New Insights on Nemolizumab: Rapid Itch Relief and Sleep Improvement

Post-hoc analyses of the ARCADIA and OLYMPIA programs show clinically meaningful itch reduction and parallel sleep improvement measurable within 48 hours.

ARCADIA enrolled patients with moderate-to-severe atopic dermatitis, while OLYMPIA enrolled patients with prurigo nodularis. The new observations derive from post-hoc analyses that focused on patient-reported worst-itch (peak-pruritus NRS) and daily sleep-disturbance NRS to capture timing of response.

Significant itch reduction was observed as early as 48 hours after initial dosing, with measurable decreases in worst-itch (peak-pruritus NRS) versus placebo. Separation was apparent at day 2, and responder proportions continued to rise over the following two weeks, indicating meaningful symptomatic benefit can emerge within days rather than weeks.

Sleep disturbance improved in parallel with itch reduction across both atopic dermatitis and prurigo nodularis cohorts, with early gains in sleep scores mirroring pruritus change.

IL-31–mediated signaling is an established driver of pruritus, and blocking the IL-31 pathway reduces pruritic signaling and its neuroimmune consequences, including sleep disruption. By reducing afferent itch signaling that perpetuates the itch-scratch cycle, IL-31 receptor inhibition provides a plausible mechanistic explanation for why symptomatic improvements can appear within days.