Inclusion Criteria:

1. Patients who were diagnosed as adenocarcinoma of gallbladder or biliary tract
histologically or cytologically

2. Unresectable locally advanced, metastatic, or recurrent biliary tract cancer

3. Patients must be ≥ 18 , ≤ 75 years old of age

4. ECOG performance status ≤ 2

5. At least one lesion that can be measured by imaging (CT/MRI) according to the
Response Evaluation Criteria in Solid Tumors (RECIST v1.1)

6. Estimated life expectancy of more than 3 months

7. Adequate bone marrow function (absolute neutrophil count [ANC] ≥ 1,500/µL, hemoglobin
≥ 9.0 g/dL [correction by transfusion is acceptable], and platelets ≥ 100,000/µL)

8. Adequate kidney function (serum creatinine < 1.5 x upper limit of normal [ULN])

9. Adequate liver function (serum total bilirubin < 3.0xULN; serum transaminases levels
< 5.0xUNL)

10. Provision of fully informed consent prior to any study specific procedures

Exclusion Criteria:

1. Other tumor type than adenocarcinoma

2. Any previous history of chemotherapy for biliary tract cancer (prior
neoadjuvant/adjuvant chemotherapy is allowed, if recurrence occurred more than 6
months after completion of previous chemotherapy)

3. Patients with second primary cancer (except, adequately treated non-melanoma skin
cancer, curatively treated in-situ cancer of the cervix, or other solid tumors
curatively treated with no evidence of disease for ≥5 years)

4. Patients who received radiotherapy on target lesion within 6 months prior to study
treatment

5. Patients with defect of central nervous system (CNS) or any psychiatric disorders and
CNS metastases

6. Patients who received major surgery within 4 weeks of starting study treatment or was
not recovered from any effects of major surgery

7. Pregnant or breastfeeding women and women of childbearing potential not employing
adequate contraception

8. Other serious illness or medical conditions A. Clinically significant cardiac disease
(uncontrolled congestive heart disease despite treatment [NYHA class III or IV],
symptomatic coronary artery disease, unstable angina or myocardial infarction,
conduction abnormality like grade 2 AV block, serious arrhythmia needed for
medication, uncontrolled hypertension) within 6 months prior to study entry B. Liver
cirrhosis (≥ Child-Pugh class B) C. History of significant neurologic or psychiatric
disorders including dementia or seizures D. Active uncontrolled infection E. Other
serious underlying medical conditions which could impair the ability of the patient
to participate in the study

9. Concomitant administration of any other experimental drug under investigation, or
concomitant chemotherapy, hormonal therapy, or immunotherapy