What is the objective of Phase II clinical trials?

The objective of Phase II clinical trials primarily focuses on evaluating the effectiveness of a drug in addition to its side effects in a larger group of patients who have the condition that the drug aims to treat. This phase follows an initial Phase I study, which mainly assesses safety and tolerability in a smaller, healthy cohort. In Phase II trials, researchers aim to gather more robust data on how well the drug works, which involves determining the appropriate dosage, understanding the therapeutic effects, and identifying any adverse reactions that may occur when a larger population is exposed to the treatment.

In contrast, other phases have distinct goals: establishing the maximum tolerated dose is a concern typically addressed in Phase I trials. Preliminary safety evaluations are also primarily conducted during the initial phase before moving on to a larger cohort. Assessing pharmacokinetics, which includes studying how the drug moves through the body, is generally part of the earlier-phase investigations, usually during Phase I and sometimes during Phase II, but the main focus shifts towards efficacy in Phase II.

Therefore, the correct answer aligns with the primary goals of Phase II clinical trials, which focus on gathering evidence of the drug's effectiveness and monitoring side effects in a relevant patient population.