The third stage in a series of trials to determine the safety and efficacy of a drug before it reaches the public. At this stage, trials can involve thousands of patients, and seek to gather additional information on a drug after preliminary evidence suggesting its effectiveness has been obtained. The benefit to risk relationship of the drug is also established and comparison studies are often made with existing treatments

See also:
See also:
Phase I trials
Phase II trials
Phase IV trials
Clinical trial
Clinical trial enrolment
Pre-clinical trials