A Multicenter Randomized Phase II Study of Docetaxel vs. Docetaxel Plus Cisplatin vs. Docetaxel Plus S-1 as Second-Line Chemotherapy in Metastatic Gastric Cancer Patients Who Had Progressed after Cisplatin Plus Either S-1 or Capecitabine.

Purpose: This study evaluated the re-challenge of S-1 or cisplatin in combination with docetaxel in metastatic gastric cancer (MGC) that had progressed on a cisplatin plus either S-1 or capecitabine regimen.

Materials And Methods: Patients with progressive disease after first-line cisplatin plus S-1 or capecitabine were randomized to receive 3-week cycles of docetaxel 75 mg/m intravenously (IV) on D1 (D), docetaxel 60 mg/m IV plus cisplatin 60 mg/m² IV on D1 (DC), or docetaxel 60 mg/m IV D1 plus oral S-1 30 mg/m twice a day on D1-14 (DS).

Results: Seventy-two patients were randomized to the D (n=23), DC (n=24), or DS (n=25) group. The confirmed response rate was 4.3% (95% confidence interval [CI], 0% to 12.6%), 4.3% (95% CI, 0% to 12.6%), and 8.7% (95% CI, 0% to 20.2%) for the D, DC, and DS groups, respectively. Compared to the D arm, the DS arm had a better progression-free survival (2.7 months vs. 1.3 months, p=0.034) without any deterioration in safety or quality of life, whereas the DC arm had a similar progression-free survival (1.8 months vs. 1.3 months, p=0.804) and poorer overall survival (5.6 months vs. 10.0 months, p=0.035).

Conclusion: A re-challenge with S-1, but not cisplatin, in combination with docetaxel has potential anticancer benefits over docetaxel alone in MGC with progression after prior cisplatin plus S-1 or capecitabine.