In April 2025, the FDA announced a new approval pathway aimed at streamlining the review of biologics and drugs developed to treat rare diseases54.
The pathway includes provisions for conditional approval based on data from single-arm trials when randomized studies are not feasible, allowing medicines to reach patients earlier24.
Approval may be granted for drugs with a "scientifically plausible" mechanism and strong surrogate endpoint data, even with limited clinical evidence24.
Post-approval, the FDA plans to use real-world data (RWD) and surveillance systems to closely monitor the safety and efficacy of treatments given conditional approval to rare disease patients24.
This programme builds on recent FDA draft guidances intended to refine the accelerated approval pathway, with stronger mechanisms for withdrawing ineffective drugs and increased flexibility for rare disease communities1.
Previous legislative proposals such as the "Promising Pathway Act" have pushed for time-limited conditional approvals in the rare disease space, influencing FDA’s revamped approach4.
Sources:
1. https://www.morganlewis.com/blogs/asprescribed/2025/02/fdas-recent-guidance-on-accelerated-approval-and-implications-for-rare-diseases
2. https://www.biospace.com/fda/fdas-prasad-vows-to-make-rare-disease-drugs-available-at-first-sign-of-promise
4. https://www.lifesciencesperspectives.com/2025/04/23/charting-a-conditional-approval-pathway-for-rare-disease-drugs-a-top-priority-for-a-revamped-fda/