A Phase III Study to Compare the Efficacy and Safety of Paclitaxel Versus Irinotecan in Patients with Metastatic or Recurrent Gastric Cancer Who Failed in First-line Therapy (KCSG ST10-01)

Lessons Learned: Irinotecan could not be proven noninferior to paclitaxel as a second-line treatment for patients with metastatic or recurrent gastric cancer. The failure to demonstrate noninferiority may have been a result of insufficient patient enrollment. Both agents were tolerable but showed different toxicity profiles. Background: This phase III study compared the efficacy and safety of paclitaxel versus irinotecan in patients with metastatic or recurrent gastric cancer (MRGC) who had experienced disease progression following first-line chemotherapy. Methods: Patients were randomized to receive either paclitaxel (70 mg/m ² ; days 1, 8, 15, every 4 weeks) or irinotecan (150 mg/m ² every other week). The primary endpoint was progression-free survival (PFS). Results: This study was stopped early due to low accrual rate. A total of 112 patients were enrolled; 54 were allocated to paclitaxel and 58 to irinotecan. Median PFS for the paclitaxel and irinotecan groups was 3.5 and 2.1 months, respectively (hazard ratio [HR], 1.27; 95% confidence interval [CI], 0.86–1.88; p =.234). Noninferiority of irinotecan to paclitaxel was not proved because the upper boundary of the 95% CI (1.88) exceeded the predefined upper margin of noninferiority (1.32). Median overall survival (OS) was 8.6 months in the paclitaxel group and 7.0 months in the irinotecan group (HR, 1.39; 95% CI, 0.91–2.11; p =.126). Among toxicities greater than or equal to grade 3, neutropenia (11.5%) was the most common, followed by peripheral neuropathy (7.7%) in the paclitaxel group, and neutropenia (34.5%) followed by nausea, vomiting, and anemia (8.6%, respectively) in the irinotecan group. Conclusion: Although paclitaxel showed numerically longer PFS and OS compared with irinotecan, this was statistically insignificant. Both irinotecan and paclitaxel are valid second-line treatment options in MRGC.