Emicizumab Prophylaxis Demonstrates Positive Interim Results in Children with Hemophilia A

A phase 3 study evaluating emicizumab prophylaxis in children younger than 12 years with hemophilia A and inhibitors to factor VIII achieved positive interim results.

After a median of 12 weeks, emicizumab prophylaxis showed a clinically meaningful reduction in the number of bleeds over time, according to a press release.

Emicizumab prophylaxis is an investigational bispecific monoclonal antibody designed join factors IXa and X to restore the blood clotting process.

The single-arm, multicenter, open-label, phase 3 HAVEN 2 study evaluated the safety, efficacy, and pharmacokinetics of once-weekly subcutaneous administration of emicizumab prophylaxis. The study will enroll 60 children total for its final analysis, planned after 52 weeks of treatment with emicizumab.

“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 Roche, said in a release. “We are encouraged that once-weekly subcutaneous emicizumab prophylaxis showed a clinically meaningful reduction in the number of bleeds over time in children and are pleased to share these results with the community as we join in celebrating World Hemophilia Day.”

Findings from the HAVEN 2 study were consistent with results from the phase 3 HAVEN 1 study in adults and adolescents 12 years or older with hemophilia A and inhibitors to factor VIII. In that study, emicizumab prophylaxis showed a statistically significant and clinically meaningful reduction in the number of bleeds over time compared with non-prophylaxis, as well as compared to prior prophylaxis with bypassing agents.

The most common adverse events in the HAVEN 2 study were injection site reactions and nasopharyngitis.

Data from both studies will be presented at an upcoming medical meeting and submitted to health authorities for approval consideration, according to the release.