WASHINGTON -- Daclizumab (Zinbryta), a long-acting, self-administered injection for treatment of relapsing multiple sclerosis, received FDA approval late Friday.
The effectiveness of the drug, which targets the α-chain of the interleukin-2 receptor CD25, was demonstrated in two clinical trials: one compared daclizumab to interferon -alpha- 1 (Avonex) and a second study compared the novel compound to placebo. Patients inject the drug once a month.
In the Zinbryta-Avonex head-to-head 144-week study, which was conducted in 1,841 patients, patients taking Zinbryta had fewer clinical relapses than controls. The placebo-controlled study enrolled 412 patients who were treated for 52 weeks. Zinbryta was superior to placebo.
In a statement the FDA said the drug "should generally be used only in patients who have had an inadequate response to two or more MS drugs because Zinbryta has serious safety risks, including liver injury and immune conditions. Because of the risks, Zinbryta has a boxed warning and is available only through a restricted distribution program under a Risk Evaluation and Mitigation Strategy."
Adverse events include severe, life-threatening liver injury. "Health care professionals should perform blood tests to monitor the patient's liver function prior to starting Zinbryta, monthly before each dose, and for up to 6 months after the last dose," the FDA said.
Other risks included in the boxed warning are non-infectious colitis, skin reactions, and lymphadenopathy, as well as anaphylaxis, angioedema, increased risk of infections, and mood disorders, including suicidal ideation.
In the trial that compared the drug to Avonex common adverse events included nasopharyngitis, upper respiratory infections, rash, flu, and dermatitis.
Zinbryta is marketed by Biogen, Inc. of Cambridge, Massachusetts.