Genentech announced at ASCO that phase III study data showed that women with metastatic breast cancer who received first-line
therapy with Avastin (bevacizumab) plus chemotherapy experienced
improved progression-free survival, compared with chemotherapy alone.
Preliminary results were released in February, and the new data provide
information about two different doses of Avastin used in the study.
The AVADO trial involved 736 patients with locally recurrent or
metastatic HER2-negative breast cancer who had not previously received
chemotherapy for their disease. Patients were randomised to receive one
of two doses of Avastin or placebo given every three weeks for a
minimum of nine cycles, and all patients also received sanofi-aventis' Taxotere (docetaxel). The findings demonstrated that
compared with chemotherapy alone, those who received the higher dose of
Avastin improved progression-free survival by up to 64 percent and
those who received the lower dose improved progression-free survival by
up to 45 percent.
After one year, 83 percent of patients who received the higher
dose of Avastin and 78 percent of patients who received the lower dose
of the drug were alive, compared to 73 percent of those who were
administered chemotherapy alone. Additionally, the data demonstrated
that response rates were 63 percent and 55 percent for those who
received the higher and the lower doses of Avastin, respectively,
compared with 44 percent for those who were administered only
Although the study was not designed to compare the two
doses, it suggests that the higher dose looks slightly better, and
the safety looks comparable. Nonetheless, in practice unless the high dose is significantly
better than the low dose, oncologists may decide that they
shouldn’t be using the higher dose, thereby saving patients money and minimising some of
the side effects.
Avastin, which received accelerated approval in the US for patients with breast cancer earlier this year, could see yearly sales of $1 billion in breast cancer alone with the publication of the latest data.