Immunotherapy of leukemia.

The data reviewed in this paper indicate that immunotherapy is effective in prolonging remission and survival in acute and chronic leukemia. The acute lymphocytic leukemias may or may not respond to immunotherapy and further work is needed in this area. No studies of immunotherapy in chronic lymphocytic leukemia have been done, but this will be an important area for investigation, since there is often profound immunodeficiency in this disease. The malignant lymphomas are another fertile area for this type of research, since they have a high response rate, tumor-associated immunodeficiency, and at least differentiation antigens if not tumor-specific antigens. The scientific basis for the use of immunotherapy in leukemia includes the demonstration of a relationship of rate and duration of remission and survival to immunocompetence, the demonstration of unique tumor-associated antigens on leukemia cells, and the demonstration of immune responses to these antigens which can be boosted by immunization. At the present time, active nonspecific immunotherapy with BCG and MER and active specific immunotherapy have been proved effective in acute myelogenous leukemia. Careful attention should be given to dose, schedule, route, and so forth. Other types of immunotherapy remain to be explored.