Sequential therapy for induction and maintenance of remission in acute myeloblastic leukemia.

A total of 114 previously untreated patients with myeloblastic leukemia was included in a sequential therapy protocol. Daunorubicin, vincristine, and prednisone were employed for the first 3 weeks, followed by two or more 5-day courses of cytosine arabinoside and 6-mercaptopurine; there was a 5-day rest between courses. Maintenance therapy was as follows: the continuing 6-mercaptopurine and methotrexate treatment was interrupted every 30 days for sequential reinforcement courses consisting of one dose of daunorubicin and vincristine and 7 days of prednisone, or by a 5-day course of cytosine arabinoside plus 6-mercaptopurine. Of the 114 patients, 48 obtained complete remission, 14 had partial remission, 16 failed to respond, and 36 died during the course of treatment. The remission rate in children (under 16) was 57%; in adults (16-45) 54%; and in those over 45, 19%. The difference in the incidence of complete remission in patients under 45 and those over 45 was statistically significant (p less than 0.01). The median duration of complete remission was 8 months: 12 months in children and 5 months in adults. The over-all survival rate was 4 months: 13 months for patients with complete remission, 4 months for those with partial remission, and 1 month for patients who did not respond to therapy. The difference in survival of those with complete remission and all the others was significant (p less than 0.01).