Poor pharmacokinetics can limit a drug's clinical usefulness. Microdosing—giving a tiny dose to predict how a full dose will behave—has worked well for small-molecule drugs, despite early doubts. This paper reports the first successful clinical microdose of a humanized recombinant protein, raising the question of how broadly this approach will succeed for protein-based drugs.
Microdosing studies in children provide pharmacokinetic data, help investigate the development of metabolic enzymes, and allow researchers to examine how drugs are distributed in the body.