Dose and schedule-finding study of oral topotecan and weekly cisplatin in patients with recurrent ovarian cancer

Both weekly cisplatin chemotherapy and single agent topotecan have proven t o be effective in recurrent ovarian cancer. Preclinical data show synergism between cisplatin and topotecan. Side effects for this combination are dru g sequence dependent and predominantly haematologic. Since preclinical data suggest that Cremophor EL (CrEL), the formulation vehicle of paclitaxel, h as a protective effect on haematological toxicity of cisplatin, CrEL was ad ded to the combination cisplatin and topotecan. In this phase I study, esca lating doses of oral topotecan administered on day 1, 2, 8, 9, 15, 16, 29, 30, 36, 37, 43, 44 were combined with weekly cisplatin 70 mg m(-2) d(-1) on day 1, 8, 15, 29, 36, 43 (scheme A) or with the presumably less myelotoxic sequence weekly cisplatin day 2, 9, 16, 30, 37, 44 (scheme B). In scheme C , CrEL 12 ml was administered prior to cisplatin in the sequence of Scheme A. 18 patients have received a total of 85 courses. In scheme A 4/10 patien ts, all treated with topotecan 0.45 mg m(-2) d(-1), experienced DLT:1 patie nt had vomiting grade 4, 1 patient had grade 4 neutropenia >5 days, 1 patie nt had >2 weeks delay due to thrombocytopenia and I patient due to neutrope nia, Both patients in scheme B (topotecan 0.45 mg m(-2) d(-1)) had DLT due to a delay >2 weeks because of prolonged haematological toxicity. No IDLT w as observed in the first 3 patients in scheme C (topotecan 0.45 mg m(-2) d( -1)). However, 2 out of 3 patients treated at dose level topotecan 0.60 mg m(-2) d(-1) in scheme C experienced DLT due to >2 weeks delay because of pe rsistent thrombocytopenia or neutropenia. We conclude that there is a modes t clinical effect of CrEL on haematological toxicity for this cisplatin-bas ed combination regimen, which seems to reduce these side effects but does n ot really enable an increase of the oral topotecan dose. (C) 2001 Cancer Re search Campaign.