Rotuximab, also known by its brand name Rituxan, is a monoclonal antibody used primarily in the treatment of certain types of cancer, including non-Hodgkin lymphoma and chronic lymphocytic leukemia, as well as autoimmune diseases like rheumatoid Arthritis. It works by targeting the CD20 protein found on the surface of B-cells, leading to their destruction and helping to modulate the immune response. Rotuximab is administered intravenously and has been a significant advancement in targeted cancer therapy.