Safety and Efficacy Study of Iodine-131 Anti-B1 Antibody Plus CHOP For Untreated Mantle Cell Lymphoma

Patients will receive an infusion of unlabeled Tositumomab (450 mg) followed by an infusion of Tositumomab (35 mg) containing 5 mCi of Iodine-131 (dosimetric dose). Whole body gamma camera scans will be obtained on Day 0; Day 2, 3, or 4; and Day 6 or 7 following the dosimetric dose. Patients will then receive an infusion of unlabeled Tositumomab (450 mg) followed by an infusion of 35 mg Tositumomab containing a patient-specific dose of Iodine-131 calculated to deliver a 75 cGy total body radiation dose (therapeutic dose). Patients who have platelet counts of 100,000-149,000 cells/mm3 will receive 65 cGy; obese patients will be dosed based upon 137% of their lean body mass. Patients will be treated with a thyroid blocking agent 24 hours prior to the dosimetric dose and continuing for 14 days following the therapeutic dose. Approximately 13 weeks following the therapeutic dose, CHOP will be administered every 21 days for a total of 6 cycles.