Health Canada has revoked approval of Avastin as a treatment for metastatic breast cancer, following closely in the footsteps of the U.S. Food and Drug Administration.
The FDA announced in mid-November that it was withdrawing approval of the drug for breast cancer, saying there is no evidence it extends the lives of women with metastatic breast cancer and use of the drug is associated with some serious risks.
After studying the data, Health Canada has come to the same conclusion. It has told drug maker Hoffman-La Roche to remove the breast cancer indication from Avastin's label. The company says it will comply.
"Suspending an authorization for a drug on the market is not a decision taken lightly," the department said in a statement.
"Health Canada has concluded that Avastin does not significantly reduce tumour size or extend lives, while it may cause serious and potentially life-threatening risks, such as heart attacks, severe high blood pressure, bleeding and the development of small tears in parts of the body such as the nose, stomach or intestines."
The statement noted that there are several alternatives available in Canada for the treatment of metastatic breast cancer that deliver equal or more benefit than Avastin, and with fewer risks. Metastatic cancers are cancers that have spread from the original source to other parts of the body.
Health Canada said the decision has no impact on Avastin's authorization as a treatment for metastatic colon, rectal, and lung cancers, as well as in the treatment of a type of brain cancer known as glioblastoma.
Avastin is the world's bestselling cancer drug, but repeated studies have shown it has only a small effect on tumour growth in breast cancer.
But women with the metastatic form of the disease have lobbied hard for access to the expensive drug, which can cost $100,000 for a year's treatment, including infusion fees.
Still, it is believed few patients in Canada have been using the drug for breast cancer, as no province has approved funding of it.
Avastin manufacturer Genentech, which is owned by Swiss drug maker Hoffman-La Roche, has argued that the drug should remain available while it conducts more research to see if certain subsets of breast cancer patients might benefit from its use. Some doctors have argued that they do see a few patients who seem to do better with Avastin than without it.
Health Canada said its decision is based on data provided by the manufacturer and information from the FDA and its European equivalent, the European Medicines Agency. Health Canada also considered advice provided by an independent expert advisory panel it convened in March 2011.
The panel — made up of 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. It said that based on the current available evidence, there is no value in maintaining Avastin as a treatment option.