Contradictory decisions made in the United States and Europe last week about a drug used to treat breast cancer are creating controversy and confusion over whether patients should still have access to it.
The confusion may be most palpable in Canada, where federal regulators have yet to decide whether Avastin should stay in use for breast cancer treatment because it helps patients live longer, or if approval needs to be revoked in light of new studies suggesting the drug is ineffective and potentially unsafe.
“We’re in the dark about all of this,” said Joel Lexchin, a professor in the school of health policy and management at York University in Toronto.
Some Canadian advocates for breast cancer patients say they want the drug to remain available as a treatment tool, while some oncologists welcome the idea that it could be dropped, citing tepid results from clinical trials and the potential for damaging side effects.
The controversy comes after the U.S. Food and Drug Administration announced last Thursday it plans to revoke approval of Avastin, the brand name of bevacizumab, as a treatment for metastatic breast cancer (cancer that has spread). New studies failed to show Avastin significantly improves survival or slows disease progression, the agency said, while it exposes patients to serious side effects, such as severe high blood pressure, bleeding and perforations in the nose, stomach and other body parts. The U.S. maker plans to appeal the decision and stands by the drug's safety and effectiveness, said Lorenzo Biondi, vice-president and regulatory affairs at Hoffmann-La Roche Canada, which sells Avastin here.
The same day, the European Medicines Agency endorsed continued use of the drug in combination with chemotherapy drug paclitaxel to treat metastatic breast cancer, although it limited use of Avastin with other chemotherapy treatments.
The divergent decisions are fuelling debate over the drug’s effectiveness, while Canadian breast cancer patients and their advocates are confused by what the mixed messages mean for patients in this country.
Health Canada spokesman David Thomas said the department hasn’t determined what action to take and is “reviewing the latest evidence.”
Avastin is the world’s bestselling cancer medication and is used in Canada to treat metastatic colon and rectal cancer, as well as metastatic lung cancer.
In February, 2009, Health Canada gave speedy approval to Avastin as a metastatic breast cancer treatment on the condition the company submit results of additional clinical trials to the regulator. Fast-tracked approvals are reserved for promising, potentially life-saving drugs.
Jackie Manthorne, chief executive officer of the Canadian Breast Cancer Network, said patients are confused about the status of this drug and highlighted the fact Europe has given it the green light for continued use.
“We believe in keeping an open mind so that Canadian women will have as many treatment options as possible,” she said.
The CBCN accepts funds from Roche and has done advocacy activities with the company. Ms. Manthorne said she doesn’t think the network is in a conflict of interest because it has a corporate policy for relationships with drug companies.
But Shailendra Verma, medical oncologist with the Ottawa Hospital Cancer Centre, said he doubts Avastin would be missed by many in Canada because it has never been proven to work well in metastatic breast cancer patients. “I think many oncologists have been very uncomfortable about endorsing it,” Dr. Verma said.
There is a lot of “exciting” research looking into better treatments for patients, Dr. Verma said, and urged women with breast cancer to get involved.
“Avastin has not been the answer to our prayers,” he said. “Women with breast cancer should not have their hopes dashed by this.”