In Phase I, what is the primary objective?

• A. Demonstrate therapeutic benefit
• B. Determine tolerability of the dose range and nature of adverse reactions
• C. Confirm marketing approval
• D. Evaluate long-term safety in general population

Answer: (B)

Phase I trials are focused on safety and how the drug behaves in people. The primary objective is to determine how tolerable different dose levels are and what kinds of adverse reactions occur across that dose range. This information helps identify dose-limiting toxicities and select a starting point and escalation plan for later studies. Demonstrating therapeutic benefit, confirming marketing approval, or assessing long-term safety in the general population are not the main goals of Phase I; those come in later phases (efficacy-focused studies and post-approval monitoring).