A Master Protocol to Evaluate DCC-3009 in Gastrointestinal Stromal Tumor (GIST)

Inclusion Criteria: Module A Part 1 (Escalation): * Any participant with histologically or cytologically confirmed advanced/unresectable or metastatic GIST with documented KIT or platelet-derived growth factor receptor alpha (PDGFRA) mutation, who has progressed on or was intolerant to at least 1 approved tyrosine kinase inhibitor (TKI) regimen in the advanced/metastatic setting * Have at least 1 measurable lesion as defined by mRECIST, v1.1 * Have Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of 0 or 1 * Adequate organ function, bone marrow function, and electrolytes * All participants agree to comply with the contraception requirements * Have a life expectancy of more than 3 months Exclusion Criteria: * Received systemic anticancer therapy or radiotherapy within 14 days prior to first dose of study drug * Prior or concurrent malignancy that requires treatment or is expected to require treatment for active cancer * Has known active central nervous system (CNS) metastases or an active primary CNS cancer * History or presence of clinically relevant cardiovascular abnormalities * Major surgery within 28 days of the first dose of study drug * Had systemic arterial thrombotic or embolic events within 6 months prior to the first dose of study drug * Had venous thrombotic events (e.g., deep vein thrombosis) or venous thrombotic embolic events (e.g., pulmonary embolism) within 1 month prior to the first dose of study drug * Known allergy or hypersensitivity to any component of the study drug * Malabsorption syndrome or other illness that could affect oral absorption * Any other clinically significant comorbidities