Docetaxel (T) followed by capecitabine (X) as first-line chemotherapy in patients (pts) with metastatic breast cancer (MBC): Preliminary findings from a phase II study

Abstract

10692 Background: X and T are highly active single agents in MBC. The XT combination leads to superior overall survival (OS), time to progression (TTP) and response rate (RR) vs. T alone in anthracycline-pretreated MBC [O’Shaughnessy et al. J Clin Oncol 2002]. The aim of this trial was to evaluate the efficacy and safety of sequentially administered T then X as first-line treatment in MBC. Methods: Pts ≥ 18 years with previously untreated, HER2neu-negative MBC, ECOG PS ≤ 2, were included in this prospective, multicenter, non-randomized, phase II study. Pts received 3 cycles of T (100mg/m2 d1) followed by 3 cycles of X (1250mg/m2 bid d1–14), every 3 weeks. Results: To date, 38 pts are evaluable for safety and 33 pts for efficacy. Baseline characteristics: median age 54.4 years (range 33–76); PS ≥ 1 50%; 36 (95%) pts had previous (neo)adjuvant anthracyclines, 8 (21%) concomitant with paclitaxel. The most frequent metastatic sites were: bone 47%, nodes 39% and liver 36%. 69% of pts had ≥ 2 metastatic sites. To date, 38 pts have received 3 cycles of T and 33 have also received 3 cycles of X. A total of 195 cycles have been administered: T 108 cycles (median 3, range 1–3); X 87 cycles (median 3, range 1–3). Dose reductions and interruptions for T vs. X were 32 vs. 21% and 21 vs. 21%, respectively. Median relative dose intensity: T 0.97 (range 0.62–1.00), X 0.93 (range 0.26–1.00). T grade 3/4 toxicities (37 evaluable pts): asthenia 19%, mucositis 16%, nausea 13%, febrile neutropenia 11%, rash 5%, diarrhea 5%, infection 3%. X grade 3/4 toxicities (33 evaluable pts): hand-foot syndrome 9%, diarrhea 9%, vomiting 9%, asthenia 6%, nausea 3%, anorexia 3%. In the 33 pts evaluable for efficacy, the RR was 61%, including 4 CRs and 16 PRs. At a median follow-up of 6.1 months, median TTP has not yet been reached. Conclusions: These preliminary results show that the sequential regimen of T followed by X is feasible, effective and well tolerated in first-line MBC, although giving X before T should also be investigated. Findings from a recent trial of XT vs. T followed by X [Beslija et al. ECCO 2005] suggest that XT should be standard in fit poor-prognosis pts with aggressive disease. No significant financial relationships to disclose.