Efficacy of capecitabine (C)-based therapy in patients with first-line metastatic breast cancer (MBC) previously treated with adjuvant anthracyclines and taxanes.

Abstract

665 Background: Anthracyclines and taxanes are used increasingly in neoadjuvant and adjuvant chemotherapy (CT) in breast cancer. Consequently, MBC is frequently diagnosed in anthracycline- and/or taxane-pretreated pts. Retreatment with these agents is commonly compromised by resistance and/or cumulative toxicity. C is effective in the management of first-line MBC; the current analysis was undertaken to determine the first-line clinical efficacy of C in pts pretreated with adjuvant CT. Methods: 3 studies of C 1000 mg/m2, bid, d1-14 q3w, were included: a retrospective study of single-agent C (n=226; Debled et al 2009); a phase II study of single-agent C (n=161; Kaufmann et al 2009); a phase III, randomized study (RIBBON-1) of C ± bevacizumab (A; 15mg/kg, d1 q3w; n=615). Results: Prior exposure to neoadjuvant and adjuvant CT was reported in around 50-75% of pts. Of these, around 60-75% and 40-45% received anthracyclines or taxanes, respectively. Overall response rate (ORR) and CBR (CR+PR+SD) were around 25% and 60%, respectively (Table). In Debled et al, univariate analysis demonstrated similar time to treatment failure (TTF) in chemotherapy-naive and -pretreated pts (8.9 vs. 8.3 months; p=0.46). A similar analysis in RIBBON-1 supports a substantial benefit with C in chemotherapy-naïve and -pretreated pts (median PFS: 6.7 and 4.4 months, respectively), with consistent effects in taxane- (6.1 and 4.2 months) and anthracycline- pretreated pts (6.4 and 4.4 months). Notably, the addition of A appeared to overcome the effect of prior taxane exposure: CA median PFS 8.7 and 8.3 months in taxane-pretreated and -naïve pts, respectively. Conclusions: These data demonstrate that C consistently achieves improved clinical outcome in pts who have received prior neoadjuvant or adjuvant CT. Debled et al 2009 Kaufmann et al 2009 RIBBON-1 Study C (n=226) C (n=161) C (n=206) CA (n=409) Neoadjuvant or adjuvant CT, % 48 54 75.7 70.4 Anthracycline, % 39 35.8 69.4 60.4 Taxane, % 5 24.5 40.8 39.4 ORR, % 56 26.1 23.6 35.4 CBR, % 76 64 60.2 72.9 TTF, months 8.8 NR NR NR PFS, months NR 7.3* 5.7 8.6 * TTP Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Roche Roche Roche