During which phase of clinical trials is dose finding conducted?

Dose finding is primarily conducted during Phase I of clinical trials. Phase I trials are designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of a drug in a small group of healthy volunteers or patients. This phase focuses on determining the appropriate dosage range and identifying any side effects, allowing researchers to gather essential information about how the drug behaves in the body at various doses.

Phase II trials, in contrast, usually involve a larger group of participants and are primarily concerned with assessing the effectiveness of the drug, further evaluating safety, and refining the dosing regimen based on the findings from Phase I. While some further dose adjustments may occur, the main dose-finding activities are completed in Phase I.

Phase III trials are aimed at confirming the drug's effectiveness, monitoring side effects, and comparing it to commonly used treatments, typically using the doses established in the earlier phases. Phase IV trials occur after a drug has been marketed and involve further studies to monitor long-term effects and the drug’s performance in the general population.

Thus, the focus on identifying the optimal doses and safety profile occurs in Phase I, making it the correct phase where dose finding is conducted.