Undetectable Dialysis Drug Is Tied to Athletes’ Deaths

A new genetically engineered kidney-disease drug, already one of biotechnology’s best-selling products, is threatening to become an undetectable killer of athletes who misuse it to enhance their performance.

The year-old designer drug, known as “go juice” among anemic dialysis patients, is widely feared to have already killed a handful of European bicyclists, although sports officials and researchers concede they may never know for sure.

The drug, which stimulates production of oxygen-carrying red blood cells, is cloned from human molecules, and there is no way to differentiate between the naturally occurring substance and the drug, called Epogen.

“The drug is a natural hormone,” said Mark Brand, a spokesman for Amgen, the Thousand Oaks firm that developed the product.

“When you make a human drug by recombinant technique, you are reproducing the natural protein made by the body. It would be extremely difficult to detect,” added Dr. Daniel Vapnek, Amgen’s senior vice president for research.

They said the firm is exploring with various sports organizations ways to develop an educational campaign against “inappropriate” Epogen use, targeting athletes.

Among such groups is the International Olympic Committee, which recently added Epogen to its list of banned substances, according to Thomas Murray, a member of the U.S. Olympic Committee’s panel on substance abuse research and education.

Epogen mimics the actions of erythropoietin (EPO), a naturally occurring protein produced by healthy kidneys. EPO circulates through the bloodstream and stimulates the bone marrow to produce red blood cells, which transport oxygen to the lungs.

In anemic dialysis patients, Epogen helps replenish red blood cells, which can fall to as little as one-third their normal level. In endurance athletes, massive infusions of EPO can provide additional aerobics capacity for superior performances.

But the danger is that an excessive number of red blood cells causes blood to thicken, forcing the heart to work harder and possibly leading to strokes and heart attacks, especially during vigorous exercise, according to Murray and Vapnek.

“This is a drug that, if used properly, is wonderful. But it has potentially serious, negative side effects if misused,” Brand said. “It can be fatal.”

In the Netherlands, health and sports officials--concerned about Epogen use--are investigating the sudden, inexplicable deaths of half a dozen or so competitive bicyclists.

A test is now available to determine a person’s EPO levels. But such one-time readings are probably meaningless since individual EPO levels can vary considerably over time. This is especially true, experts said, when an athlete has trained in high altitudes, where the air is thin, thus forcing the body to respond by producing more red blood cells.

“The only way at the present time” to detect use of Epogen by athletes, Vapnek said, is to “measure every day for six months” before competition. “But I don’t know about the practicality of it.”

Seeking to enhance athletic performance by tinkering with one’s own blood is not new.

Until the practice was banned by the International Olympic Committee in the mid-1980s, it was not uncommon for athletes to extract and freeze their own blood for infusion just before competition.

The rationale of “blood doping” was that, by the time the extracted blood was infused later, the athlete’s blood level would have returned to normal and the infusion would provide a higher concentration of red blood cells.

Murray, director of Case Western Reserve University’s center for biomedical ethics in Cleveland, said of the use of Epogen among athletes: “This is blood doping without actually having to take blood.”

About 55,000 kidney patients in the United States are receiving injections of Epogen, which also is available by prescription in Japan and Western Europe, at a cost of about $6,000 a year.

Anemia can cause extreme fatigue, depression, inability to concentrate, vertigo and insomnia. Epogen therapy has produced dramatic changes, including testimonials from once-bedridden patients who returned to work and resumed exercising.

“Epogen is one of the most important human therapeutics ever developed,” Vapnek said.