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

Which of the following is NOT a focus of Phase 1 clinical trials?

1. Safety and tolerability

2. Drug absorption mechanisms

3. Therapeutic efficacy

4. Drug metabolism

The correct answer is: Therapeutic efficacy

Phase 1 clinical trials primarily focus on evaluating the safety, tolerability, and pharmacokinetics of a drug in a small group of healthy volunteers or sometimes patients. The main objectives during this phase include determining how the drug is processed in the body (which encompasses drug metabolism and absorption mechanisms), and monitoring any adverse effects to establish what constitutes a safe dosage range. While therapeutic efficacy is an important aspect of drug development, it is not the primary focus during Phase 1. In this phase, researchers are more concerned with how the body reacts to the drug rather than whether the drug effectively treats the condition it is meant for. Evaluation of therapeutic efficacy generally occurs in subsequent phases (Phases 2 and 3), where larger groups and control measures are utilized to assess whether the drug provides meaningfully beneficial effects for the intended conditions.