HIV/AIDS Glossary

Phase 4 Trial

Testing in humans that occurs after a drug (or other treatment) has already been approved by the Food and Drug Administration (FDA) and is being marketed for sale. Phase 4 trials are conducted to determine long-term safety and effectiveness and to identify adverse effects that may not have been apparent in prior trials. Phase 4 trials usually include thousands of participants.

Related Term(s): Clinical Trial, Food and Drug Administration, Phase 1 Trial, Phase 2 Trial, Phase 3 Trial, Preclinical


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The fifth step of a clinical trial

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