Topotecan is an established
therapy for the treatment of recurrent
ovarian cancer and has demonstrated significant antitumor activity in both
platinum-sensitive and
platinum-resistant patient populations. The main toxicity associated with
topotecan when used in the standard 5-day dosing schedule is myelosuppression, which is generally predictable, reversible, noncumulative, and manageable. Comparative trials have shown that
topotecan is as effective as
paclitaxel and
pegylated liposomal doxorubicin in achieving
tumor response, disease stabilization, and improved overall survival. Follow-up data extending to 4 years indicate that the survival benefit persists in long-term
therapy without cumulative toxic effects. There appears to be little cross-resistance between
topotecan and
paclitaxel, indicating that the use of concurrent or sequential combination
therapy could be a valuable option. Encouraging preliminary data suggest that alternative dosing schedules may improve the therapeutic index of
topotecan and that
topotecan may also be active as first-line
therapy in combination with
taxanes and/or
platinum agents. Optimization of the use of
topotecan may offer potential opportunities for further improving the management of
ovarian cancer.