Phase III

A large-scale, randomized controlled multicenter trial designed to assess the effectiveness of a new intervention in comparison with the current ‘gold standard’ treatment. It involves large patient groups (300-3,000 or more) and aims to be the definitive assessment of the drug’s effectiveness. These trials are the most expensive and time-consuming due to their size and duration. They often continue while the regulatory submission is pending, allowing patients to receive potentially lifesaving drugs. The results of successful Phase III trials form the basis of the “regulatory submission” for the drug’s approval. The trials may incorporate adaptive designs to adjust to interim results. The success rate varies depending on the disease and the presence of disease biomarkers.

Source: Wikipedia