Emicizumab, Genentech’s Therapy for Hemophilia A, Granted Priority Review by the FDA

The U.S. Food and Drug Administration (FDA) has granted priority review to the therapy emicizumab for patients with hemophilia A with factor VIII inhibitors, Genetech, the drug’s developer, announced.

The FDA also announced the acceptance of Genetech’s Biologics License Application (BLA) for emicizumab prophylaxis (preventive) therapy in adults, adolescents and children with hemophilia A with factor VIII inhibitors.

This is a serious condition that may develop in patients receiving factor VIII replacement therapies. In these cases, patients react to the therapy and produce proteins (antibodies) that bind and block the replacement factor VIII from working. As a consequence, the levels of factor VIII are insufficient to stop and control bleeding.

FDA’s decision was supported by the positive results from two Phase 3 clinical trials. The HAVEN 1 study (NCT02622321) showed that patients treated with emicizumab prophylaxis (preventive therapy) had a significant decrease in the number of bleeding episodes over time when compared to on-demand treatment with infusions of bypassing agents (BPAs).

The ongoing HAVEN 2 study (NCT02795767) is investigating the effectiveness of a once-weekly subcutaneous administration of emicizumab in young children (less than 12 years) with hemophilia A and factor VIII inhibitors who require treatment with BPAs. An interim analysis at 12 weeks showed only one bleeding episode in 19 children receiving emicizumab.

“Genentech has a history of developing innovative antibody therapies to address some of the highest unmet medical needs,” Sandra Horning, MD, chief medical officer and head of Global Product Development, said in a press release. “Results of our Phase III study in adults and adolescents as well as early Phase III results in children showed that emicizumab has significant potential to help people with hemophilia A with inhibitors, who face major challenges in preventing and treating bleeds. We are working with the FDA to hopefully bring this new prophylactic treatment option to the hemophilia A inhibitor community as soon as possible,” Horning said.

FDA’s priority review designation is attributed to medicines that the regulatory agency considers have the potential for significantly improving the life of patients with serious diseases. A decision is expected by Feb. 23, 2018. In the meantime, Genetch has submitted an application for emicizumab to the European Medicines Agency (EMA), which also granted an accelerated review.