemophilia A over a 52-week period, Sanofi and Sobi said in a statement.

The key secondary endpoint was also met, demonstrating that efanesoctocog alfa was superior to prior prophylactic factor VIII replacement therapy in preventing bleeding events based on an intra-patient comparison.

In the study, efanesoctocog alfa was well-tolerated, and inhibitor development to factor VIII was not detected. The most common treatment-emergent adverse events were headache, arthralgia, fall, and back pain.

Data from the XTEND-1 phase 3 study are expected to be shared at an upcoming medical meeting and will serve as the basis for submission to FDA mid-year 2022, Sanofi and Sobi said.

John Reed, M.D., Ph.D.

The breakthrough therapy designation highlights efanesoctocog alfa’s “potential to transform treatment for people with hemophilia A by providing higher protection for longer duration,” said John Reed, M.D., Ph.D., global head of research and development at Sanofi. “This potential new class of factor VIII therapy represents how we are advancing science to address unmet needs for the hemophilia community. We are excited to work with regulatory authorities during the filing and review of this innovative therapy.”

The FDA granted efanesoctocog alfa orphan drug designation in August 2017 and fast track designation in February 2021. The European Commission also granted efanesoctocog alfa orphan drug designation in June 2019.

Efanesoctocog alfa is a novel and investigational recombinant factor VIII therapy designed to extend protection from bleeds with once-weekly prophylactic dosing.

Hemophilia A occurs in about one in 5,000 male births annually, and more rarely in females. It is a lifelong condition in which the ability of a person’s blood to clot is impaired due to a coagulation factor deficiency, Sanofi and Sobi noted. Individuals with hemophilia can experience bleeding episodes that can cause pain, irreversible joint damage, and life-threatening hemorrhages.