Rare Daily Staff

The U.S. Food and Drug Administration granted ProQR Therapeutics Rare Pediatric Disease designation for QR-421a, an experimental therapy for a rare eye disease driven by a specific genetic mutation.

QR-421a is a first-in-class investigational RNA-based oligonucleotide designed to address the underlying cause of vision loss in Usher syndrome type 2 and non-syndromic retinitis pigmentosa due to mutations in exon 13 of the USH2A gene.

The FDA grants Rare Pediatric Disease designation for serious or life-threatening diseases with manifestations in individuals aged from birth to 18 years, including access to the FDA’s expedited review and approval process. The designation makes QR-421a eligible for a Rare Pediatric Disease Priority Review voucher upon approval of the therapy by the FDA.

The vouchers can be used to reduce the time of an FDA new drug approval review to six months from ten months. The vouchers are potentially lucrative because they are transferable. Most recently, Swedish Orphan Biovitrum sold its Priority Review voucher to AstraZeneca for $95 million.


The Rare Pediatric Disease designation is the second ProQR received in recent months. In October, the FDA granted the company Rare Pediatric Disease designation for sepofarsen, its experimental RNA therapy for Leber’s congenital amaurosis 10, a form of childhood blindness.

“Both sepofarsen for LCA10, the most common cause of blindness due to genetic disease in children, and QR-421a have received rare pediatric designation, underscoring the high unmet need for patients,” said Daniel de Boer, CEO of ProQR. “We aim to make a difference for these patients as we work to advance our pipeline of programs to treat inherited retinal diseases.”

Photo: Daniel de Boer, CEO of ProQR

X