MADRID – Nemolizumab, an investigational humanized monoclonal antibody targeting the interleukin-31 receptor alpha subunit, achieved rapid and clinically meaningful improvement in both itch and skin lesions of severe prurigo nodularis in a phase 2b, randomized trial, Sonja Stander, MD, said at the annual congress of the European Academy of Dermatology and Venereology.
Dr. Sonja Stander
“We saw onset of pruritus improvement in week 1 and onset of lesion healing at week 4,” reported Dr. Stander, professor of dermatology and neurodermatology and head of the Center for Chronic Pruritus at the University of Münster (Germany).
The study results confirm IL-31 signaling as an important therapeutic target in prurigo nodularis and herald the arrival of nemolizumab as a promising potential therapy for severely affected patients, she added.
Prurigo nodularis is a chronic, highly pruritic disease that is difficult to treat and carries a high disease burden. While the disease’s pathogenesis is not completely understood, IL-31 is up-regulated in affected patients. And IL-31, a proinflammatory and immunomodulatory cytokine, is known to have a broad range of actions, including serving as a link between the immune and neural systems, as well as induction of itch and skin lesions.
Dr. Stander presented the results of a 20-center, double-blind, at weeks 0, 4, and 8, then followed off therapy out to week 18. These were severely affected patients: their mean weekly peak pruritus score on a 0-10 numeric rating scale was 8.4, with 7 being the accepted threshold for severe itch. The group had a mean Dermatologic Life Quality Index score of 16.4; 40% of patients had more than 100 nodules on their body, and the rest had 20-100.
The primary endpoint was the percentage decrease in the peak pruritus score from baseline to week 4, at which point they had only received one dose. The nemolizumab group averaged a 53.4% reduction, compared with 15.3% in placebo-treated controls. At week 12, a full month after the final injection, the split was 63.2% versus 20.2%. And at week 18, the nemolizumab group maintained a mean 58.2% reduction from baseline versus 20.9% in controls.
“The effect starts at week 1, with a 26% reduction in itch intensity in the nemolizumab group, compared to 6.7% with placebo,” the dermatologist observed.
The absolute decrease in weekly peak pruritus score at week 12 was 5.2 points with nemolizumab and 1.7 points with placebo.
Among the secondary endpoints was achievement of an Investigator Global Assessment score of 0-1, meaning clear or almost clear of skin lesions. The rate in the nemolizumab group climbed steadily from week 4 on, reaching 38.2% and still rising without a plateau at week 18, versus 5.6% in controls.
Another secondary endpoint was 75% or greater healing on the 7-item Prurigo Activity Scale. By week 4 there was already a statistically significant between-group difference: 23.5% versus 11.2%. Once again, in the nemolizumab group, this rate climbed without a plateau through the study’s end at week 18, by which point it was 44.1%, compared with 8.4% among those on placebo.
Scores on the Dermatologic Life Quality Index improved by an average of 10.2 points at week 4 in patients on nemolizumab, compared with 6 points among controls.
Self-reported sleep disturbance scores improved by 56% at week 4 in the nemolizumab group and 22.9% with placebo.
The safety profile of nemolizumab was similar to that of placebo, with roughly 5.7% of patients in each study arm withdrawing because of treatment-emergent adverse events. Unlike in the positive studies of the IL-31 inhibitor in patients with atopic dermatitis – another potential indication under active investigation – there was no signal of an increased risk of staphylococcal skin infections, conjunctivitis, or head and neck dermatitis in patients on nemolizumab for prurigo nodularis. Patients with comorbid atopic dermatitis were excluded from the prurigo nodularis trial in order to get a clearer picture of the biologic’s efficacy and safety specifically for that condition.
Dr. Stander reported serving as a consultant to Galderma, the study sponsor, as well as numerous other pharmaceutical companies.