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Phase III Trial Audio (En español)

The third step in testing an experimental drug (or other treatment) in humans. Phase III trials are conducted to confirm and expand on safety and effectiveness results from Phase I and II trials, to compare the drug to standard therapies for the disease or condition being studied, and to evaluate the overall risks and benefits of the drug. This trial phase recruits a large group of people with the disease or condition, usually ranging from 1,000 to 3,000 participants. Results from Phase III trials provide information that the Food and Drug Administration (FDA) needs to consider the drug for approval.

See Related Term(s): Clinical Trial, Food and Drug Administration, Phase II Trial, Phase I Trial, Phase IV Trial

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