Back in the 1970s and 1980s, the U.S. FDA made clear that at least two adequate and well-controlled studies were necessary to establish a new drug’s effectiveness, except in only the rarest of circumstances. Then in 1997, the FDA Modernization Act was passed, and Congress clarified that FDA may consider “data from one adequate and well-controlled clinical investigation and confirmatory evidence” to approve a new drug. However, recently IQVIA released a report finding that 25 of 59 (42%) novel drugs approved in 2018 were approved on the basis of only one trial. And one out of eight approvals relied only on Phase 1 or 2 trials, with no Phase 3 trials. Learn More