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

Key Inclusion Criteria:

Module A:

* 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

Module A Part 1 (Escalation) and Part 3 (FE and DDI):

-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

Module A Part 2 (Expansion):

-Any participant with histologically or cytologically confirmed advanced or metastatic GIST with documented KIT or PDGFRA mutation

Module A Part 3 (FE and DDI):

-Able to consume a high-fat meal

Key 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

Module A Part 3 (FE and DDI):

* Allergy or hypersensitivity to rabeprazole or any of its excipients
* Unable or unwilling to adhere to overnight fasting of 10 hours

Other protocol-specified inclusion and exclusion criteria apply.