Cytotoxic effect of dose and schedule on normal murine hematopoietic progenitor cells following the administration of 4'-deoxydoxorubicin.

In an experimental setting, 4'-deoxydoxorubicin (4'-deoxy-DX) shows minimal cardiotoxicity as well as the marked antitumoral activity shown by doxorubicin, its parent compound. In this experimental study, the haematologic toxicity of the new anthracycline was investigated by haematopoietic precursor cell (HPC) assays using in vivo (colony-forming units - spleen, CFUs) and in vitro (CFUc-culture) methods with (C57B1 X C3H)F1 mice. Dose-survival curves and time response of HPC in situ following 4'-deoxy-DX administration were determined. In the time-related experiments, the effects of a single dose, an intermittent treatment (Days 0, 2, and 5) and a prolonged biweekly administration were studied. All dose-survival curves were exponential, with statistically significant differences between the effects on the various cell classes. CFUc appeared more sensitive than CFUs. In time-related experiments, 4'-deoxy-DX toxicity for HPC seemed to be relatively mild. However, CFUc sensitivity was again high in comparison with other populations assayed. In long-term administration, the 4-deoxy-DX effects on the haematopoietic system were also rather slight.