Ustekinumab for the treatment of moderate-to-severe plaque psoriasis in paediatric patients (≥ 6 to < 12 years of age): efficacy, safety, pharmacokinetic and biomarker results from the open-label CADMUS Jr study

Background Limited options are available for treatment of paediatric psoriasis. Objectives To evaluate the efficacy and safety of ustekinumab in paediatric patients with psoriasis (>= 6 to < 12 years of age). Methods CADMUS Jr, a phase III, open-label, single-arm, multicentre study, evaluated ustekinumab in paediatric patients with moderate-to-severe plaque psoriasis. Patients received weight-based dosing of ustekinumab (< 60 kg: 0 center dot 75 mg kg(-1); >= 60 to <= 100 kg: 45 mg; > 100 kg: 90 mg) administered by subcutaneous injection at weeks 0 and 4, then every 12 weeks through week 40. Study endpoints (all at week 12) included the proportions of patients achieving a Physician's Global Assessment score of cleared/minimal (PGA 0/1) and >= 75%/90% improvement in Psoriasis Area and Severity Index (PASI 75/90), and change in Children's Dermatology Life Quality Index (CDLQI). Serum ustekinumab concentrations, antidrug antibodies and cytokine levels were measured through week 52. Safety was evaluated through week 56. Results In total, 44 patients (median age 9 center dot 5 years) received at least one dose of ustekinumab. Three patients discontinued the study agent through week 40. At week 12, 77% of patients achieved PGA 0/1, 84% achieved PASI 75 and 64% achieved PASI 90 response. The mean change in CDLQI was -6 center dot 3. Trough serum ustekinumab concentrations reached steady state at weeks 28-52. The incidence of antidrug antibodies was 10% (n = 4). Mean serum concentrations of interleukin-17A/F and interleukin-22 were significantly reduced at weeks 12 and 52. Overall, 34 patients (77%) had at least one adverse event and three (7%) had a serious adverse event. Conclusions Ustekinumab effectively treated moderate-to-severe psoriasis in paediatric patients, and no new safety concerns were identified. What is already known about this topic? Ustekinumab is approved for use in adolescents (>= 12 to < 18 years of age) and adults (>= 18 years) with moderate-to-severe psoriasis. What does this study add? Ustekinumab effectively treats moderate-to-severe psoriasis in paediatric patients (>= 6 to < 12 years of age), with no new safety concerns.