Biologic
RCSB PDB 8VGN
Rituximab
Rituxan
- Mechanism of action
- CD20-directed cytolytic antibody (mAb)
- In plain language
- A lab-made antibody that tags CD20, a marker on certain immune cells, for destruction — used for some cancers and autoimmune diseases.
- How it works
- Rituximab is a chimeric IgG1 monoclonal antibody that binds specifically to the CD20 antigen expressed on the surface of normal and malignant B lymphocytes. Binding triggers B-cell depletion through complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, and direct induction of apoptosis. In oncologic use, this depletes malignant B-cell clones; in autoimmune indications, it depletes the broader B-cell population implicated in autoantibody production. B-cell counts typically remain suppressed for 6-9 months post-treatment.
- Therapeutic applications
- FDA-approved for multiple CD20-positive B-cell malignancies, including follicular non-Hodgkin lymphoma, diffuse large B-cell lymphoma, and chronic lymphocytic leukemia. Also approved for autoimmune indications: moderately to severely active rheumatoid arthritis with inadequate TNF-antagonist response, granulomatosis with polyangiitis and microscopic polyangiitis, and moderate-to-severe pemphigus vulgaris.
- Class
- Monoclonal antibody
- Therapeutic area
- Oncology / Immunology
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