The Food and Drug Administration and Genentech have warned doctors that Avastin, used to treat colorectal cancer, increases patients' risk of suffering heart ailments - including chest pain, strokes, mini-strokes and heart attacks.
Avastin also raised the risk of patients dying from those heart ailments.
Colleen Sweeney, Genentech spokeswoman, said Friday that some patients taking Avastin died from those heart ailments but could not say how many. "I don't have the data," Sweeney said.
During clinical trials before the drug's approval, one patient died but a "clear relationship" could not be determined between Avastin use and the heart-related fatality, she said. Additional analyses led to the issuance of the drug warning.
"Right now, we're working with the FDA, with these analyses, to update the Avastin label," she said.
Genentech would not say how many patients were prescribed Avastin after FDA approval. "We don't give out prescription information," Sweeney said.
But the company did tell health care providers in its warning letter that patients whose cancer has spread to the rest of their bodies were twice as likely to suffer serious heart ailments if they received Avastin with their chemotherapy. The highest-risk individuals had a past history of such heart problems and were older than 65.
The FDA on Feb. 26 approved the product - a genetically engineered version of a mouse antibody containing mouse and human components - after testing showed patients receiving the drug intravenously lived an additional five months. The drug, the first approved angiogenesis inhibitor to treat colorectal cancer, works by blocking new blood vessels, essentially depriving cancer cells of the oxygen and nutrients they need to thrive.
According to the Centers for Disease Control, cancer of the colon or rectum is the nation's third most common cancer and is the second leading cause of cancer-related deaths.
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On the Net:
Avastin: http://www.gene.com/gene/products/information/oncology/avastin/index.jsp
