WASHINGTON (AP) - Federal health advisers say unanimously that a follow-up study of the Roche drug Avastin failed to show meaningful benefits for breast cancer patients.

A Food and Drug Administration panel of experts voted 13-0 that the risks and side effects of Avastin outweighed its benefits when used alongside a chemotherapy drug.

The FDA in 2008 approved Avastin for breast cancer based on a trial showing it significantly lengthened the time until the disease worsened. But two follow-up studies recently completed by Roche failed to show the same ability to delay disease progression.

The FDA panel is reviewing the results of the studies. Later this afternoon the panel will vote on whether Avastin's approval in breast cancer should be withdrawn.