Which stage follows preclinical development in the drug development process?

• A. Phase I
• B. IND
• C. NDA
• D. Phase III

Answer: (B)

After preclinical work, the next step is submitting an Investigational New Drug (IND) application to regulators to begin testing in humans. This filing brings together the preclinical safety and pharmacology data, manufacturing details, and the plan for the initial clinical trials. Once the IND is reviewed and allowed to proceed, testing in people can start with Phase I trials, which assess safety and dosing.

Phase I occurs after the IND is active, not immediately after preclinical work. The NDA is submitted later to seek marketing approval after successful clinical trials (typically Phase III). Phase III trials come later still, as large-scale efficacy and safety studies before an NDA.