Narrative review: mesenchymal-epithelial transition inhibitors-meeting their target.

Genetic alterations in mesenchymal-epithelial transition (MET) are commonly found in solid tumors, especially in non-small cell lung cancer (NSCLC). However, agents targeting MET have not progressed until recently. Advancements in our understanding of the role of various aberrations in carcinogenesis have allowed MET-directed therapy to find its way to clinic use. Of all alterations, exon 14 skipping ( skip or ), stands out as a true oncogenic driver. Recently, MET tyrosine kinase inhibitors (TKI) targeting skipping were able to demonstrate significant improvement in clinical outcomes including response rate and progression free survival. Of these, capmatinib was granted accelerated approval by the FDA in May 2020 for patients with advanced NSCLC harboring skip alterations. Tepotinib, another TKI, has shown significant activity in a phase II trial and received breakthrough therapy designation from the FDA in September 2019. amplification ( ) and overexpression are usually a late phenomenon in tumorigenesis and aggravate malignant properties of transformed cells. Capmatinib and savolitinib have shown activity in patients with NSCLC with high levels of . Several other agents are being developed and under evaluation in clinical trials involving multiple tumor types. In addition to TKIs, MET overexpression is also an appealing target for development of antibody conjugated chemotherapy. Understanding the mechanisms of resistance to MET TKIs and alterations in anti-tumor immunity through MET inhibition are clinically relevant areas that need further exploration.