Purpose: To determine whether continuing paclitaxel for an extended time period in women with advanced ovarian cancer who had achieved a clinically defined complete response to a platinum/paclitaxel-based chemotherapy could prolong subsequent progression-free survival (PFS) and affect ultimate survival.

Patients and Methods: Patients were randomly assigned to either three or 12 cycles of single-agent paclitaxel administered every 28 days and were then followed up for progression-free and overall survival.

Results: As of September 6, 2001, 277 patients (262 assessable) had entered the trial, with a total of 54 PFS events having developed among 222 patients with follow-up data. With the exception of peripheral neuropathy, there were no major differences in toxicity between the regimens. The median PFS was 21 and 28 months in the three-cycle and 12-cycle paclitaxel arms, respectively. One-sided P values from an unadjusted log-rank test and an adjusted Cox model analysis (for stratification factors) were .0035 and .0023, respectively, both in favor of the 12-cycle arm. The Cox model-adjusted three-cycle versus the 12-cycle progression hazard ratio was estimated to be 2.31 (99% confidence interval, 1.08 to 4.94). With a protocol-specified early termination boundary of P = .005, these findings led the Southwest Oncology Group Data Safety Monitoring Committee to discontinue the trial. As of the date of study closure, there was no difference in overall survival between the treatment arms.

Conclusion: Twelve cycles of single-agent paclitaxel administered to women with advanced ovarian cancer who attain a clinically defined complete response to initial platinum/paclitaxel-based chemotherapy significantly prolongs the duration of PFS.