Study of MRTX1133 in Patients With Advanced Solid Tumors Harboring a KRAS G12D Mutation

Inclusion Criteria: * Histologically confirmed diagnosis of a solid tumor malignancy harboring KRAS G12D mutation in tumor tissue or ctDNA. * Unresectable or metastatic disease. * Patients must have received standard therapies appropriate for their tumor type and stage; first-line treatment for PDAC for certain cohorts. * Presence of tumor lesions to be evaluated per RECIST v1.1: 1. in the Phase 1 dose escalation cohorts, patients must have measurable or evaluable disease. 2. in the Phase 1b and Phase 2 cohorts, patients must have measurable disease. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. * Adequate organ function. * Age ≥ 18 years Exclusion Criteria: * Active brain metastases or carcinomatous meningitis. * Prior treatment with a KRAS G12D inhibitor (Phase 1b \& Phase 2 only). * History of significant hemoptysis or hemorrhage within 4 weeks of the first dose of study treatment. * History of intestinal disease, inflammatory bowel disease, major gastric surgery, or other gastrointestinal conditions likely to alter absorption of study treatment or result in inability to swallow oral medications. * History of malignant small bowel obstruction. * Cardiac abnormalities.