Roche Holding AG’s Avastin may increase a cancer patient’s risk of having a fatal reaction to treatment when it is added to chemotherapy, researchers said.
Deadly side effects occurred in 2.5 percent of patients given Avastin, and were 46 percent more common in those getting it in a mix of medicines rather than chemotherapy alone, a report in the Feb. 2 Journal of the American Medical Association found. The analysis included 16 clinical trials of Avastin for breast, lung and other cancers involving 10,217 patients.
The overall chance of dying because of treatment with Avastin is low and the risks should be weighed against the drug’s benefits, the researchers said. The most common side effects that led to death were hemorrhage, gastrointestinal tract perforation and infections in patients with weakened immune systems, the study found.
“We have to optimize use of Avastin in cancer patients so we can reduce fatal events and improve patient safety,” said Shenhong Wu, senior author of the paper and assistant professor of hematology and oncology at Stony Brook University School of Medicine in New York. “Physicians and patients have to be aware and recognize the risks, monitor closely and manage adverse events appropriately.”
The risk from Avastin was greatest with chemotherapies known as taxanes or platinum agents, including Paris-based Sanofi-Aventis SA’s Eloxatin and Taxotere and generic medicines such as cisplatin and paclitaxel. Those cancer drugs are most often used for lung and colon cancers, Wu said in a telephone interview.
Avastin is approved in combination with chemotherapy for treating many types of advanced cancer including malignancies of the colon, lung, breast, kidneys and brain, according to an editorial that accompanied today’s study. Previous research has shown the drug can delay the recurrence or spread of some cancers, though it doesn’t necessarily lengthen survival.
The U.S. Food and Drug Administration moved to withdraw Avastin’s 2008 approval for breast cancer on Dec. 16, citing studies that the agency said failed to show a significant benefit to a broad population of patients to justify the drug’s toxicities. Basel, Switzerland-based Roche appealed the decision.
Sales were 6.22 billion Swiss francs in 2009, or $5.75 billion based on the average annual exchange rate.
In today’s study, the risk of fatal adverse events didn’t vary based on the type of tumor or the amount of Avastin administered, the authors said.
The analysis included tumor types that Avastin isn’t approved to treat, said Charlotte Arnold, a spokeswoman for Roche’s Genentech unit in South San Francisco, California. For patients with advanced colorectal, kidney and breast cancers, where Avastin is approved, there were a similar number of deaths, she said in a statement.
“Like other cancer medicines, Avastin has serious risks that are clearly described in its label and need to be considered by doctors and patients, in the context of its potential benefits,” Arnold said. “As we continue to study Avastin, our goal is to identify the people who will derive a more substantial benefit from the medicine.”
It is currently impossible to determine which cancer patients will benefit from Avastin, known chemically as bevacizumab, or how long they will respond to it, said Daniel Hayes, clinical director of the Breast Oncology Program at University of Michigan Comprehensive Cancer Center in Ann Arbor.
While early, prolonged treatment with the drug that can cost $50,000 a year may offer the most benefit, patients would potentially be exposed to more toxic effects and the cancer could rebound after treatment stopped, he wrote in an editorial.
“Oncologists are forced to dilute the potential effects of bevacizumab by exposing all treated patients, and society, to enormous costs and occasional life-threatening toxic effects,” Hayes wrote. “These unfortunate circumstances are sad for those who pay the bills -- and sadder for patients with solid tumors.”
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