phase 3 clinical trial

A study that tests the safety and how well a new treatment works compared with a standard treatment. For example, phase 3 clinical trials may compare which group of patients has better survival rates or fewer side effects. In most cases, treatments move into phase 3 clinical trials only after they meet the goals of phase 1 and phase 2 clinical trials. Phase 3 clinical trials may include hundreds of people. Also called phase III clinical trial.