Liposomal irinotecan in metastatic pancreatic adenocarcinoma in Asian patients: Subgroup analysis of the NAPOLI-1 study

Abstract

The global, randomized NAPOLI-1 phase 3 trial reported a survival benefit with liposomal irinotecan (nal-IRI) plus 5-fluorouracil/leucovorin (nal-IRI+5-FU/LV) in patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) after previous gemcitabine-based therapy. Median overall survival (OS) with nal-IRI+5-FU/LV was 6.1 vs 4.2 months with 5-FU/LV alone (unstratified hazard ratio [HR] = 0.67, P =.012). Herein, we report efficacy and safety results from a post-hoc subgroup analysis of Asian patients treated at Asian centers. Primary study endpoint was OS; secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety. Patients receiving nal-IRI+5-FU/LV (n = 34) had significantly longer median OS versus 5-FU/LV (n = 35) (8.9 vs 3.7 months; unstratified HR = 0.51, P =.025). Patients had significantly increased median PFS with nal-IRI+5-FU/LV versus 5-FU/LV (4.0 vs 1.4; unstratified HR = 0.48, P =.011), and increased ORR (8.8% vs 0; P =.114). nal-IRI monotherapy (n = 50) numerically improved efficacy endpoints versus 5-FU/LV (n = 48): median OS was 5.8 versus 4.3 months (HR = 0.83, P =.423) and median PFS was 2.8 versus 1.4 months (HR = 0.69, P =.155). Grade ≥3 neutropenia was reported more frequently with nal-IRI+5-FU/LV versus 5-FU/LV (54.5% vs 3.4%), and incidence of grade ≥3 diarrhea was comparable between the two arms (3.0% vs 6.9%). This subgroup analysis confirms nal-IRI+5-FU/LV as an efficacious treatment option that improves survival in Asian patients with mPDAC that progressed after gemcitabine-based therapy, with a safety profile agreeing with previous findings. The nal-IRI+5-FU/LV regimen should represent a new standard of care for these patients in Asia. (Clinicaltrials.gov: NCT01494506).