A Study of the Pan-KRAS Inhibitor LY4066434 in Participants With KRAS Mutant Solid Tumors

Inclusion Criteria: * Have evidence of KRAS G12C, G12D, G12V, G12A, G12S, or G13D mutation in tumor tissue or circulating tumor DNA * Histological or cytologically proven diagnosis of a locally advanced, unresectable, and/or metastatic solid tumor cancer * Have measurable disease per RECIST 1.1 * Have an ECOG performance status of ≤1 * Must not be pregnant and/or planning to breastfeed during the trial or within 180 days of the last dose of trial intervention * Must be able to swallow tablets * Participants with asymptomatic or treated CNS disease may be eligible Exclusion Criteria: * Have known active CNS metastases and/or carcinomatous meningitis * Have any unresolved toxicities from prior therapy greater than NCI CTCAE Version 5.0 Grade 1 at the time of starting trial treatment, except for alopecia, hearing loss, peripheral neuropathy and ongoing endocrinopathies controlled on appropriate replacement therapy * Have significant cardiovascular disease defined as unstable angina or acute coronary syndrome, history of myocardial infarction, known left ventricular ejection fraction or heart failure, uncontrolled or symptomatic arrhythmias. * Have known active hepatitis B virus (HBV), hepatitis C virus (HCV) or untreated HIV infection * Have other active malignancy unless in remission with life expectancy greater than 2 years. * Have active uncontrolled systemic bacterial, viral, fungal, or parasitic infection * Have history of non-infectious pneumonitis/interstitial lung disease that received steroids or has current clinically significant pneumonitis/interstitial lung disease