What are Clinical Trials?
A clinical trial is a research study to answer specific questions about a new medical treatment (medicine/drug, medical device, new therapies, vaccines), or new ways of using known treatments. Clinical trials (also called medical research and research studies) are used to determine whether such new treatments are both safe and effective.
Why are there clinical trials?
Carefully conducted clinical trials are the fastest and safest way to find treatments that work in people. A clinical trial is one of the final stages of a long and careful research process. Studies are done with patients to find out whether promising approaches to disease prevention, diagnosis, and treatment are safe and effective.
What are the phases of clinical trials?
Most clinical research that involves the testing of a new drug progresses in an orderly series of steps, called phases. This 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 three phases:
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Phase I trials: These first studies in people evaluate how a new drug should be given, how often, and what dose is safe. A phase I trial usually enrolls only a small number of patients, sometimes as few as a dozen.
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Phase II trials: A phase II trial continues to test the safety of the drug, and begins to evaluate how well the new drug works.
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Phase III trials: These studies test a new drug, a new combination of drugs, or a new surgical procedure in comparison to the current standard. A participant will usually be assigned to the standard group or the new group at random. Phase III trials often enroll large numbers of people.
- Phase IV trials: These trials typically continue to investigate a drug after its initial approval from the regulatory authorities. In this phase the focus is on further evaluation of the use for which approval was secured, for comparison to or combination with other established drugs and to generate more data on safety under broader use. Phase IV trials are an important tool to strengthen the understanding of the drug and to give guidance to prescribers and patients on the safe and appropriate use under various clinical conditions.
