Genotoxicity: Predictive Models
Inherent in the problem of extrapolating the findings of whole-animal studies dealing with chronic toxicity to those of human responses are the dual practical issues of time and money. To require a relatively standard set of animal studies designed to evaluate the effects of chronic exposure of a proprietary compound on rodents such as rats requires an enormous investment lasting at least several years and approaching 500,000 to 1 million dollars, depending on the size of the study and the completeness of the pathological and biochemical evaluation. If one opts to test a longer-lived model such as the dog or nonhuman higher primates, the time frame is, of course, extended considerably further. The toxicological assessment of potential products for interstate commerce, therefore, requires a considerable commitment on the part of the industry, with the hope that the substance will not fail the testing scheme. It is quite obvious that a company would not want to have too many “failures,” since they will ultimately make money only on those compounds that pass the toxicological screen.