TAS-102 Active Not Recruiting Phase 2 Trials for Refractory Bile Duct Carcinoma / Stage IIIB Intrahepatic Bile Duct Cancer AJCC v8 / Advanced Gallbladder Carcinoma / Stage IIIB Gallbladder Cancer AJCC v8 / Stage IIIA Intrahepatic Bile Duct Cancer AJCC v8 / Stage IIIA Gallbladder Cancer AJCC v8 / Stage IIIB Distal Bile Duct Cancer AJCC v8 / Stage IVB Gallbladder Cancer AJCC v8 / Stage IIIA Distal Bile Duct Cancer AJCC v8 / Advanced Bile Duct Carcinoma / Stage IV Gallbladder Cancer AJCC v8 / Stage IVA Gallbladder Cancer AJCC v8 / Stage III Intrahepatic Bile Duct Cancer AJCC v8 / Stage III Distal Bile Duct Cancer AJCC v8 / Stage IV Intrahepatic Bile Duct Cancer AJCC v8 / Refractory Gallbladder Carcinoma / Stage IV Distal Bile Duct Cancer AJCC v8 / Stage III Gallbladder Cancer AJCC v8 Treatment