Phase 2 Trial
Definition
The second stage of testing. It checks a drug's efficacy, best dose and safety in a larger group of patients with the target condition, usually hundreds of people.
Phase 2 Trial
A Phase 2 trial is the stage of drug development where efficacy is first tested rigorously in patients with the target disease. It builds on the safety and pharmacokinetic data from Phase 1 and usually enrolls hundreds of people. Phase 2 trials are often randomized, double-blind and placebo-controlled to give reliable evidence of the treatment’s effect.
Phase 2 studies often use dose-ranging designs, randomly assigning people to different doses of the drug or to placebo. This lets researchers map the dose-response relationship, find the doses most likely to work well with acceptable tolerability, and choose the best doses for Phase 3 pivotal trials. Phase 2 studies vary in length, often 12 to 48 weeks for chronic conditions like obesity and type 2 diabetes.
Retatrutide’s Phase 2 program included two landmark trials: a 48-week obesity trial published in the New England Journal of Medicine (NCT04881760) and a 36-week type 2 diabetes trial published in The Lancet (NCT04867785). These studies established retatrutide’s efficacy, showing up to 24.2% weight loss and significant HbA1c reductions, and were central to choosing doses for the Phase 3 TRIUMPH program.