The US Food and Drug Administration (FDA) has granted rare paediatric disease designation to Quoin Pharmaceuticals’ candidate in development for the treatment of Peeling Skin Syndrome (PSS), marking the second tag of this nature for the biotech’s lead asset.
As per the designation, Quoin will be eligible to receive a priority review voucher if the candidate – dubbed QRX003 – is approved in the future by the FDA. As per the framework’s rules, the voucher can be redeemed for any product in the company’s portfolio to slash four months off FDA review time.
Companies are also able to sell vouchers for cash. Since the PRV framework was installed in 2014, a secondary market of vouchers has established itself. In January 2026, Jazz Pharmaceuticals announced it had sold a voucher for $200m. Other sales in 2025 hovered around the $150m price point.
By offloading a voucher for cash or recouping R&D expenses in a more lucrative market, the rare paediatric disease designation acts as an incentive for more rare diseases to be pursued in pipeline strategies.
The latest designation means QRX003 now has two rare paediatric disease tags, after securing one for the treatment of Netherton Syndrome – a rare inherited skin condition – in June 2025. This means Quoin has two routes to a voucher if a new drug application (NDA) is approved.
Quoin’s CEO Michael Myers said: “We are very pleased to announce the receipt of rare paediatric disease designation for QRX003 for peeling skin syndrome."
QRX003 is a lotion compromised of a broad-spectrum serine protease inhibitor. This enzyme regulates several functions in skin cells.
QRX003 has already demonstrated promise in Netherton Syndrome, with a Phase II/III trial meeting its endpoint in August. Quoin has said the drug will be known under the brand name Qyleki in this indication. QRX003 is also set to enter a Phase II trial evaluating its therapeutic potential for PSS. There are currently no approved drugs for the syndrome that causes a continual shedding of the top layer of skin.
“With the investigation new drug application cleared by FDA, the Quoin team is preparing to initiate the Phase II clinical study before the end of this year with plans to enrol up to 12 paediatric and adult peeling skin patients in the US and Europe. This will be the first formal study ever conducted in the US for this disease under an open IND,” Myers added.
The rare paediatric disease legislation returned to the US pharma landscape earlier this year after a lengthy period in regulatory limbo. Patient advocacy groups and pharma industry bodies welcomed its return, calling it a win for children living with the rare diseases.
Editor's note: The headline and fifth paragraph of this article were updated after Quoin issued a revised press release with a correction regarding the number of priority review vouchers it is entitled to. Statements from Myers were also updated to reflect this change.
