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# One-Third of BTD Requests Granted: Analysis
- URL: https://www.fdaweb.com/one-third-of-btd-requests-granted-analysis/
- Published: 2023-11-07T12:00:00.000Z
- Updated: 2026-09-14T14:15:28.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5155743

Three CDER researchers say 39% of the 240 requests for a breakthrough therapy designation (BTD) submitted from 1/1/2017 through 12/31/2019 were granted by the agency, while 61% were denied. Writing in the open-source *Therapeutic Innovation & Regulatory Science*, the researchers [say](https://link.springer.com/article/10.1007/s43441-023-00589-z?ref=fdaweb.com) approval of requests was more common for conditions where no therapy was available or for orphan diseases.

Common reasons for denials included data-related issues, insufficient treatment effect, inadequate study design, endpoint attributes, safety issues, and reliance on post hoc analyses, they write.

“Among 28 drugs receiving marketing approval as of the end of 2022 for the indication for which BTD was previously granted, 21 (75%) involved a first-in-class mechanism of action,” the study reports.