FDA Approves Hemlibra for Hemophilia A With or Without Factor VIII Inhibitors

With its new FDA approval, Hemlibra (emicizumab-kxwh), a bispecific factor IXa- and factor X-directed antibody, has become the first prophylactic treatment for patients with hemophilia A with or without factor VIII inhibitors.

In November 2017, Hemlibra was first approved by the FDA for hemophilia A, a congenital factor VIII deficiency, with inhibitors. After the results of a pair of phase 3 trials, HAVEN 3 and HAVEN 4, Hemlibra was approved with the additional indication for use without factor VIII inhibitors.

“The approval of Hemlibra introduces a new class of medicine for [hemophilia A] the first time in nearly 20 years,” said Michael Callaghan, MD, at Children’s Hospital of Michigan in a statement.

HAVEN 3 was a randomized, open-label trial in patients with hemophilia A without factor VIII inhibitors. Patients who received Hemlibra once weekly or biweekly had a 96% and 97% reduction in treated bleeds, respectively, versus those with no prophylaxis.

In addition, 55.6% and 60% patients treated with Hemlibra once and twice weekly, respectively, experienced no treated bleeds compared with 0% in patients with no prophylaxis. Hemlibra prophylaxis also resulted in a 95% reduction in all bleeds in once-weekly administration and 94% reduction for biweekly administration. The results of HAVEN 3 led to the priority review and breakthrough therapy designation from the FDA.

HAVEN 4 also helped to evaluate Hemlibra dosing given every 4 weeks. The less frequent dosing schedule adds more convenience for patients in need of prophylaxis. In this study, patients with or without factor VIII inhibitors given Hemlibra every 4 weeks experienced no treated bleeds, and approximately 90% of patients experienced 3 or fewer treated bleeds.

The adverse events (AEs) associated with Hemlibra were well tolerated, with the most common AEs being injection-site reactions, headache, and joint pain. The clinical effectiveness of Hemlibra across all bleed-related endpoints marks Hemlibra as a significant preventative treatment option for patients, while only requiring weekly to monthly administrations.

“Today’s approval of Hemlibra reflects our commitment to groundbreaking science and the development of medicines with the potential to redefine the standard of care” said Sandra Horning, MD, chief medical officer and head of Global Product Development in a statement.