Emicizumab reduces bleeds among children with hemophilia A
Once-weekly subcutaneous emicizumab prophylaxis conferred a clinically meaningful reduction in the number of bleeds among children with hemophilia A and inhibitors to Factor VIII, according to interim study results released by the agent’s manufacturer.
Interim results of the phase 3 HAVEN 2 study were based on results of 19 children aged 12 years or younger who had undergone a median 12 weeks of treatment with emicizumab (Genentech), an investigational bispecific monoclonal antibody designed to bring together Factor IXa and Factor X.
The single-arm, multicenter, open-label study will include 60 children, all of whom require treatment with bypassing agents. A final analysis is planned after 52 weeks of treatment. Objectives include number of bleeds over time, safety, pharmacokinetics and health-related quality of life.
“Managing hemophilia A with inhibitors to Factor VIII is especially challenging for children and their caregivers, because bleeding is difficult to control and current treatments require frequent intravenous infusions,” Sandra Horning, MD, chief medical officer and head of global product development at Genentech, said in a company-issued press release. “We are encouraged that once-weekly subcutaneous emicizumab prophylaxis showed a clinically meaningful reduction in the number of bleeds over time in children.”
The most common adverse events associated with emicizumab in the HAVEN 2 study were injection site reactions and nasopharyngitis.
The results appeared consistent with findings from the phase 3 HAVEN 1 study, which evaluated emicizumab prophylaxis in adults and adolescents with hemophilia A and inhibitors to Factor VIII. HAVEN 1 showed emicizumab prophylaxis conferred a statistically significant and clinically meaningful reduction in the number of bleeds compared with no prophylaxis, as well as compared with prior prophylaxis with bypassing agents, according to the press release.
Results from the two trials will be presented at an upcoming medical meeting, and they also will be submitted to regulatory authorities for consideration.
Two other phase 3 studies are evaluating emicizumab prophylaxis in people aged 12 years or older with hemophilia A.
The HAVEN 3 study is assessing prophylaxis dosed once weekly or once every other week among those who do not have inhibitors to Factor VIII. The HAVEN 4 study is evaluating prophylaxis dosed every 4 weeks among those with or without inhibitors to Factor VIII.