A rare disease fast track is being used to freeze trials

An LGMD advocate argues FDA's platform designation, meant to speed shared-vector therapies, is now propagating holds across them.

Kat Bryant Knudson, who founded and runs the patient advocacy nonprofit The Speak Foundation, argues in STAT that a tool Congress built to speed rare disease treatments is now delaying them. The platform technology designation, created by the Food and Drug Omnibus Reform Act of 2022, lets what regulators learn about one shared underlying technology carry across every program that uses it, rather than being rebuilt disease by disease.

Her account of how it has gone: Sarepta won platform designation in June 2025 for a viral vector used in several muscular dystrophy therapies, one of them for LGMD2E/R4. After three deaths among nonambulatory patients, two in Duchenne programs and one in an LGMD2D/R3 program, the FDA pulled the designation and stopped the trials. It later let the Duchenne therapy restart in ambulatory patients while leaving the LGMD2E/R4 program on clinical hold for everyone. She cites a second instance: holds on gene therapies for Hurler and Hunter syndrome justified by shared platform risk, though 32 Hunter patients had gone seven years without adverse outcomes. That hold lifted after new leadership arrived at the agency.

The abundance case for platform designation was always amortization. One body of safety evidence serving many diseases is what stops a therapy for a few thousand people from being priced out of existence. But shared evidence runs both directions: the same link that would carry an approval also carries a suspension, and in a disease with two or three programs, one pause is the entire field.

This is a single advocate's opinion piece, and the FDA's own reasoning for holding the LGMD program is not represented in it. Whether that hold lifts is the thing to watch.

Source: STAT