FDA Approves Emicizumab for Hemophilia A Without Factor VIII Inhibitors

The only prophylactic treatment administered via subcutaneously at multiple dosing options (once weekly, every 2 weeks or every 4 weeks) has been approved by the US Food and Drug Administration (FDA).

Genentech’s emicizumab (Hemlibra), a prophylactic treatment for hemophilia A without factor VIII inhibitors, was approved by the FDA on October 4, 2018.

Use of emicizumab is intended for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children—aged newborn and older—with hemophilia A with and without factor VII inhibitors.

“The approval of emicizumab is an important advancement for the entire hemophilia A community, as we now have a new class of medicine for the first time in nearly 20 years,” Michael Callaghan, M.D., hematologist, Children’s Hospital of Michigan, said in a recent statement. “Hemlibra can reduce bleeds, and it offers a new subcutaneous administration once weekly, every 2 weeks or every 4 weeks.”

In the phase 3 HAVEN 3 study, statistically significant and clinically meaningful reductions in treated bleeds were observed with emicizumab prophylaxis compared to no prophylaxis (primary endpoint) and across all other bleed-related endpoints. A clinically meaningful control of bleeding was also observed in the HAVEN 4 study.

Adults and adolescents aged 12 years or older with hemophilia A without factor VIII inhibitors were included in the phase 3 HAVEN 3 study.

A 96% (95% CI: 92.5; 98.0, p<0.0001) and 97% (95% CI: 93.4; 98.3, p<0.0001) reduction in treated bleeds were observed in in patients administered emicizumab prophylaxis once weekly (n=36) or every 2 weeks (n=35), respectively, compared to those who received no prophylaxis (n=18).

While factor VIII prophylaxis has been the recommended standard of care to significantly reduce treated bleeds, emicizumab prophylaxis is the first medicine to significantly reduce treated bleeds compared to it.

A statistically significant reduction of 68% (95% CI: 48.6; 80.5, p<0.0001) in treated bleeds in a prospective intra-patient comparison (n=48) of people who were previously administered factor VIII prophylaxis in a non-interventional study and switched to emicizumab prophylaxis demonstrated the treatment’s efficacy.

In the single-arm phase III HAVEN 4 study, adults and adolescents aged 12 years or older with hemophilia A with factor VIII inhibitors (n=5) and without factor VIII inhibitors (n=36) were included.

Patients administered emicizumab prophylaxis every 4 weeks (n=41) experienced a clinically meaningful control of bleeding.

Injection site reactions (n=85), headache (n=57) and joint pain (arthralgia; n=59) included most common adverse reactions occurring in 10% or more of people treated with emicizumab in pooled studies (n=391).

“Hemlibra is now the only FDA-approved medicine for people with hemophilia A with and without factor VIII inhibitors, based on the efficacy and safety profile demonstrated across 4 pivotal studies,” Sandra Horning, M.D., chief medical officer and head of Global Product Development, added.

A version of this article previously appeared on MD Magazine.