 Rituximab Rituxan is a humanized monoclonal antibody against cluster of differentiation antigen 20 CD20 a receptor in the surface of malignant B-cell lymphocytes. The drug has activity against aggressive and nonaggressive NHL of B-cell origin, and has been used in combination with chemotherapy. Cyclophosphamide is a type of drug know as an alkylating agent. Vincristine is a type of drug called vinca alkaloids. It is typically used in lymphomas, leukemias, and other tumors. Prednisone is a type of steroid. Dexamethasone is a steroid that may have activity against lymphomas. Methotrexate is an anti-cancer drug and a folic acid antagonist. It is used to treat solid tumors, lymphomas, leukemias, and autoimmune diseases. 