Real-world (rw) outcomes of durvalumab plus gemcitabine and cisplatin (D + GemCis) or GemCis in patients (pts) with advanced biliary tract cancer in the US.

497 Background: D + GemCis is approved for the treatment of locally advanced or metastatic biliary tract cancer (aBTC) based on the results from the Phase 3 TOPAZ-1 trial (NCT03875235). This rw study describes characteristics and clinical outcomes of pts in the US with aBTC using claims-based data. Methods: This retrospective, observational study used Optum’s de-identified Market Clarity data (Optum Market Clarity) from adult pts diagnosed with de novo or recurrent aBTC receiving first-line D + GemCis on/after Mar 11, 2022 (date of NCCN guideline addition) or GemCis from Jan 1, 2019, to Nov 30, 2024. The primary objective was to describe baseline pt demographics and clinical characteristics. Exploratory objectives included assessing rw time to next treatment (rwTTNT) and overall survival (rwOS) estimated with Kaplan-Meier methods without direct comparisons. Results: A total of 581 pts met eligibility: 170 pts for D + GemCis and 411 pts for GemCis (n=340 pts prior to 2022). Demographics were similar in each cohort (Table). Most pts were diagnosed with de novo aBTC (~87% across groups) and intrahepatic cholangiocarcinoma (iCCA) (D + GemCis, 75.3%; GemCis, 68.9%). Median time from treatment initiation to the end of follow-up was 6.6 months for D + GemCis and 8.6 months for GemCis. For D + GemCis and GemCis, median (95% confidence interval [CI]) rwTTNT was 9.5 (7.1–18.8) and 7.5 (6.6–8.5) months, respectively; and median (95% CI) rwOS was 14.2 (10.7–15.6) and 11.9 (10.3–14.2), respectively. Kaplan-Meier estimates for rwOS (95% CI) for pts receiving D + GemCis and GemCis were 0.55 (0.47–0.63) and 0.49 (0.36–0.68) at 12 months, and 0.34 (0.26–0.44) and 0.20 (0.10–0.42) at 24 months, respectively. Conclusions: To our knowledge, this is the first study in the US utilizing comprehensive claims data to describe rw clinical outcomes in pts with aBTC treated with D + GemCis or GemCis. While there are limitations inherent to retrospective rw data, and there were no direct comparisons between cohorts, these results are consistent with outcomes reported in the TOPAZ-1 trial. Pt demographics and clinical characteristics. D + GemCisN=170 GemCisN=411 Age, yearsMean (standard deviation [SD]) 65.7 (10.2) 62.6 (10.8) Gender, n (%)Female 92 (54.1) 228 (55.5) aBTC diagnosis, n (%) De novo Recurrent 147 (86.5)23 (13.5) 358 (87.1)53 (12.9) BTC subtype*, n (%)iCCAExtrahepatic CCAGallbladder cancerAmpulla of VaterOther † 128 (75.3)17 (10.0)24 (14.1)