A US advisory panel recommended on Wednesday 5 December that the Roche-owned Genentech''s cancer drug Avastin should not be approved to treat women with breast cancer. The panel decided by a vote of 5 to 4 that Genentech had failed to establish a favourable balance of risks and benefits in the data it presented for Avastin''''s use in advanced breast cancer patients.
Avastin is approved by the US Food and Drug Administration (FDA) for treating lung and colon cancer, but many doctors use it to treat breast cancer. ''Off-label'' use of Avastin for breast cancer accounts for around $200 million to $250 million in sales.
FDA officials will consider the panel''''s recommendation in deciding whether to approve Avastin for breast cancer. The FDA is not bound to follow the panel''''s advice but rarely goes against it. In this case, the decision was on a closely split vote, so the FDA may go either way. A final decision is expected by 23 February 2008.
Avastin is a bestseller, with $2.65 billion in sales for the first nine months of this year. FDA approval would allow the drug to be promoted specifically for breast cancer and help get reimbursement from insurers.
Breast cancer is one of the top 10 killers of women in the US, responsible for about 41,000 deaths in 2004, according to the Centers for Disease Control and Prevention. Globally, breast cancer affects 1.2 million people a year and kills 500,000 people annually, according to the World Health Organisation (WHO).
Avastin studies did not extend overall survival, but they did meet the principal objective of extending progression-free survival - which means the patient remains alive without the disease getting worse.
Patients in the study were given a combination of a commonly used treatment called paclitaxel combined with Avastin, known generically as bevacizumab, while the control group was given paclitaxel alone.
Progression-free survival was on average five-and-a-half months longer in patients who got Avastin. FDA reviewers asked the panel to weigh that against a 20 per cent increase in serious side effects among the 722 patients in the Avastin group, including hypertension, blood clots and heart attacks. Death attributed to the side effects was about 1.7 per cent of the Avastin group versus zero in the control group.
Avastin works by choking off the blood supply that tumours need to grow, and has been cleared in Europe as a breast cancer treatment. The company does not expect an approval in February, but thinks Avastin ultimately will be cleared for breast cancer treatment after future studies. Also, a number of the physicians who are already using the drug without approval may continue to do so with explicit informed patient consent.