A preliminary report of a phase II study of weekly topotecan in platinum-sensitive recurrent ovarian and peritoneal carcinoma

5063 Background: Topotecan 1.5 mg/m2 on days 1 through 5 of a 21-day cycle is an established chemotherapeutic regimen for recurrent ovarian cancer. However, noncumulative myelosuppression has limited topotecan's use in some patients (pts). Topotecan on a weekly schedule has been reported to be active in recurrent ovarian cancer pts with significantly reduced hematologic toxicity. The aim of this trial is to evaluate the safety and antitumor activity of weekly topotecan in pts with platinum-sensitive recurrent ovarian and peritoneal carcinoma. Methods: A prospective multi-institutional study began in July 2002 and is ongoing. Pts were required to have recurrent platinum-sensitive disease and no more than 2 prior treatment regimens. Topotecan was given at a dose of 4 mg/m2 on days 1, 8, and 15 of a 28-day cycle and escalated to 5 mg/m2 if well tolerated. Results: To date, 21 pts, 18 with ovarian and 3 with peritoneal carcinoma, have been enrolled. Fifteen are evaluable for toxicity and response. Four have just enrolled, 1 pt died before tumor reassessment, and 1 pt received only 1 cycle of therapy because of unrecovered blood counts. At study entry, the median age was 65 years (range, 43 to 82), median performance status was 0, and median number of prior regimens was 1. Pts received a median of 2 (range, 1 to 8) courses of topotecan. The overall response rate was 20% (3/15, all partial responses). An additional 6 (40%) pts had stable disease. Mean time to progression for responders and pts with stable disease was 26.4 (range, 25.6 to 26.8) and 16.6 (range, 10.7 to 30.7) weeks, respectively. Grade 4 neutropenia and anemia occurred in 2 pts (13.3%) and 1 pt (6.7%), respectively. No pts had grade 4 thrombocytopenia or neutropenic fever. G-CSF was used in 1 pt (6.7%) and erythropoietin was used in 6 pts (40%). Conclusions: Weekly topotecan in this setting is active with significant reductions in hematologic toxicity. Future studies using weekly topotecan in combination with other chemotherapeutic agents seem feasible given the low levels of hematologic toxicity observed in our trial. Further studies are being conducted to confirm these preliminary results. No significant financial relationships to disclose.