Phase 3 Trial
Definition
Large-scale pivotal clinical trials designed to confirm a drug's efficacy and safety in thousands of patients, providing the definitive evidence required for regulatory approval by agencies such as the FDA.
Phase 3 Trial
A Phase 3 clinical trial is the final and most extensive stage of clinical testing before a drug can be submitted for regulatory approval. These pivotal trials enroll thousands of participants across multiple clinical sites, often internationally, and are designed to provide definitive evidence of a drug’s efficacy and safety in a broad patient population. Phase 3 trials are almost always randomized, double-blind, and controlled (either placebo-controlled, active-comparator-controlled, or both).
The primary purpose of Phase 3 trials is to confirm the efficacy signals observed in Phase 2 studies with sufficient statistical power to support a regulatory filing. These trials also generate the comprehensive safety database required by regulatory agencies, which typically expect safety data from at least 1,500 patients exposed to the drug, with a subset exposed for 12 months or longer. Phase 3 trials are also designed to evaluate the drug in subpopulations defined by age, sex, race, comorbidities, and concomitant medications.
For retatrutide, the Phase 3 program is designated TRIUMPH (Triple Receptor Agonist Intervention Utilizing Metabolic Pathways in Health) and includes multiple trials evaluating the drug in obesity and type 2 diabetes populations. The results of the TRIUMPH program will form the basis of Eli Lilly’s regulatory submissions to the FDA and other global health authorities. Phase 3 trials typically take two to four years to complete.