PHASE-II TRIAL OF I-131 B1 (ANTI-CD20) ANTIBODY THERAPY WITH AUTOLOGOUS STEM-CELL TRANSPLANTATION FOR RELAPSED B-CELL LYMPHOMAS

25 patients with relapsed B-cell lymphomas were evaluated with trace-labelled doses (2.5 mg/kg, 185-370 MBq [5-10 mCi]) of I-131-labelled anti-CD20 (B1) antibody in a phase II trial. 22 patients achieved I-131-B1 biodistributions delivering higher doses of radiation to tumour sites than to normal organs and 21 of these were treated with therapeutic infusions of I-131-B1 (12.765-29.045 GBq) followed by autologous haemopoietic stem cell reinfusion. 18 of the 21 treated patients had objective responses, including 16 complete remissions. One patient died of progressive lymphoma and one died of sepsis. Analysis of our phase I and II trials with I-131-labelled B1 reveal a progression-free survival of 62% and an overall survival of 93% with a median follow-up of 2 years. I-131-anti-CD20 (B1) antibody therapy produces complete responses of long duration in most patients with relapsed B-cell lymphomas when given at maximally tolerated doses with autologous stem cell rescue.