Which step occurs immediately before human clinical trials in the drug development timeline?

• A. Market the drug
• B. File IND
• C. Conduct phase 3 trials
• D. Formulate and scale-up

Answer: (B)

The key idea is securing permission to test in humans by submitting an Investigational New Drug (IND) application. Before any people receive an experimental drug, the sponsor must compile preclinical safety data, details on chemistry and manufacturing controls, and a plan for the initial clinical studies, and submit this to the regulatory authority. When the IND is approved, the first-in-human trials can start. The other steps occur at different times in the development timeline: formulating and scaling up are manufacturing activities that support development and can precede IND but are not the trigger for human testing; phase 3 trials come after earlier phases; and marketing happens only after successful trials and regulatory approval.