Phase 3 Study Comparing CGT9486 and Sunitinib to Sunitinib Alone in Patients with Gastrointestinal Stromal Tumors

Inclusion Criteria

• Have a confirmed diagnosis of advanced, metastatic, or inoperable gastrointestinal stromal tumor (GIST).
• Have a report on the genetic makeup of the tumor; if not available, a new or stored tumor sample may be needed.
• Have shown disease progression or intolerance to the drug imatinib.
• Have received previous treatments as follows:
  • For Part 1a: At least one prior treatment for GIST.
  • For Part 1b: At least two prior treatments with tyrosine kinase inhibitors (TKIs) for GISTs.
  • For Part 2: Only prior treatment with imatinib.
• Have at least one tumor that can be measured by scans.
• Be in good general health with an ECOG performance status of 0 to 2.
• Have acceptable results from blood tests and other lab screenings.

Exclusion Criteria

• Have specific genetic mutations known as PDGFR or succinate dehydrogenase deficiency.
• Have significant heart disease.
• Have had major surgery within 4 weeks before starting the study treatment.
• Have gastrointestinal issues that affect drug absorption, such as severe nausea, vomiting, or bowel surgery.
• Have any active bleeding, except minor bleeding like from hemorrhoids or gums.
• Test positive for HIV, hepatitis B, or hepatitis C.
• Have active, uncontrolled infections.
• Have taken strong medications that affect liver enzymes (CYP3A4) recently.
• Have taken Sunitinib within the last 3 weeks (for Part 1a and Part 1b).