Daclizumab HYP versus Interferon Beta-1a in Relapsing Multiple Sclerosis

BackgroundDaclizumab high-yield process (HYP) is a humanized monoclonal antibody that binds to CD25 (alpha subunit of the interleukin-2 receptor) and modulates interleukin-2 signaling. Abnormalities in interleukin-2 signaling have been implicated in the pathogenesis of multiple sclerosis and other autoimmune disorders. MethodsWe conducted a randomized, double-blind, active-controlled, phase 3 study involving 1841 patients with relapsing–remitting multiple sclerosis to compare daclizumab HYP, administered subcutaneously at a dose of 150 mg every 4 weeks, with interferon beta-1a, administered intramuscularly at a dose of 30 μg once weekly, for up to 144 weeks. The primary end point was the annualized relapse rate. ResultsThe annualized relapse rate was lower with daclizumab HYP than with interferon beta-1a (0.22 vs. 0.39; 45% lower rate with daclizumab HYP; P<0.001). The number of new or newly enlarged hyperintense lesions on T2-weighted magnetic resonance imaging (MRI) over a period of 96 weeks was lower w...