The term "biomarker" encompasses hundreds of proteins, antibodies, hormones and other naturally occurring substances in body fluids, particularly blood. The prostate-specific antigen (PSA), for example, is a well-known biomarker. Scientists can now analyze a small sample of blood and detect the biomarkers for a wide range of medical conditions before the patient experiences any symptoms.

The federal government has taken notice of biomarkers. In 2004, the FDA issued the Critical Path Initiative, aimed at reducing the costs and time it takes to bring a new drug to market. In March, the FDA released a list of projects that can help speed up the process, and pronounced biomarker research one of the two most important areas for improving medical product development. The other priority, streamlining clinical trials, should get a boost from the use of biomarkers.

Today, nine out of 10 experimental drugs fail when tested in humans. Pharmaceutical companies usually spend eight to 10 years to test a new drug, with a cost as high as $1 billion. These years represent missed opportunity for the pharmas–and their investors–because while the R&D teams are testing the drug, the patent sits on the shelf. Because the patent expires in 20 years, a drug that takes 10 years to get to market benefits from only 10 of those years.

Researchers, however, may be able to cut several years and millions of dollars from the trial period if they monitor the patients’ progress by testing their biomarkers. Subtle changes in biomarkers can be the earliest indicators of the effectiveness or ineffectiveness of an experimental drug–first in animal subjects, then in humans. Biomarkers can also expose side effects early in the process.

Consider the case of the $2.5 billion-a-year painkiller Vioxx, which Merck took off the market in September 2004 following a study that showed it doubled heart attack and stroke risk for those who took it for 18 months or longer. The ensuing wave of lawsuits could end up costing the company as much as $30 billion. Researchers might have been able to find evidence of heart problems in the trial stage if the kind of biomarker testing now in use had been available at the time. When biomarker testing is used, the FDA might be able to approve a drug in spite of some side effects in some patients, because doctors would be able to monitor their patients’ biomarkers for an adverse reaction and take them off the medication if necessary.

Hitting a Bull’s-Eye
All of this could lead to lower development costs for what is known as personalized medicine. This might advance more obscure drugs that treat conditions in only a small percentage of people, such as Genentech’s Herceptin. In trials, only 20 percent of patients responded well to this breast cancer drug; but it worked very well on that group.

Biomarker technology does not detect structural defects such as aneurisms, nor can it detect brain diseases. There is tremendous potential, however, for both researchers and physicians in private practice to use biomarkers as a diagnostic tool in detecting very early stages of heart disease, many forms of cancer, autoimmune diseases, infections and hormonal disorders.

There could come a day when a physician routinely conducts a checkup by taking a small blood sample and sending it to a lab for a biomarker test, but that day may be a long time in coming, partly because it would require great changes in the insurance industry. For private insurers, early detection only burdens an insurance company that might otherwise be able to pass health care costs along to a competitor when the patient changes insurers–which Americans do, on average, every three to four years. Cash-strapped public insurers in the U.S., Canada and Europe have so far been unwilling to make the cash outlay to support biomarker testing. Eventually, however, rising costs might force us all to use this very early stage detection technology, which could make it possible to treat patients with less aggressive and expensive therapies, thereby lowering health care costs.

Mark Chandler PhD is chairman and CEO of Biophysical, which develops and markets biomarker tests, and is founder of the Center for Biomarker Research.