LEKTI

Continued Clear Visual Evidence of Almost Completely Healed Skin After 6 weeks Treatment High Durability of Treatment Effect of QRX003 with Continuous Daily Dosing Patient Continues Not to Require Previously Necessary Medications With Patient’s Pruritus Almost Completely Eliminated, Patient Continues to Experience Zero Nightly Sleep Disturbance No Adverse Events Reported from 6 Weeks of Whole Body Treatment with QRX003 Approval Received to Initiate Whole Body Testing of a Second Pediatric Patient ASHBURN, Va., April 02, 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 additional highly positive clinical data from its ongoing Investigator Pediatric Netherton Syndrome (NS) study. After 6 weeks of continued whole body application of QRX003, the subject’s skin remains almost completely healed demonstrating the durability of ongoing daily treatment with the product. In addition, the patient has continued to have no requirement for previously necessary medications such as antibiotics, antivirals, antihistamines and glucocorticoids. Importantly, with the patient’s pruritus or itch almost completely eliminated, she continues to experience zero nightly sleep disturbances without the need for any sedating medication, marking the first continuous period of uninterrupted sleep in the patient’s life. No adverse events have been reported to date after 6 weeks of whole body treatment with QRX003. Quoin CEO Dr. Michael Myers, said, “As we continue to monitor the progress of this first patient to receive whole body application with QRX003, we are very pleased to announce that after 6 weeks of dosing we are seeing continued positive improvement and the patient’s skin is almost completely healed now. The patient continues to remain off previously needed medications including antihistamines, antivirals, and glucocorticoids, and she has not needed any antibiotics in the 6 weeks since the initiation of dosing with QRX003. Very importantly also, with her pruritus almost completely eliminated, the patient is still experiencing zero nightly sleep disturbances without the need for any sedating medications. For a majority of Netherton Syndrome patients, the continuous presence of chronically debilitating pruritus is the worst symptom of this disease and it severely impacts their ability to sleep or to even sit still for any period of time. Often heavy sedation is required to allow patients to sleep and sit still, which in turn has a major negative impact on their quality of life. The almost complete healing of the skin and the elimination of this chronically debilitating pruritus provides strong clinical evidence that QRX003 is successfully tackling the root causes of this disease and not merely providing symptomatic relief. Furthermore, I am very pleased to report that no adverse events have been reported after six full weeks of whole-body application of QRX003. Based on these positive results, approval has been received to initiate whole body application of QRX003 to a second pediatric Netherton patient. Testing is expected to commence in just a few weeks and we look forward to providing updates on both patients progress as we continue with our plans to further expand this study to include additional pediatric subjects.” 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 four products in development that collectively have the potential to target a broad number of rare and orphan indications, including Netherton Syndrome, Peeling Skin Syndrome, SAM Syndrome, Palmoplantar Keratoderma, Scleroderma, Epidermolysis Bullosa, 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: the potential efficacy of QRX003 as a treatment for Netherton Syndrome; testing expected to commence in a few weeks on a second pediatric patient; continue with our plans to further expand this study to include additional pediatric subjects; 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, SAM Syndrome, Palmoplantar Keratoderma, Scleroderma, Epidermolysis Bullosa, 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 deliver a safe and effective treatment for Netherton Syndrome; whether the Company’s studies successfully generate data that is sufficiently robust and comprehensive to support an NDA filing for QRX003 as an approved treatment for Netherton Syndrome; 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

Groundbreaking data from first whole body application of QRX003 underscores potential efficacy Transformational improvement in disease state after just 2 weeks of treatment Clear visual evidence of skin healing observed Improvement has eliminated need for previously required medications Patient is now experiencing zero nightly sleep disturbance for the first time No adverse events reported from whole body treatment ASHBURN, Va., Feb. 27, 2025 (GLOBE NEWSWIRE) -- Quoin Pharmaceuticals Ltd. (NASDAQ: QNRX) (the “Company” or “Quoin”), a late clinical stage, specialty pharmaceutical company focused on rare and orphan diseases, today announces highly positive clinical data from its ongoing Investigator Pediatric Netherton Syndrome (NS) study. Dramatic improvement was observed in the patient’s disease state with clear visual evidence of skin healing observed after just two weeks of whole-body application of QRX003. No adverse events have been reported to date. Both key clinical endpoints, Investigator’s Global Assessment (IGA) and Pruritus or itch, demonstrated highly significant clinical improvements from baseline after two weeks of treatment with QRX003 on patient’s whole body. Table 1: Results for First Pediatric Patient Receiving QRX003 ‘Whole-Body’ Application *Both IGA and Pruritus scores based on a 0-10 scale. Furthermore, following treatment with QRX003, the patient has now discontinued previously required medications including all antihistamines, glucocorticoids and antivirals. Importantly, the patient has not needed treatment with any antibiotics since the whole-body application of QRX003 was initiated. In addition, the patient is now experiencing zero nightly sleep disturbances for the first time in her life. No adverse events have been reported to date. Quoin CEO Dr. Michael Myers, said, “While cautioning upfront that this data is from just a single patient over a short period of time, these truly exciting and groundbreaking results provide a snapshot of the potential efficacy of QRX003 as a chronic whole-body treatment of Netherton Syndrome. After just two weeks of treatment, a transformational life change has occurred for this first patient to receive whole-body application of QRX003. At baseline, the Investigators Global Assessment, or IGA, for the patient’s skin was at 5 on a scale of 0-10. After two weeks of treatment with QRX003, the IGA was at 1, representing an almost complete elimination of the visual effects of the disease on the patient’s skin. In addition, her pruritus, which at baseline was described as “chronically debilitating itch” and a 7 on of a scale of 0-10, had significantly dropped to a “highly tolerable and non-intrusive” score of between 1 and 2 after only two weeks of treatment with QRX003. Even more encouraging is the fact that the patient has been able to discontinue ongoing treatment with a variety of previously required medications including antihistamines, antivirals, glucocorticoids and she has not needed any antibiotics since the initiation of dosing with QRX003. We believe that these results indicate that QRX003 is directly targeting the root cause of the disease and has the potential to provide NS patients with the opportunity to have lives essentially free from the ravages of this terrible disease. In addition, the patient is now, for the first time, experiencing zero nightly sleep disturbances, again providing additional evidence of the potential efficacy of QRX003. Finally, we are very pleased to report that no adverse events have been recorded after two weeks of twice-daily, whole-body application of QRX003. As we continue with our plans to expand this study to include additional pediatric subjects in other countries who would also receive whole body application of QRX003, we believe that the highly encouraging nature of the results generated to date for this patient could potentially bring hope and comfort to children and families whose lives are being so dramatically impacted by the consequences of this cruel disease.” 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 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 four 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, Epidermolysis Bullosa 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: the potential efficacy of QRX003 as a treatment for Netherton Syndrome; QRX003 directly targeting the root cause of the disease, QRX003 having the potential to provide NS patients with the opportunity to live lives essentially free from the ravages of this terrible disease, expanding the study to include additional pediatric subjects in other countries who would also receive whole body application of QRX003, 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, Epidermolysis Bullosa 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 deliver a safe and effective treatment for Netherton Syndrome; whether its studies successfully generate data that is sufficiently robust and comprehensive to support an NDA filing for QRX003 as an approved treatment for Netherton Syndrome; and other factors discussed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 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

