QRX003

September 22, 2026: Quoin Pharmaceuticals (NASDAQ: QNRX) said the FDA granted Fast Track Designation to QRX003, an investigational topical serine protease inhibitor lotion, for Peeling Skin Syndrome (PSS), described as the first Fast Track designation for a PSS therapy. The company said PSS has no approved treatment.

This follows FDA clearance in July 2026 of Quoin’s IND for QRX003 in PSS, which it said was the first IND ever submitted to the FDA for the disease; the IND was submitted on June 2, 2026. Quoin plans to start a Phase 2/3 PSS study in 2H 2026, enrolling up to 12 pediatric and adult patients in the U.S. and Europe. QRX003 is planned to be applied twice daily to more than 80% body surface area for 48 weeks, with an interim data review at 24 weeks. The company is targeting approval in 2028.

Supporting the IND were observations from an ongoing investigator-led pediatric single-subject study: improvements were reported in skin appearance, pruritus, quality-of-life measures, M-IASI, IGA, and CDLQI, with treatment ongoing for more than 15 months and no adverse events reported.

QRX003 previously received FDA Fast Track designation for Netherton Syndrome on March 11, 2026.