Pharmacokinetics, efficacy and safety of dupilumab administered with prefilled pen devices in patients aged <12 years with atopic dermatitis

Aim For children with atopic dermatitis (AD), dupilumab is available as a prefilled syringe (PFS) from the age of 6 months and as a prefilled pen (PFP) for patients aged ≥2 years, in 200‐ and 300‐mg devices. This substudy of an ongoing open‐label extension study evaluated the pharmacokinetics, efficacy and safety of switching from a dupilumab PFS device to a PFP device in children aged 2–11 years with AD. Methods Patients received 200 mg of dupilumab every 2 weeks (q2w, Cohort 1B) or 300 mg of dupilumab every 4 weeks (q4w, Cohorts 1A and 2B) based on age (2–5 or 6–11 years) and weight (15–<30 or 30–<60 kg). The first dose of the substudy was administered with a PFS, after which patients switched to 12 weeks of treatment with a PFP. Samples for dupilumab concentration included steady‐state maximum concentration ( C max ; 4 days post‐dose) and steady‐state trough concentration ( C trough ; 14 or 28 days post‐dose for q2w or q4w), collected after the PFS (reference) and the last PFP (test) doses. Results Geometric mean ratios (PFP/PFS) of C max were 1.019, 0.834 and 0.807 for Cohorts 1A, 1B and 2B, respectively, and 0.896, 1.152 and 0.817 for C trough , respectively, indicating a similar drug exposure between PFS and PFP in each cohort. No patients exhibited treatment‐emergent antidrug antibody responses after switching to PFP, and dupilumab was well tolerated. Conclusion These results support the use of dupilumab via 200‐mg and 300‐mg PFP devices for patients aged 2–11 years with AD. Clinical trial registration number: ClinicalTrials.gov Identifier: NCT02612454, posted on 23 November 2015.