Topotecan (T) and carboplatin (C) in the treatment of platinum sensitive relapsed ovarian cancer (ROC): Results of a multicenter phase I/II study

Abstract

5089 Background: Despite of the effectiveness of radical surgery and first-line chemotherapy, most patients (pts) with advanced ovarian cancer will relapse. Paclitaxel (P) in combination with C as second-line treatment improves the outcome of pts with platinum-sensitive ROC in comparison to C monotherapy. Due to polyneuropathy and alopecia this regimen can not be offered to all pts. Therefore, other platinum-combinations are required. We conducted a phase I/II study to define the dose limiting toxicities (DLT) and the tolerability of combination therapy with T and C. Methods: Pts with platinum-sensitive ROC and primary standard therapy were stratified according to treatment-free interval (TFI): 6–12 months (A) and ≥12 months (B). Following dose regimens were analysed: T 1mg/m2/d1–3 + C AUC5/d3 and T 0.75 mg/m2/d1–3 + C AUC5/d3, q21d. DLT was based on the first 4 courses and defined as: CTC grade 3/4 hematological and grade 2 non-hematological toxicity (excepted alopecia, vomiting), treatment delay >7d. Primary endpoints were DLT and tolerability. Secondary endpoints were remission rate (RR) and progression-free survival (PFS). Results: From 06/04 to 08/05, 28 pts were enrolled, 26 pts (A:13 pts, B:13 pts) were eligible. Median age was 61.5 years. A total of 141 cycles were analysed, median number of cycles was 6 (range A:2–8, B:1–10). DLTs were: leucopenia (n = 5) and thrombocytopenia (n = 1). MTD was reached at dose: T: 0.75mg/m2 and C: AUC5. Overall, grade 3/4 hematologic toxicities (in% of all cycles), for (A) and (B) respectively, were: anemia 4% vs. 4%, leucopenia 34% vs. 13%, neutropenia 30% vs. 31%, thrombocytopenia 7% vs. 6%. Febrile neutropenia 4.3% vs. 0%. Darbepoetin alfa was given in 13.5% of all cycles. Overall, grade 3/4 non-hematologic toxicities were infrequent (< 5%). Overall RR (95% CI) was 50% (29.7–70.1) [A: 30.8% (0.1–61.1), B: 69.3% (38.7–90.9)]. Median follow-up was 5.8 mo, median PFS (95% CI) was 7.7 mo (1.3–9.4) [A: 6.2 (1.3–7.2), B: 8.0 (7.3–9.4)]. Median overall survival was not reached. Conclusions: TC is a feasible and effective chemotherapy regimen for platinum sensitive ROC. Tolerability is not associated to TFI. The recommended dose for subsequent studies is T:0.75 and C:AUC5. No significant financial relationships to disclose.