Phase 3
In Phase 3 trials researchers study the drug candidate in a larger number (about 1,000-5,000) of patients to generate statistically significant data about safety, efficacy and the overall benefit-risk relationship of the drug. This phase of research is key in determining whether the drug is safe and effective. It also provides the basis for labeling instructions to help ensure proper use of the drug (e.g., information on potential interactions with other medicines).
Phase 3 trials are both the costliest and longest trials. Hundreds of sites around the United States and the world participate in the study to get a large and diverse group of patients. Coordinating all the sites and the data coming from them is a monumental task.
During the Phase 3 trial (and even in Phases 1 and 2), researchers are also conducting many other critical studies, including plans for full- scale production and preparation of the complex application required for FDA approval.
