Dose Escalation and Dose Expansion Study of RMC-6291 Monotherapy in Subjects With Advanced KRASG12C Mutant Solid Tumors

Inclusion Criteria: * Subject must be ≥18 years of age. * Subject must have pathologically documented, locally advanced or metastatic KRASG12C-mutated solid tumor malignancy (not amenable to curative surgery) that has previously been treated with standard-of-care therapies for respective tumor types, is intolerant to, or is considered ineligible for standard-of-care anticancer treatments. * ECOG performance status 0 or 1 * Prior treatment with a KRASG12C (OFF) inhibitor allowed for dose escalation and for NSCLC in dose expansion * Adequate organ function Exclusion Criteria: * Primary central nervous system (CNS) tumors * Active brain metastases * Known impairment of GI function that would alter the absorption * Major surgical procedures within 28 days or non-study-related minor procedures within 7 days of treatment. * Prior therapy with KRASG12C (ON) inhibitor Other inclusion/exclusion criteria may apply.