A phase II trial of intravenous etoposide (VP-16-213) in epithelial ovarian cancer resistant to cisplatin or carboplatin: clinical and serological evidence of activity.

Etoposide (VP16) was administered intravenously at a dose of 150 mg/m2 daily for 2 days every 2 weeks to 24 patients with progressing epithelial ovarian carcinoma which was resistant to platinum analogues. Using standard response criteria there were five clinical partial responses (21%, 95% confidence limits 5-37%) and three disease stabilizations. However, the aim of our study was to determine if etoposide was non-cross-resistant with platinum analogues and therefore we also developed additional response criteria based on serial CA 125 levels. This was to enable us to differentiate within the heterogeneous group of responses that form the stable disease category. Nine of 23 patients (39%, 95% confidence limits 19-59%) demonstrated a fall (all rising prior to etoposide) and of these, three had a serologic partial remission (65% or greater fall). The serologic and clinical responses were strongly correlated. Falling CA 125 levels occurred in the eight patients with either clinical partial responses or disease stabilizations.