Genentech's prophylaxis has the potential for further indications in adult and pediatric patients with hemophilia A.
Emicizumab (Hemlibra), a bleeding episode prophylaxis approved by the US Food and Drug Administration (FDA) last week for patients with hemophilia A, has returned phase 3 results that show a significant reduction in bleeds in hemophilia A patients previously not indicated by the FDA.
Genentech announced that Hemlibra has shown clinically meaningful reduction in bleeding episodes for pediatric and adult patients without antibodies called factor VIII (FVIII) inhibitors. The FDA indicated Hemlibra for hemophilia A patients who have developed FVIII inhibitors.
Hemlibra is a bispecific factor IXa- and factor X-directed antibody, designed to bring together factor IXa and factor X, proteins required to activate the natural coagulation cascade and restore the blood clotting process for hemophilia A patients
The HAVEN 3 trial, a randomized, multicenter, open-label study, featured 152 patients, aged 12 years or older, with hemophilia A. All patients were previously treated with factor VIII therapy either on-demand or as a prophylaxis.
Its preceding studies, HAVEN 1 and HAVEN 2, showed Hemlibra’s efficacy and safety in pediatric and adult males with hemophilia A, and were included in Genentech’s approved FDA drug application.
Researchers reported a statistically significant reduction in the rate of treated bleeds over a treatment period in patients receiving Hemlibra every week, versus a control population. The study’s secondary endpoint, a reduction in the rate of treated bleeds in patients receiving Hemlibra every 2 weeks versus control, was also met in the study.
The once-weekly Hemlibra therapy reported superiority in reducing treated bleeds to factor VIII prophylaxis in an intra-patient comparison, according to Genentech. Sandra Horning, MD, the company’s Chief Medical Officer and Head of Global Product Development, said it is the first therapy to show greater efficacy than factor VIII prophylaxis.
“These results in people with hemophilia A without inhibitors represent the next step forward in our clinical trial program, which includes the positive HAVEN 1 and interim HAVEN 2 data in people with inhibitors,” Horning said. “We look forward to working with health authorities to make this treatment available for all people with hemophilia A as soon as possible.”
The HAVEN 3 Hemlibra patient population commonly reported injection site reactions. Neither thrombotic microangiopathy nor thrombotic events occurred in the study’s patients.
While prophylaxis is the preferred therapy method for hemophilia A, its required regimen of frequent intravenous infusions can be a burden for patients — who can still experience bleeds during treatment. Hemlibra’s investigated versatility could address such issues, Johnny Mahlangu, Faculty of Health Sciences, University of the Witwatersrand and NHLS, Johannesburg, South Africa, said.
“Given its potential to be dosed through subcutaneous injection only once weekly or every other week, Hemlibra may provide a further effective prophylactic treatment option for more people with hemophilia A and help alleviate some of the administration burden associated with current treatment,” Mahlangu said.
The HAVEN 3 study data will be presented at an upcoming medical meeting, according to Genentech, and will be submitted to health authorities for regulatory consideration.