Long-Term Drug Screening Identifies PARP Inhibitors as Irinotecan Combination Partners in BRCA1/2-Wild-Type Pancreatic Ductal Adenocarcinoma

Background/Objectives: Irinotecan is a component of standard first-line regimens for advanced pancreatic ductal adenocarcinoma (PDAC), yet cells that survive irinotecan treatment may retain the capacity to re-establish growth. Most anticancer drug screens use short-term growth inhibition as an initial criterion for compound selection, potentially excluding compounds with limited acute activity. We asked whether some of these excluded candidates might nevertheless show substantial long-term activity and enhance irinotecan responses in combination.