Which phase of a clinical trial involves testing on a healthy population?

Phase 1 of a clinical trial is specifically designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of a drug in healthy volunteers. The primary objective during this phase is to determine how the drug behaves in the human body, which includes assessing how it is absorbed, metabolized, and excreted. This phase typically involves a small number of participants and focuses on safety before larger numbers of patients are exposed to the treatment in later phases.

In contrast, Phase 0 involves very early exploratory testing with a limited number of subjects to gather preliminary data, often using subtherapeutic doses. Although it may involve healthy subjects, its primary function is not to assess safety comprehensively.

Phase 2 involves testing the drug on a larger group of patients who have the condition the drug is intended to treat, emphasizing effectiveness and further safety data. Phase 3 generally takes place after the drug has shown promise in earlier phases and tests it in an even larger population, continuing to assess effectiveness and monitor adverse reactions compared to standard treatments.

The focus on healthy participants in Phase 1 is crucial, as it sets the foundation for understanding the drug’s effects before it is tested in populations with disease, ensuring that safety concerns are identified and managed