A phase II study of two topotecan regimens evaluated in recurrent platinum-sensitive ovarian, fallopian tube or primary peritoneal cancer: a Gynecologic Oncology Group Study (GOG 146Q).

Objective: To evaluate the efficacy and safety of topotecan in patients with recurrent ovarian, primary peritoneal, and fallopian tube carcinomas.

Methods: A randomized phase II analysis of platinum-sensitive patients with measurable disease was performed independently assessing intravenous topotecan 1.25 mg/m2 daily×5 every 21 days (regimen I) and topotecan 4.0 mg/m2/day on days 1, 8, and 15 of a 28-day cycle (regimen II). All patients were treated until disease progression, unmanageable toxicity, or patient refusal. Insufficient accrual related to regimen I resulted in a redesign of the study as a single arm phase II trial assessing only regimen II. More complete efficacy data is presented for regimen II as enrollment on regimen I was insufficient for some analyses.

Results: A total of 81 patients were enrolled. One patient was ineligible. Fifteen patients received regimen I, while 65 patients were treated with regimen II. The response rate on regimen I (daily×5) was 27% (90% CI: 10-51%) and 12% (90% CI: 6-21%) on regimen II (weekly). The median PFS and OS were 4.8 and 27.8 months, respectively, for regimen II. Grade 3/4 neutropenia rate was 93% with daily×5 dosing and 28% for weekly treatment. Febrile neutropenia was very low in both groups.

Conclusion: The weekly regimen of topotecan appeared less active but resulted in less toxicity than the daily regimen in platinum-sensitive recurrent ovarian cancer patients.