INTERFERON ALFA-2A AS COMPARED WITH CONVENTIONAL CHEMOTHERAPY FOR THE TREATMENT OF CHRONIC MYELOID LEUKEMIA

Background. In view of studies showing that interferon alfa was effective treatment for chronic myeloid leukemia and that it prolonged survival, we organized a prospective, controlled comparative study of this treatment. Methods. We compared recombinant interferon alfa-2a with conventional chemotherapy (hydroxyurea or busulfan) in a trial designed to have a power of 80 percent to detect a difference of 20 percent in median survival between the group given interferon and the group given conventional chemotherapy. Between 1986 and 1988, 322 patients with previously untreated or minimally treated Philadelphia chromosome-positive chronic myeloid leukemia were randomly assigned to treatment with either interferon alfa-2a (218 patients) or conventional chemotherapy (104 patients). Results. The rate of karyotypic response (defined as >33 percent of metaphases negative for the Philadelphia chromosome) was 30 percent in the interferon groupand 5 percent in the conventional-chemotherapy group (P72 vs. 45 months; P