Inclusion Criteria:

1. age ≥ 18

2. histologically or cytologically confirmed adenocarcinoma of biliary tract

3. unresectable or metastatic

4. ECOG performance status of 0~2

5. measurable or evaluable lesion per RECIST criteria

6. adequate marrow, hepatic, renal and cardiac functions

7. One prior treatment of cytotoxic chemotherapy (including adjuvant treatment within 12
months)

8. provision of a signed written informed consent

Exclusion Criteria:

1. severe co-morbid illness and/or active infections

2. pregnant or lactating women

3. active CNS metastases not controllable with radiotherapy or corticosteroids

4. known history of hypersensitivity to study drugs