Identifying Metabolic Pathways of c‐MET Tyrosine Kinase Inhibitor Tepotinib in Human and Mouse Liver Microsomes

Abstract

Tepotinib (TPB) is a highly selective and potent c‐Met inhibitor that has shown promising activity in a phase I trial for non‐small cell lung cancer (NSCLC). Recent studies indicate that TPB can overcome resistance to epidermal growth factor receptor inhibitors driven by aberrant MET activation, and the Food and Drug Administration has granted a breakthrough therapy designation for tepotinib in patients with metastatic NSCLC harboring METex14 skipping alterations who have progressed on prior platinum‐based chemotherapy. The metabolism of TPB remains largely unknown, but is likely to play a critical role in both safety and efficacy: understanding the metabolism of TPB could improve safety and predict possible adverse effects and drug‐drug interactions. In the current study, we investigated the metabolism and bioactivation of TPB in human and mouse liver microsomes (HLM and MLM) using LC‐MS‐based metabolomic approaches. We identified over 20 TPB metabolites and adducts in liver microsomes. Monohydroxyl‐TPB (O+TPB) is the dominant metabolite in both HLM and MLM, and demethyl‐TPB is secondary to O+TPB. Using methoxyamine as a trapping agent, we infer that two aldehydes are generated in HLM; one of these was also observed in MLM. No adducts were observed in liver microsomes incubated with TPB in the presence of trapping agents glutathione or potassium cyanide. Using recombinant CYP450 isoenzymes, we showed that CYP3A4 and CYP3A5 are the primary contributors to the formation of both monohydroxyl‐TPB and the methoxyamine‐trapped TPB aldehydes. This study offers a comprehensive view of TPB metabolism and identifies metabolites that will be helpful to evaluate adverse effects of TPB and possible drug‐drug interactions in TPB‐treated hepatocytes and model organisms.Support or Funding InformationThis work was supported by Cancer Prevention & Research Institute of Texas (RP160805), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (P01 HD087157‐01A1), Welch Foundation Grant (H‐Q‐0042), and Bill and Melinda Gates Foundation (INV‐001902) to Dr. Martin M. Matzuk and the National Institute of Diabetes and Digestive and Kidney (R01‐DK121970) to Dr. Feng Li.