Prediction of in vivo cytotoxicity of chemotherapeutic agents by their effect on malignant leukocytes in vitro.

A DRUG for the treatment of a patient with leukemia, the physician makes a choice based on a statistical analysis of the response of a large group of patients to the agent under consideration. Treatment is often initiated with the knowledge that a significant percentage of patients will not be benefited by the chosen compound. The ability to predict which drug will not be effective or, even better, which dnig will be effective in the treatment of a particular patiesit would be highly desirable. Previous attempts to select chemotherapeutic agents bydetermining their effects in vitro on some parameter of cell metabolism have been unsuccessful either because tile test systems were not sufficiently reliable in predicting clinical effects or were too cumbersome for routine use.’’ This report describes a test metilod for predicting the in vivo cytotoxicity of chemotherapeutic agents based on their effect on the iiicorporation of H’� uridine iiltO the rii)onucleic acid ( RNA ) of neoplastic cells in tissue culture. In