Many Drugs Approved by FDA Based on Results of a Single Study, Analysis Finds

Industry-sponsored studies were also on the rise from 2016 to 2024, and it was taking longer for study results to be reported to the public.

Matt MacKenzie

Aug. 28, 2026

2 min read

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Key Highlights

- Over two-thirds of new drugs approved in 2024 were based on a single supporting study, a sharp increase from previous years.
- The average number of studies per approval has declined from 3.41 in 2016 to 1.39 in 2024, indicating fewer trials are used to support drug approvals.
- Industry-funded studies now constitute over 80% of the research supporting FDA approvals, up from less than 45% in 2016.
- There has been a rise in delays between study completion and public reporting, with the average increasing from 682 to 783 days.
- The decline in the number of supporting studies coincides with the 2016 enactment of the 21st Century Cures Act, which aimed to accelerate drug development.

A new analysis found that more than two-thirds of new drugs approved by the FDA in 2024 were sanctioned based on results from a single study. CIDRAP has the news.

The number of studies used to grant approval overall seemed to decline since 2016. There was also a sharp rise in industry-sponsored studies, a decrease in studies sponsored by the NIH, and delays in reporting study results to the public. The decline in the number of studies coincided with implementation of the 21st Century Cures Act, which was signed into law in 2016 to accelerate the development of new medical products and drugs.

Researchers analyzed 6,763 studies associated with new FDA drug approvals from 2016 through 2024. The mean number of studies supporting an approval was 3.41, but that number fell to 1.50 in 2022 and 1.39 in 2024. In 2016, 59.1% of novel drugs were approved based on three or more trials, but by 2024, that figure had fallen to 5.6%. 69.4% of medical products approved in 2024 were approved based on a single study.

80.4% of the studies associated with approvals in 2024 were industry-funded, compared to 44.6% in 2016. The average number of days between a study’s completion date and the results being made public rose from 682 in 2016 to 783 in 2023.