Long-term efficacy and safety of dupilumab with concomitant topical corticosteroids in Japanese pediatric patients with moderate-to-severe atopic dermatitis: Results from a phase 3 open-label extension study.

Background: Dupilumab is approved in Japan for the treatment of atopic dermatitis in patients aged 6 months to 18 years. However, long-term data are lacking in this patient population. Here we report the final analysis of a long-term open-label extension (OLE) of a phase 3 study that assessed dupilumab in Japanese patients aged ≥6 months to <18 years with moderate-to-severe atopic dermatitis inadequately controlled with existing therapies.

Methods: Study participants were randomly assigned to dupilumab or placebo with concomitant topical corticosteroids for 16 weeks, then to open-label dupilumab until approval or for 3 years, whichever came first.

Results: Of the 62 participants randomized, 60 entered the OLE and continued to receive dupilumab (n = 28) or initiated dupilumab (n = 32). Improvements in clinical severity scores seen with dupilumab at Week 16 persisted up to Week 116, as confirmed by several efficacy endpoints (proportion of patients who achieved ≥75 % or ≥90 % improvement in Eczema Area and Severity Index [EASI] score, and Investigator's Global Assessment score of 0/1, and percent change in EASI scores from baseline). During the dupilumab exposure period, 93.5 % of patients experienced a treatment-emergent adverse event (TEAE). No adverse events leading to death, or TEAEs leading to study treatment discontinuation were observed during the OLE period. One (3.1 %) treatment-emergent positive anti-drug antibody response was observed during the OLE period in the placebo/dupilumab group.

Conclusions: This analysis supports the long-term efficacy and safety of dupilumab in Japanese patients aged ≥6 months to <18 years with moderate-to-severe atopic dermatitis.