ASHBURN, Va. — September 22, 2026

Quoin Pharmaceuticals announced that the U.S. Food and Drug Administration has granted Fast Track Designation to investigational QRX003 for the treatment of Peeling Skin Syndrome (PSS). The company said the designation is the first Fast Track Designation granted for a PSS therapy and represents the second Fast Track designation for QRX003, following its designation for Netherton Syndrome in March 2026. The regulatory milestone follows FDA clearance in July 2026 of Quoin’s IND for PSS, which the company said was the first IND submitted to the FDA for the rare genetic skin disease.

QRX003 Advances Toward Phase 2/3 PSS Study

Quoin expects to initiate a Phase 2/3 clinical study of QRX003 in PSS during the second half of 2026, with enrollment of up to 12 pediatric and adult patients in the United States and Europe. The planned study will evaluate twice-daily application of QRX003 across more than 80% of body surface area for 48 weeks, with an interim assessment at Week 24. The company is targeting potential approval of QRX003 for PSS in 2028, subject to clinical and regulatory outcomes.

Clinical Observations Support Further Development

QRX003 is an investigational topical serine protease inhibitor lotion supported by clinical observations from an ongoing investigator-led pediatric study involving a single patient. Quoin reported improvements in skin appearance and changes in pruritus and quality-of-life measures, as well as improvements across measures including the Modified Ichthyosis Area Severity Index and Investigator’s Global Assessment. Treatment has continued for more than 15 months without reported adverse events in that individual. These observations are from a single-subject investigator-led study and are not controlled clinical efficacy evidence.

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Fast Track Expands QRX003 Rare Disease Program

Fast Track status may facilitate more frequent FDA interactions, potential rolling review and potential eligibility for Accelerated Approval or Priority Review when applicable criteria are met. QRX003 is already being evaluated in Phase 2/3 whole-body trials for Netherton Syndrome and has received FDA Orphan Drug, Rare Pediatric Disease and Fast Track designations for that indication. For PSS, QRX003 is being developed for a disease caused by loss-of-function variants in the CDSN gene, resulting in excessive shedding of superficial epidermal layers. With no approved treatment currently available for PSS, Quoin is expanding QRX003 development across rare dermatologic diseases..

Source :Quoin Pharmaceuticals, press release