Before a new drug finds its place on pharmacy shelves or a new device lands in the hands of a surgeon, it goes through a long and complex approval process by the U.S. Food and Drug Administration.

A new drug, for instance, goes through laboratory testing and animal studies before the drugmaker submits an application to FDA’s Center for Drug Evaluation and Research. If it gets the agency’s green light, then the human clinical trials begin, starting with a small number of participants at initial phases and growing to hundreds if not thousands of participants in the ...