High Quality Content by WIKIPEDIA articles! Ocrelizumab is a humanized anti-CD20 monoclonal antibody. It targets mature B lymphocytes and hence is an immunosuppressive drug candidate. It is under development by Hoffmann La Roche's subsidiary Genentech, and Biogen Idec. It had reached Phase III clinical trials for rheumatoid arthritis and lupus erythematosus, and Phase II for multiple sclerosis and hematological cancer. In March 2010, Roche announced the suspension of clinical trials in rheumatoid arthritis and lupus erythematosus. This step followed the occurrence of deaths due to opportunistic infections while development for multiple sclerosis is ongoing.