New active drugs in the treatment of lymphomas.

Lymphomas include a vast number of pathologic conditions in which the search for new active drugs follows different routes. Hodgkin's disease and high-grade non-Hodgkin's lymphoma are very sensitive to chemotherapy, responding well to existing regimens; the inability to cure seems to be caused by acquired drug resistance. Newer strategies using classic chemotherapeutic agents and the use of modulators of resistance are the main focus of research in these malignancies. For indolent lymphomas, the inability to cure may be caused by the difficulty in eradicating completely an apparently sensitive disease. The search for new drugs in this field has focused on chemotherapeutic agents with new mechanisms of action, among which the purine analogues are the most important novelty, and on biologic therapy. There is evidence of activity of drug targeting, using monoclonal antibodies, immunotoxins, and radioimmunotherapy. Their role in the treatment of these malignancies will probably be different from that of traditional drugs, perhaps in the context of eradication of minimal residual disease after effective conventional therapy.