Study of RMC-6291 in Combination with RMC-6236 in Participants with Advanced KRAS G12C Mutant Solid Tumors

Inclusion Criteria:

• 18 years of age

• Histology: pathologically documented, KRAS G12C-mutated, advanced or metastaticsolid tumors not amendable to curative therapy

1. Part 1. Dose Escalation: solid tumors, previously treated

2. Part 2. Dose Expansion: i. NSCLC, previously treated with immunotherapy, chemotherapy, and KRAS G12C (OFF)inhibitors, ii. NSCLC, previously treated with immunotherapy and chemotherapy, naïveto KRAS G12C (OFF) inhibitors, iii. NSCLC, previously treated with immunotherapy,chemotherapy, with untreated, asymptomatic central nervous system (CNS) metastases <2 cm in size iv. Solid tumors, previously treated, naïve to KRAS G12C (OFF)inhibitors.

• ECOG performance status 0 or 1

• 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 procedureswithin 7 days of treatment