Sanofi to Continue Hemophilia Drug Trial After FDA Lifts Clinical Hold

Sanofi Genzyme and its development partner Alnylam Pharmaceuticals are now free to continue clinical trials of their investigational hemophilia drug, fitusiran after the US Food and Drug Administration (FDA) lifted its clinical hold. Trials of the drug were halted in September after a patient died of a thrombotic event.

“We are pleased with the FDA’s decision to lift the clinical hold, as fitusiran holds the potential to help improve the lives of people living with hemophilia,” said Dr. Akin Akinc, Vice President and General Manager, Fitusiran at Alnylam. “With the additional risk mitigation measures in place, we look forward to the continued late-stage development of fitusiran and expect to resume dosing around year-end.”

Fitusiran is a RNAi therapeutic designed to block the production of antithrombin in patients with moderate to severe hemophilia A or B. By lowering levels of antithrombin, the hope is that these patients will be able to generate a sufficient amount of the pro-coagulation factor thrombin, to allow the body to form blood clots when needed.

The companies reached an agreement with the FDA to include new risk-mitigation measures and make other changes to the study protocol. Sanofi and Alnylam will likely commence dosing before the end of 2017 in both their Phase II open-label extension study, and their Phase III ATLAS trial.