A murine CD 20 monoclonal antibody conjugated with iodine-131.
Binds to CD 20, a stable cell-surface molecule in B-cell non-Hodgkin’s lymphoma, so that the tumor receives high doses of radiation over several days with minimal damage to healthy tissues.
Thyroid dysfunction associated with treatment in about 5% of patients.
Radiation dose the bone marrow is one tenth that absorbed by the tumor.
Overall response rates 47-68% with 20-38% complete remissions in follicular lymphoma patients who have relapse after chemotherapy or refractory to chemotherapy and or rituximab.
Approximately one third of patients responding with recurrent or refractory follicular lymphoma have remission from 1-10 years.
In an analysis of 531 patients with follicular lymphoma the overall 15 years survival was 70% and cure estimated overall rate of 42% were treated with CHOP followed by I131-tositumomab  radioimmunotherapy:representing a paradigm shift in the understanding and approach to follicular lymphoma. (Shadman M).