Ixabepilone plus capecitabine vs capecitabine in patients with metastatic breast cancer receiving ixabepilone in the first line setting: a pooled analysis from two phase III studies.

Abstract

Abstract Abstract #6117 Background: Patients (pts) with breast cancer who progress within 1 year of adjuvant anthracycline (A) / taxane (T) therapy have limited options for first line treatment. Ixabepilone (ixa), the first in a new class of antineoplastic agents, showed clinical benefit in combination with capecitabine (C) in 2 large clinical trials in metastatic breast cancer (MBC) pts whose tumors were resistant to (study 046; JCO, 2007) or pretreated with A and T (study 048). In 048, ixa plus C, compared to C alone, demonstrated significant increases in PFS (HR 0.79 [0.69-0.90]) and ORR (43 vs. 29%). A trend towards increased OS was seen in both 048 (HR 0.90 [0.78-1.03] and 046 (HR 0.90 [0.77-1.05]) which did not reach statistical significance. Here we present a pooled analysis of efficacy outcomes (ORR, PFS and OS) from the 2 studies of pts who recurred within 1 year of adjuvant A/T therapy and received no prior metastatic treatment.
 Methods: 1973 pts with MBC previously treated with A and T were randomized in open-label, multinational trials (046 and 048) to receive either ixa (40 mg/m2 IV over 3h Q3w) + C (1000 mg/m2 PO BID x 14d Q3w) or C alone (1250 mg/m2 PO BID x 14d Q3w). Due to the similarity of the study populations, individual patient data from both studies was pooled to better evaluate treatment effect within pre-planned patient subgroups. 293 pts were randomized to ixa + C or C alone in the first line setting.
 Results: ORR and PFS favored ixa + C in this pt population, and there was a trend towards increased OS, which did not reach statistical significance (see table).
 
 Conclusions: Pooled analysis of individual studies confirmed significant ORR and PFS benefit of ixa + C compared to C in pts whose disease relapsed within 12 months of adjuvant A/T. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6117.