Inclusion Criteria:  Male or female patients ≥ 18 years of age Histologic or cytologic evidence of NSCLC Known G12C KRAS mutation Have not received a KRAS inhibitor to be included in Part A and Part B, Cohort 1 Received at least 1 dose of a G12C inhibitor to be included in Part A or Part B Cohort 2 Must have received appropriate treatment with at least one prior systemic regimen, but no more than 3 prior regimens, for Stage 3B-C or 4 NSCLC Measurable disease according to RECIST 1.1 An Eastern Cooperative Group (ECOG) performance status ≤ 1 Adequate organ function Adequate recovery from toxicities related to prior treatments Agreement to use highly effective method of contraceptive  Exclusion Criteria:  Systemic anti-cancer therapy within 4 weeks of the first dose of study therapy History of prior malignancy, with the exception of curatively treated malignancies Major surgery within 4 weeks (excluding placement of vascular access) History of treatment with a direct and specific inhibitor of MEK Exposure to strong CYP3A4 inhibitors or inducers within 14 days prior to the first dose and during the course of therapy Symptomatic brain metastases requiring steroids or other local interventions. Known SARS-Cov2 infection ≤28 days prior to first dose of study therapy Known hepatitis B, hepatitis C, or human immunodeficiency virus infection that is active Active skin disorder that has required systemic therapy within the past year History of rhabdomyolysis Concurrent ocular disorders Concurrent heart disease or severe obstructive pulmonary disease Inability to swallow oral medications Female patients that are pregnant or breastfeeding