The Role of Human Guinea Pigs in Drug Tests

Before a new drug can be offered to the public, its manufacturer must prove that it is safe and effective. To do this, scientists must test the drug in human beings. As it turns out, this human testing, referred to as clinical trials, is the most costly and time-consuming component of the drug-development process.

Only about 20 percent of the compounds submitted to the Food and Drug Administration (FDA) for clinical trials gain approval for marketing. Critics charge that the testing process is too costly, complicated, and lengthy; they point to other countries where it is much easier to get new drugs approved.

In recent years, the FDA has tried to speed up the procedure, especially for drugs to treat AIDS, but the process still costs an average of $125 million and it lakes eight lo nine years to bring a new drug to the marketplace.

How Human Testing Works

Contrary to a common public assumption, the FDA itself does not conduct human testing — this is carried out by a pharmaceutical manufacturer, research organization, or a public or private agency. But the FDA reviews and approves the testing procedure, or protocol, as well as the results — often a truckfoad of volumes.

In the initial, or Phase 1, clinical trials, an experimental drug is given to 20 to 100 healthy volunteers for several months to make sure it is safe. About 70 percent of drugs pass this safety test.

During the next, or Phase 2, testing, several hundred patient volunteers take the drug for a few months to two years to determine whether it is effective as well as safe. For this phase, the volunteers are often divided into two groups, with a number receiving the experimental drug and others getting a placebo. In some instances, a third group may be taking an existing medication in order to find out if the new drug really is superior.

Some 25 to 30 percent of experimental drugs go on to the final Phase 3 testing, which typically involves several thousand patients and lasts for one to four years. During this period, the safety, effectiveness, and dosages are tested. Even if the drug is among the 20 percent that are eventually offered to the public, it must still be monitored for adverse reactions, long-term safety, and efficacy.

How to Volunteer

So-called human guinea pigs are recruited in many ways. Often, a hospital, drug company, or agency simply advertises for participants. Doctors are sometimes enlisted to conduct clinical trials, and may use their own patients or recruit additional volunteers. Teaching hospitals and health agencies, such as the National Cancer Institute, also participate in clinical trials and offer both experimental drugs and treatments to selected patients.

Regardless of who conducts the tests, all participants must be fully informed of any risks involved and then sign an informed consent form. Volunteers are not told whether they are receiving the actual drug or a placebo, because knowing might alter test results.

If it becomes apparent that an experimental drug can save lives or prevent irreversible damage, the study must stop and volunteers receiving a placebo must be offered the new drug. This happened during the human testing of AZT to treat AIDS. After eight months of Phase 2 testing, it was obvious that patients receiving AZT were living longer than those in the placebo group. The test was halted, and a month later the treatment protocol was approved. It took another six months for the FDA to grant final approval. This was in March 1987, some 29 months after the October 1984 start of preclinical tests, a short time compared with the average of 100 months that it usually takes for the entire process.

False Hopes

Desperate patients with incurable diseases often look to experimental treatments as a last resort for a cure. Some clinical studies actually fulfill this hope, and provide excellent medical care during the process. Others fall short of expectations, but still succeed in advancing medical knowledge.

Unfortunately, some people who volunteer for a previously untried treatment become victims of quackery or medical fraud. Always be suspicious if you are asked to pay for an experimental drug; in such cases, ask to see evidence that the FDA has approved the study. Be suspicious too if you learn about the drug from supermarket tabloids or other sensationalized reports. If the source is doubtful, check with your doctor or your nearest FDA office (listed in the US Government section of your phone book) before volunteering.