Efficacy and Safety of Risankizumab in Paediatric Patients With Psoriasis in the OptIMMize-1 Phase III Study

Treatment options for paediatric patients with psoriasis are limited, and additional, more advanced therapies are needed. Risankizumab is an interleukin-23 inhibitor approved to treat moderate-to-severe psoriasis in adults.

To evaluate efficacy and safety of risankizumab through 52 weeks in paediatric patients with moderate-to-severe psoriasis.

OptIMMize-1 (NCT04435600) was a phase III, multicentre, 4-part study. Parts 1, 3, and 4 were 52-week, open-label studies. Part 2 consisted of a 16-week initial treatment period (Period A; 2:1 risankizumab:ustekinumab randomization), followed by an up to 36-week randomized treatment or withdrawal period (Period B) for risankizumab responders, with a potential 16-week retreatment period (Period C) for patients who experience a disease flare. Risankizumab nonresponders and patients randomized to ustekinumab in Period A received risankizumab during Period B. Key outcomes included the proportion of patients achieving a static Physician's Global Assessment (sPGA) score of clear/almost clear (sPGA0/1), sPGA0/1 with ≥2-grade improvement (sPGA0/1+≥2GI), or ≥75%/≥90%/100% improvement in PASI (PASI75/90/100). The study also assessed itch severity, quality of life, and safety.

A total of 137 patients enrolled. In Part 2 (risankizumab, n = 54; ustekinumab, n = 28), week 16 response rates were similar: sPGA0/1 was 79.6% for risankizumab and 75.0% for ustekinumab; sPGA0/1+≥2 GI rates were 68.5% vs. 67.9%; PASI75 rates were 85.2% vs. 85.7%; and PASI90 rates were 64.8% vs. 60.7%. PASI100 responses were higher with risankizumab (40.7%) than with ustekinumab (17.9%). In Part 4 (n = 30), week 16 rates were sPGA0/1: 90.0%, sPGA0/1+≥2GI: 83.3%, PASI75: 86.7%, PASI90: 76.7%, and PASI100: 43.3%; week 52 responses were maintained or improved. Skin clearance outcomes in Parts 1 and 3 were consistent with those observed with continuous risankizumab treatment in Parts 2 and 4. Improvements in itch and quality of life (assessed in Part 2 only) were observed at weeks 16 and 52. Risankizumab safety profiles were consistent with those observed in prior adult psoriasis studies.

Risankizumab was well tolerated in paediatric patients, resulting in marked improvements in skin clearance, itching, and quality of life after 16 weeks of treatment. Efficacy was maintained or improved at week 52, supporting risankizumab use for moderate-to-severe psoriasis in this population.