Late intensification with POMP chemotherapy prolongs survival in acute myelogenous leukemia--results of a Southwest Oncology Group study of rubidazone versus adriamycin for remission induction, prophylactic intrathecal therapy, late intensification, and levamisole maintenance.

Between August 1978 and September 1982, 642 patients with newly diagnosed acute myelogenous leukemia (AML) were entered onto a Southwest Oncology Group Study which addressed four questions. (i) What is the comparative utility of rubidazone versus adriamycin in remission induction? (ii) What is the role of prophylactic intrathecal therapy in AML? (iii) Does late intensification affect treatment outcome? (iv) Does maintenance with levamisole affect disease-free survival or overall survival? Among 611 evaluable patients, 329 (54%) achieved complete remission. There was no difference in the remission rate between those patients receiving rubidazone (54%) and those receiving adriamycin (54%) as part of the induction regimen. Prophylactic intrathecal therapy with cytosine arabinoside had no effect on the incidence of central nervous system disease or survival. After nine months of complete remission, patients were randomized between late intensification with POMP (mercaptopurine + vincristine + methotrexate + prednisone) or continued maintenance with OAP (vincristine + cytosine arabinoside + prednisone). T patients randomized to late intensification had better survival and disease-free survival, compared to those randomized to receive no late intensification (p = 0.027 and 0.030, respectively). At twelve months of remission, surviving patients were randomized to receive levamisole or no further treatment. There was no evidence that levamisole affected survival or disease-free survival.