[131I]tositumomab

Compound class

Radiolabeled murine anti-CD20 IgG2a monoclonal antibody

Target / mechanism

Targets CD20 antigen on B-cells; I-131 irradiates antibody-bound cells and surrounding tissue PMID 17060972

Clinical application

Radioimmunotherapy for non-Hodgkin's lymphoma PMID 19707321

Theranostic pair

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FDA

Yes — 2003; BEXXAR (tositumomab and iodine I 131 tositumomab); GlaxoSmithKline LLC; approved 2003-06-27. Approval of the rituximab-naive indication was withdrawn 2013-10-23 at the sponsor's request; the notice states this does not otherwise affect the approved indication. Product is not present in the current openFDA Drugs@FDA listing Federal Register, FR Doc 2013-24840, notice of 2013-10-23 (FDA / CDER; docket FDA-2013-N-1137) — https://www.federalregister.gov/documents/2013/10/23/2013-24840/glaxosmithkline-llc-withdrawal-of-approval-of-the-indication-for-treatment-of-patients-with-relapsed ; openFDA Drugs@FDA queries for brand 'BEXXAR', ingredient 'TOSITUMOMAB', BLA 125011 return no record (queried 2026-09-18)

EMA (centralised)

No EMA medicines register (JSON export 2026-09-18): no tositumomab / Bexxar entry (authorised, withdrawn or refused)

Other approvals

Canada: BEXXAR THERAPY, DIN 02270471, GlaxoSmithKline Inc.; Health Canada status 'Cancelled Post Market' (status date 2014-07-31); original market date 2006-04-10

Brand names

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Clinical studies in the indexed corpus, ordered by design (multicentre, prospective, retrospective, others, case reports last) and then by year. Titles and links only, as published; this is not a summary of the evidence.

1. Cyclophosphamide, vincristine, and prednisone followed by tositumomab and iodine-131-tositumomab in patients with untreated low-grade follicular lymphoma: eight-year follow-up of a multicenter phase II study.
   2010 · J Clin Oncol · Multicentre · Phase II
2. Radioimmunotherapy in Non-Hodgkin's Lymphoma: Retrospective Adverse Event Profiling of Zevalin and Bexxar.
   2019 · Pharmaceuticals (Basel) · Retrospective
3. Observational Retrospective Study of Altered Biodistribution of Tositumomab and 131I-Tositumomab.
   2015 · J Nucl Med · Retrospective
4. 131I-Tositumomab (Bexxar) vs. 90Y-Ibritumomab (Zevalin) therapy of low-grade refractory/relapsed non-Hodgkin lymphoma.
   2010 · Mol Imaging Biol · Retrospective
5. Phase 2 Study of Iodine-131 Tositumomab Plus Chemotherapy in Patients With Previously Untreated Mantle-Cell Lymphoma.
   2020 · Clin Lymphoma Myeloma Leuk · Clinical study · Phase II
6. Long-term follow-up of previously treated and treatment-naïve patients who received tositumomab and I-131 tositumomab.
   2016 · Leuk Lymphoma · Clinical study
7. R-CHOP with iodine-131 tositumomab consolidation for advanced stage diffuse large B-cell lymphoma (DLBCL): SWOG S0433.
   2014 · Br J Haematol · Clinical study
8. A comparative analysis of prognostic factor models for follicular lymphoma based on a phase III trial of CHOP-rituximab versus CHOP + 131iodine--tositumomab.
   2013 · Clin Cancer Res · Clinical study · Phase III
9. Six of 12 relapsed or refractory indolent lymphoma patients treated 10 years ago with 131I-tositumomab remain in complete remission.
   2011 · J Nucl Med · Clinical study
10. Radioimmunotherapy in non-Hodgkin lymphoma: opinions of nuclear medicine physicians and radiation oncologists.
    2011 · J Nucl Med · Clinical study