Investigators worldwide are recruiting subjects for a study of alemtuzumab (Genzyme Corporation) for the treatment of relapsing-remitting MS. In the CARE-MSSM II study, approximately 700 subjects at over 200 study sites will be randomly assigned to receive treatment with alemtuzumab or Rebif® (interferon beta-1a, EMD Serono and Pfizer). This study is funded by Genzyme Corporation and Bayer Healthcare Pharmaceuticals.

Rationale: Alemtuzumab is a humanized monoclonal antibody directed at CD52 (a protein on the surface of immune cells) that is currently approved by the U.S. FDA as a single agent for treatment of patients with B-cell chronic lymphocytic leukemia. Its ability to target immune cells has led investigators to test its potential as a treatment for relapsing-remitting MS. A phase 2 study compared two dose levels of alemtuzumab with Rebif in 334 subjects with relapsing-remitting MS who had never taken any other disease-modifying therapies. Those taking alemtuzumab had a 74% reduction in the risk of MS relapse compared with those on Rebif, and a 71% reduction in the risk for sustained accumulation of disability (New England Journal of Medicine 2008 359;17: 30-45). ..news from the National MS Society