Effective treatment of MET exon 14 skipping mutation-positive non-small cell lung cancer using capmatinib following serious maculopapular rash caused by two MET inhibitors: a case report

Background: Multi -gene panel testing and advancements in molecular targeted therapy have improved the overall survival of patients with driver mutation -positive non -small cell lung cancer (NSCLC). Mesenchymal-epithelial transition factor ( MET ) exon 14 skipping mutation -positive NSCLC, which remains untreated with MET inhibitors, shows a poorer prognosis than do cases of NSCLC without MET mutations. However, serious treatment -related adverse events (TRAEs) act as substantial treatment barriers. Case Description: Herein, we report a case of advanced NSCLC in a male in his 40s with MET exon 14 skipping mutation. A MET -inhibitory investigational drug was administered as first -line treatment; the development of grade 3 maculopapular rash necessitated dose reduction, which resulted in disease progression. Tepotinib was then administered with dexamethasone as a third -line treatment but was discontinued owing to the re -development of the grade 3 maculopapular rash. Finally, capmatinib administration as the fifth -line treatment appeared partially effective, with no serious adverse events. The patient could successfully resume work. Conclusions: This is the first report of MET exon 14 skipping mutation -positive NSCLC wherein partial response was achieved without severe TRAEs by alternating between two MET inhibitors. If no alternative treatments are available, cautious repeated re -administration of MET inhibitors after resolving serious rashes can be considered a potential approach.