Hemlibra Named a Breakthrough Therapy for Hemophilia A Without Inhibitors

The U.S. Food and Drug Administration granted breakthrough therapy designation to Genentech’s Hemlibra (emicizumab-kxwh) for people with hemophilia A without factor VIII inhibitors.

Hemlibra is designed to bring together the proteins required to activate the natural coagulation cascade and restore the blood clotting process for patients with hemophilia A.

The FDA’s breakthrough therapy status is granted to accelerate the development and review of treatments intended to treat serious conditions once preliminary evidence has shown that they demonstrate a substantial improvement over existing therapies.

Hemlibra’s designation was based on results from the Phase 3 (HAVEN 3) clinical trial (NCT02847637), a randomized open-label study of Hemlibra in 152 people older than 12 with severe hemophilia A without inhibitors against factor VIII.

The ongoing study is evaluating two preventive regimens of Hemlibra compared to no prophylaxis (preventive therapy) with an emphasis on efficacy, safety, and pharmacokinetics (the drug’s properties).

So far, HAVEN 3 appears to show that Hemlibra is the first medicine to demonstrate superior efficacy over previous factor VIII preventive treatments.

“Hemlibra is the first medicine to show superior efficacy compared to factor VIII prophylaxis, the standard of care for people with hemophilia A without inhibitors, in an intra-patient comparison,” Sandra Horning, MD, chief medical officer and head of global product development at Genentech, said in a press release.

In HAVEN 3, Hemlibra prophylaxis dosed subcutaneously weekly or every two weeks is showing a statistically significant and clinically meaningful reduction in treated bleeds compared to no prophylaxis.

Hemlibra was approved by the FDA in November 2017 for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in children and adults with hemophilia A with factor VIII inhibitors, based on results from the HAVEN 1 (NCT02622321) and HAVEN 2 (NCT02795767) studies.

The new breakthrough therapy designation seeks to include approval for patients of hemophilia A without factor VIII inhibitors.

“We look forward to working with health authorities to make Hemlibra available to people without inhibitors as soon as possible, and we are excited to share this news with the community as we join in celebrating World Hemophilia Day,” Horning added.

The breakthrough therapy designation was announced on April 17, World Hemophilia Day, an event promoted by the World Federation of Hemophilia.

In March, Genentech issued a statement reassuring the hemophilia community that the deaths of five hemophilia A patients, which had created a buzz about the safety of Hemlibra, were unrelated to the treatment.

Despite the serious side effects associated with Hemlibra, the most common are injection site reactions, headaches, and joint pain (additional prescribing information is available here), according to Genentech.

The company adds that its medical communications line at 800-821-8590 is open for patients, concerned community members, and healthcare providers seeking more information.

Patients are encouraged to reach out to Genentech or to their treating physician with any questions or concerns.