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Posted on Nov 07, 2006, 10 a.m.
By Bill Freeman
Grace LeClair had just finished eating dinner with friends when she got the phone call every parent dreads. The chaplain at the Medical College of Virginia was on the other end.
Grace LeClair had just finished eating dinner with friends when she got the phone call every parent dreads. The chaplain at the Medical College of Virginia was on the other end. “Your daughter has been in a serious accident. You should come to Richmond right away.” LeClair was in Virginia Beach at the time, a two-hour drive from 20-year-old Bess-Lyn, who was now lying in a coma in a Richmond hospital bed.
The friend who was with Bess-Lyn has since filled in the details of that day in March. The two women were bicycling down a steep hill, headed toward a busy intersection, when Bess-Lyn yelled that her brakes weren’t working and she couldn’t slow down. Her friend screamed for her to turn into an alley just before the intersection. But Bess-Lyn didn’t turn sharply enough and crashed, headfirst, into a concrete wall. She wasn’t wearing a helmet. By the time the ambulance reached the hospital, Bess-Lyn was officially counted among the 1.5 million Americans who will suffer a traumatic brain injury (TBI) this year.
Bess-Lyn’s mom was halfway to Richmond when she received a second call, this time from a doctor. “He was telling me that she had a very serious injury, that she had to have surgery to save her life and that if I would give permission, they would use this experimental, not-approved-by-the-FDA drug,” Grace LeClair recalls. “He said that it would increase the oxygen supply to her brain. To me that only made sense, so I said yes.”
With her mother’s verbal consent, Bess-Lyn was treated with a type of artificial blood called Oxycyte, the subject of a clinical trial led by doctors at the teaching hospital of Virginia Commonwealth University. In animal tests, the compound has been proven to cut the effects of brain damage nearly in half, presumably because its tiny particles can ferry oxygen through swollen, injured vessels our own red blood cells can’t squeeze through. (The suffocation of brain cells is a major contributor to brain damage.) The doctors’ next step is to get the same result in accident victims like Bess-Lyn, who became the third of eight patients to be enrolled in the hospital’s pilot Phase II clinical trial, designed to test the drug’s safety and efficacy. If Oxycyte performs well in subsequent trials, it will become the first drug the FDA approves to treat traumatic brain injury in the U.S. and in hot spots like Iraq, where TBI has become horrifyingly common.
THE RED AND THE WHITE
Oxycyte is the newest product in a family of compounds known as artificial blood. The search for a synthetic substitute for human blood began at least as early as the 19th century, when doctors actually tried using milk to replenish blood loss. With the onset of the AIDS crisis in the early 1980s, pharmaceutical companies took on the cause in force, competing to create an artificial substance that could eliminate the problems—including tainted blood and supply shortages—associated with donated blood. The idea was that these substitutes could replace the use of donated blood in transfusions, during surgery, and in patients who had experienced major blood loss through injury.
Two categories of contenders soon emerged. The first was a red-colored substitute made in part from human or animal hemoglobin, the protein in our red blood cells that carries oxygen. The second was a snow-white, completely synthetic substance made from perfluorocarbons, or PFCs, a compound whose chemical makeup closely resembles the nonstick Teflon in your frying pan. PFCs have the highest gas-dissolving capacity of any liquid and, when used with supplemental oxygen, allow blood to carry many times more oxygen than it normally does (and to carry more oxygen faster and more easily than hemoglobin-based substitutes).
In large-scale clinical trials in the 1980s and 1990s in which researchers pitted the fake bloods against the real thing, patients who received the artificial stuff experienced a disproportionate number of heart attacks and strokes. Those outcomes—widely attributed to a combination of poorly designed trials and first-generation formulations—effectively shut down human studies and, in some cases, bankrupted biotech firms.
After two decades and a billion dollars’ worth of research, the most valuable lesson learned was that real blood and these artificial bloods were apples and oranges: The life-giving liquid in our veins acts like a supply line for everything from nutrients to hormones to oxygen, even working double-time to regulate our blood pressure and fight infection. The manufactured substances, on the other hand, are one-trick ponies for oxygen delivery. But it’s a trick they perform remarkably well—in the case of PFC-based substitutes, carrying oxygen at rates roughly 50 times that of our own blood.
