Phase 3 trial

Large multi-site trial — last step before FDA approval.

Phase 3 is the final pre-approval clinical trial stage. Hundreds to thousands of patients across multiple sites, randomized vs placebo or active comparator, with the protocol designed to support FDA registration. Examples: SURMOUNT-1 (tirzepatide phase 3 in obesity), STEP-1 (semaglutide phase 3 in obesity), TRIUMPH-3 (retatrutide phase 3). Phase 3 results are the strongest evidence available before approval.

Related terms

FDA-approved
Cleared by the FDA for at least one indication.
Phase 2 trial
Smaller dose-finding trial. Establishes efficacy + side effect profile.
NCT (ClinicalTrials.gov)
Unique identifier for a registered clinical trial.

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