Emicizumab Shows Promise in Trials as Preventive Treatment in Hemophilia A for All Ages

Results from two Phase 3 trials support the use of emicizumab for the preventive treatment of hemophilia A in children, adolescents, and adults, Genentech announced.

These results will be presented at the 26th International Society on Thrombosis and Haemostasis (ISTH) Meeting July 8-13 in Berlin, Germany.

Emicizumab is an investigational antibody designed to activate the natural coagulation mechanisms and restore the blood clotting process that is deficient in hemophilia patients.

The Phase 3 HAVEN 1 study (NCT02622321) enrolled 109 adolescent and adult patients with hemophilia A with factor VIII inhibitors who were previously treated with on-demand or prophylactic (preventive) bypassing agents (BPAs), such as aPCC and recombinant factor VIIa (rFVIIa).

Emicizumab prophylaxis was associated with a significant and clinically relevant decrease in the number of bleeds over time (87 percent) compared to on-demand treatment with BPAs.

According to a news release, at week 31, 62.9 percent of patients on emicizumab had zero treated bleeds vs. 5.6 percent of patients taking on-demand BPAs. Compared to on-demand BPAs, emicizumab decreased the rate of all bleeds (80 percent), treated spontaneous bleeds (92 percent), treated joint bleeds (89 percent), and treated target joint bleeds (95 percent).

After 25 weeks of treatment, patients reported 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.

The Phase 3 HAVEN 2 study (NCT02795767) is currently investigating the effects of once-weekly subcutaneous administration of emicizumab for the treatment of children younger than 12 with hemophilia A and factor VIII inhibitors who require treatment with BPAs. So far, 19 children have been dosed, but 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 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 percent) in treated bleeds after receiving emicizumab.

Data also revealed that emicizumab can be administered to children, adolescents, and adults in the same dose. The most common side effects associated with the treatment included injection site reactions and symptoms of common cold.

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.