[Treatment of leukemias and lymphomas by interferons: II. Phase II of the trial treatment of chronic lymphoid leukemia by human interferon alpha+].

Nine patients with chronic lymphoid leukemia (CLL) were treated with subcutaneous human (leukocyte) interferon alpha (IF alpha). In the first part of the study, 7 patients received intermittent 10 day courses, with free intervals of 10 to 15 days and with a rising dose in the same patient from cycle to cycle, if tolerance permits, from 1.5 to 6 X 10(6) units daily. As we observed a decrease of peripheral lymphocytosis with low doses, and as high doses gave more side-effect in the second part of the study, 4 patients (including two who had previously received intermittent courses) were treated for three months or more at a dose of 1.5 X 10(6) units daily. Tumor mass reduction was seen in only three patients, but significant decrease in peripheral lymphocytosis was seen in 7 patients sustained in the continuous treatment group with relapse at treatment discontinuation in one patient and despite continuation in another. Immune monitoring with currently available T, B, NK and macrophage tests, showed, in this population of patients, a very good correlation between NK cell activity and clinical response. Further studies are warranted to determine the best modalities of treatment as well as the population of patients likely to benefit from it, and the possible special respective indications of IF, and of the other treatments of CLL. One can already consider as a reasonable indication CLL presentations with myeloid insufficiency as IF is not myelotoxic, contrary to chemotherapy.