Dupilumab Safety and Efficacy in a Phase III Open-Label Extension Trial in Children 6–11 Years of Age with Severe Atopic Dermatitis

Background For children aged 6–11 years with uncontrolled severe atopic dermatitis (AD), 16 weeks of treatment with dupilumab resulted in substantial clinical benefit compared with placebo with an acceptable safety profile. However, longer-term safety and efficacy data are important to inform longitudinal AD management. Objectives This analysis of data from an open-label extension study (LIBERTY AD PED-OLE, NCT02612454) reports the long-term safety, efficacy, and pharmacokinetics of dupilumab in children with severe AD who had participated in the pivotal dupilumab LIBERTY AD PEDS study (NCT03345914). Methods Enrolled patients initially received subcutaneous dupilumab 300 mg every 4 weeks (q4w). The q4w regimen could be uptitrated to dupilumab dose regimens of 200 or 300 mg every 2 weeks (q2w; for body weight < 60 or ≥ 60 kg, respectively) for patients who did not achieve an Investigator’s Global Assessment (IGA) score of 0/1 (clear/almost clear skin) at week 16, or prior to week 16 as rescue treatment. Additional patients were uptitrated to a weight-tiered q2w regimen following a protocol amendment. Patients who maintained an IGA score of 0/1 continuously for a 12-week period after week 40 discontinued dupilumab. They were monitored for relapse and were reinitiated on dupilumab if required. Results Data for 321 patients (mean age 8.6 years) were analyzed, 254 (79%) of whom had completed the scheduled 52-week visit at the database lock. Most treatment-emergent adverse events were mild/moderate. By week 52, 41% of patients achieved an IGA score of 0/1, and 97%, 82%, and 50%, respectively, had at least a 50%, 75%, and 90% improvement from the parent study baseline in Eczema Area and Severity Index (EASI). By week 52, 29% of patients in the overall population had clear/almost clear skin sustained for 12 weeks and had stopped medication; of these, 40% relapsed and were subsequently reinitiated on treatment, with a mean time to reinitiation of 13.5 (standard deviation 5.2) weeks. Following reinitiation of dupilumab, 41% of the patients with evaluable data at the time of database lock had regained an IGA 0/1 clinical response. Conclusions Consistent with results seen in adults and adolescents, long-term treatment with dupilumab in children aged 6–11 years with severe AD showed an acceptable safety profile and incremental clinical benefit. A substantial proportion of children who stopped dupilumab treatment after achieving clear/almost clear skin subsequently experienced disease recurrence, and required reinitiation of dupilumab, suggesting that continuous treatment may be necessary for maintenance of clinical benefit. Trial Registration ClinicalTrials.gov Identifier NCT02612454.