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SILVER SPRING: The US Navy should not be allowed to test emergency transfusions of an experimental blood substitute on civilian trauma patients because most of those patients would be unable to give consent, a federal advisory panel said on Thursday.
The Food and Drug Administration panel of independent experts, in an 11-8 vote, said the Navy lacked enough information to support its proposal to test Biopure Corp.'s Hemopure, which is made from cow blood.
“I do think there is a potential benefit. We just don't have the data,” said panelist Dr. Thomas Quinn of Johns Hopkins University in Baltimore.
The FDA is not bound by the vote but usually follows the recommendations of its advisory panels.
The Naval Medical Research Center proposed a trial of Hemopure in hopes it might eventually win U.S. approval for treating hemorrhagic shock after traumatic injury. Hemopure has already been studied for surgery in humans and in animals.
The product could save lives in combat zones when victims cannot quickly reach a hospital, Navy officials said.
“This is especially important in close-quarter urban combat and in other special situations where evacuation may be dangerous or delayed or both,” said Navy Deputy Surgeon General Dr. John Mateczun.
“We didn't have the luxury of a hospital out there,” Sgt. James “Eddie” Wright, a U.S. Marine who lost both hands in Iraq in 2004, said on behalf of the Navy. “There is no gray area … it's either 'he's going to die or we can try this.”
Hemopure, also known as HBOC-201, can help deliver oxygen to vital organs until real blood is available. It can be stored for long periods without refrigeration.
A key issue is whether Hemopure can be tested when patients are in shock, unconscious or unable to give consent. While FDA regulations allow such trials, critics have questioned them, saying the public cannot easily opt out.
The Navy submitted a revised plan after the FDA rejected a previous proposal due to safety concerns.
Under the Navy's revised plan, patients between 18 and 70 years old would receive up to three units of Hemopure from emergency medical technicians at participating city hospitals. Paramedics would try to explain the trial to patients and get consent, if possible, under the Navy proposal.
Studying civilians is necessary because battlefield trials are impossible, the Navy's Dr. Dan Freilich said. “In a combat setting, there are bullets flying — you just can't,” he said.
FDA staff told panelists they were troubled by Hemopure's side effects, which include a higher risk of heart attack, cardiac arrest and death. “The has been no adequate safety demonstrated in any trial,” said Dr. Toby Silverman, head of review for the FDA's hematology division.
Most panelists agreed, saying a smaller trauma study should be done first. Others said there was no way to test the product for emergencies without allowing waived consent.
Consumer advocate Dr. Sidney Wolfe of Public Citizen urged the panel to reject the Navy's plan, saying the study was unethical. “This product is far too dangerous,” he said.
Hemopure is already sold in South Africa and is awaiting an approval decision in Britain.
Shares of Biopure closed down more than 6 percent at 59 cents on the Nasdaq, prior to the panel's decision.
Another company, Northfield Laboratories Inc, has also faced criticism for studies of its Polyheme blood substitute, made from human hemoglobin.
