Radioimmunotherapy of acquired immunodeficiency syndrome (AIDS) associated lymphoma.

Standard therapy for AIDS associated NHL (AANHL) is toxic and often ineffective. Radioimmunotherapy (RIT) is an appealing alternative to chemotherapy because of the radiosensitivity of NHL and the ability of the Lym-1 monoclonal antibody to target therapeutic irradiation to NHL while relatively sparing normal tissue. A Phase I/II study of Y-90-2IT-BAD-Lym-1 was designed specifically for RIT of AANHL. The first patient has been treated with 15 mCi (7.5 mCi/m(2)) of Y-90-2IT-BAD-Lym-1, after an imaging dose of In-111-2IT-BAD-Lym-1. Before Rm: AANHL in the maxillary sinus extended into the oral cavity and axillary adenopathy was present. Imaging showed excellent accumulation of In-111-2IT-BAD-Lym-1 in the tumors. Substantial shrinkage of the oral lymphoma was observed 18 hours after the therapy dose of Y-90-2IT-BAD-Lym-1 and axillary adenopathy had disappeared by one week after RIT. Transient Grade IV myelosuppression was the only notable toxicity. Further RIT cycles were precluded by development of an antibody response (HAMA) against Lym-1. This novel preliminary study has shown that Lym-1 can target AANHL and produce significant tumor regression thereby providing encouragement to proceed with additional patients.