Pharmacokinetics, pharmacodynamics, and exposure–efficacy of dupilumab in adults with atopic dermatitis

The pharmacokinetics (PKs) and exposure–efficacy of dupilumab have not been fully described for adults with atopic dermatitis (AD). Our objectives were to analyze the PKs and exposure–efficacy of dupilumab in adults with AD and compare the results of Japanese and overall populations. Adults with moderate‐to‐severe AD were randomly assigned to dupilumab (300 mg weekly [qw] or every 2 weeks [q2w], 200 mg q2w, 300 mg every 4 weeks [q4w], or 100 mg q4w) or placebo for 16 weeks in a randomized, double‐blind, placebo‐controlled, dose‐ranging phase IIb trial (NCT01859988). This analysis included 379 patients (58 Japanese). Functional dupilumab concentrations increased in a dose‐dependent manner; at lower concentrations, increases were greater than dose‐proportional because of nonlinear, target‐mediated clearance. Dupilumab pharmacokinetics were comparable in Japanese and non‐Japanese patients with similar body weights. Week 16 efficacy parameters, including Investigator’s Global Assessment score 0/1, greater than or equal to 75% reduction from baseline in the Eczema Area and Severity Index (EASI), and percentage change from baseline in EASI and pruritus Numerical Rating Scale, generally increased with week 16 trough concentration; the plateau of these exposure–efficacy relationships occurred for most patients at exposures associated with the 300 mg q2w and 300 mg qw regimens. Japanese ethnicity did not remain in the population PK model as covariate with or without accounting for body weight differences. In Japanese and non‐Japanese patients, efficacy responses increased with week 16 dupilumab trough concentrations in a similar manner. Dupilumab 300 mg qw and q2w regimens were recommended for further evaluation in larger phase III studies.