FDA Approves New Hemophilia A Treatment

NOVEMBER 16, 2017
Officials with the FDA have approved emicizumab-kxwh (Hemlibra, Genentech) as a treatment for patients with hemophilia A who have factor VIII inhibitors, according to a press release from the agency.

Patients with hemophilia A are missing a gene which produces factor VIII, a protein that enables blood to clot. Emicizumab-kxwh is indicated for adult and pediatric patients with hemophilia A who have developed antibodies called factor VIII inhibitors. It is a preventive treatment given weekly via subcutaneous injection.

Emicizumab-kxwh’s approval is based on data from 2 clinical trials that demonstrated the treatment’s safety and efficacy. In the first trial, 109 males aged 12 years and older with hemophilia A with FVIII inhibitors were randomly assigned into 2 groups.

The researchers compared treatment with emicizumab-kxwh to no prophylactic treatment in 53 patients who were previously treated with on-demand therapy with a bypassing agent before enrolling in the trial. Patients who took emicizumab-kxwh experienced less bleeding episodes per year (2.9) compared to those who did not receive prophylactic treatment (23.3).

Patients who were treated with emicizumab-kxwh also reported an improvement in hemophilia-related symptoms, such as painful swellings and joint pain, as well as physical function compared to patients in the other group.

In the second trial, which included 23 boys younger than age 12, 87% of the patients taking emicizumab-kxwh did not experience a bleeding episode that required treatment.

Common adverse effects reported include injection site reactions, headache, and joint pain.  Emicizumab-kxwh contains a boxed warning, alerting health care providers and patients that severe blood clots have been observed in patients who were also given a rescue treatment to treat bleeds for 24 hours or more while on the treatment.


FDA approves new treatment to prevent bleeding in certain patients with hemophilia A [news release]. FDA’s website. . Accessed November 16, 2017.