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)
RM et al. (Sat,) studied this question.