The FDA expanded the approval of Hemlibra (emicizumab-kxwh) to include routine prophylaxis to prevent or reduce the frequency of bleeding episodes among individuals with hemophilia A without factor VIII inhibitors.
Hemlibra is now the only prophylactic treatment for people with hemophilia A with and without factor VIII inhibitors that can be administered subcutaneously (under the skin) and at multiple dosing options (once weekly, every two weeks or every four weeks). This approval is based on positive results from the Phase III HAVEN 3 and HAVEN 4 studies. Hemlibra prophylaxis led to statistically significant and clinically meaningful reductions in treated bleeds compared to no prophylaxis (primary endpoint) and across all other bleed-related endpoints in the HAVEN 3 study, and showed a clinically meaningful control of bleeding in the HAVEN 4 study.
The FDA based the latest approval on results from the phase 3 HAVEN 3 and HAVEN 4 studies, which assessed emicizumab-kxwh among adults and adolescents aged 12 years or older. In the HAVEN 3 study, researchers assigned 36 patients to once-weekly emicizumab-kxwh, 35 patients to emicizumab-kxwh every 2 weeks and 18 patients to no prophylaxis. Results showed a 96% (95% CI, 92.5-98) reduction in treated bleeds among those treated weekly and a 97% (95% CI, 93.4-98.3) reduction among those treated every 2 weeks.
In the HAVEN 4 study, researchers assessed dosing every 4 weeks among 36 patients without factor VIII inhibitors and five with factor VIII inhibitors. All patients had previously received factor VIII or bypassing agents, on-demand or as prophylaxis. Results showed 56.1% (95% CI, 39.7-71.5) of patients experienced zero treated bleeds and 90.2% (95% CI, 76.9-97.3) experienced three or fewer treated bleeds.
“Many preventative treatment options for people with hemophilia A without factor VIII inhibitors require intravenous infusions several times a week. Even then, people can still experience bleeds, and there has been a need for more treatment options,” Michael Callaghan, MD, hematologist at Children’s Hospital of Michigan, said in a company-issued press release. “The approval of Hemlibra 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. Hemlibra can reduce bleeds, and it offers a new subcutaneous administration once weekly, every 2 weeks or every 4 weeks.”
In both studies, the most common adverse reactions occurring in 10% or more of treated patients (n = 391) included injection site reactions (n = 85), headache (n = 57) and arthralgia (n = 59).
“Today’s approval of Hemlibra reflects our commitment to groundbreaking science and the development of medicines with the potential to redefine the standard of care,” Sandra Horning, MD, chief medical officer and head of global product development at Genentech, said in the release. “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 four pivotal studies.”