BACKGROUND: Nemolizumab is a subcutaneously administered humanized monoclonal 
antibody against interleukin-31 receptor A, which is involved in pruritus and 
inflammation in atopic dermatitis. In phase 2 studies, nemolizumab lessened the 
severity of atopic dermatitis.
METHODS: In a 16-week, double-blind, phase 3 trial, we randomly assigned 
Japanese patients with atopic dermatitis and moderate-to-severe pruritus and an 
inadequate response to topical agents in a 2:1 ratio to receive subcutaneous 
nemolizumab (60 mg) or placebo every 4 weeks until week 16, with concomitant 
topical agents. The primary end point was the mean percent change in the 
visual-analogue scale (VAS) score for pruritus (range, 0 to 100, with higher 
scores indicating worse pruritus) from baseline to week 16. Secondary end points 
included the time course of change in the VAS score for pruritus up to week 4, 
the change in the Eczema Area and Severity Index (EASI) score (range, 0 to 72, 
with higher scores indicating greater severity), a score of 4 or less on the 
Dermatology Life Quality Index (DLQI; range, 0 to 30, with higher scores 
indicating a greater effect on daily life), a score of 7 or less on the Insomnia 
Severity Index (ISI; range, 0 to 28, with higher scores indicating greater 
severity), and safety.
RESULTS: A total of 143 patients were randomly assigned to receive nemolizumab 
and 72 to receive placebo. The median VAS score for pruritus at baseline was 75. 
At week 16, the mean percent change in the VAS score was -42.8% in the 
nemolizumab group and -21.4% in the placebo group (difference, -21.5 percentage 
points; 95% confidence interval, -30.2 to -12.7; P<0.001). The mean percent 
change in the EASI score was -45.9% with nemolizumab and -33.2% with placebo. 
The percentage of patients with a DLQI score of 4 or less was 40% in the 
nemolizumab group and 22% in the placebo group; the percentage of patients with 
an ISI score of 7 or less was 55% and 21%, respectively. The incidence of 
injection-related reactions was 8% with nemolizumab and 3% with placebo.
CONCLUSIONS: In this 16-week trial, the use of subcutaneous nemolizumab in 
addition to topical agents for atopic dermatitis resulted in a greater reduction 
in pruritus than placebo plus topical agents. The incidence of injection-site 
reactions was greater with nemolizumab than with placebo. Longer and larger 
trials are necessary to determine whether nemolizumab has a durable effect and 
is safe for atopic dermatitis. (Funded by Maruho; JapicCTI number, 173740.).