263 Background: Gemcitabine (Gem) monotherapy or Gem-based combination therapy is a standard first-line therapy for advanced pancreatic cancer (PC). There is no consensus on second-line therapy in patients (pts) with disease progression (PD) after Gem-based therapy. S-1, an oral fluoropyrimidine derivative, is commonly used for the second-line treatment of PC in Japan. Shitara et al previously reported that IRIS regimen showed that 44% of response rate (RR), 4.9 mo of median progression free survival (PFS), and 11.3 mo of median overall survival (OS), respectively. Therefore a randomized phase II trial was conducted to evaluate the efficacy and safety of IRIS compared with S-1 alone in the second-line setting. Methods: The inclusion criteria were as follows: (1) histologically or cytologically proven pancreatic adenocarcinoma or adenosquamous carcinoma; (2) confirmed PD after Gem treatment; (3) ECOG PS, 0-1; (4) measurable metastatic lesion based on RECIST criteria; (5) age ≥ 20 years; (6) total bilirubin < 2.0 mg/dL. Patients were randomized to receive either IRIS (CPT-11 100 mg/m2, iv, d1,15 plus S-1 80/100/120 mg/day based on BSA, po, d1-14, q4w; Arm A) or S-1 (80/100/120 mg/day based on BSA, po, d1-28, q6w; Arm B). The primary endpoint was to compare PFS in Arm A and Arm B. Results: Of a total of 137 pts enrolled between Nov 2008 and Mar 2011, 127 were eligible (60 randomized to Arm A and 67 to B). Median PFS in Arm A and B was 107 and 58 days, respectively (HR= 0.767; 95% CI, 0.527-1.114; p=0.1750). Median OS in Arm A and B was 208 and 176 days, respectively (HR=0.749; 95% CI, 0.512-1.093; p=0.1338). RR was 18.3% in Arm A (11/60; 95% CI, 9.5-30.4) and 6.0% in Arm B (4/67; 95% CI, 1.7-14.6)(p=0.0311). The incidences of grade 3/4 toxicities were as follows: neutropenia (15.6% and 4.3%), anorexia (23.4% and 17.3%), nausea (6.3% and 2.9%), and diarrhea (3.1% and 2.9%) in Arm A and B, respectively. Both regimens were tolerable. Conclusions: Although IRIS showed no significant improvement in PFS or OS compared with S-1 alone in this study, it showed significant advantage in RR, and favorable HR in both of PFS and OS. IRIS might have potential power to treat second-line PC patients. Further study is warranted. Clinical trial information: JapicCTI-080657.
First-in-human phase II trial of the botanical formulation PHY906 with capecitabine as second-line therapy in patients with advanced pancreatic cancer
