Transaminase elevation on placebo during Phase I trials: prevalence and significance

Aims To evaluate the prevalence of transaminase elevation on placebo during Phase I trials. Methods Retrospective review of pooled transaminase data collected on place bo during 13 Phase I trials in 93 healthy volunteers hospitalized for 14 da ys, with determination of the prevalence of abnormally high values. Results 20.4% of the 93 subjects showed at least one ALT value above the up per limit of the normal range (ULN), and 7.5% had at lease one value twice ULN. Conclusions Laboratory safety results of Phase I trials should be interpret ed with caution, in the light of data on placebo, to avoid premature discon tinuation of the development of safe drugs wrongly believed to be hepatotox ic.