Inclusion Criteria:
1. Patients with cytologically or histologically confirmed BTC.
2. Patients must have late stage (locally advanced, recurrent or metastatic)
BTC. Patients must not have received systemic treatment for advanced
disease. Prior adjuvant therapy is allowed as long as recurrences
occurred 6 months or later from all treatment completion.
3. ECOG Performance Status from 0-2.
4. Adequate bone marrow function, as assessed by:
a. Absolute Neutrophil Count (ANC) ≥ 1.5 x 109/L
b. Platelet count ≥ 100,000 x 109/L
c. Hemoglobin ≥ 8 g/dL
5. Adequate renal function, with creatinine < 1.5 x the upper limit of
institutional normal (ULN) or Cockcroft calculated creatinine clearance
of ≥60 mL/min.
6. Adequate liver function, as measured by:
a. AST and ALT ≤ 3 x ULN
b. Total bilirubin ≤ 1.5 x ULN

Exclusion Criteria:
1. History of autoimmune disease requiring systemic treatment in the past
2 years.
2. Pregnancy or breastfeeding.
3. Active infection requiring systemic therapy.
4. History of solid organ or allogeneic bone marrow transplantation.
5. Underlying medical condition that will make administration of study
drugs hazardous in the opinion of the treating physician.
6. Prior treatment with immune checkpoint inhibitors.