Synonym: first-in-man (FIM).

First study of a novel intervention in humans.

First-in-human studies are usually carried out in healthy volunteers. Their principal role is to assess the safety of new interventions. They may incorporate a dose-escalation study design (single ascending dose or SAD study) to identify the optimum dose for use in future trials. First-in-human studies are also used to gather data on the effects of a new drug in humans and how it is metabolized. First-in-human studies are phase 1 trials.