Liposomal irinotecan and 5-fluorouracil/leucovorin in older patients with metastatic pancreatic cancer – A subgroup analysis of the pivotal NAPOLI-1 trial

Objectives: Pancreatic cancer is a highly lethal disease predominantly affecting older patients. Characterization of outcomes in these patients may help optimise treatment decisions. The global, phase 3 NAPOLI-1 trial (NCT01494506) demonstrated an overall survival (OS) benefit with liposomal irinotecan and 5-flurouracil/leucovorin (nal-IRI + 5-FU/LV) versus 5-FU/LV. This subgroup analysis explored impact of age on outcomes in NAPOLI-1 patients, and nal-IRI + 5-FU/LV efficacy and safety in older patients. Materials and Methods: This exploratory, post-hoc analysis of the NAPOLI-1 trial included patients aged ≥eighteen years (no upper limit) with metastatic pancreatic adenocarcinoma that had progressed on gemcitabine-based therapy. Patients were stratified by age (cut-offs at 65, 70, and 75 years); OS and progression-free survival (PFS) were estimated by Kaplan-Meier analysis. Results: Of 417 randomized patients, 192 (46%), 110 (26%) and 43 (10%) were aged ≥65, ≥70 and ≥ 75 years, respectively. Mortality risk and risk of disease progression were similar in older and younger patients independent of treatment (HRs for median [m]OS/mPFS comparisons were 0.88/0.95 [<65 versus ≥65 years], 0.89/0.88 [<70 versus ≥70 years] and 1.04/0.98 [<75 versus ≥75 years]; P > .25). Reduced mortality/morbidity risk with nal-IRI + 5-FU/LV in older subgroups was in line with the wider population. No additional toxicities with nal-IRI + 5-FU/LV were observed in older patients: 86% of patients ≥75 years versus 69% <75 years required a dose delay or reduction due to toxicities (43% versus 32% dose reductions). Discussion: Results suggest that older patients with metastatic pancreatic adenocarcinoma that progressed on prior gemcitabine-based treatment can benefit from second-line therapy, supporting nal-IRI + 5-FU/LV treatment in older patients.