Treatment patterns and clinical outcomes among patients with biliary tract cancers in a large commercially insured US population

398 Background: The American Cancer Society estimates 11,980 new cases of biliary tract cancers (BTCs), including gall bladder and nearby large bile ducts, to occur in the US in 2021. BTCs are characterized by poor prognosis and limited treatment choices. Gemcitabine (GEM) plus platinum chemotherapy is the standard of care. However, there are limited data regarding real-world treatment patterns and clinical outcomes for BTCs patients receiving systemic treatments (ST). Methods: A retrospective cohort study of BTCs patients who received first line (1L) ST, using US private payer Cancer Care Quality Program (CCQP) data and administrative claims from the HealthCore Integrated Research Database (HIRD) between 07/01/2014 - 03/31/2021, was performed. Index date was defined as first claim of ST within 60 days of documented 1L therapy in the CCQP from 01/01/2015 - 09/30/2020. Adult BTCs patients with ≥6 months pre-index enrollment were included. Patients with ampullary cancer, brain/ CNS metastases, other primary cancer before BTCs diagnosis were excluded. Treatment patterns and clinical outcomes were examined. Results: A total of 413 patients [Stage IV (n=315), III (n=44), II/I (n=54)] were identified. The mean (SD) age was 61 (10) years, 55% were female, and there were 67% intrahepatic, 22% gall bladder, and 11% extrahepatic BTCs. There were 150 (36%), 203 (49%), 27 (7%) patients with baseline ECOG scores of 0, 1, 2+, respectively. At pre-index, frequently observed conditions included non-alcoholic liver diseases (75%), hypertension (65%), dyslipidemia (48%), mental health conditions (47%), gallstones (41%), gastrointestinal disorders (39%), and obesity (32%). GEM was commonly used as monotherapy (6%) or in combinations (85%): GEM + Cisplatin (64%), GEM + Oxaliplatin (6%), GEM + Capecitabine (5%), GEM + others (10%). Median overall survival was 11.5 months. The table summarizes clinical outcomes by stage. Conclusions: Most patients with BTCs received 1L GEM-based therapies, experienced poor survival and had high hospitalization rates. These data indicate need for future innovative approaches for management of BTC.[Table: see text]