Phase 3 trial

Also known as: Phase III, pivotal trial

Large randomised registration trial (300–3000+ patients) used to support regulatory approval.

Definition

Phase 3 trials are large, randomised, controlled studies (typically 300–3000+ patients) that confirm efficacy and monitor safety at the proposed therapeutic dose. They are the primary basis for NDA/BLA filings. The standard design is double-blind versus placebo or standard of care, with a hierarchical primary/key secondary endpoint structure.

See also

• Phase 2 trial — Mid-stage trial testing efficacy and dose-response in 100–500 patients with the target disease.
• Primary endpoint — The pre-specified outcome measure used to determine whether a trial succeeded.

Other clinical terms

• Phase 1 trial
• Phase 2 trial
• Primary endpoint
• Surrogate endpoint
• CDx
• OS