Association of Clinical Research Professionals (ACRP) Certified Professional Practice Exam

Which phase of clinical trials emphasizes safety, tolerability, pharmacokinetics, and early measurement of drug activity?

1. Phase 1

2. Phase 2

3. Phase 3

4. Phase 4

The correct answer is: Phase 1

The emphasis on safety, tolerability, pharmacokinetics, and the initial measurement of drug activity is a hallmark of Phase 1 clinical trials. During this phase, the primary goal is to assess how a new drug affects human subjects. It typically involves a small number of healthy volunteers and focuses on determining whether the drug is safe to use, how it is processed in the body, and what effects it may produce at various dosages. Phase 1 trials are crucial for establishing a baseline understanding of the drug's profile before advancing to larger populations in subsequent trial phases. It lays the groundwork for later studies that will further evaluate the drug's efficacy (typically in Phase 2 and Phase 3 trials) and its long-term safety (in Phase 4 trials). In contrast, later phases prioritize different objectives; for instance, Phase 2 pivots toward assessing efficacy while continuing to monitor safety, Phase 3 expands on this by comparing the new treatment to standard therapies, and Phase 4 occurs after the drug has been approved and focuses on long-term effects and broader population impacts.