Reardon, Josh

Treatment with cisplatin and gemcitabine demonstrates a survival benefit in patients with advanced biliary tract cancer (ABTC). However, the weekly administration can add significant toxicities that may prohibit prolonged treatment. Based on previous studies, we implemented a modified biweekly regimen of GC in an attempt to optimize the prescribed regimen with an improved toxicity profile, added convenience to patients while maintaining efficacy. Patients with ABTC were treated with fixed dose rate (FDR) gemcitabine (1,000 mg/m2/min) and cisplatin 20 mg/m2 on days 1 and 15 of every 28‐day cycle. Patients received treatment until time of progression, death, or discontinuation due to intolerance. Collected data included demographics, clinico‐pathologic features, toxicities, and survival. Kaplan‐Meier curves were used to calculate the median overall survival (OS) and progression free survival (PFS). The study included 107 evaluable pts with unresectable ABTC who received the biweekly regimen. Sites of tumor included gallbladder (21.5%), ampullary (3.7%), and bile duct (74.8%). Median number of cycles was 6 (1–27). Median PFS was 8.34 (6.74, 9.23) months and median OS was 10.32 (9.10, 11.43) months. Most common grade ≥3 adverse events included neutropenia (11%), fatigue (10%), and thrombocytopenia (6.4%). Biweekly FDR GC in ABTC is associated with a more favorable toxicity profile while maintaining efficacy similar to that observed in prior clinical trials. Minimal toxicities were observed despite a prolonged course for many patients. Further prospective trials should consider evaluating the role of biweekly GC regimen in ABTC, including a potentially more favorable platform in novel experimental strategies.

434 Background: Based on the ABC 02 trial, standard therapy for ABTC is CG for up to 8 cycles. However, a recent abstract (Doherty et al, ASCO 2016) confirmed that a cohort of pts does benefit from continued therapy. The weekly administration of G and C can add significant toxicities that may prohibit prolonged treatment (trmt). Previous studies have shown that a biweekly schedule (Ko AH et al JCO 2012) of fixed dose rate (FDR) G helps optimize the prescribed regimen with an improved toxicity profile and added convenience to pts while maintaining efficacy. Methods: Pts with ABTC treated with FDR G (1000mg/m2 at 10mg/m2/min) with C 20mg/m2(GC) on days 1 and 15 of every 28-day cycle were included for analysis. Pts received trmt until time of progression. Data was collected including demographics, clinico-pathologic features, toxicities and survival. Kaplan-Meier curves were used to calculate the median overall survival (OS) and progression free survival (PFS). Results: The study included 109 evaluable pts with ABTC who received CG. Pts had disease that was locally advanced (16.5%) or metastatic (83.5%). Median age was 60 years (28-86). Sites of tumor included gallbladder (21.1%), ampullary (3.6%) and bile duct (75.2%). Median number of cycles was 6 (1-27). Median PFS was 8.34 (6.74, 9.23) months and median OS was 10.32 (9.10, 11.43) months. Most common grade 3 or 4 adverse events included neutropenia (11%), fatigue (10%), thrombocytopenia (TCP) (6.4%), anemia (2.8%), and abnormal liver function tests (2.8%). Fifty-two percent of pts received second line therapy. Conclusions: Biweekly CG in ABTC is associated with a more favorable toxicity profile while maintaining efficacy similar to that observed in prior clinical trials. Minimal toxicities were observed despite a prolonged course for many. Further prospective exploration should consider evaluating the role of biweekly gemcitabine and cisplatin regimen in ABTC especially as a potentially more favorable platform to combine with novel agents. [Table: see text]