What should be adequate to support the proposed clinical trial regarding the investigational product?

• A. Only preclinical data are necessary.
• B. The available nonclinical and clinical information on the investigational product should be adequate to support the proposed clinical trial.
• C. Clinical data from unrelated products can substitute for missing data.
• D. Extensive post-marketing data is sufficient to start a new trial.

Answer: (B)

To start a clinical trial, you must have adequate information about the investigational product that combines both nonclinical and clinical data. Nonclinical studies—like pharmacology and toxicology—help you understand potential risks, appropriate exposure ranges, and how the product behaves in the body. Any available clinical information from prior human use of the product, or from closely related products, supports safe dosing decisions, study design, and monitoring plans. This combined information justifies the risk-benefit balance and guides how the trial should be conducted.

Relying only on preclinical data leaves safety and pharmacokinetic questions unanswered. Data from unrelated products may not be applicable due to differences in mechanism, formulation, or patient population. Post-marketing data, while valuable after a product is approved, cannot substitute for the foundational data needed to initiate a new trial.