This is a open-label, phase II, umbrella study enrolling advanced biliary tract cancer patients who have failed to 1st-line chemotherapy. Patients will be enrolled to AZD6738 and Durvalumab combination or AZD6738 and Olaparib combination cohorts. Based on the new emerging therapies, cohorts can be added into existing protocol.~AZD6738 + Durvalumab cohort:~Durvalumab 1500 mg iv on D1~AZD6738 240 mg bid on D15-D28 Every 4 weeks C1D1 dose of durvalumab will be delivered, and AZD6738 of 240 mg bid will be dosed at D15-D28. Every cycle consists of 4 weeks.~AZD6738 + Olaparib cohort:~AZD6738 160 mg qd on D1-D7~Olaparib 300 mg bid on D1-D28 Every 4 weeks Every cycle consists of 4 weeks. AZD6738 of 160 mg qd will be administered on D1-D7. Olaparib will be delivered as 300 mg bid dose on D1-D28.~One cycle consists of 4weeks. Response evaluation will be done every 8 weeks (every 2 cycles) of treatment~tumor biopsy is mandatory : screening, after 8weeks (1st-response evaluation), at disease progression (PD)~blood sampling for biomarker study is mandatory: every cycles~To evaluate the metabolic changes, 18 F-FDG PET is mandatory at screening and after 8 weeks (1st-response evaluation).
To assess the effect of AZD6738 and Durvalumab combination or AZD6738 and Olaparib combination in biliary tract cancer patients who have failed to 1st-line chemotherapy.