Phase III OptIMMize-1 trial: Risankizumab in children and adolescents with plaque PsO

Results from the multicenter, 4-part, phase III OptIMMize-1 trial (NCT04435600), evaluating risankizumab in children (aged 6 to <12 years) and adolescents (aged 12 to <18 years) with moderate-to-severe plaque psoriasis (PsO) eligible for systemic therapy, were published in the British Journal of Dermatology by Magnolo et al. Parts 1 (adolescents) and 3 (children) were open-label pharmacokinetic studies conducted to inform dosing in Parts 2 and 4, respectively. In Part 2, adolescents were randomized to risankizumab or ustekinumab for 16 weeks. At Week 16, risankizumab responders were re-randomized to continue or withdraw risankizumab until disease flare, whereas non-responders and patients receiving ustekinumab switched to risankizumab. Part 4 was a single-arm, open-label study in children. The coprimary endpoints at Week 16 were ≥75% improvement in Psoriasis Area and Severity Index (PASI75) and a static Physicians’ Global Assessment score of clear/almost clear (sPGA 0/1; outside the US) or sPGA 0/1 with a ≥2-grade improvement (GI; US). 

Key data: Among adolescent patients, Week 16 PASI75 rates were 85.2% with risankizumab (n = 54) vs 85.7% with ustekinumab (n = 28), sPGA 0/1 rates were 79.6% vs 75.0%, and sPGA 0/1 + ≥2-GI rates were 68.5% vs 67.9%. At Week 52, sPGA 0/1 rates were 95.5% in Week 16 responders who continued risankizumab (n = 22) vs 42.9% in responders randomized to withdrawal (n = 21). Among patients who withdrew from risankizumab, eight experienced a disease flare and were retreated; 62.5% achieved sPGA 0/1 after 16 weeks. At Week 52, sPGA 0/1 rates in Week 16 nonresponders (n = 10) and patients who switched from ustekinumab (n = 28) were 50.0% and 89.3%, respectively. Among children receiving risankizumab (n = 30), Week 16 PASI75, sPGA 0/1 and sPGA 0/1 + ≥2-GI rates were 86.7%, 90.0% and 83.3%, respectively; responses were maintained or improved through Week 52. Risankizumab was well tolerated, with no treatment-emergent adverse events (TEAEs) leading to discontinuation or death. 

Key learning: In the OptIMMize-1 trial, risankizumab demonstrated improved skin clearance and a tolerable safety profile through Week 52 in children and adolescents with moderate-to-severe plaque PsO, supporting its use in this patient population.