A multicenter phase 3 trial conducted across 77 centers in 10 countries found that nemolizumab reduced pruritus in 58.4% of patients with moderate to severe prurigo nodularis, compared to only 16.7% in the placebo group by week 16.

Researchers conducted the OLYMPIA 1 randomized clinical trial to assess the efficacy and safety of nemolizumab monotherapy in patients with moderate to severe prurigo nodularis (PN). The findings, published in JAMA Dermatology, demonstrated significant improvements in pruritus and skin lesions among nemolizumab-treated patients compared with placebo.

The trial included 286 adults (mean age 57.5 years, 58% female) with moderate to severe PN diagnosed for at least 6 months. Eligible participants had at least 20 nodules, an Investigator's Global Assessment (IGA) score of at least 3, and a Peak Pruritus Numerical Rating Scale (PP-NRS) score of at least 7. Participants were randomized in a 2:1 ratio to receive subcutaneous nemolizumab (30 mg or 60 mg, based on body weight) or placebo every four weeks for 24 weeks, followed by an 8-week follow-up period.

At week 16, 111/190 (58.4%) patients in the nemolizumab group achieved the primary pruritus endpoint compared to 16/96 (16.7%) in the placebo group (adjusted difference, 40.1%; 95% confidence interval [CI], 29.4%-50.8%; P < .001). IGA success was reported in 50/190 (26.3%) nemolizumab-treated patients versus 7/96 (7.3%) in the placebo group (adjusted difference, 14.6%; 95% CI, 6.7%-22.6%; P = .003). In ad hoc analysis through week 24, these improvements were sustained, with 58.3% achieving itch response and 58/190 (30.5%) reaching IGA success, compared to 20.4% and 9/96 (9.4%) in the placebo group, respectively.

Secondary outcomes supported the primary findings, with significant improvements observed as early as week 4. Sleep disturbance, measured by the Sleep Disturbance Numerical Rating Scale, improved by at least 4 points in 95/190 (50.0%) of nemolizumab recipients versus 11/96 (11.5%) in placebo-treated patients at week 16 (adjusted difference, 38.0%; 95% CI, 27.8%-48.2%).

Adverse events occurred in 134/187 (71.7%) of nemolizumab-treated patients compared to 62/95 (65.3%) in the placebo group, with headache and eczema being the most common. Most events were mild to moderate and resolved by the end of the study. Serious adverse events were infrequent and balanced between groups.

These findings, which build upon the previous OLYMPIA 2 trial results, suggest that nemolizumab demonstrates efficacy and safety in targeting interleukin-31 signaling for PN, with statistically significant improvements in symptoms and an acceptable safety profile.

Full disclosures can be found in the published study.