Developing new medicines (or drugs) is a long and complicated process called drug development. It has many stages, and the "clinical" stage is when the medicine is tested in people. This stage requires doctors and study teams to find volunteers who are willing to to participate in clinical trials (or studies) to gather detailed information about how the medicine may work. All approved medicines have been tested in many people (sometimes even thousands of people) before being approved and made available to the public. The development of new medicines would not be possible without volunteers who are willing to participate in clinical trials.
PHASES OF A CLINICAL TRIAL
Clinical trials are conducted in phases, typically beginning with Phase I, and usually progressing through Phase III before the drug is considered for approval. Each of the phases is explained here:
- Phase I - Researchers test the experimental drug in a small number of healthy volunteers and monitor them closely to determine if the drug is safe enough to test in a larger group of people.
- Phase II - Researchers test the experimental drug in a slightly larger number of patients, who have a particular disease or condition, to determine if the drug shows some improvement in these patients and continues to be safe.
- Phase III - Researchers test the experimental drug in a larger number of patients to determine if the drug is both safe and effective, and to sometimes compare the new drug with currently approved drugs. Data gathered in this phase are used to request approval to make the drug available to patients.
- Phase IV - Sometimes, researchers would like to continue studying the drug and gather data in patients. Studies in this phase are sometimes called post-marketing studies because they take place when a new drug is already on the market.
There are two main types of clinical studies: clinical trials (also called interventional studies) and observational studies.
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ClinicalTrials.gov - a service of the U.S. National Institutes of Health