An FDA advisory panel on Tuesday heard testimony from patients regarding the risks and benefits of Roche’s Avastin (bevacizumab) in breast cancer, an indication which the agency proposed last December to recall approval.

Medical experts argued that if the FDA were to reinstate the breast cancer indication, it would undermine the integrity of the agency’s accelerated approval process, particularly in terms of being able to revoke approvals if subsequent data don’t support use of the drugs.

"We cannot permit sponsors to evergreen approval of a drug that has not been shown to be safe and effective," John Jenkins, director of the FDA's Office of New Drugs, told the appeals hearing.

To support its case to withdraw the drug in this indication, the FDA in a rare move offered the accounts of patients that have experienced adverse events while taking Avastin, with agency official Patricia Keegan noting that "women are dying."

However, Ed Lang, a spokesman for Roche’s Genentech unit noted that the side effects of the therapy are known and disclosed. Company spokeswoman Charlotte Arnold added that Genentech will present new analyses to "help clarify some of mischaracterisations that have been made about Avastin's data

." She further noted that "ultimately, maintaining accelerated approval while we conduct a new trial is allowed by law, supported by science and is in the best interest of the patients who may need this medicine." Still, an FDA official noted that it would be inappropriate at this time to retain the breast cancer indication as the studies would take at least three years.

Weighing in on the financial aspect of the hearing, Royal Bank of Scotland analyst Michael Leacock said an agency reversal to retain the breast cancer indication with a warning would probably let them recover "a few hundred million francs" in sales.

"We’ve made the assumption, perhaps harshly, that Avastin is not used in metastatic breast cancer based on the FDA maintaining its position,” he noted, adding that "anything other than the FDA sticking to its guns would be a benefit to our Roche view." Leacock previously trimmed $1 billion from his Avastin peak sales estimate after the FDA proposed to withdraw approval in breast cancer.

The appeals panel will make its recommendation as early as Wednesday, with FDA Commissioner Margaret Hamburg expected to make a final decision at a later date. Most analysts believe the panel will not change its mind, especially as five of the six members voted against Avastin's use in breast cancer at a hearing last July.