A comparative clinical trial of 5-azacytidine and guanazole in previously treated adults with acute nonlymphocytic leukemia.

Adults with previously treated acute nonlymphocytic leukemia received either 5-azacytidine or guanazole in a randomized study. Eighteen patients were treated with 5-azacytidine at a dosage of 200-250 mg/m2/day X 5 intravenously (i.v.) and six achieved a remission (five complete). The median duration of complete remission was 100 days. Among the 12 patients who received guanazole, at a dosage of 25-30 g/m2/day X 5 by continuous i.v. infusion, only one partial remission ensued. Pm 600 WBC/mm3) than nonresponders (median 1700 WBC/mm3). Both the time taken to reach the nadir white blood coung (median, 14 days) and theduration of the nadir (median, 17 days) were long after each course of 5-azacytidine, particularly for those patients who achieved a remission. Principal toxicities seen after 5-azacytidine administration were gastrointestinal tolerance, fever, and neuromuscular toxicity. Fever was the principal toxicity observed after guanazole therapy; one patient developed erythema nodosum with arthralgias and another, recurrent pulmonary infiltrates. Survival from the start of therapy was clearly longer for the patients receiving 5-azacytidine (median 140 days) because of the prolongation of survival seen in the responding patients (median 266 + days). 5-Azacytidine has significant activity as an induction agent in adults with acute nonlymphocytic leukemia, but guanazole does not appear to be of particular value for patients with this disease.