A phase I/II study of topotecan in combination with carboplatin in recurrent epithelial ovarian cancer

Objective. The purpose of this study was to define the maximum tolerated dose (MTD) of topotecan given as escalating doses combined to a fixed dosage of carboplatin in late relapsing ovarian carcinomas. Methods. Women with relapsing ovarian cancer more than 6 months after first-line treatment were eligible for the study. In the first phase of the trial, patients were allocated to escalating topotecan doses with a carboplatin fixed dose (AUC 5, according to Cockcroft's formula). If no "severe" adverse event occurred in 1 or more of the patients, the topotecan dose was increased. The starting dose of topotecan was 0.50 mg/m ²/day, for 3 consecutive days, and the dose step was of 0.25 mg/m ²/day, till 1.5 mg/m ²/day. The study progressed then in a phase II trial. Results. A total of 39 patients entered the trial. Twenty took part in the escalating topotecan dose phase (4 per dose level, 0.50, 0.75, 1, 1.25, and 1.50 mg/m ²/day) and 19 in the phase II. No severe adverse event was observed in the phase I of the trial, so the MTD was not reached. In the phase II trial topotecan was given to 1 mg/m ²/day. Overall grade 3-4 neutropenia, lasting 7 days or less, was observed in 58.9% (23 patients). Thrombocytopenia occurred in 30.8% (12 patients) and grade 3 anemia in 25.6% (10 patients) of subjects. No life-threatening event occurred. Platelets or red blood cell transfusions were given in three cases (7.8%). Conclusions. This daily-times-3-day schedule of topotecan in combination with carboplatin is safe.