Rituximab, sold under the brand name Rituxan among others, is a monoclonal antibody medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin lymphoma, chronic lymphocytic leukemia (in non-geriatric patients), rheumatoid arthritis, granulomatosis with polyangiitis, idiopathic thrombocytopenic purpura, pemphigus vulgaris, myasthenia gravis and Epstein–Barr virus-positive mucocutaneous ulcers. It is given by slow injection into a vein. Biosimilars of Rituxan include Blitzima, Riabni, Ritemvia, Rituenza (F.K.A. Tuxella), Rixathon, Ruxience, and Truxima.Common side effects which often occur within two hours of the medication being given include rash, itchiness, low blood pressure, and shortness of breath. Infections are also common.Severe side effects include reactivation of hepatitis B in those previously infected, progressive multifocal leukoencephalopathy, toxic epidermal necrolysis, and death. It is unclear if use during pregnancy is safe for the developing fetus or newborn baby, but it is not proven harmful. Rituximab is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells. When it binds to this protein it triggers cell death.Rituximab was approved for medical use in 1997. It is on the World Health Organizations List of Essential Medicines. Medical uses
Rituximab is a chimeric monoclonal antibody targeted against CD20 which is a surface antigen present on B cells.
Therefore, it acts by depleting normal as well as pathogenic B cells while sparing plasma cells and hematopoietic stem cells as they do not express the CD20 surface antigen.In the United States, rituximab is indicated to treat:

non-Hodgkin lymphoma (NHL)
chronic lymphocytic leukemia (CLL)
rheumatoid arthritis having inadequate response to one or more TNF inhibitors
vasculitis such as granulomatosis with polyangiitis and microscopic polyangiitis
moderate to severe pemphigus vulgaris
in combination with chemotherapy for children (≥6 months to <18 years) with previously untreated, advanced stage, CD20-positive diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), Burkitt-like lymphoma (BLL), or mature B-cell acute leukemia (B-AL). Blood cancers
Rituximab is used to treat cancers of the white blood system such as leukemias and lymphomas, including non-Hodgkins lymphoma, chronic lymphocytic leukemia, and nodular lymphocyte predominant Hodgkins lymphoma. This also includes Waldenströms macroglobulinemia, a type of NHL. Rituximab in combination with hyaluronidase human, sold under the brand names MabThera SC and Rituxan Hycela, is used to treat follicular lymphoma, diffuse large B-cell lymphoma, and chronic lymphocytic leukemia. It is used in combination with fludarabine and cyclophosphamide to treat previously untreated and previously treated CD20-positive chronic lymphocytic leukemia. Autoimmune diseases
Rituximab has been shown to be an effective rheumatoid arthritis treatment in three randomised controlled trials and is now licensed for use in refractory rheumatoid disease. In the United States, it has been FDA-approved for use in combination with methotrexate (MTX) for reducing signs and symptoms in adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to one or more anti-TNF-alpha therapy.