Inclusion Criteria:  Histologically confirmed diagnosis of a solid tumor malignancy with KRAS G12C mutation Unresectable or metastatic disease. No available treatment with curative intent Adequate organ function  Exclusion Criteria:  History of significant toxicity on prior KRAS G12C or CDK4/6 inhibitor therapies History of intestinal disease, inflammatory bowel disease, major gastric surgery, or other gastrointestinal conditions likely to alter the absorption of study treatment or result in an inability to swallow Other active cancer Cardiac abnormalities