Background: Liposomal irinotecan + 5-fluorouracil/leucovorin (5-FU/LV) is approved in the USA and Europe for mPDAC following progression with gemcitabine-based therapy. A phase 1/2 study (NCT02551991) demonstrated promising anti-tumor activity in patients with mPDAC who received first-line liposomal irinotecan 50 mg/m² + 5-FU 2400 mg/m² + LV 400 mg/m² + oxaliplatin 60 mg/m² (NALIRIFOX). Here, we present results from NAPOLI 3 (NCT04083235), a randomized, open-label, phase 3 study investigating the efficacy and safety of NALIRIFOX compared with nab-paclitaxel 125 mg/m² + gemcitabine 1000 mg/m² (Gem+NabP) as first-line therapy in patients with mPDAC. Methods: Eligible patients with histopathologically/cytologically confirmed untreated mPDAC were randomized (1:1; stratified by Eastern Cooperative Oncology Group [ECOG] performance status, geographic region and presence/absence of liver metastases) to receive NALIRIFOX on days 1 and 15 of a 28-day cycle or Gem+NabP on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival (PFS), overall response rate (ORR) and safety. OS was evaluated when at least 543 events were observed using a stratified log-rank test with an overall one-sided significance level of 0.025. Results: Overall, 770 patients (NALIRIFOX, n = 383; Gem+NabP, n = 387) were included. Baseline characteristics were balanced between arms. At a median follow-up of 16.1 months, 544 events had occurred. Median OS was 11.1 months in the NALIRIFOX group versus 9.2 months in the Gem+NabP group; median PFS was 7.4 months versus 5.6 months. Median (95% CI) duration of response was 7.3 (5.8–7.6) and 5.0 (3.8–5.6) months in patients who received NALIRIFOX and Gem+NabP, respectively. Grade 3/4 treatment-emergent adverse events occurring in at least 10% of patients receiving NALIRIFOX versus Gem+NabP included diarrhea (20.3% vs 4.5%), nausea (11.9% vs 2.6%), hypokalemia (15.1% vs 4.0%), anemia (10.5% vs 17.4%) and neutropenia (14.1% vs 24.5%). Conclusions: First-line NALIRIFOX demonstrated clinically meaningful and statistically significant improvement in OS and PFS compared with Gem+NabP in patients with mPDAC. The NALIRIFOX safety profile was consistent with the profiles of the regimen components and generally manageable. Clinical trial information: NCT04083235.