Avastin, one of the best-selling cancer drugs in the world, could be banned from the treatment of breast cancer after a Federal Drug Administration (FDA) panel found for the second time the drug was ineffective and unsafe in breast cancer treatment.

The FDA had earlier recommended the stoppage of the use of Avastin in breast cancer treatment after studies had found that the drug hardly made a difference in the longevity of patients undergoing treatment with it.

The latest decision by an advisory committee to the FDA, which decided against the drug's continued use by 6-0 votes, will lead to the revoking of the drug's approval for use in breast cancer patients.

The FDA panel reiterated that the drug was neither safe nor effective and threw out manufacturer Genentech's plea that approval should not be revoked until fresh trials are done.

Avastin has been found hugely successful in the treatment of colon cancer. In 2008 the FDA approved its use in the treatment of breast cancer.

According to initial studies, the administration of Avastin prevented blood flow to tumors, thereby extending the amount of time before the tumor worsens. It was thought the drug could buy up to five months for the patient. However, later studies showed that the drug could not possibly be adding even one extra month of life.

The effectiveness of the drug was apparently too low to justify the high cost. It is calculated that a year's Avastin treatment would cost about $100,000. The drug was supposed to be administered to at least 17,500 breast cancer patients in one year.

Following studies that showed poor results, the FDA advisory panel voted 12-1 in July 2010 to cancel the endorsement of Avastin in breast cancer treatment. Following this, in December, FDA proposed to revoke approval of Avastin in breast cancer treatment, in combination with chemotherapy drug paclitaxel.

In 2008, Avastin had been given accelerated approval under a program that fast tracks the approval for drugs for serious diseases, meaning that the approval was subject to further trials.

Genentech, which makes the drug, said it was disappointed by the FDA panel's decision. We are very disappointed by the committee's recommendation and hope the Commissioner does not decide to remove this important medicine for women with an incurable disease who already have too few treatment options, it said. Genentech, a unit of Swiss drugmaker Roche Holding AG.

The decision to revoke Avastin's approval would mean a loss of millions of dollars for Roche. Avastin sales last year had brought in about $7 billion in revenue.

Though doctors would still be able to prescribe Avastin for other types of tumors, insurers will not pay for this expensive medicine. Avastin will remain on the market as a treatment for other cancers, including colon, lung and brain, so doctors could use it off label. But insurers might be less likely to pay for Avastin, which costs about $88,000 a year, according to Seattle Times.