First case of an anti-drug antibody reported in Hemlibra trial

Roche has reported that a young patient in the HAVEN 2 clinical trial for Hemlibra (emicizumab) has developed an anti-drug antibody to Hemlibra resulting in a loss of efficacy. The patient’s family decided to discontinue treatment with Hemlibra and resume treatment with a previous therapy.  This is the first confirmed report of a detectable anti-drug antibody that has impacted the efficacy of Hemlibra in a person with hemophilia A with inhibitors.

The anti-drug antibody to Hemlibra is not an inhibitor to Factor VIII and does not interfere with natural or infused Factor VIII proteins. The potential development of an anti-drug antibody to treatment products such as Hemlibra is a known risk for all protein therapies and was anticipated by the manufacturer and regulators. To date, more than 600 persons with hemophilia A, with or without inhibitors to factor VIII, have been treated with Hemlibra. No other case of an anti-drug antibody impacting the efficacy of Hemlibra has been reported.

It is important for doctors and patients to remain vigilant regarding the efficacy of Hemlibra as they should for all hemophilia treatment products. Loss of efficacy of Hemlibra may be demonstrated by an increase in breakthrough bleeds. Patients concerned about a loss of efficacy should seek prompt evaluation by their doctor.

The National Hemophilia Foundation Medical and Scientific Advisory Council (MASAC) has a more detailed report and statement on this event here:

A statement from Roche can be seen here.