HAVEN 3 Data Supports Use of Hemlibra to Treat Hemophilia A Patients Without Factor VIII Inhibitors

Administration of once-weekly Hemlibra (emicizumab-kxwh) significantly reduced bleeding rates in patients with Hemophilia A compared to other clotting factor VIII prophylaxis (preventive) therapy, according to the latest results of the Phase 3 HAVEN 3 study announced by Roche.

Developed by Chugai Pharmaceutical, Roche, and Genentech, Hemlibra is an antibody designed to be administered by an injection of a ready-to-use solution under the skin. It will activate the natural coagulation cascade and restore the blood clotting process in patients with hemophilia A.

Earlier this month the U.S. Food and Drug Administration (FDA) approved Hemlibra as prophylactic (preventative) therapy to prevent or reduce bleeding episodes in children and adults with hemophilia A with factor VIII inhibitors. The FDA’s positive decision was based on safety and efficacy data from the HAVEN 1 (NCT02622321) and HAVEN 2 (NCT02795767) trials.

Hemlibra is still under regulatory review by the European Medicines Agency (EMA) to be granted marketing authorization in Europe

“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, faculty of health sciences at the University of the Witwatersrand and NHLS, in Johannesburg, South Africa, said in a press 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,” he said.

The most recent open-label HAVEN 3 trial (NCT02847637) evaluated Hemlibra’s therapeutic potential in a group of patients with hemophilia A, but without inhibitors to factor VIII. The study included 152 patients aged 12 years or older who already had been treated with another factor VIII therapy, either on-demand or in prophylaxis regimens.

Those who received prior on-demand therapy were randomly assigned to three treatment groups. The patients received 3 mg/kg of Hemlibra per week for up to four weeks followed by injections of 1.5 mg/kg once-weekly or 3 mg/kg once every two weeks until the end of the study. Those included in the third group did not receive any prophylactic treatment during the study period.

The patients who were receiving prior prophylaxis treatment with another factor VIII therapy switched to Hemlibra at 3 mg/kg dose per week for 4 weeks, followed by once-weekly 1.5 mg/kg until completion of the study.

HAVEN 3 clinical data showed that patients who received injections of Hemlibra once-weekly or every two weeks had significantly fewer bleeding episodes over time compared to those who did not receive the treatment. In addition, the investigators reported that once-weekly Hemlibra prophylaxis was more efficient in reducing the number of bleeding episodes than prior factor VIII prophylaxis therapies.

“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, which includes the positive HAVEN 1 and interim HAVEN 2 data in people with inhibitors,” Sandra Horning, MD, chief medical officer and head of global product development at Roche. “We look forward to working with health authorities to make this treatment available for all people with hemophilia A as soon as possible.”

No additional safety concerns were reported during HAVEN 3. Similarly to what had been reported in prior trials, the most common adverse effects associated to Hemlibra administration were injection site reactions.

Hemlibra’s safety and effectiveness are currently being evaluated in the HAVEN 4 (NCT03020160) trial in patients with hemophilia A, with or without inhibitors. In this study participants will receive 6 mg/kg of the therapy every four weeks after an initial one-month “loading” period.