[1] A successful pivotal trial is required as evidence for drug marketing approval by the relevant approval authorities, such as the European Medicines Agency, Health Canada or United States Food and Drug Administration (FDA).
[1] In drug research, a pivotal Phase III trial may be referred to as a "therapeutic confirmatory study",[1] and is conducted in a large number (hundreds to thousands) of subjects.
[2] Such pivotal trials are also designed to discover and estimate the prevalence of common adverse events, but based on their size only have the statistical power to establish an adverse effect rate of not less than 1 in 100 subjects.
[3] In 2017 in the United States, the median cost of a pivotal trial across all clinical indications was US$19 million.
[2] The cost of a pivotal trial increased when more subjects were added to clarify a treatment effect, when active drug comparators were used to improve understanding of the trial drug characteristics, or when specific clinical endpoints were measured rather than using surrogate outcomes.