Phase II of clinical drug development involves testing the drug in which population?

• A. A small group of healthy volunteers to test safety
• B. A larger group of sick people to test drug works and safety
• C. Post-marketing surveillance after drug approval
• D. Product development and marketing steps before clinical trials

Answer: (B)

In Phase II, the drug is tested in patients who have the condition to see whether it works and to gather more safety data. This phase builds on Phase I, which largely studied safety in healthy volunteers, by starting to evaluate real therapeutic effect in people who actually need the treatment and by refining the dosing that seems effective and safe. The group is larger than Phase I, often in the hundreds, but not as large as Phase III trials, and the study design usually looks at initial evidence of efficacy while continuing to monitor adverse effects.

Post-marketing surveillance is Phase IV, occurring after approval. Preclinical steps and product development occur before clinical trials.