Monitoring liver safety in drug development: The GSK experience

To promptly identify and evaluate liver safety events, an evidence-based liver safety system was created for global Phase I–III clinical trials. The goals of this system included improving clinical trial subject safety, expanding information on liver safety events, and improving data quality across studies by establishing and communicating: • Liver chemistry subject stopping criteria. • Hepatitis B and C screening and exclusion criteria. • Close monitoring and follow-up of subjects to determine the etiology of the liver event. Two different algorithms for liver stopping criteria were developed. The most stringent criteria were selected for healthy volunteers in Phase I studies, where no treatment benefit is anticipated and clinical safety data are limited. With an interest in assessing potential liver “tolerance” or adaptation with accruing safety information, slightly higher liver chemistry thresholds were set for Phase II–III studies. This paper will describe the importance of liver safety in drug development, laboratory tests used to monitor liver safety, the rationale for selected liver chemistry subject stopping criteria, and implementation of this safety system.