Testing Drugs on Animals No Longer Suitable Option
By Deborah Wilson, M.D.

This op-ed by a PCRM member doctor was published in the Arizona Republic on April 23, 2006

As debate continues over Covance's plan to build an animal drug-testing facility in

Chandler, I am troubled by its controversial record of animal care and the reported suffering of animals in its experiments.

I also have serious concerns about the harm pharmaceutical testing on animals can cause to humans. Animal tests such as the ones that would be conducted at the proposed Covance facility have led to a string of public health disasters.

Vioxx, Phenactin, E-Ferol, Oraflex, Zomax, Suprol and Selacryn are a few of the drugs that appeared safe in animal tests but were pulled from the market in recent years for causing the death or seriously harming thousands of people.

Vioxx, for example, seemed to protect the cardiovascular system in some animal experiments. About 20 million Americans used the drug before a clinical study revealed in 2004 that it could double the risk of heart attack or stroke. After that revelation, Merck withdrew Vioxx from the market. But considerable damage had already been done: Tens of thousands of people may have suffered heart attacks or strokes related to Vioxx.

Such tragedies are remarkably common. The U.S. Government Accountability Office found that among all new drugs marketed during a 10-year period, 52 percent had seriously toxic or fatal effects that were not predicted by animal experiments.

The problem comes down to basic biology. Many species of animals metabolize drugs differently from humans. The manner in which compounds are broken down, transported and distributed to various organs and excreted from the body varies widely from species to species.

In August 2004, the Food and Drug Administration announced that only 8 percent of drugs that pass animal tests make it to the marketplace. In other words, a remarkable 92 percent of drugs found to be safe and effective in animals have turned out to be unsafe or ineffective in humans.

Health and Human Services Secretary Mike Leavitt expressed a similar concern earlier this year.

"Currently, nine out of 10 experimental drugs fail in clinical studies because we cannot accurately predict how they will behave in people based on laboratory and animal studies," he said.

One recent example of a perilously misleading study, reported earlier this month in the New York Times, involved an immune stimulant known as TGN1412.

After tests of the drug in monkeys showed "no significant trouble," it was given to six healthy young men. All six came close to dying. The men "moaned in uncontrollable pain, vomited and struggled for breath," the Times reported. The drug has left all six with seriously damaged immune systems.

The drug company said the human trial went forward because "doses hundreds of times more powerful" had been found safe in the animal test.

Non-animal testing works better. Human cellular tests assembled by the Multicenter Evaluation of In-Vitro Cytotoxicity, an international group of scientists, have proved more predictive of human safety than animal tests.

Such evidence has prompted the FDA to propose better methods for ensuring drug safety. In January, the agency announced that it will rely more on non-animal methods, including human microdosing, which will provide more accurate results. Microdosing is already being implemented with great success in the United Kingdom.

The private sector is also moving forward with alternatives. Pharmagene uses computer technologies built on our knowledge of human genetics and molecular biology to show the effect of drugs on the body. As Gordon Baxter, co-founder of Pharmagene, said, "If you have information on human genes, what's the point of going back to animals?"

Such projects represent the future of drug testing, unlike the outmoded and unreliable animal experiments that would take place at the proposed Covance facility.

Deborah Wilson, M.D., is a Scottsdale gynecologist and laparoscopic surgeon.

Founded in 1985, the Physicians Committee for Responsible Medicine is a nonprofit health organization that promotes preventive medicine, especially good nutrition. PCRM also conducts clinical research studies, opposes unethical human experimentation, and promotes alternatives to animal research.