Chronic Pruritus of Unknown Origin (CPUO) is characterized by a persistent, chronic itch with an unknown cause and is associated with very high burden of disease due to severe itch, sleep deprivation and mental distress1
Galderma’s phase II study builds on emerging research that reinforces the role of IL-31 – a neuroimmune cytokine that is involved in driving itch – in CPUO1
Nemolizumab is a monoclonal antibody that specifically targets the IL-31 receptor alpha, inhibiting the signaling of IL-312
It is approved by multiple regulatory authorities for the treatment of moderate-to-severe atopic dermatitis and prurigo nodularis – conditions in which IL-31 plays a key role in driving itch, inflammation, epidermal dysregulation, and, in prurigo nodularis, fibrosis2-6

ZUG, Switzerland--(BUSINESS WIRE)--Galderma (SIX: GALD), the pure-play dermatology category leader, today announced the first patient enrollment for its phase II study investigating the efficacy and safety of nemolizumab in treating patients living with Chronic Pruritus of Unknown Origin (CPUO). The first patient of the trial – which is taking place in the United States – was enrolled at Dr. Vlada Groysman’s site in Birmingham, Alabama.

CPUO is an underdiagnosed condition defined as itch lasting for more than six weeks without an identified cause.1 It is a common condition and prevalent in nearly 30% of the elderly in certain populations, but despite its debilitating impact – with effects on sleep, mental health, and overall quality of life – there are currently no approved treatments.1,7

Nemolizumab is a monoclonal antibody that specifically targets the IL-31 receptor alpha, inhibiting the signaling of IL-31, a neuroimmune cytokine that plays a key role in CPUO by driving itch, its main symptom.1-4 This randomized, double-blind, placebo-controlled phase II study will determine the therapeutic potential of nemolizumab in adults with CPUO, to support progression to late-stage development.8

“We’re excited to launch this study exploring nemolizumab’s potential in patients with CPUO, many of whom have struggled for years without effective treatment options. Nemolizumab has shown outstanding efficacy in prurigo nodularis – a condition that shares important clinical and mechanistic features with CPUO – through its targeted inhibition of IL-31 signaling. With recent research further reinforcing IL-31 as a key driver of itch in CPUO, we’re hopeful that nemolizumab could offer meaningful relief to patients with this condition.” DOCTOR SHAWN KWATRA, M.D. LEAD INVESTIGATOR, CHRONIC PRURITUS OF UNKNOWN ORIGIN PHASE II STUDY

 

New data provides a better understanding of the key drivers of CPUO, underscoring the role of IL-31
Galderma’s study builds on a recent investigation into the causes of inflammation in CPUO, which uncovered critical insights into its complex inflammatory profile. The research – presented at the Society of Investigative Dermatology annual meeting in San Diego in May 2025 – found a significant increase in IL-31-producing CD4+ T cells in CPUO patients, reinforcing IL-31 as a key driver of the disease.9 These results open the door to targeted therapies that address the root causes of CPUO, a disease with significant unmet needs that currently has no approved treatment options.1,9

“The first patient enrollment in this study marks an important milestone in our commitment to advancing dermatology for every skin story – especially in areas of high unmet need. CPUO is a deeply distressing condition for patients, and the absence of approved treatments has left many without options. With nemolizumab’s targeted mechanism of action and promising results in related conditions, we’re hopeful this study will pave the way for a new therapeutic approach for those living with CPUO.” BALDO SCASSELLATI SFORZOLINI, M.D., PH.D. GLOBAL HEAD OF R&D GALDERMA

 

More information about the study is available on the clinicaltrials.gov website.

About nemolizumab
Nemolizumab was approved in August 2024 by the United States Food and Drug Administration (U.S. FDA) for the treatment of adults with prurigo nodularis.3 In December 2024, it was also approved by the U.S. FDA for the treatment of patients 12 years and older with moderate-to-severe atopic dermatitis, in combination with topical corticosteroids and/or calcineurin inhibitors when the disease is not adequately controlled with topical prescription therapies.3 To date, nemolizumab is approved for both moderate-to-severe atopic dermatitis and prurigo nodularis by multiple regulatory authorities around the world, including in the European Union, Australia, Singapore, Switzerland and the United Kingdom. Additional regulatory submissions and reviews are ongoing.

Nemolizumab was initially developed by Chugai Pharmaceutical Co., Ltd. In 2016, Galderma obtained exclusive rights to the development and marketing of nemolizumab worldwide, except in Japan. In Japan, nemolizumab is marketed as Mitchga® and is approved for the treatment of prurigo nodularis, as well as pruritus associated with atopic dermatitis in pediatric, adolescent, and adult patients.10,11

About Galderma
Galderma (SIX: GALD) is the pure-play dermatology category leader, present in approximately 90 countries. We deliver an innovative, science-based portfolio of premium flagship brands and services that span the full spectrum of the fast-growing dermatology market through Injectable Aesthetics, Dermatological Skincare and Therapeutic Dermatology. Since our foundation in 1981, we have dedicated our focus and passion to the human body’s largest organ – the skin – meeting individual consumer and patient needs with superior outcomes in partnership with healthcare professionals. Because we understand that the skin we are in shapes our lives, we are advancing dermatology for every skin story. For more information: www.galderma.com.

References

1. Teresa J, et al. Therapeutics in chronic pruritus of unknown origin. Itch. 2023;8(1): pe64. doi: 10.1097/itx.0000000000000064
2. Silverberg JI, et al. Phase 2B randomized study of nemolizumab in adults with moderate-to-severe atopic dermatitis and severe pruritus. J Allergy Clin Immunol. 2020;145(1): 173-182. doi: 10.1016/j.jaci.2019.08.013
3. Nemluvio® U.S. Prescribing Information. Available online. Accessed October 2025
4. Nemluvio® European Medicines Agency. Summary of Product Characteristics. Available online. Accessed October 2025
5. Bewley A, et al. Prurigo Nodularis: A Review of IL-31RA Blockade and Other Potential Treatments. Dermatol Ther (Heidelb). 2022;12(9):2039–2048. doi: 10.1007/s13555- 022-00782-2
6. Kwatra SG, Misery L, Clibborn C, Steinhoff M. Molecular and cellular mechanisms of itch and pain in atopic dermatitis and implications for novel therapeutics. Clin Transl Immunology. 2022;11(5):e1390. doi: 10.1002/cti2.1390
7. Andrade E, et al. Interventions for chronic pruritus of unknown origin. CDSR. 2020;1(1): CD013128. doi: 10.1002/14651858.CD013128.pub2
8. ClinicalTrials.Gov. Proof of Concept Study to Assess the Pharmacokinetics/​Pharmacodynamics of Nemolizumab in Adults With Chronic Pruritus of Unknown Origin (CPUO) (CPUO). Available online. Last accessed October 2025
9. Gage G, et al. Peripheral blood high-dimension flow cytometry of chronic pruritus of unknown origin reveals il-31 and oncostatin m+ producing circulating blood CD4+ T cells. Abstract 0966. Society for Investigative Dermatology (SID) 2025 Meeting Abstract Supplement. J Invest Dermatol Volume 145 Issue 8 SupplementS1-S266
10. Chugai Pharmaceutical Co., Ltd. Maruho Obtained Regulatory Approval for Mitchga, the first Antibody Targeting IL-31 for Itching Associated with Atopic Dermatitis. Available online. Accessed October 2025
11. Chugai Pharmaceutical Co., Ltd. Mitchga Approved for Itching in Pediatric Atopic Dermatitis and Prurigo Nodularis, for its Subcutaneous Injection 30mg Vials. Available online. Accessed October 2025