What is a clinical trial?

Pharmaceutical companies develop numerous compounds for the treatment or prevention of human disease through extensive research. Before a new drug is found to be safe and effective enough to be tested in humans, it must go through extensive preclinical and laboratory testing. This research involves years of experiments in animal and human cells. If this stage of testing is successful, a drug company provides this data to the Food and Drug Administration (FDA), requesting approval to begin testing the drug in humans. The FDA reviews the results of these tests and approves or denies a request for testing in human clinical trials. If approval is obtained, the first phase of extensive clinical trials begins.

A clinical trial is a carefully designed study that involves people like you who volunteer to receive investigational treatments under close supervision by a physician. Pharmaceutical companies who have developed new treatments select qualified physicians, also called investigators, to conduct trials. It is through these clinical trials that investigational drugs may show their benefits.

The clinical testing of an investigational drug is a careful step-by-step process that ensures you receive close medical attention. All clinical trials are closely overseen by the U.S. government’s Food and Drug Administration (FDA) and by Institutional Review Boards (IRBs). IRBs are independent committees whose job is to make sure your rights are fully protected and that you are not exposed to any unnecessary risks. IRBs are also responsible for ensuring you sign a consent form before agreeing to participate in a trial.

Clinical testing of experimental drugs is normally done in three phases - each phase involving a larger number of people.

Phase One
Phase I studies are primarily concerned with assessing the drug’s safety. This initial phase of testing is normally done in a small number of healthy volunteers (20-100). The study is designed to determine what happens to the drug in the human body - how it is absorbed, metabolized, and excreted. A phase I study will investigate side effects that occur as dosage levels are increased. This phase of testing usually takes several months. Upon completion of phase I, data is submitted to the FDA for review to support continued testing. About 70 percent of experimental drugs pass this phase of testing. We do not participate in these types of trials at this time.

Phase Two
Phase II studies focus on the effectiveness of the drug in treating people who have the specific disease for which the drug is designed to treat. This phase of testing may last from several months to two years, and involves several hundred patients. Most phase II studies are “randomized” trials. One group will receive a standard treatment or placebo (a sugar pill). Often these studies are “blinded” - neither the patients nor the researchers know who is getting the experimental drug or the placebo. The study can provide the drug company and the FDA comparative information about the relative safety of the new drug and its effectiveness. Only about one-third of experimental drugs successfully complete both phase I and II studies.

Phase Three
Phase III studies are by far the most extensive. This phase of research focuses on drug safety, effectiveness, and optimum dosage schedules in large patient populations in many research sites throughout the United States (US). During this phase, the investigational drug may be compared to other marketed drugs for the same condition and/or to a placebo. Phase III studies can last several years. About 80% of the drugs that get to the Phase III stage successfully complete this phase. Once enough information is collected to substantiate the safety and effectiveness of a new drug, the data is submitted to the FDA for approval for use in the general population. The FDA reviews all data from human clinical trials and determines whether the new drug is safe and effective. Approval is either granted or denied. The FDA has the right to audit any clinical research site, IRB or drug company.

Phase IV/Post-Marketing Studies
Phase IV, or Post-marketing research studies are conducted to gain further understanding of the safety of the drug, or to further substantiate claims for an approved indication. Phase IV studies are conducted after FDA approval of the drug.

The drugs researched today may someday be used by your physician as new treatments or cures. Every medication prescribed by your doctor has, at one time, undergone this precise, necessary process.