Phase II study of SOXIRI (S-1/oxaliplatin/irinotecan) chemotherapy in patients with unresectable pancreatic ductal adenocarcinoma.

BACKGROUND: To provide data on the safety and efficacy of a combination chemotherapy regimen consisting of S-1, oxaliplatin, and irinotecan (SOXIRI) as a first-line therapy in unresectable pancreatic ductal adenocarcinoma (UPDA) patients.

METHODS: Patients with UPDA and no prior treatment chemotherapy in the UPDA setting were enrolled. The primary endpoint was the objective response rate (ORR). Secondary endpoints were overall survival (OS), progression-free survival (PFS) and adverse events. Patients received 80 mg/m2 S-1 twice a day for 2 weeks in an alternate-day administration cycle, 85 mg/m2 oxaliplatin on Day 1, and 150 mg/m2 irinotecan on Day 1 of a 2-week cycle.

RESULTS: In these 62 enrolled patients, the ORR was 27.4 %, median OS was 12.1 months, and median PFS was 6.5 months. Major grade 3 or 4 toxicity included neutropenia (22.3 %), leucopenia (16.1 %), nausea (9.7 %), vomiting (9.7 %), thrombocytopenia (6.5 %), anorexia (8.5 %), anemia (4.8 %), and diarrhea (1.6 %). No treatment-related deaths occurred. In addition, the analysis of 32 patients suffering pain revealed that the rate of pain relief was 34.4 %.

CONCLUSION: SOXIRI might be a standard regimen with an acceptable toxicity profile and favorable efficacy for use as chemotherapy in patients with UPDA.