• Histologically or cytologically confirmed NSCLC with Stage IIIB-IIIC or Stage IV disease, not suitable for curative intent radical surgery or radiation therapy.

• Part B and Safety Lead-In Part B: the histology of the tumor must be predominantly non-squamous (in line with pemetrexed label).

• Must have disease with evidence of KRAS G12C mutation.

• Must have known programmed death-ligand 1 (PD-L1) expression

‣ Part A: Greater than or equal to (≥)50 percent (%).

⁃ Part B: 0% to 100%.

• Must have measurable disease per RECIST v1.1.

• Must have an ECOG performance status of 0 or 1.

• Estimated life expectancy ≥12 weeks.

• Ability to swallow capsules.

• Must have adequate laboratory parameters.

• Contraceptive use should be consistent with local regulations for those participating in clinical studies.

• Women of childbearing potential must

‣ Have a negative pregnancy test.

⁃ Not be breastfeeding during treatment