Center for Clinical Research
What is Clinical Research?
Clinical trials are research studies which try to answer scientific questions and to find better ways to treat or prevent diseases. A clinical trial is conducted to determine whether a new drug or treatment is both safe and effective in people. These research studies rely on patients who volunteer to participate and try a new drug or treatment. Some of these drugs have not yet been approved by the Food and Drug Administration (FDA) for sale in the United States. Sometimes the drugs are currently available for sale, but are being tested for a new disease or additional information.
Most clinical trials that involve the testing of a new drug follow a series of steps, called phases. This process allows researchers to ask and answer questions in a way that results in reliable information about the drug and protects the patients. Clinical trials are usually classified into one of four phases:
In Phase I trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
In Phase II trials, the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
In Phase III trials, the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
In Phase IV trials, post marketing studies delineate additional information including the drug’s risks, benefits, and optimal use.