Influence of idarubicinol on the antileukemic effect of idarubicin.

We investigated the antileukemic potency of idarubicinol (IDAol), a 13-dihydro (13-OH) metabolite of idarubicin (IDA), on the HL60 line of human leukemia cells. In contrast to daunorubicinol (DNRol) and to doxorubicinol (DOXol), IDAol showed an extensive accumulation in HL60 cells. The high affinity for DNA and the strong DNA cleavage activity of IDAol were comparable to values for IDA; consequently, IDAol was strongly cytotoxic against HL60 cells. IDAol may play an important role in the clinical efficacy of IDA in patients with acute leukemia, particularly since it persists in the blood for prolonged periods after the administration of IDA.