Long-term Efficacy and Safety of Up to 108 Weeks of Ixekizumab in Pediatric Patients With Moderate to Severe Plaque Psoriasis: The IXORA-PEDS Randomized Clinical Trial

IMPORTANCE: About 1% of children and adolescents worldwide are affected by plaque psoriasis. OBJECTIVE: To evaluate the long-term efficacy and safety of ixekizumab for pediatric patients with moderate to severe psoriasis. DESIGN, SETTING, AND PARTICIPANTS: This multicenter randomized clinical trial (IXORA-PEDS) evaluated pediatric patients with plaque psoriasis. Participants were aged 6 years to younger than 18 years; had moderate to severe psoriasis, which was defined as Psoriasis Area and Severity Index (PASI) of 12 or higher, static Physician’s Global Assessment (sPGA) score of 3 or higher, and psoriasis-affected body surface area of 10% or greater at screening and baseline; were candidates for phototherapy or systemic therapy; or had psoriasis that was not adequately controlled by topical therapies. Data analysis, which followed the intention-to-treat principle, was conducted from May to October 2021. INTERVENTIONS: Pediatric patients were randomized 2:1 to receive either a weight-based dose of ixekizumab every 4 weeks or placebo. After a 12-week placebo-controlled period, patients entered a 48-week, open-label ixekizumab maintenance period (weeks 12-60), followed by an extension period that lasted through 108 weeks. A substudy evaluated the randomized withdrawal of ixekizumab after week 60. MAIN OUTCOMES AND MEASURES: Efficacy outcomes at week 108 included the percentage of patients achieving 75% (PASI 75), 90% (PASI 90), or 100% (PASI 100) improvement from baseline; an sPGA score of 0 or 1 or score of 0; and improvement of 4 points or higher from baseline in the Itch Numeric Rating Scale. Safety outcomes included assessments of adverse events (AEs), including treatment-emergent AEs, serious AEs, and AEs of special interest, as well as improvement from baseline in a range of challenging body areas. Missing data for categorical outcomes were imputed using modified nonresponder imputation. RESULTS: A total of 171 patients (mean [SD] age, 13.5 [3.04] years; 99 female children [57.9%]) were randomized to either ixekizumab (n = 115) or placebo (n = 56). Of 166 patients who entered the maintenance period, 139 (83.7%) completed week 108 of the trial. Primary and gated secondary end points were sustained through week 108, with patients achieving PASI 75 (91.7% [n = 86]), PASI 90 (79.0% [n = 74]), PASI 100 (55.1% [n = 52]), sPGA 0 or 1 (78.3% [n = 74]), and sPGA 0 (52.4% [n = 49]). Fifty-five patients (78.5%) reported an Itch Numeric Rating Scale improvement of 4 points or higher. In patients who received ixekizumab, at week 108, clearance of nail psoriasis was reported in 68.1% (n = 28), clearance of palmoplantar psoriasis was reported in 90.0% (n = 10), clearance of scalp psoriasis was reported in 76.2% (n = 83), and clearance of genital psoriasis was reported in 87.5% (n = 24). There were no new safety findings during weeks 48 to 108 of the trial, including no new cases of inflammatory bowel disease or candida infection. CONCLUSIONS AND RELEVANCE: Results of this study showed improvements across patient-reported outcomes and objective measures of complete skin clearance of psoriasis among pediatric patients who received ixekizumab, and these response rates were sustained through week 108 of the trial. Safety of ixekizumab was consistent with previously reported findings in this population and the known safety profile of this treatment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03073200