Rituximab
RituxanRCSB PDB 8VGN · 3D model
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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 manufactured antibody engineered to recognize and stick to a specific protein tag, CD20, that sits on the surface of B cells, a type of immune cell. Once attached, it recruits the body's own defenses to kill the tagged B cells. In cancers like lymphoma, this wipes out the cancerous B cells. In autoimmune diseases, it clears out the B cells that are mistakenly attacking the body's own tissues. The effect lasts several months while the body slowly regrows a fresh population of B cells.
What it’s used for
Used to treat several types of B-cell blood cancers, including common forms of non-Hodgkin lymphoma and chronic lymphocytic leukemia, often alongside chemotherapy. Also used for autoimmune conditions including rheumatoid arthritis that hasn't responded to other treatments, two rare blood-vessel inflammation disorders, and a serious blistering skin condition.
- Mechanism
- CD20-directed cytolytic antibody (mAb)
- Drug class
- Monoclonal antibody
- Therapeutic area
- Oncology / Immunology
The antibody that opened the era of biologic cancer therapy
Rituximab was the first lab-made antibody ever approved to treat cancer. It works by recognizing a marker called CD20 on the surface of B cells, including the cancerous ones in certain lymphomas, and flagging them for destruction by the immune system. Before this, cancer antibodies were mostly experimental; Rituximab proved the concept could work as an actual approved treatment, and it opened the door to the wave of antibody-based cancer and immune drugs that followed, including trastuzumab and pembrolizumab, both also on this site.
Pivotal trial
A multicenter, single-arm trial of a four-dose regimen in patients with relapsed or refractory low-grade or follicular B-cell lymphoma, conducted 1996-1997, before clinical trial registries existed, so no NCT number applies.