High Quality Content by WIKIPEDIA articles! Ofatumumab (trade name Arzerra, also known as HuMax-CD20) is a human monoclonal antibody (for the CD20 protein) which appears to inhibit early-stage B lymphocyte activation. It is FDA approved for treating chronic lymphocytic leukemia that is refractory to fludarabine and alemtuzumab and has also shown potential in treating follicular non-Hodgkin’s lymphoma, diffuse large B cell lymphoma, rheumatoid arthritis and relapsing remitting multiple sclerosis. Ofatumumab has also received conditional approval in Europe for the treatment of refractory chronic lymphocytic leukemia. This makes ofatumumab the first marketing application for an antibody produced by Genmab, as well as the first human monoclonal antibody which targets the CD20 molecule that will be available for patients with refractory CLL.