Dose modifications of liposomal irinotecan (nal-IRI) + 5-fluorouracil/leucovorin (5-FU/LV) in NAPOLI-1: Impact on efficacy.

Abstract

388 Background: In NAPOLI-1 (NCT01494506), a randomized phase 3 study in patients with metastatic pancreatic cancer previously treated with gemcitabine-based therapy, nal-IRI+5-FU/LV improved overall survival (OS; primary endpoint) vs 5-FU/LV (6.1 mos vs 4.2 mos; HR = 0·67, 95% CI 0.49–0.92; P = 0.012). This exploratory analysis examined the impact of dose modifications or delays used to manage adverse events (AEs) on OS. The study protocol allowed ≤2 dose reductions for nal-IRI and 5-FU and for up to 3 weeks. Methods: Patient who had a dose delay or reduction within the planned first 6 weeks of the study were included. Delays were defined as any delay in dosing > 3 days from target dosing date and dose reductions were defined as any reduction in dose from initial administered dose. OS was compared within the nal-IRI+5-FU/LV arm and with the 5-FU/LV arm. Comparisons were made using the cohort of 5-FU/LV and nal-IRI+5-FU/LV patients enrolled under protocol version 2. Median OS was based on Kaplan-Meier estimates and Cox regression analysis was used to calculate HRs. Results: More patients in the nal-IRI+5-FU/LV treatment group experienced AEs that required dose delay and/or reduction than in the 5-FU/LV treatment group (62% vs 33%). Within the nal-IRI+5-FU/LV arm, median OS was numerically but not significantly different between patients who did (n = 34) vs did not (n = 83) have a dose reduction (9.3 vs 5.4 mos; HR = 0.66 [95% CI 0.43, 1.01]) and for those who did (n = 49) vs did not (n = 68) have a dose delay (8.4 vs 5.6 mos; 0.82 [95% CI 0.56, 1.23]). Between treatment arms, OS was greater in the nal-IRI+5-FU/LV arm regardless of dose delay or reduction (Table). Conclusions: Dose modifications in the nal-IRI+5-FU/LV arm did not significantly impact OS compared with those who did not need a dose modification, and OS remained greater than in 5-FU/LV-treated patients. This suggests that appropriate dose modification of nal-IRI+5-FU/LV for AEs may not adversely affect outcomes. Clinical trial information: NCT01494506. [Table: see text]