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

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)
The global NAPOLI‐1 phase 3 trial (NCT01494506) evaluated the safety and efficacy of liposomal irinotecan (nal‐IRI) and 5‐fluorouracil/leucovorin (5‐FU/LV) compared with 5‐FU/LV in patients with metastatic pancreatic adenocarcinoma that progressed following gemcitabine‐based therapy. We report data from a post‐hoc subgroup analysis focusing on Asian patients at centers in South Korea and Taiwan. Our findings are consistent with those from the primary analysis and show that, despite association with higher incidence of manageable grade 3‐4 neutropenia, the nal‐IRI+5‐FU/LV regimen is an effective treatment option in Asian patients with gemcitabine‐failed metastatic pancreatic cancer.