A Study to Learn About Study Medicine ALTA3263 in Adults With Advanced Solid Tumors With KRAS Mutations

This is an open-label, multicenter, Phase 1/1b study of ALTA3263, an orally bioavailable KRAS isoform-selective inhibitor that inhibits multiple mutant forms of KRAS, in adults with advanced solid tumor malignancies with KRAS mutations. This study will evaluate the safety, tolerability, pharmacokinetics (PK), and preliminary clinical activity of ALTA3263 as a monotherapy and as a combination regimen. The study consists of two parts: Part 1 - Dose Escalation and Part 1b - Dose Expansion.