Study on the Safety and Effectiveness of IDX-1197 with XELOX or Irinotecan for Advanced Stomach Cancer

Inclusion Criteria

• Group 1: Patients who have not received any treatment for their recurrent or advanced stomach cancer, including cancer at the gastroesophageal junction or upper stomach.
• Group 2: Patients with recurrent or advanced stomach cancer, including cancer at the gastroesophageal junction or upper stomach, who have already received at least two rounds of chemotherapy.
• Must have at least one tumor that can be evaluated or measured by scans.
• Must be in good overall health with a performance status score of 0 or 1, meaning fully active or restricted in physically strenuous activity but ambulatory.
• For Group 2 Part C: Must have a specific genetic test (UGT1A1 genotype) done during or before the screening process.

Exclusion Criteria

• Have symptoms or uncontrolled cancer spread to the brain.
• Have cancer in the brain's protective layers or a history of it.
• For Group 1: Patients who are HER 2 positive.
• Have any other serious or uncontrolled illness, such as active infections needing IV antibiotics, uncontrolled diabetes, or severe liver, kidney, or lung disease.
• Have had recent severe heart problems, such as heart attack, heart failure, or significant heart rhythm issues within the last 6 months.
• Have uncontrolled high blood pressure.
• Have a weakened immune system, such as from HIV.
• Have active Hepatitis B or C.
• Have active or symptomatic lung inflammation or a history of lung inflammation needing steroids.
• Have a blood disorder like myelodysplastic syndrome or acute myeloid leukemia.
• Have unresolved significant side effects from previous treatments.
• Have a heart rhythm issue called long QT syndrome or a family history of it.
• Are currently using certain medications that affect liver enzymes or the UGT1A1 enzyme.