Gemcitabine/paclitaxel compared to gemcitabine/vinorelbine in metastatic breast cancer: An interim analysis

Abstract

1097 Background: New combinations and strategies have been developed over the past 10 years including new drugs such as taxanes and gemcitabine. It is not clear whether the activity of the gemcitabine-paclitaxel (GP) combination regimen would translate into better progression-free or overall survival (OS) when compared with gemcitabine-vinorelbine (GV) especially in metastatic breast cancer. This study was conducted to evaluate the overall response rate (RR) of GP Vs GV. Secondary objectives included individual responses of GP and GV, time to progression (TTP), time to treatment failure (TTF), OS, and toxicities. Methods: Patients(pts) with histological diagnosis of stage IV or recurrent breast cancer who had PS =2 and measurable disease were randomized to receive GP (Gemcitabine: 1,250mg/m2 D1 & D8- paclitaxel: 175 mg/m2 D1, D1=D28) or GV (Gemcitabine: 1,250mg/m2 D1 & D8 - vinorelbine: 25mg/m2 D1 & D8, D1=D21). Pts received anthracycline and/or capecitabine chemotherapy in adjuvant and/or metastatic setting. Results: Of 47 patients enrolled, 24 patients were randomized to GP arm and 23 to GV arm. 72% of patients were stage IV and 28% recurrent disease. To date, all patients were qualified for safety, TTF, TTP and OS analysis. Hematologic toxicities were: Neutropenia in 23% in GP Vs 17% in GV, Anemia in 12% in GP Vs 9% in GV. Non hematologic toxicities were essentially nausea and vomiting grad 2–3 in 27% in GP Vs 31% in GV. Anti-emetic agents were administrated to decrease them. The Complete Response (CR) was 27% in GP Vs 30% in GV, the Partial Response (PR) was 23% in GP Vs 17% in GV; with an Overall Response Rate (ORR) of 50% in GP Vs 47% in GV. Median TTF in weeks was 12 in GP Vs 14 in GV. Median TTP (weeks) was 14 in GP Vs 19 in GV. Median OS (weeks) was 32 in GP Vs 50 in GV. Conclusions: In our experience, schedules incriminating gemcitabine are efficient and produce clinical benefit and there activities are very interesting. The analysis of the useful of paclitaxel or vinorelbine associated to gemcitabine demonstrates that these associations are active with no significant differences in toxicities. Therefore, the questions are what regimens, for what patients to what high responses in pre-treated metastatic breast cancer. No significant financial relationships to disclose.