QRX003 Lotion Shows Promising Results in Netherton Syndrome Trial
Early results from a small trial of a lotion for Netherton syndrome
Quoin Pharmaceuticals recently shared interim results from a mid-stage study testing a new topical medicine called QRX003 for people with Netherton syndrome. The company reports that a majority of the first participants showed some improvement after 12 weeks of treatment, and the lotion appeared to be well tolerated. These are early findings from a small group, so they are promising but not definitive. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
Quick summary
In the first six people who finished 12 weeks of treatment, four improved by at least one grade on a clinician-rated scale that measures overall skin disease. Another clinician-rated test and a patient-rated itch score also showed improvements for some participants. No treatment-related serious problems were reported in this small group. The company plans to enroll about 20 people in total and expects to finish enrollment by the end of 2026 with topline results in mid-2027. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
What is Netherton syndrome?
Netherton syndrome is a rare genetic skin condition caused by changes in a gene called SPINK5. People with this condition often have a weak skin barrier, ongoing inflammation, very dry or scaly skin, and intense itch. It is uncommon, and currently there are no treatments specifically approved by the U.S. Food and Drug Administration for Netherton syndrome. (Source: Quoin Pharmaceuticals press release, 2026.)
How the study was set up
The study, called CL-QRX003-004, is a combined phase 2/3 trial being done at sites in the United States and the United Kingdom. It is an open-label study, which means both doctors and participants know they are using QRX003. The lotion, QRX003 4%, was applied twice daily to the whole body except the scalp for 12 weeks, then participants had a 4-week follow-up visit. People aged 4 years and older can join. For this interim report, the company looked at the first 6 participants who completed the 12-week treatment period. About 20 evaluable participants are planned for the full study. Participants stopped their usual prescription skin treatments for the duration of the trial. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
What the main results were
Here are the key findings from the six-person interim group, reported by the company:
- Investigator Global Assessment (IGA): This is a clinician-rated score that looks at how severe the skin disease is over the treatment area. Four of six participants (66.7%) had at least a one-grade improvement at 12 weeks. Two of those four improved by two or more grades. The company says this met the study’s prespecified statistical threshold. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
- Ichthyosis Area and Severity Index (IASI): This scale measures severity of scaly skin conditions. Four of six participants had more than a 25% reduction in disease severity, with individual improvements ranging from 31% to 87%. The same four people who improved on the IGA also improved on the IASI. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
- Itch (Worst Itch Numeric Rating Scale, WI-NRS): This patient-reported scale runs from 0 to 10, with higher numbers meaning worse itch. Three of six people (50%) had at least a 3-point drop in itch at week 12. All three people who started the study with moderate to severe itch met that threshold, and one person’s itch dropped by more than 6 points. The statistical result for itch did not meet the company’s prespecified cutoff. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
Safety and side effects
In this small interim group, QRX003 was reported to be well tolerated. There were no deaths or treatment-related serious adverse events, and no important changes in ECGs, lab tests, or vital signs were found. These safety results come from the same company report described above. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
What QRX003 is and how it’s being developed
QRX003 is an experimental lotion that targets increased activity of certain enzymes called serine proteases, which are thought to play a role in Netherton syndrome. The drug has received several special designations from the FDA meant to speed development for rare and serious conditions, including Orphan Drug, Rare Pediatric Disease, and Fast Track designations. If approved, QRX003 could become the first FDA-approved therapy for Netherton syndrome. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
Why these early results matter — and what they don’t
The results are encouraging because some people in the small early group showed clear improvements in clinician-rated and patient-reported measures. However, this was an open-label interim analysis of only six people, reported by the company running the study. That means there was no placebo comparison, and the sample is very small. Larger numbers and longer follow-up are needed to understand how well QRX003 works and how safe it is for more people. The company plans to continue enrolling roughly 20 evaluable participants and to report topline results around the second quarter of 2027. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
Tracking skin changes
If you have a visible skin condition, keeping a simple log of photos and notes about symptoms such as itch, pain, or redness can help you notice changes over time and prepare for medical visits. This can be useful when talking with your dermatologist about treatment options or trial participation.
When to see a doctor
If you or a child has persistent skin problems, intense or worsening itch, signs of skin infection (such as increasing pain, pus, spreading redness), bleeding, or any sudden change in skin symptoms, see a healthcare professional. Always discuss treatment decisions with a doctor or dermatologist before starting or stopping any medications.
Disclaimer
This article summarizes an interim company report and is not medical advice. The results described are early and based on a small group of participants. Treatment choices should be made with a healthcare professional. For urgent concerns or sudden worsening of symptoms, seek medical care promptly.
Sources
- Quoin Pharmaceuticals reports positive interim data from ongoing phase 2/3 study of QRX003 in Netherton syndrome. Quoin Pharmaceuticals, Inc. Press release, August 28, 2026. (Source: Quoin Pharmaceuticals press release, CL-QRX003-004 interim results, 2026.)
- Quoin Pharmaceuticals. Company information. Accessed August 28, 2026. (Source: Quoin Pharmaceuticals company website, 2026.)