A Pharmacogenomics Study of TAS-102

Intervention name : TAS-102 Dosage And administration of the intervention : 35 mg/m2/dose, orally, twice daily on days 1-5 and 8-12 of each 28-day cycle. Number of cycles: until at least one of the discontinuation criteria are met. Control intervention name : Placebo Dosage And administration of the control intervention : Placebo tablets, orally, twice daily on days 1-5 and 8-12 of each 28-day cycle. Number of cycles: until at least one of the discontinuation criteria are met. Primary outcome(s): Correlation between the relative factor and disease control rate, overall survival, or progression-free survival RECIST (ver.1.1) Study Design: Multinational, double-blind, two-arm, parallel, randomized Phase 3 comparison study