Navigating CYP1A Induction and Arylhydrocarbon Receptor Agonism in Drug Discovery. A Case History with S1P(1) Agonists

摘要

This article describes the finding of substantial upregulation of mRNA and enzymes of the cytochrome P450 1A family during a lead optimization campaign for small molecule S1P(1). agonists. Fold changes in mRNA up to 10 000-fold for CYP1A1 in vivo in rat and cynomolgus monkey and up to 45-fold for GYP1A1 and GYP1A2 in vitro in rat and human hepatocytes were observed. Challenges observed with correlating induction in vitro and induction in vivo resulted in the implementation of a short, 4 day in vivo screening study in the rat which successfully identified noninducers. Subtle structure-activity relationships in this series of S1P(1) agonists are described extending beyond planarity and lipophilicity, and the impact and considerations of AhR and CYPIA induction in the context of drug development are discussed.