Hematologic Remission and Cytogenetic Improvement Induced by Recombinant Human Interferon Alpha_A in Chronic Myelogenous Leukemia

We treated 17 patients who had Philadelphia-Chromosome-Positive chronic myelogenous leukemia (4 of whom had not received therapy and 13 of whom had been treated with hydroxyurea or busulfan for less than six months) with recombinant human interferon alpha-A (Roferon-A). The interferon was given as 5x10⁶ units per square meter of body-surface area per day intramuscularly during induction therapy. Fourteen patients responded to the treatment, of whom 13 had a hematologic remission and 1 had a partial hematologic remission. The median number of white cells in those patients declined from 60.9x10³to 3.4x10³ per microliter, and the median number of platelets decreased from 476 x10³ to 231 x10³ per microliter. Among the five responding patients who had splenomegaly before treatment, the spleen size returned to normal in four and decreased by 75 percent in one, although it remained enlarged. Bone marrow cellularity declined from a median of 92.5 percent to a median of 57.5 percent. In six of the patients with hematologic remission, complete suppression of Philadelphia cells was observed on at least one examination. Of the 14 patients who responded, 11 have received the interferon therapy for 9 to 15 months. One patient relapsed during the treatment, and the treatment has been temporarily interrupted in two patients because of toxicity. These data are preliminary and will need further confirmation, but they suggest that recombinant human interferon alpha_A is effective in inducing hematologic remission in most patients with benign-phase chronic myelogenous leukemia and in suppressing the Philadelphia chromosome in some of these patients. (N Engl J Med 1986; 314:1065–9.), CHRONIC myelogenous leukemia in patients with the Philadelphia (Ph) chromosome has a typical progressive clinical course that starts with a benign phase and ends in a blastic phase. The benign phase of the disease is easily controlled by single-agent chemotherapy with such agents as busulfan and hydroxyurea. However, these agents do not alter the progressive course of the disease.¹ The introduction of aggressive combination chemotherapy has resulted in reproducible suppression of Ph cells in the bone marrow of patients with chronic myelogenous leukemia, but the effect was invariably transient.^{2 3 4} Only the use of supralethal chemotherapy and allogeneic bone marrow transplantation…