Rituxan

Rituxan is the brand name for rituximab, a chimeric monoclonal antibody that targets the CD20 antigen on B lymphocytes. Developed by Genentech and marketed by Roche, it depletes B cells through mechanisms including antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and induction of apoptosis. B-cell depletion underpins its use in treating certain cancers and autoimmune diseases.

Indications approved in many regions include several B-cell non-Hodgkin lymphomas (such as follicular lymphoma, diffuse large B-cell lymphoma, and mantle cell lymphoma) and chronic lymphocytic leukemia/small lymphocytic lymphoma. Rituxan is also approved for rheumatoid arthritis in adults with an inadequate response to TNF inhibitors, usually in combination with methotrexate, and for granulomatosis with polyangiitis and microscopic polyangiitis.

Administration and dosing vary by indication and regimen. Rituxan is given by intravenous infusion, with premedication to reduce infusion reactions. The initial dose is followed by additional infusions across a planned schedule, and premedication typically includes acetaminophen and an antihistamine, with steroids used in some regimens. Infusion reactions are most common at the first dose and are managed by adjusting the infusion rate and supportive care.

Safety considerations include infusion-related reactions, increased risk of infections, hepatitis B reactivation, and rare cases of progressive multifocal leukoencephalopathy. Patients should be evaluated for infections and vaccination status before starting treatment when possible. The use of Rituxan during pregnancy is generally avoided unless potential benefits outweigh risks.

History and status: Rituxan was approved by the U.S. FDA in 1997 for CD20-positive B-cell non-Hodgkin lymphoma and has since gained additional indications for autoimmune diseases and other B-cell conditions. Biosimilars have been developed and approved in many regions.