Background: The combination of carboplatin and paclitaxel is the standard of care for the treatment of ovarian cancer, yet rates of recurrence and death remain high. We performed a prospective randomized phase III study to examine whether sequential administration of topotecan can improve the efficacy of carboplatin and paclitaxel in first-line treatment of advanced epithelial ovarian cancer.
Methods: A total of 1308 patients with previously untreated ovarian cancer (International Federation of Gynecology and Obstetrics stages IIB-IV) were randomly assigned to receive six cycles of paclitaxel and carboplatin followed by either four cycles of topotecan (TC-Top; 658 patients) or surveillance (TC; 650 patients) on a 3-week per cycle schedule. The primary endpoint was overall survival, and secondary endpoints were progression-free survival, response rate, toxicity, and quality of life. Time-to-event data were analyzed using the Kaplan-Meier method, and a stratified log-rank test was used to compare distributions between treatment groups. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a Cox proportional hazards model. Categorical data were compared using a stratified Cochran-Mantel-Haenszel test. All statistical tests were two-sided.
Results: Median progression-free survival was 18.2 months in the TC-Top arm versus 18.5 months in the TC arm (stratum-adjusted HR = 0.97 [95% CI = 0.85 to 1.10]; P = .688). Median overall survival was 43.1 months for the TC-Top arm versus 44.5 months for the TC arm (stratum-adjusted HR = 1.01 [95% CI = 0.86 to 1.18]; P = .885). At 3 years, overall survival in both arms was 57% (58.5% in the TC arm and 55.7% in the TC-Top arm). Compared with patients in the TC arm, patients in the TC-Top arm had more grade 3-4 hematologic toxic effects (requiring more supportive care) and more grade 3-4 infections (5.1% versus 2.7%; P = .034) but did not have a statistically significant increase in febrile neutropenia (3.3% versus 3.1%; P = .80). Among patients who had measurable disease (TC, n = 147; TC-Top, n = 145), overall (i.e., complete or partial) response was 69.0% (95% CI = 61.4% to 76.5%) in the TC-Top arm and 76.2% (95% CI = 69.3% to 83.1%) in the TC arm (P = .166).
Conclusions: The sequential addition of topotecan to carboplatin-paclitaxel did not result in superior overall response or progression-free or overall survival. Therefore, this regimen is not recommended as standard of care treatment for ovarian cancer.