Phase 3 Trial
Definition
Large pivotal trials that confirm a drug's efficacy and safety in thousands of patients and give regulators such as the FDA the definitive evidence for approval.
Phase 3 Trial
A Phase 3 trial is the last and largest stage of clinical testing before a drug can be submitted for approval. These pivotal trials enroll thousands of people at many sites, often in several countries, and are designed to give definitive evidence of a drug’s efficacy and safety in a broad population. Phase 3 trials are almost always randomized, double-blind and controlled (against placebo, an active comparator or both).
Phase 3 trials exist mainly to confirm the efficacy seen in Phase 2, with enough statistical power to support a regulatory filing. They also build the large safety database regulators require, which usually means data from at least 1,500 patients exposed to the drug, some of them for 12 months or longer. Phase 3 trials also look at how the drug performs in subgroups defined by age, sex, race, other conditions and other medicines.
Retatrutide’s Phase 3 program is called TRIUMPH and includes several trials in people with obesity and type 2 diabetes. Its results will form the basis of Eli Lilly’s submissions to the FDA and other health authorities around the world. Phase 3 trials usually take two to four years to complete.