Phase 2 trial

Also known as: Phase II

Mid-stage trial testing efficacy and dose-response in 100–500 patients with the target disease.

Definition

Phase 2 trials evaluate efficacy and further safety in a larger group (100–500) of patients with the target indication. They are typically randomised, often dose-ranging, and increasingly include adaptive designs. Failure rates are high — about 30% of Phase 2 trials succeed.

See also

• Phase 1 trial — First-in-human study, primarily testing safety and pharmacokinetics in 20–100 participants.
• Phase 3 trial — Large randomised registration trial (300–3000+ patients) used to support regulatory approval.

Other clinical terms

• Phase 1 trial
• Phase 3 trial
• Primary endpoint
• Surrogate endpoint
• CDx
• OS