A Study Evaluating the Safety, Activity, and Pharmacokinetics of Divarasib as a Single Agent or in Combination With Other Anti-Cancer Therapies in Participants With Previously Untreated Advanced or Metastatic Non-Small Cell Lung Cancer With a KRAS G12C Mutation

Inclusion Criteria:

• Confirmation of Biomarker eligibility

• Pre-treatment tumor tissue along with an associated pathology report is required forall participants enrolled on study. Representative tumor specimens must be informalin-fixed, paraffin embedded (FFPE) blocks (preferred) or 15 unstained, freshlycut, serial slides. Although 15 slides are required, if only 10 slides areavailable, the participant may be eligible for the study following consultation withthe Sponsor.

• Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1

• Histologically or cytologically documented locally advanced unresectable ormetastatic NSCLC that is not eligible for curative surgery and/or definitivechemoradiotherapy

• No prior systemic treatment for advanced unresectable or metastatic NSCLC

• Measurable disease, as defined by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Additionally, for participants in cohort D, measurable brainmetastases defined as at least 5 millimeters and twice the slice thickness, but lessthan 20 mm, that is asymptomatic and does not require local therapy at the time ofenrollment.

Exclusion Criteria:

• Known concomitant second oncogenic driver with available targeted treatment

• Squamous cell histology NSCLC

• Symptomatic, untreated, or actively progressing CNS metastases (Cohorts A, B, and C)

• Prior treatment with a KRAS G12C inhibitor

• Known hypersensitivity to any of the components of divarasib or pembrolizumab; orknown hypersensitivity to pemetrexed, carboplatin, or cisplatin (Cohort B only)

• History of idiopathic pulmonary fibrosis, organizing pneumonia (e.g., bronchiolitisobliterans), drug-induced pneumonitis, or idiopathic pneumonitis, or evidence ofactive pneumonitis, active tuberculosis, significant cardiovascular disease within 3months prior to initiation of study treatment

• History of malignancy other than NSCLC within 5 years prior to initiation of studytreatment, with the exception of malignancies with a negligible risk of metastasisor death (e.g., 5-year OS rate more >90%), such as adequately treated carcinoma insitu of the cervix, non-melanoma skin carcinoma, localized prostate cancer, ductalbreast carcinoma in situ, or Stage I uterine cancer

• Uncontrolled tumor related pain, pleural effusion, pericardial effusion, or ascitesrequiring recurrent drainage procedures, uncontrolled or symptomatic hypercalcemia

• Co-morbid condition that is an absolute contraindication to treatment withcorticosteroids

• Inability or unwillingness to take prophylactic treatments such as corticosteroids,anti-emetics, folic acid, or vitamin B12 supplementation.

• Participants with brain metastases for whom complete surgical resections isclinically appropriate