Treatment patterns and outcomes of patients with a diagnosis of metastatic pancreatic adenocarcinoma in the United States, 2019-2024.

Background: Approximately half of patients with pancreatic cancer present with metastatic disease at diagnosis, for whom 5-year survival remains ~3%. This retrospective study assessed treatment patterns, characteristics associated with first-line (1L) regimen selection, and real-world survival and treatment outcomes in US patients with metastatic pancreatic adenocarcinoma (mPAC). Methods: US adults newly diagnosed with mPAC between 1 January 2019 and 1 August 2024 from the electronic health record-derived Flatiron Health Research Database were included. Treatment patterns across the first three lines of therapy were summarized among patients who initiated systemic therapy within 180 days of metastatic diagnosis. Associations between baseline characteristics and 1L regimen selection (across multiple regimen categories) were evaluated using multinomial logistic regression. Overall survival (OS) and time-to-treatment discontinuation (TTD) were assessed using standard survival methods. Results: Among 9,439 patients with mPAC, 6,279 initiated 1L systemic therapy. The most common 1L regimens were gemcitabine plus nab-paclitaxel (Gem-Nab; 41.5%) and folinic acid (leucovorin), fluorouracil (FU), irinotecan, and oxaliplatin (FOLFIRINOX) (36.3%). Mean time to 1L initiation after metastatic diagnosis was 26.9 days. Patients receiving 1L FOLFIRINOX were generally younger, more frequently had baseline Eastern Cooperative Oncology Group performance status 0 or 1, more often presented with Conclusions: Among treated patients, clinical and sociodemographic factors strongly influenced regimen selection, and FOLFIRINOX use was associated with longer survival and treatment persistence than Gem-Nab; although these findings should be interpreted as associative given the substantial differences in patient characteristics between treatment groups. Conversely, one-third of patients did not initiate systemic therapy within 180 days of metastatic diagnosis, which may reflect unmet need or gaps in access to care.