Clinical Trial, Phase III

**Definition:** Work that is a report of a pre-planned, usually controlled, clinical study of the safety and efficacy of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques after phase II trials. A large enough group of patients is studied and closely monitored by physicians for adverse response to long-term exposure, over a period of about three years in either the United States or a foreign country.

**Tree numbers:** - V03.175.250.300

**Synonyms:** - Clinical Trial, Phase 3