Only 43% of accelerated approval drugs showed clinical benefit in confirmatory studies

Of the 46 cancer drugs for which the US Food and Drug Administration (FDA) granted accelerated approval between 2013-2017, 63% were converted to regular approval even though only 43% demonstrated a clinical benefit in confirmatory trials after more than five years of follow-up, according to a study presented at the American Association for Cancer Research (AACR) 2024 annual meeting.

“Accelerated approvals make up a large percentage of new cancer drug approvals, but we knew that oncology accelerated approvals are often not subsequently confirmed as having an effect on ‘hard’ clinical endpoints such as overall survival (OS),” said Dr Ian Lui, who worked on the study and is a postdoctoral research fellow with the Program On Regulation, Therapeutics And Law (PORTAL) within the Division of Pharmacoepidemiology and Pharmacoeconomics at Brigham and Women’s Hospital and Harvard Medical School.

The FDA’s accelerated approval pathway was established more than 30 years ago to allow drugs that treat serious conditions and fill an unmet medical need to be approved early based on a surrogate endpoint. The FDA defines a surrogate endpoint as a marker or measure that is “thought to predict clinical benefit but is not itself a measure of clinical benefit.”