Emicizumab Approved by FDA for Hemophilia A Without Factor VIII Inhibitors

The US Food and Drug Administration (FDA) has approved Genentech’s emicizumab (Hemlibra) for the treatment of hemophilia A without factor VIII inhibitors. 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.”

Emicizumab is currently the only prophylactic treatment administered via subcutaneously at multiple dosing options (once weekly, every 2 weeks or every 4 weeks) for this subset of the hemophilia patient population.

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.