FDA ponders use of biomarkers in drug trials

WASHINGTON The Food and Drug Administration may soon support using biomarkers during tests in an effort to identify risk of experimental drugs in patients sooner, which could lead to the drugs being marketed quicker, according to published reports.

A biomarker is an indicator that can be used to test a biological function. Some biomarkers turn up when organs are injured and cells within the damaged tissue release substances into the blood, urine or saliva. These substances can then be used to detect dangerous side effects.

Currently, experimental drugs are tested in animals before being taken to human clinical trails. But animals' reactions aren't always the best predictor of whether substances will be safe for humans. Drugs harmless to animals can hurt humans, and vice versa. If a drug toxic to the kidneys passes animal tests today, the damage might not show up until it is too late.

"Using current tests, you have lost about 70 percent of the kidney function before you pick it up," says William Mattes, director of toxicology at the Critical Path Institute.

The new biomarker process has the potential to save a patient's kidneys.The ultimate goal of the pharmaceutical industry is to have a range of such marker tests that would signal such dangerous side effects as heart failure, liver damage or cancer. Samples of blood, urine or saliva, for example, would be taken from participants in a clinical trial. If certain biomarkers indicated the patient was at risk, the trial could be stopped before any major damage occurs.

Seventeen companies have joined the research into biomarkers at the Critical Path Institute. These include giants like Bristol-Myers Squibb, GlaxoSmithKline, Johnson & Johnson, Merck and Pfizer.

Initially, seven biomarker testing processes will be qualified by the FDA for use in preclinical animal studies, and only as a complement to current tests.