The FDA has approved emicizumab-kxwh as prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients with hemophilia A with or without factor VIII (FVIII) inhibitors. The drug was first approved in 2017 for patients with hemophilia A with FVIII inhibitors.
The approval also provided new dosing regimens for these patients.
The agency’s approval is based on results from the phase III HAVEN 3 and HAVEN 4 clinical trials. In the HAVEN 3 study, 89 adults and adolescents with hemophilia A without factor VIII inhibitors received either no prophylactic treatment or prophylactic treatment with emicizumab-kxwh 1.5 mg/kg once weekly or 3 mg/kg once every two weeks. The weekly and biweekly arms experienced 96-percent and 97-percent reductions in their annualized bleed rates (ABRs) for treated bleeds, respectively, compared with the control group (p<0.0001).
In the single-arm HAVEN 4 trial, 48 adult and adolescent patients with hemophilia A with and without FVIII inhibitors were treated with prophylactic emicizumab-kxwh 6 mg/kg once every four weeks for at least 24 weeks. The ABR for treated bleeds was 2.4 and the median ABR was zero (range = 0-2.08).
Common adverse events occurring in both trials included injection-site reactions, headache, and joint pain. The prescribing information includes a warning that patients should be monitored for the development of thrombotic microangiopathy and thrombotic events if activated prothrombin complex concentrate is administered.
Source: FDA news release, October 4, 2018.