Health Canada has suspended its approval for use of the drug Avastin by patients with metastatic breast cancer, concluding after a review such treatment does not affect tumour size or extend life expectancy, and is linked to potentially life-threatening risks.
The move comes 10 days after the U.S. Federal Drug Administration announced that its own probe found no proof the drug's benefits outweigh its potentially dangerous side effects.
Health Canada said Monday that Avastin, which is the brand name for the drug bevacizumab, "has not shown to be safe and effective" when used to treat breast cancer that has metastasized, or spread, to other parts of the body.
The agency said it has asked the drug's maker, Hoffmann-La Roche, to remove the directive for use treating metastatic breast cancer from the label. The company has told the agency it will comply with the request.
Avastin is still authorized to treat metastatic colon, rectal and lung cancers, as well as glioblastoma, a type of cancer of the brain.
Health Canada first authorized Avastin as a treatment for metastatic breast cancer in February 2009, with conditions.
The agency said it grants such approval for drugs that show "promising evidence of clinical effectiveness, subject to follow-up studies that confirm the benefit."
But Health Canada has since found that the drug does not have a significant impact on tumour size or life expectancy, and carries serious risks, such as heart attacks, severe high blood pressure, bleeding and small tears in other body parts such as the nose, stomach or intestines.
The agency said it reached its conclusion after reviewing clinical trial data from the drugmaker, as well as from the FDA and the European Medicines Agency. It also convened an independent advisory panel in March 2011 to advise the agency on the drug.
"The panel, which included oncologists, scientists and breast cancer patient advocates, unanimously concluded that the potential harm of using Avastin is of such magnitude that the risks of the drug far outweigh potential benefits, and that, based on the current available evidence, there is no value in maintaining Avastin as a treatment option," Health Canada said.
