FDA Unveils Framework to Speed Up Personalized Therapies for Ultra-Rare Diseases

Rare Daily Staff

The U.S. Food and Drug Administration on Monday released draft guidance outlining a new regulatory framework aimed at accelerating the development and approval of individualized therapies for ultra-rare diseases, where traditional randomized trials are often infeasible.

The draft guidance, issued jointly by the agency’s Center for Biologics Evaluation and Research and Center for Drug Evaluation and Research, establishes criteria for demonstrating the safety and effectiveness of treatments that directly target a known genetic or molecular cause of disease.

It focuses on genome-editing and RNA-based therapies, such as antisense oligonucleotides, while leaving room for other precision approaches that address underlying disease mechanisms.

“It is our priority to remove barriers and exercise regulatory flexibility to encourage scientific advances and deliver more cures and meaningful treatments for patients suffering from rare diseases,” said FDA Commissioner Marty Makary, who called the guidance a major step in adapting the agency’s regulatory model to the realities of ultra-rare conditions.

Under the new framework, therapies may qualify for approval if they can show they directly act on a verified disease-causing abnormality, supported by natural history data in untreated patients, and evidence confirming target engagement. For traditional approval, sponsors must still show improvement in clinical outcomes, or in validated biomarkers predictive of benefit.

The guidance also allows for potential “master protocols” that evaluate multiple product variants — such as different edits of the same gene — under a single regulatory study design. A well-supported mechanism of action may then justify the inclusion of additional variants at later stages, streamlining review of similar therapies.

FDA officials emphasized that even small clinical investigations must produce data robust enough to rule out chance findings. Determinations of effectiveness will depend on disease context and available science.

The draft guidance is open for public comment for 60 days following its publication in the Federal Register. Comments can be submitted at Regulations.gov.