Emicizumab Gets FDA Greenlight for Treatment of Hemophilia A

The US Food and Drug Administration (FDA) has approved emicizumab (Hemlibra/Genentech) to prevent and reduce bleeding episodes in adult and pediatric patients with hemophilia A who have developed antibodies called factor VIII (FVIII) inhibitors.

According to an agency statement, emicizumab is a first-in-class therapy that works by bridging other Factors in the blood to restore blood clotting. It is a preventative treatment given weekly via subcutaneous injection, and carries a boxed warning, stating that thrombotic microangiopathy and thromboembolism have been observed in patients who were also given a rescue treatment to treat bleeds for 24 hours or more while taking the treatment.

Genentech released positive preliminary results from the HAVEN 1 study in April, 2017, and announced positive preliminary HAVEN 2 data in June, with both showing a substantial and clinically meaningful reduction in the number of bleeds.

“Reducing the frequency or preventing bleeding episodes is an important part of disease management for patients with hemophilia. Today’s approval provides a new preventative treatment that has been shown to significantly reduce the number of bleeding episodes in patients with hemophilia A with Factor VIII inhibitors,” said Richard Pazdur, M.D., acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “In addition, patients treated with Hemlibra reported an improvement in their physical functioning.”

Emicizumab demonstrated safety and efficacy in 2 clinical trials. The first included 109 males aged 12 and older with hemophilia A with FVIII inhibitors, wherein the emicizumab-treated patient cohort experienced an 87% reduction in the rate of treated bleeds, as well as a patient-reported improvement in hemophilia-related symptoms and physical functioning.

The second trial was a single arm trial of 23 males under the age of 12 with the same condition. In this cohort, 87% of patients taking emicizumab did not experience a bleeding episode that required treatment during the trial period.

“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,” said Sandra Horning, MD, chief medical officer and head of Global Product Development at Genentech in April.

Emicizumab’s New Drug Application (NDA) was granted Priority Review and Breakthrough Designations. Emicizumab also received Orphan Drug designation for its potential to treat rare diseases.