Two antibodies against the same CD20 target on B-cells — one an older oncology and rheumatology mainstay, the other purpose-built and licensed for multiple sclerosis.
RITUXAN is a CD20-directed cytolytic antibody indicated for the treatment of: Adult patients with Non-Hodgkin's Lymphoma (NHL) ( 1.1 ). Relapsed or refractory, low grade or follicular, CD20-positive B-cell NHL as a single agent. Previously untreated follicular, CD20-positive, B-cell NHL in combination with first line chemotherapy and, in patients achieving a complete or partial response to a rituximab product in combination with chemotherapy, as single-agent maintenance therapy. Non-progressing (including stable disease), low-grade, CD20-positive, B-cell NHL as a single agent after first-line cyclophosphamide, vincristine, and prednisone (CVP) chemotherapy. Previously untreated diffuse large B-cell, CD20-positive NHL in combination with (cyclophosphamide, doxorubicin, vincristine, and prednisone) (CHOP) or other anthracycline-based chemotherapy regimens. Pediatric patients aged 6 months…
OCREVUS is indicated for the treatment of: Relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults Primary progressive MS, in adults Relapsing-remitting MS, in pediatric patients 10 years of age and older who weigh 25 kg or more. OCREVUS is a CD20-directed cytolytic antibody indicated for the treatment of: Relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults ( 1 ) Primary progressive MS, in adults ( 1 ) Relapsing-remitting MS, in pediatric patients 10 years of age and older who weigh 25 kg or more ( 1 )
12.1 Mechanism of Action Rituximab is a monoclonal antibody that targets the CD20 antigen expressed on the surface of pre-B and mature B-lymphocytes. Upon binding to CD20, rituximab mediates B-cell lysis. Possible mechanisms of cell lysis include complement dependent cytotoxicity (CDC) and antibody dependent cell mediated cytotoxicity (ADCC). B cells are believed to play a role in the pathogenesis of rheumatoid arthritis (RA) and associated chronic synovitis. In this setting, B cells may be acting at multiple sites in the autoimmune/inflammatory process, including through production of rheumatoid factor (RF) and other autoantibodies, antigen presentation, T-cell activation, and/or proinflam…
12.1 Mechanism of Action The precise mechanism by which ocrelizumab exerts its therapeutic effects in multiple sclerosis is unknown, but is presumed to involve binding to CD20, a cell surface antigen present on pre-B and mature B lymphocytes. Following cell surface binding to B lymphocytes, ocrelizumab results in antibody-dependent cellular cytolysis and complement-mediated lysis.
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Plain-English summaries and drug-class explainers are written and reviewed by the Priya Life Science editorial team, led by Sreepriya Prasannan (MSc Digital Transformation of Life Sciences (Innopharma Education / Griffith College); MSc & BSc Botany). Data is retrieved automatically from the sources above and cross-checked with AI-assisted verification (Anthropic's Claude) — brand and generic names are matched against the exact FDA product record so that a combination product or a different formulation cannot be mistaken for the drug on this page. An editor reviews the result before publication. We describe this in full in our editorial standards and corrections policy. The FDA data on this page was last retrieved on 22 Aug 2026.