Ixabepilone plus capecitabine in advanced breast cancer patients with early relapse after adjuvant anthracyclines and taxanes: A pooled subset analysis of two phase III studies

BACKGROUND: Metastatic breast cancer (MBC) patients with rapid disease relapse after neo/adjuvant chemotherapy including anthracyclines and taxanes have limited treatment options and their efficacy is marginal. Two phase III studies compared ixabepilone plus capecitabine vs. capecitabine alone as first-line treatment in MBC patients pretreated with anthracyclines and taxanes in the neo/adjuvant setting. Here we report the efficacy and safety of these treatments in a prespecified subset of patients whose disease relapsed within 12 months. PATIENTS AND METHODS: Of 1973 patients across two studies, 293 relapsed within 12 months of neo/adjuvant treatment and received ixabepilone plus capecitabine (n = 149) or capecitabine alone (n = 144) as first-line chemotherapy for MBC. Analysis included progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and toxicity. RESULTS: In 293 patients, ixabepilone plus capecitabine, as compared to capecitabine alone, increased PFS (median: 5.6 months vs. 2.8 months; hazard ratio, 0.58; p < 0.0001), ORR (46% vs. 24%) and OS (median: 15.1 months vs. 12.5 months; hazard ratio, 0.84; p = 0.208). Major toxicities of this regimen included neuropathy, neutropenia and hand-foot syndrome, but were manageable. CONCLUSIONS: Patients with breast cancer with early relapse following neo/adjuvant treatment with anthracyclines and taxanes may benefit from ixabepilone plus capecitabine. (ClinicalTrials.gov identifiers: NCT00080301 and NCT00082433.).