Tositumomab is a drug for the treatment of follicular lymphoma. It is an IgG2a anti-CD20 monoclonal antibody derived from immortalized mouse cells.
Tositumomab is applied in a sequential infusion followed by iodine (131I) tositumomab, which is the same antibody covalently bound to the radionuclide iodine-131 (131I). 131I emits both beta and gamma radiation and decays with a half-life of 8 days.
Clinical trials have established the efficacy of the tositumomab/iodine (131I) tositumomab regimen in patients with relapsed or chemotherapy/rituxan refractory follicular lymphoma.
This drug combination is manufactured by Corixa (now GlaxoSmithKline). It sells in the U.S. under the trade name Bexxar.
Bexxar was developed by Dr. Mark Kaminski and Dr. Richard Wahl.
There is some evidence that it may cause a smaller decrease in platelet counts than ibritumomab tiuxetan does.
External links 
- Bexxar regimen entry in the public domain NCI Dictionary of Cancer Terms