Study of Iodine-131 Anti-B1 Antibody for Patients With Non Hodgkin's Lymphoma Who Have Previously Received Rituximab

Patients will receive an infusion of unlabeled Anti-B1 Antibody (450 mg) followed by an infusion of Anti-B1 Antibody (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 Anti-B1 Antibody (450 mg) followed by an infusion of 35 mg Anti-B1 Antibody 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 100,001-149,999 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.