Treatment patterns and outcomes of patients diagnosed with metastatic pancreatic adenocarcinoma.

685 Background: About 50% of patients with pancreatic cancer have metastatic disease at diagnosis, at which point the 5-year survival rate is ~3%. This retrospective study analyzed treatment patterns in patients (pts) with metastatic pancreatic adenocarcinoma (mPAC), the association of patient characteristics and receipt of treatment in the first-line (1L) setting, and overall survival (OS) by trial emulation. Methods: Adult US pts with a new mPAC diagnosis (index date) between January 1, 2019–August 1, 2024 were included from the electronic health record-derived deidentified Flatiron Health Research Database. First-line treatments were stratified by baseline Eastern Cooperative Oncology Group performance status (ECOG PS). The association between patient characteristics and 1L treatment was evaluated using multinomial logistic regression adopting a complete case analysis. OS was compared between FOLFIRINOX and gemcitabine with protein-bound paclitaxel (Gem-Nab) using Cox regression in a target trial emulation approach, in which real-world data was analyzed to mimic the design of landmark trials NAPOLI-3 and ACCORD 11 to reduce bias and improve causal inference. Additional inclusion/exclusion criteria were applied as similar to clinical trials and weighted using Inverse Probability of Treatment Weighting. Results: The analysis included 9439 pts with mPAC; of these, 3160 (33.5%) did not receive any systemic anticancer therapy within 180 days after index date. Among 6279 (66.5%) pts who received 1L treatment, median time from index date to treatment was 21 days (first quartile [Q1]–third quartile [Q3], 13–34). The most frequent 1L treatment in the overall population and across both ECOG PS groups was Gem-Nab (Table). Compared with pts who received 1L Gem-Nab, pts who received 1L FOLFIRINOX were significantly younger; more likely to be treated at academic centers, reside in areas with higher socioeconomic indicators, present with de novo metastatic disease, and have lower ECOG PS (0–1 vs 2–4); and less likely to be covered by Medicaid. For trial emulation, 1053 and 1162 pts were included for 1L Gem-Nab and 1L FOLFIRINOX, respectively. After weighting, in the Kaplan-Meier 1L analysis median OS for Gem-Nab was 8.8 months (95% CI, 8.0–9.4) and for FOLFIRINOX was 11.0 months (95% CI, 10.2–12.1); hazard ratio was 0.76 (median follow-up 34 months, Q1–Q3: 16.4–51.2). Conclusions: About one-third of pts did not receive systemic anticancer therapy, underscoring a substantial gap in care. Among those who were treated, therapeutic choices were strongly influenced by both clinical and demographic characteristics. Most common 1L treatment regimens. n (%) ECOG PS 0–1 n = 4595 ECOG PS 2–4 n = 957 Gem-Nab, n = 2605 1877 (40.8) 454 (47.4) FOLFIRINOX, n = 2277 1800 (39.2) 180 (18.8) Gemcitabine alone, n = 371 193 (4.2) 139 (14.5) FOLFOX/FOLFIRI, n = 330 201 (4.4) 72 (7.5)