Quoin Pharmaceuticals Announces Recruitment of Three Additional Patients in Investigator Pediatric Netherton Syndrome Study and Provides Positive 9 month ‘Whole Body’ Data Update from Ongoing Study

• Recruitment of Three Additional Pediatric Patients in Austria and Ireland Achieves Investigator Study Target
• Current Pediatric Patient in Ongoing Study Has Completely Healed Skin After 9 months of ‘Whole Body’ Treatment
• Investigator’s Global Assessment (IGA) Materially Improved from Baseline 4 (Severe) to 0 (Clear)
• Pruritus (itch) Reduced from 5 at baseline to 0, reflecting a complete absence of pruritus
• High Durability of Treatment Effect of QRX003 with Continuous Daily Dosing
• Patient Continues Not to Require Previously Necessary Medications and is Experiencing Zero Nightly Sleep Disturbance
• No Adverse Events Reported After 9 Months of Continuous Dosing with QRX003

ASHBURN, Va., Oct. 28, 2025 (GLOBE NEWSWIRE) — Quoin Pharmaceuticals Ltd. (NASDAQ: QNRX) (the “Company” or “Quoin”), a late clinical stage, specialty pharmaceutical company focused on the development and commercialization of therapeutic products that treat rare and orphan diseases, today announces recruitment of three additional patients in its investigator led pediatric Netherton Syndrome (NS) study as well as highly positive 9 month clinical data from the first pediatric patient in the study.

After 9 months of continued whole body application of QRX003, the subject’s skin remains completely healed demonstrating the durability of ongoing daily treatment with the product. At baseline, prior to initiation of treatment with QRX003, the subject’s skin had an Investigator’s Global Assessment (IGA) of 4, on a scale of 0-4 where 4 is the most severe score possible. At 9 months, the IGA had materially improved to 0 and the subject’s skin is completely clear. In addition, the subject’s pruritus score (on a scale from 0-10, with 10 being the worst itch imaginable) changed from 5 at baseline to 0 at 9 months. The subject continues to experience zero nightly sleep disturbances without the need for any sedating medication, marking the first continuous period of uninterrupted sleep in their life. Furthermore, since being treated with QRX003, the subject has continued to have no requirement for previously necessary medications such as antibiotics, antivirals, antihistamines and glucocorticoids. No adverse events have been reported to date after 9 months of daily, whole-body treatment with QRX003.

In conjunction with the announcement of this highly positive data, Quoin is pleased to announce that it has recruited three additional pediatric subjects into this investigator led pediatric NS study. All three subjects will receive twice-daily whole-body application of QRX003, initially for a period of twelve weeks before continuing in a long-term extension protocol until regulatory approval has been obtained. Two of the subjects reside in Austria and the third lives in Ireland. Quoin believes data from these additional subjects will significantly add to the growing body of positive clinical data supporting QRX003 as a potential treatment for NS.

Quoin CEO Dr. Michael Myers, said, “We are pleased to announce these two significant milestone events for Quoin and our QRX003 NS program. First, the achievement of, and continued retention of, both fully healed skin and the complete elimination of pruritus in the first pediatric subject is a testament to the clinical benefit of QRX003 in NS. With no need for previously required medications, such as antibiotics, antivirals, antihistamines and glucocorticoids, and zero nightly sleep disturbance, treatment with QRX003 has truly been completely life transforming for this little girl. Second, we are excited to announce the recruitment of three additional NS subjects in Austria and Ireland. We believe that the clinical data from these subjects will continue to demonstrate positive clinical outcomes of QRX003 in NS without adverse events.”

About Netherton Syndrome
Netherton Syndrome, a form of Ichthyosis, is a rare hereditary skin disorder caused by a mutation in the SPINK5 gene (serine protease inhibitor, Kazal Type 5) that leads to severe skin barrier defects and recurring infections, as well as a pronounced predisposition to allergies, asthma, and eczema. Patients often suffer from severe dehydration, chronic skin inflammation and stunted growth. Currently, there is no cure for Netherton Syndrome, nor are there any approved therapeutic treatments.

About QRX003
QRX003 is a topical lotion formulated with a proprietary delivery technology that contains a broad-spectrum serine protease inhibitor, whose mechanism of action is intended to perform the function of a specific protein called LEKTI. The absence of LEKTI in Netherton patients leads to excessive skin shedding, resulting in a highly porous and compromised skin barrier. QRX003 is designed to promote a more normalized skin-shedding process and the formation of a stronger and more effective skin barrier. For more information about Quoin’s current clinical trials please visit: https://www.nethertonsyndromeclinicaltrials.com/

About Quoin Pharmaceuticals Ltd.
Quoin Pharmaceuticals Ltd. is a late clinical-stage specialty pharmaceutical company focused on developing and commercializing therapeutic products that treat rare and orphan diseases. We are committed to addressing unmet medical needs for patients, their families, communities and care teams. Quoin’s innovative pipeline comprises several products in development that collectively have the potential to target a broad number of rare and orphan indications, including Netherton Syndrome, Peeling Skin Syndrome, Palmoplantar Keratoderma, Scleroderma, Microcystic Lymphatic Malformations, Venous Malformations, Angiofibroma and others. For more information, visit: www.quoinpharma.com or LinkedIn for updates.

Cautionary Note Regarding Forward Looking Statements
The Company cautions that statements in this press release that are not descriptions of historical facts are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words referencing future events or circumstances, such as “expect,” “intend,” “hope,” “plan,” “potential,” “anticipate,” “look forward,” “believe,” “may,” and “will,” among others. All statements that reflect the Company’s expectations, assumptions, projections, beliefs, or opinions about the future, other than statements of historical fact, are forward-looking statements, including, without limitation, statements relating to: providing the additional subjects with twice-daily whole-body application of QRX003 for a period of twelve weeks before continuing in a long-term extension protocol until regulatory approval has been obtained; the data from the additional subjects significantly adding to the growing body of positive clinical data of QRX003 as a potential treatment for NS; the clinical data from the additional subjects demonstrating positive clinical outcomes of QRX003 in NS without adverse events ; and Quoin’s products in development collectively having the potential to target a broad number of rare and orphan indications, including Netherton Syndrome, Peeling Skin Syndrome, Palmoplantar Keratoderma, Scleroderma, Microcystic Lymphatic Malformations, Venous Malformations, Angiofibroma and others. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These forward-looking statements are based upon the Company’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties including, but not limited to, the Company’s ability to pursue its regulatory strategy; the Company’s ability to obtain regulatory approvals for commercialization of product candidates or to comply with ongoing regulatory requirements; the Company’s ability to complete clinical trials on time and achieve desired results and benefits as expected; and other factors discussed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 and in other filings the Company has made and may make with the SEC in the future. One should not place undue reliance on these forward-looking statements, which speak only as of the date on which they were made. The Company undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as may be required by law.

For further information, contact:
Quoin Pharmaceuticals Ltd.
Michael Myers, Ph.D., CEO
mmyers@quoinpharma.com

Investor Relations
PCG Advisory
Jeff Ramson
jramson@pcgadvisory.com
(646) 863-6341