Background: Three randomised trials have demonstrated that combining bevacizumab with first-line chemotherapy significantly improves progression-free survival versus chemotherapy alone in HER2-negative locally recurrent/metastatic breast cancer (LR/mBC). However, data from Chinese populations are limited and possible differences between ethnic and geographic populations are unknown. This study was conducted to determine whether there are differences in safety and efficacy in patients with HER2-negative LR/mRC between Chinese and Western populations after they receive first-line bevacizumab combined with taxane-based therapy.
Methods: In the single-arm, open-label, Avastin Therapy for Advanced Breast Cancer (ATHENA) study (NCT00448591), patients with HER2-negative LR/mBC received first-line bevacizumab (investigator's choice of 10 mg/kg every 2 weeks or 15 mg/kg every 3 weeks) combined with taxane-based therapy. The primary endpoint was safety profile and the secondary is time to progression (TTP). A subpopulation analysis was conducted to assess safety and efficacy in Chinese patients.
Results: Of 2264 patients treated in ATHENA, 202 were enrolled in China. Bevacizumab was combined with docetaxel in 90% of Chinese patients and paclitaxel in 10%. The most common grade 3/4 adverse events were diarrhoea (in 5.0% of patients) and hypertension (in 2.5% of patients). Grade 3/4 proteinuria occurred in 0.5%. After median follow-up of 17.6 months and events in 56% of patients, median TTP was 9.0 months (95%CI, 8.4-11.1). Overall survival data were immature.
Conclusions: We found no evidence of increased bevacizumab-related toxicity or reduced efficacy in Chinese LR/mBC patients receiving first-line bevacizumab-taxane therapy compared with predominantly Western populations. The safety profile was generally similar to previously reported LR/mBC trials. Subtle differences may be attributable to different lifestyle and cardiovascular risk factors in Chinese patients compared with the overall population. It appears reasonable to extrapolate findings from bevacizumab-based randomised trials to Chinese populations.