Phase II is characterized by which of the following?

Phase II is characterized by which of the following?

• A. Involves 50 to 200 participants and assesses dosing range
• B. Involves 1000 to 5000 participants and confirms long-term safety
• C. Involves 100 to 500 participants and evaluates effectiveness and adverse effects
• D. Involves 20 to 100 participants and studies post-marketing outcomes

Answer: (C)

Phase II trials focus on whether the drug shows real therapeutic effect in patients who have the condition, while continuing to monitor safety and adverse effects. At this stage, researchers also start to explore dosing to find an optimal amount that provides effectiveness with acceptable safety. The typical group size is in the hundreds, which is large enough to detect a real effect but smaller than the thousands involved in later studies. That’s why the option describing a study with about one hundred to five hundred participants and evaluating both effectiveness and adverse effects best fits Phase II. It captures the dual goals of proving some efficacy and further assessing safety, after initial Phase I safety work and before the large, definitive Phase III trials. The other choices reflect later or different phases: Phase III involves many more participants and long-term safety; post-marketing studies occur after approval; and the first option emphasizes dosing range but uses a smaller sample size.

Phase II trials focus on whether the drug shows real therapeutic effect in patients who have the condition, while continuing to monitor safety and adverse effects. At this stage, researchers also start to explore dosing to find an optimal amount that provides effectiveness with acceptable safety. The typical group size is in the hundreds, which is large enough to detect a real effect but smaller than the thousands involved in later studies.

That’s why the option describing a study with about one hundred to five hundred participants and evaluating both effectiveness and adverse effects best fits Phase II. It captures the dual goals of proving some efficacy and further assessing safety, after initial Phase I safety work and before the large, definitive Phase III trials. The other choices reflect later or different phases: Phase III involves many more participants and long-term safety; post-marketing studies occur after approval; and the first option emphasizes dosing range but uses a smaller sample size.