Four Weeks After Discontinuation of Treatment with QRX003 Complete Reversal of Positive Clinical Improvements Across all Measured Endpoints Observed Data Supports QRX003 Mechanism of Action as a Competitive Broad Spectrum Serine Protease Inhibitor ASHBURN, Va., Jan. 23, 2025 (GLOBE NEWSWIRE) -- Quoin Pharmaceuticals Ltd. (NASDAQ: QNRX) (the “Company” or “Quoin”), a clinical stage, specialty pharmaceutical company focused on rare and orphan diseases, today announces further clinical evidence of the potential efficacy of QRX003 in Netherton Syndrome. In December 2024 and January 2025, Quoin announced positive data from the mid-point and at completion of 12 weeks of testing the first subject dosed twice-daily in Quoin’s ongoing open-label study which demonstrated evidence of clear improvement across all measured clinical endpoints. Today Quoin is sharing additional data on that subject at 4 weeks post-discontinuation of treatment with QRX003. As the table below illustrates all of the positive clinical benefits observed after 12 weeks of testing with QRX003 were completely reversed by 4 weeks after discontinuation of treatment resulting in the subject’s disease state reverting to the baseline status observed prior to QRX003 treatment. These results strongly indicate that ongoing, chronic treatment with QRX003 is necessary for a continued positive clinical outcome in Netherton Syndrome patients. Table 1: First Patient Data from Open Label Study Part B- Dosed Twice Daily with QRX003 *M-IASI: Modified Ichthyosis Area of Severity Index, a score used to assess the severity and extent of skin symptoms associated with ichthyosis. Lower scores indicate improvement. **WINRS: Worst Itch Numeric Rating Scale, which measures the severity of itch on an 11-point scale (0 = no itch, 10 = worst imaginable itch). ***IGA: Investigator’s Global Assessment, which uses descriptive categories (e.g., clear, mild, moderate, severe) to evaluate the overall severity of Netherton Syndrome symptoms. Quoin CEO, Dr. Michael Myers, said, “This data set provides the clearest clinical evidence to date that the active ingredient in QRX003 is a competitive broad spectrum serine protease inhibitor and that discontinuation of treatment with QRX003 results in a complete reversal of all clinical benefits derived from continued treatment with the product. The rapid reversal of all observed clinical benefits to baseline disease status after just 4 weeks of treatment discontinuation serves to further underscore that chronic, whole-body treatment with QRX003 is potentially required to maintain the positive clinical outcomes observed in our clinical study. These results increase our commitment to complete the clinical development of QRX003 as expeditiously as possible with a goal of making the product widely available to the Netherton community once approved. With four clinical studies in Netherton subjects underway, three of which are being conducted under an open Investigational New Drug (IND) application with the FDA, we believe Quoin is assembling a broad and diverse clinical data package to support a New Drug Application (NDA) filing for QRX003 as potentially the first approved treatment for Netherton Syndrome.” 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://quoinpharma.com/pipeline/#trials About Quoin Pharmaceuticals Ltd. Quoin Pharmaceuticals Ltd. is a 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 four 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, Epidermolysis Bullosa 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 a description 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,” “plan,” “anticipate,” “believe,” 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, the potential efficacy of QRX003 as a treatment for Netherton Syndrome, the goal of making the product widely available to the Netherton community once approved, we believe Quoin is assembling a broad and diverse clinical data package to support a New Drug Application (NDA) filing for QRX003 as potentially the first approved treatment for Netherton 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, Epidermolysis Bullosa 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 deliver a safe and effective treatment for Netherton Syndrome, its studies may not be successful or may not generate data which is sufficiently robust and comprehensive to an NDA filing for QRXOO3 as an approved treatment for Netherton Syndrome and other factors discussed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 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