Summary
Objectives The aim of this study was to evaluate the safety and efficacy of intravenous and intraperitoneal paclitaxel (PTX) combined with S-1 for treatment of gemcitabine-refractory pancreatic cancer with malignant ascites. Methods After the feasibility of this regimen was first confirmed in an interim analysis in 10 patients, a total of 35 patients were enrolled between April 2011 and December 2014. PTX was administered intravenously (50 mg/m2) and intraperitoneally (20 mg/m2) on days 1 and 8, and 80 mg/m2 S-1 was administered on days 1–14 every 3 weeks. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), the objective tumor response, efficacy against malignant ascites, and safety. Result In all 35 patients, the median OS and PFS were 4.8 (95 % confidence interval [CI], 2.1–5.3) months and 2.8 (95 % CI, 0.9–4.1) months, respectively. The 26 patients who were evaluable for efficacy achieved a response rate of 8 % and a disease control rate of 69 %. Malignant ascites had disappeared or decreased in 18 (69 %) patients, including complete resolution in 4 (15 %), and a negative change in cytological status was achieved in 8 (31 %) patients. The major grade 3/4 adverse events included neutropenia (34 %), anemia (31 %), nausea (9 %), and catheter-related infections (6 %). Conclusion Combination chemotherapy consisting of intravenous and intraperitoneal PTX with S-1 showed acceptable toxicity and favorable efficacy in pancreatic cancer patients with malignant ascites. (Clinical trial registration number: UMIN000005306)