Phase II evaluation of 24-h continuous infusion topotecan in recurrent, potentially platinum-sensitive ovarian cancer: A Gynecologic Oncology Group study

Objectives. The aim of this study was to develop an alternative effective and more convenient administration schedule for intravenous topotecan when used as palliative treatment in ovarian cancer. Methods. The Gynecologic Oncology Group conducted a Phase II trial of 24-h infusional topotecan (8.5 mg/m²) with treatment repeated every 3 weeks in 29 patients with platinum-sensitive recurrent ovarian cancer (prior response to platinum- based chemotherapy with a minimum treatment-free interval ≥6 months). Results. The major toxicities of therapy were grade 4 neutropenia and thrombocytopenia which developed in 86 and 14% of patients, respectively. Other severe side effects were uncommon. Only 2 partial responses (7%) were observed in the 28 patients evaluable for response. Conclusions. Despite the relatively favorable ovarian cancer patient population treated in this trial (platinum-sensitive recurrent disease), the response rate was disappointingly low. Considering the three- to fivefold higher objective response rates observed in other trials employing topotecan in individuals with platinum- sensitive ovarian cancer utilizing a 5-day treatment program (delivered every 3 weeks), the results of the current study provide strong support for the conclusion that clinically relevant antineoplastic activity of this agent is highly schedule dependent. (C) 2000 Academic Press.