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# More Consistent Rare Disease Flexibility Needed: Attorneys
- URL: https://www.fdaweb.com/more-consistent-rare-disease-flexibility-needed-attorneys/
- Published: 2026-02-18T12:00:00.000Z
- Updated: 2026-09-14T13:33:56.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5160683

Three Hyman, Phelps & McNamara attorneys mark Rare Disease Month by expressing their desire for a future in which regulatory flexibility is applied consistently when appropriate. Writing in their firm’s *FDA Law Blog*, the attorneys [say](https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/bertrand-p-cole-doactivmed-practices-and-research-llc-723495-02022026?ref=fdaweb.com) that while the agency’s Rare Disease Innovation Hub aims to “enhance and strengthen coordination and alignment between medical product Centers,” they have seen the limitations of those efforts.

“Each application is unique,” they say, “but addressing the challenges of rare diseases requires a different paradigm than for non-rare diseases, where randomized, concurrently controlled trials present fewer issues. In rare diseases, the numbers are necessarily smaller, meaning that demonstrating effectiveness will be more challenging, and accrual and retention are persistent challenges.”

The authors say there have been approvals based on single-arm studies for rare diseases where FDA has been willing to extend a measure of flexibility, but also examples where the agency has been unwilling to be flexible. They also cite a variety of recent complete response letters with deficiencies covering manufacturing issues, issues with data from externally-controlled studies, and other clinical trial challenges inherent in rare disease drug development.

“While it is not clear whether consistent flexibility could have resulted in more positive outcomes for these and other recent programs,” the attorneys conclude, “it is clear that some of these challenges have been able to be overcome in other rare disease contexts.”