Sanofi’s Treatment for Hemophilia A has a Concrete FDA Decision Date

On August 30, the United States Food and Drug Administration (FDA) accepted the Biologics License Application (BLA) for Sanofi’s efanesoctocog alfa (BIVV001) for priority review. Efanesoctocog alfa is a treatment for hemophilia A, a rare and life-threatening bleeding disorder.

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What is efanesoctocog alfa, and how does it work?

Hemophilia A is a genetic bleeding disorder caused by a lack of Factor VIII, a blood protein. Factor VIII is a clotting factor, a specialized protein essential for normal clotting. Due to this lack of Factor VIII, individuals with hemophilia A have difficulty stopping bleeding as their wounds do not properly clot.

Current treatments for hemophilia A include methods to either replace or substitute the function of Factor VIII. An example of this is Genentech and Chugai’s HEMLIBRA. HEMLIBRA plays the part of Factor VIII as it performs its job of uniting two other proteins, Factor IXa and Factor X, inducing clotting. 

On the other hand, Sanofi’s efanesoctocog alfa works slightly differently. Efanesoctocog alfa extends the protection from bleeds through decoupling Factor VIII from von Willebrand factor (VWF) in circulation. The VWF protein helps platelets stick together and adhere to the walls of blood vessels at a wound, forming temporary clots. 

Due to promising results from a Phase 3 study, Sanofi submitted a BLA for efanesoctocog alfa to the FDA.

The Trial that the FDA Will Decide On

XTEND-1 was a Phase 3 trial evaluating the safety, efficacy, and pharmacokinetics of once-weekly efanesoctocog alfa. The study subjects were patients 12 years or older with severe hemophilia A, previously treated with factor VIII replacement therapy. The trial compared the results of efanesoctocog alfa to patients receiving their prior replacement therapy.

Sanofi presented the results of XTEND-1 at the 30th International Society of Thrombosis and Haemostasis Congress. The data showed that efanesoctocog alfa prevented bleeds superiorly than prior factor VIII replacement therapy. In addition, patients tolerated efanesoctocog alfa well. 

On the results, Dietmar Berger, MD, PhD, Global Head of Development and Chief Medical Officer at Sanofi, said, “The results from the pivotal XTEND-1 Phase 3 study demonstrate efanesoctocog alfa’s ability to reduce annualized bleeding rates, which supports its potential as a therapy with best-in-disease efficacy. We look forward to working closely with the FDA during the review process as we aim to bring this novel therapy to the hemophilia A community.”

The results of XTEND-1 formed the foundation of Sanofi’s submission for priority review. In May of this year, the FDA also granted efanesoctocog alfa its Breakthrough Therapy Designation. In addition, efanesoctocog alfa received Fast Track Designation from the FDA in 

With the data from XTEND-1 under review, the FDA plans to decide on efanesoctocog alfa’s approval by February 28, 2023. Sanofi intends to submit the treatment for hemophilia A for regulatory submission in the EU once the ongoing trial, XTEND-Kids, concludes sometime in early 2023. 

Author

Max Heirich