A narrative review of MET inhibitors in non-small cell lung cancer with MET exon 14 skipping mutations

Treatment of advanced non-small cell lung cancer (NSCLC) has radically improved in the last years due to development and clinical approval of highly effective agents including immune checkpoint inhibitors (ICIs) and oncogene-directed therapies. Molecular profiling of lung cancer samples for activated oncogenes, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1) and BRAF, is routinely performed to select the most appropriate up-front treatment. However, the identification of new therapeutic targets remains a high priority. Recently, MET exon 14 skipping mutations have emerged as novel actionable oncogenic alterations in NSCLC, sensitive to MET inhibition. In this review we discuss: (I) MET gene and MET receptor structure and signaling pathway; (II) MET exon 14 alterations; (III) current data on MET inhibitors, mainly focusing on selective MET tyrosine kinase inhibitors (TKIs), in the treatment of NSCLC with MET exon 14 skipping mutations. We identified the references for this review through a literature search of papers about MET, MET exon 14 skipping mutations, and MET inhibitors, published up to September 2020, by using PubMed, Scopus and Web of Science databases. We also searched on websites of main international cancer congresses (ASCO, ESMO, IASLC) for ongoing studies presented as abstracts. MET exon 14 skipping mutations have been associated with clinical activity of selective MET inhibitors, including capmatinib, that has recently received approval by FDA for clinical use in this subgroup of NSCLC patients. A large number of trials are testing MET inhibitors, also in combinatorial therapeutic strategies, in MET exon 14-altered NSCLC. Results from these trials are eagerly awaited to definitively establish the role and setting for use of these agents in NSCLC patients.