Cancer treatment bevacizumab (Avastin) should be stripped of its approval for use against breast cancer, according to a panel of Food and Drug Administration advisers.

The panel voted 12 to 1 to revoke the approval, which now has to be confirmed by the FDA.

Bevacizumab, manufactured by Roche’s Genentech subsidiary, was approved under a fast-track procedure, but studies concluded since that approval have not convinced the FDA panel of its effectiveness in breast cancer.

The drug is one of Roche’s top selling products, reaching sales of 6.2 billion Swiss francs ($5.9 bn US) for colorectal, breast, lung, kidney and brain cancer last year. Roche’s 2009 annual report noted that sales growth in the US was being “driven mainly by use in advanced breast cancer” along with brain and kidney cancer.

Industry analysis Tim Anderson, of Sanford Bernstein, says that the treatment should make $6.5 billion in sales this year, with $1.2 billion of that coming from breast cancer (BusinessWeek, PharmaTimes).

Pharmalot’s Ed Silverman notes that this is the second time that an accelerated approval has cause problems for the FDA, with Pfizer recently pulling a leukaemia drug after follow up studies uncovered problems. “The question now is whether the agency will now rethink its approach to the program,” he notes.