This is a phase 3, randomized, double-blind study of adjuvant MK-1084 plus subcutaneous pembrolizumab and berahyaluronidase alfa (MK-3475A) versus adjuvant placebo plus MK-3475a in participants with completely resected stage IIA-IIIB (N2), KRAS G12C-mutant non-small cell lung cancer following receipt of either neoadjuvant pembrolizumab plus chemotherapy or adjuvant chemotherapy. The primary goal of the study is to compare adjuvant MK-1084 plus MK-3475A to adjuvant placebo plus MK-3475A with respect to disease-free survival (DFS) as assessed by the investigator.