Non-Hodgkin's lymphoma (CD20 antigen-expressing relapsed or refractory, low grade, follicular, transformed, or rituximab-refractory).
See literature. Pretreat with acetaminophen 650mg and oral diphenhydramine 50mg and thyroid blockers; continue thyroid blockers 2 weeks after therapeutic dose. Give by IV infusion. Dosimetric step: Tositumomab 450mg over 1hr, then Iodine I131 tositumomab (containing 5mCi I131 and 35mg tositumomab) over 20 minutes. Therapeutic step (7–14 days after dosimetric step if biodistribution acceptable): tositumomab 450mg over 1hr, then calculated therapeutic dose of Iodine I131 tositumomab over 20 minutes. Reduce infusion rate by 50% if infusional toxicity occurs; stop if severe; may continue at 50% rate if severe symptoms resolve.
Radionuclide (B-lymphocyte-restricted differentiation antigen [CD20] inhibitor).
Hypersensitivity to murine proteins. Pregnancy (Cat.X).
Use only by physicians trained in radionuclide therapy. Handle and dispose of properly. See literature on patient contact restrictions. Not for initial treatment. >25% lymphoma marrow involvement and/or impaired bone marrow reserve, platelet count <100000cells/mm3, neutrophil count <1500cells/mm3, or intolerant to thyroid blockers: not recommended. High tumor burden. Splenomegaly. Renal impairment. Screen for human anti-mouse antibodies (increases anaphylaxis risk). Obtain CBCs and platelet counts before and for up to 12 weeks after therapy. Monitor TSH (before and annually), serum creatinine (before). Use adequate contraception during and for 12 months after therapy. Elderly. Nursing mothers: not recommended.
Concomitant other forms of irradiation or chemotherapy: not recommended. Caution with live viral vaccines, anticoagulants, platelet aggregation inhibitors.
Thrombocytopenia, neutropenia, anemia, headache, asthenia, fever, chills, pain, GI upset, cough, pneumonia, pleural effusion, dehydration, rash, infection, hemorrhage, hypersensitivity reactions (may be fatal), myelodysplastic syndrome, secondary malignancies, antibody formation.
For technical questions call (877) 423-9927.
Dosimetric pack (tositumomab 2 x 225mg/vial + 1 x 35mg/vial and
Iodine I131 tositumomab 1 x 20mL single-use vial)—1
Therapeutic pack (tositumomab 2 x 225mg/vial + 1 x 35mg/vial and
Iodine I131 tositumomab 1 or 2 x 20mL single-use vial)—1