KRAS G12C Mutations in NSCLC: From Target to Resistance

SIMPLE SUMMARY: A better understanding of the role of KRAS and its different mutations has led to the development of specific small-molecule inhibitors able to target KRAS G12C, an oncogenic driver mutation in a number of cancers, including non-small cell lung cancer. While these therapies hold great promise, they face the same limitation as other kinase inhibitors, the emergence of resistant mechanisms. The biology behind KRAS G12C inhibitor resistance has been investigated with genome-wide approaches, in the hopes of finding a way to improve the efficacy of these new molecules. Here, we review the biology of KRAS G12C, mechanisms of drug resistance and potential approaches to overcome the later. ABSTRACT: Lung cancer represents the most common form of cancer, accounting for 1.8 million deaths globally in 2020. Over the last decade the treatment for advanced and metastatic non-small cell lung cancer have dramatically improved largely thanks to the emergence of two therapeutic breakthroughs: the discovery of immune checkpoint inhibitors and targeting of oncogenic driver alterations. While these therapies hold great promise, they face the same limitation as other inhibitors: the emergence of resistant mechanisms. One such alteration in non-small cell lung cancer is the Kirsten Rat Sarcoma (KRAS) oncogene. KRAS mutations are the most common oncogenic driver in NSCLC, representing roughly 20–25% of cases. The mutation is almost exclusively detected in adenocarcinoma and is found among smokers 90% of the time. Along with the development of new drugs that have been showing promising activity, resistance mechanisms have begun to be clarified. The aim of this review is to unwrap the biology of KRAS in NSCLC with a specific focus on primary and secondary resistance mechanisms and their possible clinical implications.