Ashburn, Va. – August 28, 2026
Quoin Pharmaceuticals announced positive interim results from the ongoing Phase 2/3 CL-QRX003-004 study evaluating QRX003 4% lotion in patients with Netherton Syndrome, a rare genetic skin disorder with no specifically approved treatment in the United States. In the first six participants to complete 12 weeks of treatment, four of six patients (66.7%) achieved a one-grade or greater improvement in Investigator Global Assessment (IGA), meeting the pre-specified statistical threshold with a p-value of 0.0087 versus an alpha of 0.0215. The key secondary endpoint evaluating Global Impression of Change also achieved statistical significance at Week 12, with a p-value of 0.0070. For cGxP.wire, the key development is the positive interim efficacy signal from the first six evaluable participants, alongside clinically meaningful improvements in disease severity and pruritus and a favorable safety profile. Quoin expects to complete enrollment of approximately 20 participants by the end of 2026 and report topline results in the second quarter of 2027.
Quoin Reports Statistically Significant IGA Improvement With QRX003
The primary endpoint of the CL-QRX003-004 Phase 2/3 study is the proportion of participants achieving at least a one-grade improvement from baseline in IGA across the entire treatment area at Week 12. Among the first six participants completing treatment, four achieved the predefined response, representing 66.67% of the cohort, with a 95% confidence interval of 22.28% to 95.67%. The result produced a p-value of 0.0087, exceeding the pre-specified alpha threshold of 0.0215 for the interim analysis. Two of the four responders achieved a two-grade or greater improvement in IGA. The interim analysis therefore provides an early clinical efficacy signal for QRX003, although the sample size remains very small and the study is open-label and baseline-controlled rather than randomized against a placebo or active comparator. The remaining participants and the eventual full dataset will be important for determining whether the observed response is reproducible across a larger Netherton Syndrome population.
QRX003 Shows Improvements in Skin Severity and Pruritus
The interim findings also showed consistent improvements across additional measures of Netherton Syndrome severity. On the Ichthyosis Area and Severity Index (IASI), four of the six participants achieved more than a 25% reduction in disease severity, with individual improvements ranging from 31% to 87% from baseline. Importantly, the same four participants who achieved the primary IGA response also demonstrated clinically meaningful IASI improvements, providing consistency between two physician-assessed measures of skin disease. Pruritus also showed a notable signal. All three participants who had moderate-to-severe itching at baseline achieved at least a three-grade improvement on the Worst Itch Numeric Rating Scale after 12 weeks of treatment, with one participant achieving a greater than six-grade improvement. The Global Impression of Change secondary endpoint also reached statistical significance, with a mean change of -1.5 and a p-value of 0.0070. These findings suggest QRX003 may have effects across both visible skin disease and patient-relevant symptoms, although confirmation in the complete study population is still required.
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Quoin Advances QRX003 Toward Potential First Approved Netherton Therapy
QRX003 is an investigational topical serine protease inhibitor formulated as a 4% lotion and administered twice daily across the body excluding the scalp in the Phase 2/3 study. Netherton Syndrome is caused by mutations in the SPINK5 gene and is associated with impaired skin-barrier function, persistent inflammation and excessive serine protease activity. QRX003 is designed to inhibit this pathway and potentially address an underlying disease mechanism rather than providing only symptomatic treatment. The company reported that the treatment was well tolerated, with no deaths, treatment-related serious adverse events or clinically significant ECG, laboratory or vital-sign abnormalities observed in the interim cohort. Quoin plans to enroll approximately 20 evaluable participants aged four years and older, complete recruitment by the end of 2026 and report topline data in Q2 2027. If the full dataset confirms the interim findings and supports regulatory requirements, QRX003 could potentially become the first FDA-approved treatment specifically indicated for Netherton Syndrome. However, the current results are preliminary, based on only six completed participants, so they should not yet be viewed as definitive evidence of efficacy…
Source: Quoin Pharmaceuticals,, press relese
