CITI Training Practice Exam

Which phase involves controlled studies enrolling a limited number of patients?

1. Phase I

2. Phase II

3. Phase III

4. Phase IV

The correct answer is: Phase II

Phase II involves controlled studies enrolling a limited number of patients. This phase typically involves 100-300 patients and evaluates the effectiveness of the treatment on a particular disease or condition. Options A, C, and D are incorrect because Phase I involves testing a new treatment on a small group of healthy individuals, Phase III involves larger-scale studies comparing the new treatment to standard treatments, and Phase IV involves post-approval studies to monitor safety and effectiveness in a larger population.