Absence of cross-toxicity between MET inhibitors in a non-small-cell lung cancer with a MET exon 14 skipping mutation.

Introduction: Selective tyrosine kinase inhibitors are proven effective in patients with non-small lung cancer (NSCLC) with a MET exon 14 skipping mutation.

Case presentation: The patient developed a metastatic lung adenocarcinoma with a MET exon 14 skipping mutation. She was treated with a first 1b MET inhibitor, Capmatinib, but had to stop the drug because of major hepatotoxicity. A few months later, she started Tepotinib, another 1b MET inhibitor with this time, no sign of hepatotoxicity.

Discussion: Adverse events are frequent with 1b MET inhibitors. However, there is a wide interpatient variability. Absence of cross-toxicity between Capmatinib and Tepotinib is misunderstood but can be explained by slight differences in phamarcodynamics and pharmacokinetics. Practitionners have to be warned about severe adverse events to stop or change the drug if necessary.

Conclusion: This is the first case showing the absence of cross-toxicity between 1b MET inhibitors.