Phase 1 trial

Also known as: Phase I

First-in-human study, primarily testing safety and pharmacokinetics in 20–100 participants.

Definition

Phase 1 trials are the first studies of a drug in humans. They are primarily designed to assess safety, tolerability, pharmacokinetics, and dose-finding in a small group (typically 20–100 healthy volunteers, or in oncology, patients with refractory disease). Efficacy is not the primary endpoint, but early signals are tracked.

See also

• Phase 2 trial — Mid-stage trial testing efficacy and dose-response in 100–500 patients with the target disease.
• Phase 3 trial — Large randomised registration trial (300–3000+ patients) used to support regulatory approval.

Other clinical terms

• Phase 2 trial
• Phase 3 trial
• Primary endpoint
• Surrogate endpoint
• CDx
• OS