A Study Evaluating FMC-376 in Participants With KRAS G12C Mutated Solid Tumors

Inclusion Criteria: * Histologically or cytologically confirmed locally advanced unresectable or metastatic solid tumors with KRAS G12C mutation * Received and progressed or been intolerant to prior standard therapy OR standard therapy is considered inappropriate OR an investigational agent is considered standard of care * NSCLC Participants (in the first-line advanced or metastatic setting who refused standard therapy or standard therapy was considered inappropriate) * Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 * Adequate hematological, renal, and hepatic function * Agrees not to participate in another interventional study while receiving study drug * For patients receiving FMC-376 in combination with pembrolizumab: No history of autoimmune disease, and no history of immune-related adverse events or hepatitis Exclusion Criteria: * Leptomeningeal disease or carcinomatous meningitis * Clinically significant toxicity resulting from prior cancer therapies * Known or suspected hypersensitivity to FMC-376 or any components of the study drug * Condition that would interfere with study drug absorption * Any illness or medical history that would impact safety or compliance with study requirements or impact ability to interpret study data * For patients receiving FMC-376 in combination with pembrolizumab: Has severe hypersensitivity (≥ Grade 3) to pembrolizumab, history of radiation-related toxicities, or history of non-infectious pneumonitis.