rituximab
Rituxan (rituximab) is a CD20-directed monoclonal antibody from Genentech used across blood cancers and immune diseases. It depletes B cells that carry the CD20 marker, and is used in non-Hodgkin lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, certain vasculitides, and pemphigus vulgaris.
This page is based on FDA prescribing information and the EMA medicine record for rituximab, cross-checked with DailyMed and the National Cancer Institute dictionary; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Rituximab is a homing tag that sticks to CD20, a marker covering B cells, whether healthy or cancerous. Once tagged, the body's own defence crews recognise the cells as targets and break them down. For lymphomas this removes malignant B cells; in autoimmune disease it removes the B cells driving the mistaken attack, and they gradually repopulate afterwards.
In simple terms
Rituximab is a chimeric antibody given by infusion that binds CD20, a protein found on pre-B cells and mature B lymphocytes, including many B-cell cancers. After binding, it triggers the host's cytotoxic immune response against CD20-positive cells, depleting them. In blood cancers this directly removes malignant cells; in rheumatoid arthritis, vasculitis, and pemphigus vulgaris it reduces the antibody-driven immune attack on joints, blood vessels, and skin.
In depth
Rituximab is a recombinant chimeric murine/human antibody directed against the CD20 antigen, a hydrophobic transmembrane protein located on normal pre-B and mature B lymphocytes. Following binding, rituximab triggers a host cytotoxic immune response against CD20-positive cells through mechanisms including antibody-dependent cellular cytotoxicity and complement activation. The resulting B-cell depletion underlies its activity in CD20-positive non-Hodgkin lymphoma and chronic lymphocytic leukemia and its immunomodulatory effect in rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis, and pemphigus vulgaris.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
How rituximab tags CD20 to deplete B cells across lymphoma and autoimmune disease
- Rituximab is a homing tag that sticks to CD20, a marker covering B cells, whether healthy or cancerous.
- Rituximab is a recombinant chimeric murine/human antibody directed against the CD20 antigen, a hydrophobic transmembrane protein located on normal pre-B and mature B lymphocytes.
- Following binding, rituximab triggers a host cytotoxic immune response against CD20-positive cells through mechanisms including antibody-dependent cellular cytotoxicity and complement activation.
- The resulting B-cell depletion underlies its activity in CD20-positive non-Hodgkin lymphoma and chronic lymphocytic leukemia and its immunomodulatory effect in rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis, and pemphigus vulgaris.
Target: CD20 antigen on B cells
A hydrophobic transmembrane protein located on normal pre-B and mature B lymphocytes as well as many B-cell cancers; marking it lets the immune system destroy those cells.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- As a single agent, for the treatment of adults with relapsed or refractory, low-grade or follicular, CD20-positive B-cell non-Hodgkin's lymphoma (NHL)
- In combination with first-line chemotherapy, for previously untreated follicular, CD20-positive B-cell NHL, and as single-agent maintenance therapy in patients achieving a complete or partial response
- As a single agent, for non-progressing (including stable disease), low-grade, CD20-positive B-cell NHL after first-line cyclophosphamide, vincristine, and prednisone (CVP) chemotherapy
- In combination with cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or other anthracycline-based chemotherapy regimens, for previously untreated diffuse large B-cell, CD20-positive NHL
- In combination with chemotherapy, for pediatric patients aged 6 months and older with previously untreated, advanced stage, CD20-positive diffuse large B-cell lymphoma, Burkitt lymphoma, Burkitt-like lymphoma, or mature B-cell acute leukemia
- In combination with fludarabine and cyclophosphamide, for the treatment of adults with previously untreated and previously treated CD20-positive chronic lymphocytic leukemia
- In combination with methotrexate, for the treatment of adults with moderately- to severely-active rheumatoid arthritis who have had an inadequate response to one or more TNF antagonist therapies
- In combination with glucocorticoids, for the treatment of adults and pediatric patients 2 years of age and older with granulomatosis with polyangiitis (Wegener's granulomatosis) and microscopic polyangiitis
- For the treatment of adults with moderate to severe pemphigus vulgaris
Approved uses in European Union
EMA- In combination with chemotherapy, for previously untreated adults with stage III-IV follicular lymphoma, as maintenance therapy for adults responding to induction therapy, and as monotherapy for adults with stage III-IV follicular lymphoma who are chemoresistant or in their second or subsequent relapse after chemotherapy
- In combination with CHOP chemotherapy, for adults with CD20-positive diffuse large B-cell non-Hodgkin's lymphoma
- In combination with chemotherapy, for pediatric patients aged 6 months to less than 18 years with previously untreated advanced stage CD20-positive diffuse large B-cell lymphoma, Burkitt lymphoma or Burkitt leukemia (mature B-cell acute leukemia), or Burkitt-like lymphoma
- In combination with chemotherapy, for adults with previously untreated and relapsed or refractory chronic lymphocytic leukemia
- In combination with methotrexate, for adults with severe active rheumatoid arthritis who have had an inadequate response or intolerance to other disease-modifying anti-rheumatic drugs including one or more tumour necrosis factor inhibitor therapies
Official sources
The statements on this page trace back to these records.
- MabThera (rituximab) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- DailyMed: RITUXAN (rituximab) official US label
U.S. National Library of Medicine, DailyMed
- U.S. Food and Drug Administration: rituximab prescribing information
U.S. Food and Drug Administration
- National Cancer Institute: rituximab
National Cancer Institute
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.