Dupilumab treatment in patients with atopic dermatitis: a comparative cohort study between the Netherlands and Japan shows a discrepancy in patient-reported outcome measures

Abstract

Background: Dupilumab was equally effective among all racial subgroups in clinical trials, but a direct comparison in daily practice is lacking.

Objectives: To investigate the effectiveness of dupilumab in patients with atopic dermatitis (AD) in the Netherlands and Japan over 80 weeks of treatment.

Methods: A longitudinal comparative cohort study was conducted in patients with AD who were treated with dupilumab in daily practice. We used linear mixed-effects models to determine changes over time.

Results: We found statistically significant differences in sex, disease onset, body mass index and therapeutic history between Dutch (n = 208) and Japanese (n = 153) patients. The baseline Eczema Area and Severity Index (EASI) score was higher in Japanese patients (23·8 vs. 14·8), while baseline Patient-Reported Outcome Measures (PROMs) were higher in Dutch patients. EASI scores decreased quickly to a level indicating 'mild disease' (EASI < 7), and remained low in both countries. However, PROMs showed different trajectories with better scores in Japan.

Conclusions: Dupilumab showed significant, comparable and sustained improvement of EASI scores in Japanese and Dutch patients. However, we found striking differences in the effect on PROMs between the countries, with a better outcome in Japanese patients.

Figure 1

Effectiveness of dupilumab in patients with atopic dermatitis: outcome measures over time during dupilumab treatment. All outcome measures have shown clinically relevant improvement with at least one unit of minimal clinically important difference. (a) The EASI score shows a rapid decrease with comparable trajectories in both countries, while Patient‐Reported Outcome Measures (PROMs) [(b) Patient‐Oriented Eczema Measure and (c) Numeric Rating Scale (NRS)‐Pruritus] showed different trajectories with relatively high scores and a clinically relevant, better outcome for PROMs in JP patients. (c) NRS‐Pruritus shows peak pruritus past 24 h (NL) and mean pruritus past 7 days (JP). (d) DLQI score in time during dupilumab treatment. (e) TARC levels after starting dupilumab treatment (in JP patients). Bands show 95% confidence intervals