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US Navy asks to test human blood substitute without patient consent

The Associated Press
Published: December 14, 2006

WASHINGTON: The U.S. Navy's latest proposal to test a blood substitute on 1,100 trauma victims appears more likely to earn a go-ahead from regulators who had blocked the experiment over safety concerns.

The Navy wants to test the product, derived from cow blood, on civilian trauma victims in emergency situations. It proposes doing so without obtaining their consent in advance, as is customary in clinical trials.

The substitute blood, called Hemopure, would be given on the way to the hospital to patients ages 18 to 69 who have lost dangerous amounts of blood. It would substitute the saline fluids typically given in ambulances when donated blood is unavailable for transfusion.

Three times since June 2005, the Food and Drug Administration has blocked Hemopure trials from starting. Each time, it has cited safety concerns. Its manufacturer, Biopure Corp., based in Cambridge, Massachusetts, contends that the benefits of Hemopure outweigh its risks.

The Navy, which is overseeing the government-funded study, has since revised its design. It now says the product will not be given to patients 70 or older, and it is limiting the amount of Hemopure that would be given to trauma victims.

Those changes may persuade the FDA to allow the experiment to proceed.

"The restriction on age and on the volume of the test article suggests that the clinical requirements for exception from informed consent are much closer to being met than in the original protocol," an anonymous FDA reviewer wrote in agency documents. There "appears to be sufficient information provided to consider approval under waiver of consent," the reviewer added.

The FDA released the documents ahead of a public meeting of agency advisers convened to discuss the proposed experiment. The meeting Thursday originally was to have been held in secret in July but was postponed at the last minute.

Researchers say blood substitutes can both counter a dangerous drop in blood pressure in bleeding victims and carry oxygen from the lungs to the body. Saline fluids can do the former but not the latter. While blood can do both, it has its own limitations. Unlike blood, blood substitutes theoretically could be stored for years and then used without concern for infection or blood type.

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