What is the primary purpose of a Phase I clinical trial?

The primary purpose of a Phase I clinical trial is to assess safety in a small group of healthy volunteers. This stage of clinical research is focused primarily on evaluating the pharmacokinetics and pharmacodynamics of a drug, as well as identifying any potential side effects or adverse reactions that may occur. During Phase I, the drug is typically administered to a limited number of participants, allowing researchers to monitor how the drug is processed in the body and determine an appropriate dosage range.

In this phase, researchers aim to ensure that the drug is safe for humans before proceeding to larger trials that will involve individuals who have the condition the drug is intended to treat. It is essential for establishing a foundational safety profile that will guide later phases of development. Therefore, the focus on safety evaluation distinguishes Phase I trials from subsequent phases, where effectiveness and efficacy become more central in the study design.