Chugai Pharmaceutical Files New Drug Application for Hemophilia A Treatment Emicizumab

Chugai Pharmaceutical filed a New Drug Application for the use of emicizumab as a potential treatment to prevent or decrease the occurrence of bleeding episodes in patients with hemophilia A with factor VIII inhibitors.

The application is based on promising results from the HAVEN 1 study (NCT02622321) and the ongoing HAVEN 2 study (NCT02795767), conducted via a collaboration between Chugai, Roche, and Genentech.

Hemophilia A is a hereditary bleeding disorder resulting from a deficiency in factor VIII, an essential protein for blood clotting and the wound-healing process. Emicizumab is an investigational antibody designed to activate the natural coagulation mechanisms and restore the blood clotting process in these patients.

The Phase 3 HAVEN 1 study enrolled 109 adolescent and adult patients with hemophilia A with factor VIII inhibitors who were previously treated with on-demand or prophylactic bypassing agents (BPAs), such as aPCC and recombinant factor VIIa (rFVIIa).

Patients treated with emicizumab experienced a significant and clinically relevant decrease (87%) in the number of bleeds over time compared to on-demand treatment with BPAs. After 31 weeks of treatment, 62.9% of patients given emicizumab had zero treated bleeds, compared to 5.6% of patients on on-demand BPAs. Emicizumab also reduced the rate of all bleeds (80%), treated spontaneous bleeds (92%), treated joint bleeds (89%) and treated target joint bleeds (95%) compared to the BPAs.

Results also showed that patients given emicizumab had a significant and clinically relevant improvement in health-related quality of life (HRQoL). Most common side effects associated with the treatment included injection site reactions, headache, fatigue, and upper respiratory tract infection.

Data from the HAVEN 1 study were published in The New England Journal of Medicine, in a paper titled, “Emicizumab Prophylaxis in Hemophilia A with Inhibitors.”

The Phase 3 HAVEN 2 study is currently assessing the effects of once-weekly subcutaneous administration of emicizumab for the treatment of patients younger than 12 with hemophilia A and factor VIII inhibitors who require BPAs. The study is expected to enroll 60 children, who will receive treatment for 52 weeks.

Preliminary results at week 12 showed that only one of the dosed 19 children on emicizumab reported a treated bleed, and no patient experienced joint or muscle bleeds. Also, patients who had been previously treated with BPAs had a complete reduction (100%) in treated bleeds after receiving emicizumab. The most common side effects associated with the treatment included injection site reactions and symptoms of the common cold.