Clinical Outcome and Safety of Triweekly Modified FOLFIRINOX Therapy in Patients with Advanced Pancreatic Cancer.

Purpose: Modified FOLFIRINOX (mFFX) therapy is widely used as first- or second-line treatment for advanced pancreatic cancer. However, adverse effects (AEs), such as cytopenia, often prevent the intended biweekly administration of mFFX therapy. Extending the dosing interval may decrease AEs and allow safer and longer mFFX therapy continuation. Therefore, this study evaluated the efficacy and safety of triweekly mFFX therapy at our institution.

Methods: We retrospectively reviewed 17 patients with unresectable pancreatic ductal adenocarcinoma who received mFFX therapy for more than 3 months and switched to a triweekly administration schedule within 2 months of initiating therapy at our institution between April 2017 and December 2023.

Results: Patient median age was 58 years (range: 36-75, 52.9% male). Eleven patients received mFFX therapy as the first-line treatment, while the other four patients received it as the second-line treatment. The median number of mFFX cycles was nine (range: 5-56). The median overall survival (OS) and progression-free survival (PFS) for all patients were 14.2 (95% confidence interval [CI], 10.5-26.3) and 6.7 (95% CI, 3.9-9.5) months, respectively. Regarding AEs, because patients with severe hematologic toxicity in the early phase were switched to triweekly treatment, the proportions of grade ≥ 3 leukopenia and neutropenia were high. In contrast, for grade ≥ 3 non-hematologic toxicity, diarrhea and anorexia were observed in only 1 of 17 patients.

Conclusion: Triweekly mFFX therapy for unresectable pancreatic cancer may be a feasible treatment option, with relatively low toxicity and valid efficacy.