Rubidazone in adults with previously treated acute leukemia and blast cell phase of chronic myelocytic leukemia: a Southwest Oncology Group Study.

Rubidazone, a new anthracycline antibiotic, is the benzoyl hydrazone derivative of daunorubicin. The Southwest Oncology Group carried out a phase II study of the drug in 126 patients with previously treated acute leukemia; 116 patients were evaluable. Good-risk patients were given doses of 450 mg/m2, and poor-risk patients were given doses of 300 mg/m2 approximately every 3 weeks. No complete response was observed in 25 patients with chronic myelocytic leukemia blast cell transformation. In the remaining patients the overall complete response rate was 22% and the rate of complete plus partial response was 29%. In good-risk patients these rates were 27% and 35%, respectively. Toxicity was similar to that observed with other anthracyclines except that acute febrile reactions were more pronounced. On the basis of the results, there are plans for a large-scale comparison study of rubidazone versus doxorubicin, each in combination with cytarabine, vincristine, and prednisone.