Conditions for effective use of liposomal irinotecan with fluorouracil and leucovorin in unresectable pancreatic cancer after FOLFIRINOX treatment.

Abstract

Background: Liposomal irinotecan + fluorouracil/leucovorin (nal-IRI + 5FU/LV) is commonly used as a second- or later-line treatment for pancreatic ductal adenocarcinoma (PDAC) and offers survival benefits. However, its efficacy and safety in patients previously treated with FOLFIRINOX, which includes irinotecan, remain unclear. We evaluated the efficacy and safety of nal-IRI + 5FU/LV in patients with unresectable PDAC who received previous FOLFIRINOX therapy and those who did not.

Methods: This retrospective observational study included 42 patients with PDAC who were treated with nal-IRI + 5FU/LV (October 2020-November 2023). Patients were grouped based on prior FOLFIRINOX treatment.

Results: The progression-free survival (PFS) in patients who previously received modified FOLFIRINOX (mFFX) therapy was shorter than that in patients who did not (2.5 vs. 3.5 months, P = 0.07). When patients with greater than- and less than the cut-off value of irinotecan-free interval (IFI) were classified into the long and short IFI groups, respectively, PFS was significantly longer in the long-IFI group than that in the short IFI group (4.0 vs. 2.1 months, P = 0.01). Moreover, the C-reactive protein/albumin ratio (CAR) was also a significant predictor of PFS (P = 0.03). Furthermore, both factors were found to be independent factors influencing PFS in the univariate Cox regression analysis (P = 0.02 and P = 0.04).

Conclusion: Nal-IRI + 5FU/LV therapy may be a safe and effective option as a second- or later-line treatment, particularly for patients who have not previously received mFFX therapy. For patients who received prior mFFX exposure, a longer IFI and lower CAR may indicate greater potential benefit, thus aiding in more personalized treatment approaches.