Liposomal irinotecan, oxaliplatin, and S-1 as first-line therapy for patients with locally advanced or metastatic pancreatic adenocarcinoma (NASOX): A multicenter phase I/IIa study.

INTRODUCTION

This multicenter phase I/IIa study aimed to determine the recommended phase II dose (RP2D) and evaluate the safety and preliminary efficacy of liposomal irinotecan (nal-IRI), oxaliplatin, and S-1 (NASOX) as first-line treatment for advanced pancreatic adenocarcinoma.

METHODS

Patients with locally advanced or metastatic pancreatic adenocarcinoma without prior systemic treatment for advanced disease, aged ≥ 19 years, with measurable disease, and Eastern Cooperative Oncology Group performance status of 0-1 were eligible. The primary endpoints were to determine the dose-limiting toxicity (DLT) in the phase I cohort and overall response rate (ORR) in the phase IIa cohort. The intention-to-treat (ITT) analysis included patients who received the RP2D.

RESULTS

In phase I, seven patients were screened, and six were assessed for DLT. None experienced DLT during the first cycle. The RP2D was determined as nal-IRI 50 mg/m and oxaliplatin 60 mg/m on day 1, S-1 40 mg/m twice daily on days 1-7 every 14 days. For the ITT (N = 41; 7, and 34 from phases I and IIa, respectively), the most common grade 3-4 treatment-emergent adverse events were neutropenia (31.7 %), enterocolitis (9.8 %), anorexia (7.3 %), and diarrhea (2.4 %). The ORR was 58.5 % (1 complete, and 23 partial responses). Two underwent conversion surgery; both achieved R0 resection. With median follow-up of 17.5 months, median progression-free survival was 6.5 months (95 % confidence interval [CI], 5.0-8.1) and median overall survival was 11.4 months (95 % CI, 9.8-15.5).

CONCLUSION

NASOX exhibited a manageable safety profile and encouraging efficacy outcomes consistent with NALIRIFOX, showing potential to replace infusional 5-fluorouracil with oral S-1 in the triplet regimen.