Long-Term Efficacy and Safety of Nemolizumab in Prurigo Nodularis

In a significant advancement for dermatological therapeutics, nemolizumab, a monoclonal antibody targeting the interleukin-31 receptor-α, has demonstrated substantial and sustained efficacy in the treatment of moderate to severe prurigo nodularis over a two-year period, according to findings presented at the XIV International Congress of Dermatology on June 18, 2025. This chronic neuroimmune skin disorder is characterized by intense itching and the development of thick skin nodules, severely impacting patients' quality of life.

Nemolizumab, marketed as Nemluvio by Galderma, is noteworthy for being the first biologic approved for both prurigo nodularis and atopic dermatitis, administered through subcutaneous injection every four weeks. The drug’s innovative mechanism involves the inhibition of IL-31 signaling, which is crucial in the pathophysiology of prurigo nodularis.

Dr. Baldo Scassellati Sforzolini, MD, PhD, the global head of research and development at Galderma, expressed optimism regarding the expanding evidence base supporting nemolizumab's clinical utility. "As this treatment becomes available in more countries around the world, it’s highly encouraging to see its robust evidence base continue to expand and strengthen," he stated.

The pivotal phase 3 OLYMPIA trials, which included 560 participants, established the drug’s safety and efficacy. In the long-term extension study, which included 508 patients from the OLYMPIA trials, more than 90% of patients reported significant improvements in itch and skin lesions after 100 weeks of treatment. Specifically, at least 70% of patients achieved a four-point or greater improvement on the Peak-Pruritus Numerical Rating Scale, while over 80% experienced substantial healing of pruriginous lesions, as assessed by the Investigator’s Global Assessment score.

A parallel long-term extension study, known as ARCADIA, also reported sustained improvements in atopic dermatitis symptoms, reinforcing the drug’s suitability for chronic inflammatory skin conditions. Professor Sonja Stander, lead investigator of the OLYMPIA studies at University Hospital Münster, highlighted, "These impressive results give us even more confidence in the value of nemolizumab—a much-needed innovative medicine that has the potential to deeply impact the prurigo nodularis treatment landscape."

The FDA's approval of nemolizumab in August 2024 followed extensive clinical trials demonstrating a favorable safety profile without new safety signals identified during long-term treatment.

The results from these studies not only raise hopes for improved patient outcomes but also pave the way for further investigations into the underlying mechanisms of prurigo nodularis and the broader applications of biologic therapies in dermatology. As the treatment landscape evolves, stakeholders in the healthcare community remain focused on understanding the implications of these findings for clinical practice and patient care.

Future studies are expected to explore the long-term benefits and potential applications of nemolizumab in other inflammatory skin diseases, as the need for effective treatment options remains critical in this patient population. The emergence of nemolizumab as a viable therapeutic option marks a significant milestone in addressing the unmet needs of patients suffering from prurigo nodularis and related conditions.