In drug research, guinea pigs of choice are humans

<div class="section1"><div class="Normal">Researchers at the University of Munich repeated the experiment 70 times: a healthy volunteer would receive a chemical injection, then be left alone to ride out an artificially induced panic attack. From the next room, doctors watched the volunteer''s restlessness via video camera, measured quickening pulse and rise in blood pressure, and used an intercom to question the person about feelings of impending doom.The attacks typically lasted 5 to 10 minutes. <br /><br />Each volunteer was put through the same test a few days later, but this time most of them first received an experimental anti-anxiety drug. The drug quelled anxiety well enough in those experiments last year that its developer, the Swiss pharmaceutical company Novartis, gained the confidence to conduct large clinical trials. <br /><br />The company''s approach is part of a trend in pharmaceutical industry. Drug researchers are conducting small, fast, relatively inexpensive tests on people to get a quick gauge of a drug''s promise before committing to full-scale clinical trials that may involve hundreds of patients, millions of dollars and many years of study. Often called experimental medicine, the approach is meant to reduce the huge costs of drug development and speed the most promising treatments into the marketplace. <br /><br />In the past, many of the tests might have been done only on animals. But, scientists and industry executives say that experiments on people are more reliable, because animal tests often fail to accurately predict whether a drug will work on people. "Humans are the experimental animals here," said Roger Perlmutter, executive V-P at Amgen, a biotech company. <br /><br />Amgen, for instance, gave different potential arthritis drugs to human volunteers and then used a blood test to gauge the best one to take forward into clinical trials. The results were almost the opposite of what Amgen found when it conducted similar tests in animals. <br /><br />Pfizer has done experiments in which volunteers were injected with radioactive tracers and given PET scans to see if the drugs were reaching their expected targets. It has abandoned several drugs that did not, said Stephen Williams, who directs clinical technology. <br /><br />It is too soon to know whether experimental medicine will really transform drug development. But the industry needs to do something. Despite rising R&D cost, last year only 21 new compounds were approved as drugs, compared with more than 30 a year in the late 1990''s. Only about 8% of drugs entering clinical trials now make it to market, according to FDA, and companies want to be able to spot losers before a lot is spent. Even a small improvement in ability to predict failures could save $100 million in development costs per drug, the FDA said in a report.<br /><br />While not abandoning animal studies, scientists might now move back and forth between animal and human studies. Phase 1 trials might be used to gauge efficacy, not just safety. In some cases, human testing is being done even before a drug is given - for example, to validate the imaging system that will be used in the trial. Some scientists call these "phase 0" trials. The impact of experimental medicine could become clear in a few years, as the early drugs that have gone through the process move closer to market. <br /><br /><span style="" font-style:="" italic="">NYT News Service</span></div> </div>