Background: First-line bevacizumab combined with chemotherapy significantly improves efficacy versus chemotherapy alone in HER2-negative locally recurrent/metastatic breast cancer (LR/mBC). ATHENA, a multinational, open-label, single-arm study, further evaluated first-line bevacizumab in combination with standard chemotherapy in patients treated in routine oncology practice.

Patients and methods: Eligible patients had HER2-negative LR/mBC, ECOG performance status 0-2, and had received no prior chemotherapy for LR/mBC. They received bevacizumab 10 mg/kg q2w or 15 mg/kg q3w in combination with taxane-based chemotherapy (or other non-anthracycline chemotherapy) until disease progression, unacceptable toxicity, or patient withdrawal. The primary endpoint was safety; secondary endpoints included time to progression (TTP) and overall survival (OS). Results: Between September 2006 and March 2009, 2264 patients began therapy with bevacizumab, combined with single-agent paclitaxel (34%), single-agent docetaxel (33%), taxane-based combination therapy (11%), non-taxane-containing therapy (10%), or sequential chemotherapy (switching chemotherapy regimen before disease progression while continuing on bevacizumab; 12%). After final data cut-off in July 2010, the median duration of follow-up was 20.1 months (range 0.1-43.6 months). Bevacizumab therapy was continued for ≥1 year in 473 patients (21%). The safety profile and median TTP were very similar to those previously reported after median follow-up of 12.7 months and are consistent with findings from randomized phase III trials. Final OS results in the overall population and in clinically important subgroups are reported below for the first time.

Conclusion: Median OS in the overall population is consistent with OS results reported from three randomized phase III trials in the first-line setting (25.2-30.2 months). OS results in subsets of patients with TN disease or aged ≥70 years suggest that bevacizumab-containing therapy is an effective option for these patients, who typically have fewer treatment options available.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-16-06.