Nal-IRI/5-FU/LV versus modified FOLFIRINOX and FOLFIRI as second-line chemotherapy for unresectable pancreatic cancer: A single center retrospective study

The preferred regimen for unresectable pancreatic cancer following gemcitabine-based chemotherapy is not well-established. This study compared the efficacy of (ⅰ) liposomal irinotecan (nal-IRI) plus 5-fluorouracil (5-FU)/leucovorin (LV) (nal-IRI/5-FU/LV) versus modified FOLFIRINOX (mFFX) and (ⅱ) nal-IRI/5-FU/LV versus FOLFIRI, respectively, and the safety of the three regimens each other, as second-line chemotherapies for unresectable pancreatic cancer. This was a retrospective single-center analysis of all patients who were administered nal-IRI/5-FU/LV, mFFX, or FOLFIRI from December 2014 to July 2021 as second-line chemotherapy for pancreatic cancer. The primary endpoint was the overall survival (OS) of all patients, excluding those with locally advanced pancreatic cancer. Regarding safety, we assessed the incidence of grade ≥3 adverse events of interest in all patients. A total of 137 patients (nal-IRI/5-FU/LV, n = 55; mFFX, n = 39; FOLFIRI, n = 43) were included. The median OS in the nal-IRI/5-FU/LV group, the mFFX group, and the FOLFIRI group was 7.4, 11.8, and 8.4 months, respectively. Compared with the nal-IRI/5-FU/LV group, the mFFX and FOLFIRI groups displayed a hazard ratio of 0.66 [95% confidence interval 0.40–1.08] and 0.87 [95% confidence interval 0.55–1.39], respectively. In the FOLFIRI group, the incidence of grade ≥3 treatment-related adverse events tended to be low among all three groups. Given the trend toward longer OS in the mFFX group and the lower incidence of adverse events in the FOLFIRI group, both mFFX and FOLFIRI, as well as nal-IRI/5-FU/LV, can be treatment options for second-line chemotherapy for unresectable pancreatic cancer.