A Randomized Comparison of Doxorubicin and Doxorubicin-DNA in the Treatment of Acute NonLymphoblastic Leukemia

In the light of previous findings that treatment of leukemia patients with DNA-linked doxorubicin gave higher doxorubicin concentrations in leukemic cells than treatment with doxorubicin alone, the Leukemia Group of Middle Sweden performed a randomized clinical trial to compare the effects of doxorubicin and doxorubicin-DNA in patients with acute non-lymphoblastic leukemia. One hundred and twenty consecutive patients within the age range 15 to 60 years were randomized to one of three treatment groups. In two of these, remission induction treatment was performed with prednisolone, vincristine, ara-C and thioguanine combined with either doxorubicin or doxorubicin-DNA. Patients entering a complete remission received intensive consolidation during 16 months with 4 courses each of doxorubicin (+/ - DNA)/ara-C, doxorubicin (+/ - DNA)/azacytidine, ara-C and amsacrine. The third treatment group followed a protocol from a previous study with daunorubicin and ara-C for induction therapy and a less intensive maintenance therapy. No further patients were assigned to this "control" group after 3 years or to the two other groups after 6 years. This report is based on a follow-up 31 months thereafter. The overall rate of complete remission was 67% and the mean time to complete remission was 71 days, with no differences between the treatment groups. Patients treated with the doxorubicin-DNA conjugate had a significantly longer survival [median for all patients 27.2 months (p < 0.01) and for patients in CR 47.0 months (p < 0.025)] and longer duration of first remission (median 23.6 months, p < 0.025) than the other groups. There were significantly fewer reports of cardiotoxicity (p < 0.05) and severe intestinal toxicity (p < 0.02) in patients treated with the doxorubicin-DNA conjugate and there was a tendency towards less hepatic (p < 0.08) and renal toxicity (p < 0.08). The frequency of myelosuppression, fever and infectious complications was similar in all three groups. Complex binding to DNA appears to increase the therapeutic effects and reduce some toxic effects of doxorubicin in patients with ANLL.