FDA Grants Priority Review to Genentech’s Emicizumab for Hemophilia A with Inhibitors

Genentech announced the U.S. Food and Drug Administration (FDA) has accepted the company’s Biologics License Application (BLA) and granted Priority Review for emicizumab prophylaxis (preventative) as a once-weekly subcutaneous treatment for adults, adolescents and children with hemophilia A with factor VIII inhibitors. Nearly one in three people with hemophilia A develop inhibitors to standard factor VIII replacement therapies, which limits treatment options and increases the risk of life-threatening bleeds and repeated bleeds, particularly in joints, that cause long-term damage.

"Genentech has a history of developing innovative antibody therapies to address some of the highest unmet medical needs," said Sandra Horning, M.D., chief medical officer and head of Global Product Development. "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."

The BLA for emicizumab is based on results from the Phase III HAVEN 1 study in adults and adolescents 12 years of age and older, as well as interim results from the Phase III HAVEN 2 study in children younger than 12 years of age.

The FDA is expected to make a decision on approval by February 23, 2018. Priority Review designation is granted to medicines that the FDA has determined to have the potential to provide significant improvements in the safety and effectiveness of the treatment, prevention or diagnosis of a serious disease. The FDA granted Breakthrough Therapy Designation for emicizumab in adults and adolescents with hemophilia A with inhibitors in September 2015. Breakthrough Therapy Designation is designed to expedite the development and review of medicines intended to treat a serious condition with preliminary evidence that indicates they may demonstrate substantial improvement over existing therapies.

Data from both HAVEN 1 and HAVEN 2 have also been submitted for approval consideration to the European Medicines Agency (EMA) and will be reviewed under accelerated assessment. Additional studies evaluating emicizumab in people with hemophilia A both with and without inhibitors and exploring less frequent dosing regimens are ongoing.

HAVEN 1 is a randomized, multicenter, open-label, Phase III study evaluating the efficacy, safety and pharmacokinetics of emicizumab prophylaxis compared to on-demand bypassing agents (BPAs) (no prophylaxis; episodic use only) in adults and adolescents with hemophilia A with inhibitors to factor VIII. The study included 109 patients (12 years of age and older) with hemophilia A with inhibitors to factor VIII, who were previously treated with BPAs on-demand or as prophylaxis. Patients previously treated with on-demand BPAs were randomized in a 2:1 fashion to receive emicizumab prophylaxis (Arm A) or no prophylaxis (Arm B). Patients previously treated with prophylactic BPAs received emicizumab prophylaxis (Arm C). Additional patients previously on BPAs (on-demand or prophylaxis) were also enrolled in a separate arm (Arm D). On-demand treatment of breakthrough bleeds with BPAs was allowed per protocol in all arms.