Sensitivity of normal human bone marrow myeloid progenitor cells to anthracycline, cisplatin, anthracene and flavone acetic acid derivatives, and its relevance for the prediction of human plasma concentrations of anticancer drugs.
Many in vitro investigations with anticancer agents are performed at concentrations equal to the peak concentrations or fractions of the peak concentrations achieved in human plasma after administration of these agents. In an effort to develop an in vitro test capable of predicting these peak plasma concentrations prior to the completion of pharmacokinetic studies, the effect of several classes of anticancer agents against normal human bone marrow myeloid progenitor cells (CFU-GM) was studied. The investigated agents included anthracycline antibiotics, cisplatin and its analogs, anthracene derivatives and two flavone acetic acid derivatives. The CFU-GM were exposed to these agents for 30-60 min. An exponential relationship between drug concentration and CFU-GM growth was observed for all compounds with the exception of the flavone acetic acid derivatives which were inactive. For the latter two compounds, an inhibition of CFU-GM growth was observed after continuous exposure. When compared to the plasma concentrations after parenteral administration of these agents, there was a very good agreement between 1/10 of the peak plasma concentration and the concentration inducing a 90% inhibition of the CFU-GM growth for the anthracycline antibiotics and anthracene derivatives. In contrast, for cisplatin and its analogs, there was a better agreement between 1/10 of the peak plasma concentration and the concentration inducing a 10% inhibition of CFU-GM growth. The combination of concentrations inducing inhibitions of 10 and 90% of the CFU-GM growth provides a range of concentrations that predict reasonably well the peak plasma concentrations of several anticancer agents and that could be used as guides for other in vitro investigations.