An Open-label, Phase 2trial of Sotorasib in KRAS G12C-mutant Non-small-cell Lung Cancer(NSCLC) Patients and a Translational Study to Find Acquired Resistance Mechanism to Sotorasib

Lung cancer is the most common type of cancer occurring in both males and females worldwide (WHO statistics, 2018), and the 5-year survival rate for advanced NSCLC is low (between 6% and 33%, depending on the stage. The rat sarcoma (RAS) proto-oncogene has been identified as an oncogenic driver of tumorigenesis in several cancers, including NSCLC. The RAS proteins can be mutationally activated at codons 12, 13, or 61, leading to human cancers. Different tumor types are associated with mutations in certain isoforms of RAS, with Kirsten rat sarcoma viral oncogene homolog (KRAS) being the most frequently mutated isoform in most cancers. While the role of KRAS mutations in human cancers has been known for decades, no anti-cancer therapies specifically targeting KRAS mutations have been successfully developed, largely because the protein has been intractable for inhibition by small molecules. AMG 510 is a small molecule that specifically and irreversibly inhibits the KRAS G12C mutated protein. Nonclinical studies of AMG 510 have demonstrated inhibition of growth and regression of cells and tumors harboring KRAS p.G12C, and in clinical Study 20170543, AMG 510 demonstrated antitumor activity in KRAS p.G12C mutated NSCLC. These data suggest that inhibition of KRAS G12C may have therapeutic benefit for subjects with KRAS p.G12C driven cancers. Recently development of liquid biopsy technology has enabled detection of KRAS-driven cancer with plasma ctDNA analysis. Therefore, in this study, we aim to conduct a phase 2 trial of sotorasib in KRAS G12C mutant-patients, and conduct pre-treatment and post-treatment biopsies using tissue and liquid to identify novel mechanisms of acquired resistance to sotorasib in these patients. Total sample size is 37 patients, Sotorasib will be given 960mg daily until disease progression or unacceptable toxicity.