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Phase IV

Phase IV trials are conducted after the new drug has been granted a license. In these studies, the new drug is prescribed in an everyday healthcare environment, which allows results to be developed using a much larger group of participants.

Phase IV trials enable new uses for the new drug to be developed, comparisons with other treatments for the same condition to be made and to determine the clinical effectiveness of the new drug in a wider variety of patient types. Safety is a major part of Phase IV trials which often involve several thousand patients so that more rare side effects, if any, may be detected.