Expanded Access Study Of BEXXAR® For Low Grade And Transformed Low-Grade Non-Hodgkin's Lymphoma

Patients will receive unlabeled Tositumomab (450 mg) followed by Tositumomab (35 mg) which has been trace-labeled with 5 mCi of Iodine-131 (dosimetric dose). Whole body counts using a gamma camera will be obtained 3 times between Days 0 and 7 following the dosimetric dose to determine a patient-specific mCi dose of Iodine-131 calculated to deliver the desired total body dose of radiation (either 65 cGy or 75 cGy). The therapeutic dose is administered 7-14 days after the dosimetric dose. Patients will receive unlabeled Tositumomab (450 mg) followed by Tositumomab (35 mg) labeled with the patient-specific dose of Iodine-131 (median dose in previous studies was approximately 85 mCi). Patients who are obese will be dosed based upon 137% of their calculated lean body mass. Patients will be treated with thyroid blocking medication at least 24 hours prior to the dosimetric dose and continuing for 14 days following the therapeutic dose.