演題番号 : WS37-6
The aim of this study was to explore whether continuation of S-1 in addition to paclitaxel offers any benefit to the patients pretreated by S-1.
Gastric cancer patients who developed progression during the S-1-based first-line chemotherapy or had recurrence during the postoperative adjuvant chemotherapy by S-1 were randomly assigned to receive second-line treatment either by weekly administration of paclitaxel (PTX) at 80 mg/m2 three times every 4 weeks or daily oral S-1 (80 mg/m2) for 2 weeks plus PTX (50 mg/m2) given on days 1 and 8, every 3 weeks (S-1 plus PTX). The primary end point was progression-free survival (PFS) at 4 months after the initiation of the treatment.
A total of 78 patients were eligible for efficacy analyses, 40 were assigned to the PTX group and 38 to the S-1 plus PTX group. PFS at 4 months was similar between the groups (50% for PTX vs. 55% for S-1 plus PTX, P = 0.641). There were no differences between the groups either in progression free survival (4.6 months vs. 4.6 months, respectively, HR: 0.862, 95% CI: 0.543-1.367, P = 0.526), overall survival (10.0 months vs. 10.0 months, respectively, HR: 0.834, 95% CI: 0.511-1.359, P = 0.464), time to treatment failure (4.6 months vs. 2.8 months, respectively, HR: 1.248, 95% CI: 0.785-1.985, P = 0.346) or overall response rate (27% vs. 22%, respectively, P = 0.767). The incidences of grade 3 or 4 hematological and non-hematological toxicities were also equivalent between the two groups (25% vs. 26% and 24% vs. 26%, respectively).
Neither benefit nor shortcomings of S-1 administration beyond progression was shown when paclitaxel was selected as the key-drug for the second-line chemotherapy. Referring to the results of RAINBOW study, a new standard in the second-line chemotherapy for gastric cancer would therefore be ramucirumab combined with paclitaxel, and exerting further efforts to combine ramucirumab with paclitaxel and S-1 will not be considered worthwhile.