Fractionated radioimmunotherapy of B-cell malignancies with 131I-Lym-1.

Eighteen patients with Stage 4 B-cell malignancies, which were primarily of intermediate or high grade and progressive despite multiple drug chemotherapy and external irradiation, were treated with fractionated doses of 131I-labeled Lym-1. Lym-1 is an IgG2a monoclonal antibody that was produced by immunizing mice with Raji cell nuclei that originated from a patient with African Burkitt's lymphoma. Despite advanced disease, 10 of the patients had objective evidence for a complete or partial remission. Toxicity was very modest except in one patient who developed hypotension. Dose-dependent hepatic uptake of Lym-1 was observed in the patients and in BALB/c mice suggesting receptor-mediated recognition of this murine antibody.