Blood substitutes raise risk of death, study says
FDA criticized for not stopping studies
NEW YORK - Artificial blood raised death risks by 30 percent and almost tripled the odds of heart attacks in 16 clinical trials analyzed by researchers who say US regulators should have stopped the studies eight years ago.
Five trials involving substitute blood products are ongoing, and a new one is about to begin, the researchers reported. The Food and Drug Administration is holding a workshop in Bethesda, Md., today to discuss safety of the products.
The researchers, in a report in the Journal of the American Medical Association, said the FDA in 2000 received data on individual studies showing increased risks that should have triggered suspension of testing until a large-scale analysis. Now the agency should end all trials and Congress should review rules forcing the FDA to keep information on new products confidential for competitive reasons, the researchers said.
"If you have secret science, things like this can happen," lead researcher Charles Natanson, who studies septic shock at the National Institutes of Health, said. "Once you've randomized patients, your results can't be a trade secret. It's a measure of protection to the American public."
The blood substitutes studied in the analysis were made by Baxter International Inc., Biopure Corp., Hemosol BioPharma Inc., Northfield Laboratories Inc., and Sangart Inc.
Some finished studies still aren't public. Five trials are ongoing internationally, in places including the United Kingdom, and at least one more is planned, the researchers said.
"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," the researchers wrote.
Jay Epstein, director of the office of blood research and review at the FDA, said analyzing several studies together as one, a process called meta-analysis, has its limitations. The agency also has unpublished information not available to the study's authors that shows potential benefits of artificial blood, he said.
"There are vast differences among these products that make any pooling of data flawed," said Tiana Gorham, spokeswoman for Cambridge-based Biopure. Baxter, of Deerfield, Ill., discontinued work on such products more than five years ago, said a company spokeswoman. Sangart, of San Diego, had no comment. An official at Hemosol didn't return a call for comment.
"Meta-analysis is not designed to provide answers about specific products or to examine fully the risk/benefit ratio of any particular product," said Northfield Labs chief executive Steven Gould.
"The most important thing is to recognize there's an important medical need," the FDA's Epstein said. "Both in the past and recently, the FDA has placed studies on clinical hold when there were safety concerns that outweighed clinical benefit."
