Abstract Purpose: 5-Fluorouracil (5-FU) is one of the standard chemotherapy drugs used to treat pancreatic cancer. However, treatment only extends survival modestly, and disease recurrence is typical due to systemic instability, drug resistance, severe adverse effects, and limited benefits in patients with locally advanced tumors. These shortcomings have necessitated new strategies to develop safer and more effective anticancer agents. The study’s objective was to synthesize, characterize, and evaluate the cytotoxic effects of novel 5-FU analogs in pancreatic cancer cells. Methods: The analogs, XYZ-I-71 and XYZ-I-73, were synthesized by introducing a tetrahydrofuran ring on 5-fluorocytosine (a precursor of 5-FU) and conjugation with octanoyl chloride and lauroyl chloride, respectively. They were characterized by NMR, HPLC, micro-elemental analysis, and mass spectrometry. Cytotoxicity and cell migration studies were performed to determine the effectiveness of the analogs against MiaPaCa-2, PANC-1, and BxPC-3 pancreatic cancer cells. PARP apoptosis study was conducted in MiaPaca-2 cells using the analogs and 5-FU. The metabolic stability of analogs was determined by using human liver microsomes and quantified by HPLC. Results: Analysis of the 1H-NMR spectra displayed amide bonds at 7.80 ppm and 7.73 ppm, confirming the conjugation of octanoyl and lauroyl chloride to 5-fluorocutosine, respectively. The purity of both analogs was 99.6%. We found that the XYZ-I-73 (IC50 3.6 ± 0.4μM) analog was most effective against MiaPaCa-2 cells compared to XYZ-I-71(IC50 12.3±1.7μM), GemHCl (IC50 24.2 ± 1.3 μM), Irinotecan (IC50 10.1 ± 1.5 μM) and 5-FU (IC50 13.2 ± 1.1 μM). For PANC-1 cell growth inhibition, XYZ-I-73 (IC50 3.9 ± 0.5) was again observed as the most effective agent compared to XYZ-I-71(IC50 8.7±0.9 μM), GemHCl (IC50 10.07±0.9), 5-FU (IC50 20.43±1.2) and Irinotecan (IC50 11.6 ±1.1). A similar pattern of XYZ-I-73 (IC50 5.9±0.7) anticancer activity against BxPC-3 cells was found to be higher than XYZ-I-71(IC50 7.7 ± 0.8), GemHCl (IC50 10.95±0.9), 5-FU (IC50 14±1.1) and Irinotecan (IC50 9.5±1.0). For 24-hour MiaPaCa-2 cell migration studies, XYZ-I-73 (5µM) analog significantly reduced migration (# of migrated cells, 168±2.9) followed by XYZ-I-71(315±2.1), Gem-HCl (762±3.1) and 5-FU (710±3.2). PARP studies demonstrated significant inhibition of PARP expression of XYZ-I-73 treated cells compared to 5-FU and XYZ-I-71. Further, BAX and p53 expressions were significantly increased in cells treated with XYZ-I-73 compared to 5-FU and XYZ-I-71. Metabolic stability studies showed that 80 ± 5.9 % of XYZ-I-71 and XYZ-I-73 remained intact after 2-hour exposure in liver microsomal solution compared to 5-FU. Conclusion: XYZ-I-73 demonstrated a remarkable cytotoxic effect and improved in vitro metabolic stability over the selected standard drugs and may have potential anticancer activity against pancreatic cancer. Citation Format: Esther Frimpong, Raviteja Bulusu, Joy Okoro, Andriana Inkoom, Nkafu Ndemazie, Sherise Rogers, Xue Zhu, Bo Han, Edward Agyare. Synthesis and biological evaluation of novel 5-FU analogs against pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1825.