PSUMMIT-Jr phase III: Ustekinumab in pediatric patients with active juvenile PsA

At the European Alliance of Associations for Rheumatology (EULAR) 2026 Congress, June 3–6, 2026, London, UK, Nicolino Ruperto presented results from the multicenter, open-label, phase III PSUMMIT-Jr study (NCT05083182), evaluating subcutaneous ustekinumab in pediatric patients aged ≥5 to <18 years with active juvenile psoriatic arthritis (jPsA; N = 18). The primary efficacy endpoint was the Juvenile Idiopathic Arthritis American College of Rheumatology (JIA-ACR) 30 response at Week 24. 

Key data: JIA-ACR 30, 50, and 70 responses at Week 24 were achieved by 88.9%, 83.3%, and 61.1% of patients, respectively; responses were maintained at Week 52 (77.8%, 77.8%, and 61.1%, respectively). Median time to JIA-ACR 30 response was 4.3 weeks (95% confidence interval [CI], 4.1–8.1), and 67% of patients responded by Week 4. Mean changes from baseline in clinical Juvenile Arthritis Disease Activity Score 10 (cJADAS-10), JADAS-10, JADAS-27, and JADAS-71 at Week 24 were −13.3, −14.9, −13.0, and −16.2, respectively. Serious and severe adverse events (AEs) were reported in one patient each (6%); no AEs led to ustekinumab discontinuation, and no deaths or new safety signals were reported.  

Key learning: Subcutaneous ustekinumab demonstrated rapid and durable improvements in joint disease activity and psoriasis symptoms, with no new safety signals through Week 52, supporting extrapolation to expand treatment options for pediatric patients with active jPsA.