The FDA has granted Rare Pediatric Disease (RPD) Designation to QRX003, Quoin Pharmaceuticals' lead investigational asset, for the treatment of peeling skin syndrome (PSS), the company announced September 8, 2026. The designation is the second RPD designation granted for QRX003, following an earlier designation for Netherton syndrome in June 2025.1,2
Quoin Pharmaceuticals Ltd (NASDAQ: QNRX) is a late clinical-stage specialty pharmaceutical company focused on rare and orphan diseases. There are currently no approved treatments for PSS, according to the company.1
The FDA cleared Quoin's investigational new drug (IND) application for QRX003 in PSS in July 2026, allowing the company to proceed with a planned phase 2 clinical study.3
Priority Review Voucher Potential
According to Quoin, the FDA's RPD Designation program is intended to encourage development of therapies for serious and life-threatening diseases that primarily affect individuals younger than 18 years. If a new drug application (NDA) for QRX003 in PSS is ultimately approved, Quoin may qualify to receive a Priority Review Voucher (PRV).1
A PRV can be redeemed for priority review of another marketing application or sold or transferred. Because QRX003 also holds RPD designation in Netherton syndrome, Quoin said it could potentially receive 2 PRVs. Michael Myers, PhD, chief executive officer of Quoin Pharmaceuticals, estimated that, based on current PRV trading values, the vouchers could have an aggregate nondilutive cash value exceeding $300 million.1
Quoin has not disclosed an expected NDA filing timeline for QRX003 in PSS.
FREQUENTLY ASKED QUESTIONS:
- What is the FDA's Rare Pediatric Disease Designation for QRX003 in Peeling Skin Syndrome? The FDA granted QRX003 RPD Designation for PSS on September 8, 2026, marking the second RPD designation for the asset after an earlier designation in Netherton syndrome. The designation can make Quoin eligible for a Priority Review Voucher if an NDA for QRX003 in PSS is later approved.
- What is Quoin's Phase 2 study plan for QRX003 in Peeling Skin Syndrome? Quoin plans to begin the Phase 2 study in the second half of 2026, enrolling up to 12 pediatric and adult PSS patients at sites in the United States and Europe. The company said the trial will be the first formal U.S. study conducted for PSS under an active IND.
- Why does the Rare Pediatric Disease Designation matter for Quoin's PSS program? According to CEO Michael Myers, PhD, approval of QRX003 in both Netherton syndrome and PSS could yield two separate Priority Review Vouchers with a combined non-dilutive value Quoin estimates at more than $300 million.
Phase 2 Study Planned Before End of 2026
Quoin plans to initiate its phase 2 study of QRX003 in PSS before the end of 2026, following FDA clearance of the IND in July. The company plans to enroll up to 12 pediatric and adult patients with PSS at sites in the United States and Europe.1,3
According to Quoin, the trial will be the first formal clinical study conducted in the United States for PSS under an active IND. The company did not disclose specific dosing regimens, treatment duration, or study endpoints in its September 8 announcement.1
No safety or tolerability data specific to patients with PSS were included in the announcement, as dosing in the planned phase 2 study has not yet begun.
“With the IND cleared by FDA, the Quoin team is preparing to initiate the Phase 2 clinical study before the end of this year with plans to enroll up to 12 pediatric and adult Peeling Skin patients in the U.S. and Europe,” Myers said. “This will be the first formal study ever conducted in the U.S. for this disease under an open IND.”1
Understanding Peeling Skin Syndrome
Generalized inflammatory PSS is a rare autosomal recessive genodermatosis associated with loss-of-function disease-causing variants in the CDSN gene, which encodes corneodesmosin. The condition results in excessive shedding of the superficial layers of the epidermis and can cause symptoms including severe pain and chronic pruritus.1
QRX003 Expands Quoin's Rare Disease Pipeline
QRX003 is one of 2 platform products in Quoin's pipeline, alongside QRX009. The company's development pipeline encompasses rare and orphan indications including Netherton syndrome, PSS, palmoplantar keratoderma, pachyonychia congenita, Gorlin syndrome, tuberous sclerosis complex, microcystic lymphatic malformations, venous malformations, and angiofibromas.1
References
- Quoin Pharmaceuticals announces FDA grants Rare Pediatric Disease Designation for QRX003 in peeling skin syndrome. GlobeNewswire. Published September 8, 2026. Accessed September 8, 2026. https://www.globenewswire.com/news-release/2026/09/08/3357647/0/en/quoin-pharmaceuticals-announces-fda-grants-rare-pediatric-disease-designation-for-qrx003-in-peeling-skin-syndrome.html
- Quoin Pharmaceuticals announces FDA grants Rare Pediatric Disease Designation for QRX003 in Netherton syndrome. GlobeNewswire. Published June 24, 2025. Accessed September 8, 2026. https://www.globenewswire.com/news-release/2025/06/24/3104239/0/en/Quoin-Pharmaceuticals-Announces-FDA-Grants-Rare-Pediatric-Disease-Designation-QRX003-Netherton-Syndrome.html
- Quoin Pharmaceuticals receives FDA IND clearance to initiate phase 2 study of QRX003 in peeling skin syndrome. GlobeNewswire. Published July 9, 2026. Accessed September 8, 2026. https://www.globenewswire.com/news-release/2026/07/09/3324798/0/en/Quoin-Pharmaceuticals-Receives-FDA-IND-Clearance-to-Initiate-Phase-2-Study-of-QRX003-in-Peeling-Skin-Syndrome.html
