Hemlibra prophylaxis reduces treated bleeds for certain patients with hemophilia A
A randomized phase 3 trial designed to assess emicizumab-kxwh for adults and adolescents with hemophilia A without factor VIII inhibitors met its primary endpoint, according to the agent’s manufacturer.
The HAVEN 3 study showed weekly prophylaxis with emicizumab-kxwh (Hemlibra, Genentech) — a bispecific factor IXa- and factor X-directed antibody — significantly reduced the number of treated bleeds over time compared with no prophylaxis.
The trial also met key secondary endpoints, including a significant reduction in treated bleeds with emicizumab-kxwh prophylaxis dosed every 2 weeks compared with no prophylaxis.
An intrapatient comparison showed once-weekly prophylaxis with emicizumab-kxwh significantly reduced treated bleeds compared with prior factor VIII prophylaxis.
“Hemlibra is the first product to show superior efficacy to factor VIII prophylaxis. These results in people with hemophilia A without inhibitors represent the next step forward in our clinical trial program,” Sandra Horning, MD, chief medical officer and head of global product development for Genentech, said in a company-issued press release. “We look forward to working with health authorities to make this treatment available for all people with hemophilia A as soon as possible.”
HAVEN 3 included 152 patients aged 12 years or older with hemophilia A without inhibitors to factor VIII who received prior factor VIII therapy on demand or for prophylaxis.
Patients previously treated with on-demand factor VIII were randomly assigned 2:2:1 to one of three treatment groups: subcutaneous Hemlibra prophylaxis at 3 mg/kg per week for 4 weeks, followed by 1.5 mg/kg per week until the end of the study (Arm A); subcutaneous Hemlibra prophylaxis at 3 mg/kg per week for 4 weeks, followed by 3 mg/kg every 2 weeks until the end of study (Arm B); or no prophylaxis (Arm C).
Patients previously treated with factor VIII prophylaxis received subcutaneous Hemlibra prophylaxis at 3 mg/kg per week for 4 weeks, followed by 1.5 mg/kg per week until the end of study (Arm D).
Study protocol allowed episodic treatment of breakthrough bleeds with factor VIII therapy.
The most common adverse events reported among patients treated with emicizumab-kxwh were injection site reactions. Researchers observed no new safety signals, and no thrombotic events or thrombotic microangiopathy occurred.
“It is well established that prophylaxis is the preferred approach for treatment of hemophilia A, but this can require frequent intravenous infusions, and some patients on prophylaxis can still experience bleeds, while others prefer on-demand treatment,” Johnny Mahlangu, MB BCh, BSc(Lab Med), FCPath(HAEM), MMed, member of the faculty of health sciences at University of the Witwatersrand and NHLS in South Africa, said in the release. “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.”
Results from HAVEN 3 will be presented at a future medical meeting. They also will be submitted to global health authorities.
As HemOnc Today previously reported, the FDA last week approved emicizumab-kxwh for adults and children with hemophilia A with factor VIII inhibitors. The agency based that approval on results of the HAVEN 1 and HAVEN 2 studies.