Avastin is controversial in breast cancer, in several settings. The AVADO trial was a Phase III, double-blind, placebo-controlled trial comparing the combination of Avastin and Taxotere to Taxotere alone in locally recurrent or metastatic breast cancer. Patients with locally recurrent or metastatic, HER2-negative breast cancer were randomized to Taxotere (100 mg/m2 every three weeks for up to nine cycles) plus placebo or Taxotere plus Avastin (either 7.5 or 15mg/kg continued until disease progression or unacceptable toxicity). Initial results, presented at the 2008 annual ASCO meeting, demonstrated a significant improvement in progression-free survival in the Avastin arm. The exploratory analysis of the AVADO trial presented at 2009 SABCS included patients from all arms of the study who had discontinued treatment with Taxotere (Group A), as well as those who had already received at least one treatment with maintenance therapy (either Avastin or placebo; Group B). At the time of this analysis, approximately 70% of patients in each arm of the study had received at least one dose of maintenance therapy.
In group A (n=702), the median time to disease progression following discontinuation of Taxotere was significantly improved among patients randomized to Avastin (HR = 0.71-0.75; p value £ 0.01).
In Group B (n=469), the median time to disease progression following discontinuation of Taxotere trended toward improvement among patients treated with at least one dose of Avastin maintenance versus placebo maintenance (HR=0.75-0.80; p =0.614-0.1244).
The researchers concluded that maintenance Avastin may delay time to disease progression among women with HER2-negative, locally recurrent or metastatic breast cancer; however, longer follow-up is necessary to determine if these outcomes reach statistical significance.
ASCO 2009 presented the proof of concept of maintenance therapy with Alimta and with Avastin Tarceva in LUNG cancer. It is as of yet not proven for breast cancer.
Fumoleau P, Greil R, Rayson D, et al. Bevacizumab (BV) maintenance therapy significantly delays disease progression (PD) or death compared with placebo (PL) in the AVADO trial (BV + docetaxel [D] vs D + PL in 1st-line HER2-negative locally recurrent [LR] or metastatic breast cancer [mBC]). 2008 San Antonio Breast Cancer Symposium. Abstract 903.
S. E. Waintraub, V. Tuchman The role of maintenance bevacizumab in patients with metastatic breast cancer treated with chemotherapy and bevacizumab upon achieving complete response or maximal radiologic response with stable disease.
J Clin Oncol 26: 2008 (May 20 suppl; abstr 12022)