Cisplatin, an intravenously administered platinum agent, in combination with an intravenously administered taxane and capecitabine has been shown to improve time to disease progression and overall survival in previously untreated patients with gastric cancer.

This study is being performed to evaluate an orally administered taxane (tesetaxel) in combination with cisplatin and capecitabine in previously untreated patients with gastric cancer.

Primary Inclusion Criteria:

• At least 20 years of age
• Histologically or cytologically confirmed gastric carcinoma, including gastric or gastroesophageal-junction adenocarcinoma.
• Measurable disease (revised RECIST) based on computed tomography, or nonmeasurable disease
• Previously untreated, unresectable advanced (M0) or unresectable metastatic (M1) disease except for prior adjuvant (or neo-adjuvant) chemotherapy.
• ECOG performance status 0 or 1
• At least 4 weeks and recovery from effects of prior major surgery
• Adequate bone marrow, hepatic, and renal function

Primary Exclusion Criteria:

• Operable gastric or gastroesophageal-junction cancer
• Known brain metastasis
• Second cancer
• Previous adjuvant or neo-adjuvant chemotherapy with capecitabine and cisplatin in combination. (Previous adjuvant or neo-adjuvant monotherapy with capecitabine or S-1 or therapy with S-1 and cisplatin in combination or 5-FU and cisplatin in combination is allowed.)
• Uncontrolled diarrhea
• Nausea or vomiting for at least 3 consecutive days within the 14 days prior to registration despite the administration of standard antiemetic therapy
• Symptomatic peripheral neuropathy ≥ Grade 2
• Malabsorption syndrome or other disease that significantly affects gastrointestinal function
• Other uncontrolled systemic illness