The activity and safety of adagrasib, a covalent and highly selective inhibitor of KRAS G12C , have been explored in patients with advanced KRAS G12C -mutant solid tumors in the KRYSTAL-1 trial, with positive results previously reported for non-small cell lung cancer (NSCLC) from the phase I/Ib part of the study. 1,2 In the registrational phase II cohort, patients with unresectable or metastatic KRAS G12C -positive NSCLC, who were previously treated with a programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) inhibitor in combination or in sequence with chemotherapy, received adagrasib at a dose of 600 mg twice daily. 3,4 Of note, patients with treated and stable central nervous system (CNS) metastases were eligible. The primary endpoint was objective response rate (ORR) and secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety.