Rucaparib in Combination With Nivolumab in Patients With Advanced or Metastatic Biliary Tract Cancer Following Platinum Therapy

Inclusion Criteria * Patients must have a pathologically confirmed adenocarcinoma of the biliary tract (intra-hepatic, extra-hepatic (hilar, distal) or gall bladder) that is not eligible for curative resection, transplantation, or ablative therapies. Tumors of mixed histology are excluded. * Patients must have received 1st line platinum-based systemic chemotherapy for advanced BTC for 4-6 months without radiologic or clinical progression. Last systemic infusion of 1st line platinum-based therapy may not be more than 4 weeks from study informed consent. Prior peri-operative chemotherapy is permitted provided it was completed \> 6 months from start of platinum-based therapy for advanced disease. * Prior surgical resection, radiation, chemoembolization, radioembolization or other local ablative therapies are permitted if completed \> 4 weeks prior to enrollment AND if patient has recovered to \< 1 grade 1 toxicity. * Patients must have measurable disease (as per RECISTv1.1) in at least one site not previously treated with radiation or liver directed therapy (including bland, chemo- or radio-embolization, or ablation) either within the liver or in a metastatic site unless the patient has had complete response to 1st line platinum-based therapy. * Age≥18 years * Child-Pugh score of A or B7 (Scoring system used to assess the prognosis of chronic liver disease, mainly cirrhosis) * ECOG performance status of 0-1 (Eastern Cooperative Oncology Group scoring system used to quantify gen…