[Clinical investigation of interferons in the preleukemic state (CML and MDS)].

We treated 11 patients who had Philadelphia-chromosome-positive chronic myelogenous leukemia with natural interferon alpha (human lymphoblastoid interferon; HLBI). HLBI was given at 6-12 X 10(6) u/day i.m. or i.s.c. during induction therapy. Nine patients responded to the treatment, of whom 7 had hematologic remission and 2 had partial remission. Six patients with MDS or hypoplastic leukemia, and 3 patients with overt leukemia from MDS were treated with recombinant interferon gamma (GI-3). GI-3 was given at 0.4 X 10(6) u/m2 of body-surface area per day i.s.c. or i.v. for 4-6 weeks. In 2 patients with RAEB and hypoplastic leukemia, the blast cell count in bone marrow decreased from 8-16% to 2-3% after 4 weeks of administration. In another patient with hypoplastic leukemia, blast cells in the marrow did not decrease, but anemia was improved without transfusion, increasing the bone marrow NCC and erythroblast count. In patients with overt leukemia and CMML, no clinical effect was obtained. Interferons can therefore be offered to patients in a preleukemic state.