Efficacy and safety of adalimumab every other week versus methotrexate once weekly in children and adolescents with severe chronic plaque psoriasis: a randomised, double-blind, phase 3 trial.

BACKGROUND: Adalimumab is indicated for the treatment of moderate to severe psoriasis in adults. We assessed the efficacy and safety of adalimumab in children and adolescents with severe plaque psoriasis.

METHODS: This randomised, double-blind, multiperiod, phase 3 trial was done at 38 clinics in 13 countries. Patients (aged ≥4 to <18 years) with severe plaque psoriasis who had not responded to topical therapy were randomly assigned with an interactive voice or web-response system (1:1:1) to receive adalimumab 0·8 mg/kg or 0·4 mg/kg subcutaneously at week 0, then every other week starting at week 1, or oral methotrexate once weekly (0·1-0·4 mg/kg) for 16 weeks. Randomisation was stratified by history of etanercept treatment, with a block size of three. Responders were withdrawn from treatment (for up to 36 weeks) and re-treated with adalimumab (for 16 weeks) if disease became uncontrolled. Ranked primary efficacy endpoints were the proportion of patients who achieved at least 75% improvement from baseline in Psoriasis Area and Severity Index (PASI75) score and clear or minimal physician global assessment (PGA) score at week 16, comparing adalimumab 0·8 mg/kg with methotrexate. Efficacy analysis was by intention to treat, and safety analysis included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT01251614, and has been completed.

FINDINGS: Between Dec 14, 2010, and Feb 5, 2015, 114 patients were randomly assigned to adalimumab 0·8 mg/kg (n=38), adalimumab 0·4 mg/kg (n=39) or methotrexate (n=37). At week 16, PASI75 was achieved in 22 (58%) of 38 patients in the adalimumab 0·8 mg/kg group compared with 12 (32%) of 37 patients in the methotrexate group (p=0·027). 23 (61%) of 38 patients in the adalimumab 0·8 mg/kg group and 15 (41%) of 37 in the methotrexate group achieved clear or minimal PGA (p=0·083). In the adalimumab 0·4 mg/kg group, 17 (44%) of 39 patients achieved PASI75 and 16 (41%) achieved clear or minimal PGA. The most frequent adverse events were infections (17 [45%] of 38 in the adalimumab 0·8 mg/kg group during initial treatment; 22 [56%] of 39 in the adalimumab 0·4 mg/kg group; 21 [57%] of 37 in the methotrexate group). Three serious adverse events were reported, all in patients in the adalimumab 0·4 mg/kg group, and were not judged to be related to study drug.

INTERPRETATION: Treatment with adalimumab 0·8 mg/kg in children and adolescents with severe plaque psoriasis provided significant improvements in PASI75 and a non-significant increase in the proportion of patients who achieved clear or minimal PGA compared with methotrexate. No new safety risks were identified.

FUNDING: AbbVie.