Drug used to treat eczema may provide relief for patients with intensely itchy skin diseases

"Very few treatments exist for prurigo nodularis and chronic pruritus of unknown origin; patients often suffer for years in horrible discomfort, which can lead to anxiety and depression, severely impacting their quality of life," said Shawn Kwatra, MD, the Joseph W. Burnett Endowed Professor and Chair of Dermatology at UMSOM and Chief of Service Dermatology at the University of Maryland Medical Center (UMMC). "The rationale for this study came from my laboratory's studies findings of altered inflammatory mediators in these conditions that all function through JAK1. Through this trial, we hope to continue to move the needle toward personalized therapies that can provide sustainable relief for coping with these debilitating conditions."

Affecting at least 130,000 Americans, prurigo nodularis causes dozens of extremely itchy and disfiguring bumps, usually on the chest, arms, and legs. Dr. Kwatra's previous research indicates that prurigo nodularis occurs more than 3 times as frequently in Black patients than white patients, tends to be more common in women, and is associated with depression, diabetes, chronic kidney disease, and HIV. Chronic pruritus of unknown origin is most prevalent among older adults and causes severe itching lasting longer than six weeks. Current therapies used to help manage symptoms include over-the-counter and prescription itch relief ointments and anti-inflammatory drugs such as antihistamines and corticosteroids. None of these medications, however, provide sustained relief.

The study involved a total of 20 patients, half of whom had prurigo nodularis and half of whom had chronic pruritus of unknown origin. They were all given a 200-milligram pill of abrocitinib once a day for 12 weeks; the patients knew they were being given an experimental treatment, and the study did not include a placebo group. Abrocitinib was found to reduce itching and pain symptoms by 78 percent in the prurigo nodularis patients. Patients with chronic pruritus of unknown origin experienced a 54 percent reduction in itching and pain symptoms. Patients in both groups also reported an improvement in their quality of life and in their sleep habits.

None of the patients experienced serious adverse events. The most common side effect, in 10 percent of patients, was small acne-like bumps.

Abrocitinib is a JAK1 inhibitor drug that works to suppress inflammation, specifically pro-inflammatory chemicals called cytokines that are involved in an overactive immune system. The drugs appear to slow down immune activity by suppressing intracellular signaling of these cytokines.

"This is not only an encouraging study but also sets the stage for a Phase 3 clinical trial," said Mark T. Gladwin, MD, who is the John Z. and Akiko K. Bowers Distinguished Professor and Dean of UMSOM, and Vice President for Medical Affairs at University of Maryland, Baltimore. "It holds promise for introducing a novel treatment to patients in underserved communities disproportionately affected by prurigo nodularis, a condition historically overlooked by dermatology."

Since beginning his position at UMSOM, Dr. Kwatra has created the Maryland Itch Center at UMMC and is currently continuing his research there.