Capecitabine/Tesetaxel Versus Capecitabine/Placebo as Second-line Therapy for Gastric Cancer

Key inclusion criteria: 1. Histologically or cytologically confirmed gastric adenocarcinoma, including gastric or gastroesophageal-junction adenocarcinoma (Histologically confirmed adenocarcinoma of the lower esophagus acceptable with radiographic or endoscopic documentation of gastroesophageal-junction or proximal-stomach involvement.) 2. Measurable disease (revised RECIST) based on computed tomography, or nonmeasurable disease 3. ECOG performance status 0 or 1 4. Treatment with only 1 prior regimen (as first-line therapy) that must have included a fluoropyrimidine and a platinum-containing agent (Prior adjuvant or neo-adjuvant chemotherapy acceptable provided 6 months elapsed between the end of this therapy and the start of first-line therapy.) 5. Disease progression after the start of the 1 prior regimen based on computed tomography 6. Adequate bone marrow, hepatic, and renal function 7. Ability to swallow an oral solid-dosage form of medication Key exclusion criteria: 1. Squamous cell gastric carcinoma 2. Bone-only metastatic disease 3. History or presence of brain metastasis or leptomeningeal disease 4. Operable gastric or gastroesophageal-junction cancer 5. HER2-positive disease if the patient has not previously been treated with an anti-HER2 agent 6. Uncontrolled diarrhea, nausea, or vomiting 7. Known malabsorptive disorder 8. Significant medical disease other than gastric cancer 9. Presence of neuropathy \> Grade 1 (NCI Common Toxicity Criteria) 10. Prior treatment (including adjuvant therapy) with a taxane or other tubulin-targeted agent (indibulin, eribulin, etc.) 11. Prior radiation therapy to more than 25% of the bone marrow 12. Need to continue any regularly-taken medication that is a potent inhibitor or inducer of the CYP3A pathway 13. Pregnancy or lactation