WASHINGTON (Reuters) - Certain experimental blood substitutes can significantly raise the risk of heart attack and sudden death and regulators should stop their use in new experiments until safety issues have been cleared up, researchers said on Monday.
Health advocates who teamed up in an unusual joint study with federal government researchers said their study of blood substitutes showed Food and Drug Administration’s confidential oversight of corporate research was putting patients at risk.
They called not only for a halt to trials of the blood replacement products, but an overhaul of the FDA’s requirements to keep corporate secrets.
The study of various trials of five blood substitutes showed a 30 percent increased risk of death and a 2.7 times higher risk of heart attack, they reported in the Journal of the American Medical Association.
All of the products in question use hemoglobin, the molecule that transports oxygen in red blood cells.
The researchers also plan to present their findings at an FDA public workshop on the safety of the products this week.
“The case study detailed here underscores both the scientific inefficiency and the real risks to patients of the current failure to report data promptly,” wrote Dr. Charles Natanson of the National Institutes of Health and colleagues there and at Public Citizen.
“When ‘secret science’ is allowed, scientists are unable to build on the successes or failures of other researchers testing similar products, and patients can be repeatedly exposed to risks unnecessarily,” they added.
“One straightforward solution to these problems would be for Congress to reverse the FDA’s policy of treating as confidential all corporate materials submitted during the product development process, including the investigational new drug application.”
The FDA defended its oversight of the trials and said it was aware of the safety issues.
“There is a major unmet medical need,” said Dr. Jay Epstein, director of FDA’s office of blood research and review.
“Independent of this recent meta-analysis, FDA had already, based on our own analysis, identified concerns about an increasing body of data that has emerged about the safety of (hemoglobin based blood substitutes),” Epstein told reporters.
For their study, Natanson and colleagues looked at the data from 16 trials involving five products and 3,711 patients.
They included Baxter’s HemAssist, Biopure’s Hemopure, Hemosol BioPharma Inc’s Hemolink, Northfield Laboratories’ PolyHeme and Sangart Inc.’s Hemospan.
They said if the FDA had done a similar analysis, it would have been obvious by 2000 that the products raised the risk of death. “Had the agency placed a moratorium on trials at that point, product-related deaths and MIs (heart attacks) in subsequent trials most likely would have been prevented,” they wrote.
Epstein disagreed. He said the FDA was aware of “certain signals” and only allowed a few trials of the products to proceed.
Epstein said he concurred with the Natanson team’s findings that the products may affect a molecule called nitric oxide, and also that the products may cause inflammation, with both affecting blood pressure and blood flow. (Editing by Alan Elsner)