Risankizumab Hits PASI 100 in 41% of Adolescents in OptIMMize-1

Risankizumab delivered complete skin clearance (PASI 100) in 41% of adolescents with moderate-to-severe plaque psoriasis at week 16 — more than double the 18% rate seen with ustekinumab — according to phase 3 OptIMMize-1 data published in the British Journal of Dermatology on September 26, 2026.

The 52-week, multicenter study (NCT04435600) enrolled 137 patients aged 6 to under 18 years and found sustained improvements in skin clearance, itch, and health-related quality of life with the IL-23 inhibitor, with a safety profile consistent with prior adult trials. First author N. Magnolo and colleagues — including Wine Lee and Reich — reported the results for risankizumab (Skyrizi; AbbVie).

How was the study designed?

OptIMMize-1 was a 4-part phase 3 trial in children (6 to <12 years) and adolescents (12 to <18 years). Participants received subcutaneous risankizumab at weeks 0 and 4, then every 12 weeks. Dosing was weight-based in most groups: 150 mg for patients weighing at least 40 kg, 55 mg for those under 40 kg.

Part 2 featured a randomized, assessor-blinded head-to-head against ustekinumab over an initial 16-week treatment period. Later phases evaluated continued treatment, treatment withdrawal, and retreatment after disease flare. Investigators measured outcomes with PASI and static Physician's Global Assessment (sPGA), plus patient-reported itch, quality of life, and safety.

What were the efficacy numbers at week 16?

Among the 54 adolescents randomized to risankizumab:

• 80% achieved clear or almost clear skin (sPGA 0/1) vs 75% of the 28 ustekinumab patients
• PASI 75: 85% vs 86%
• PASI 90: 65% vs 61%
• PASI 100: 41% vs 18%

For the younger cohort, the signals were at least as strong. Among 30 children in Part 4, 90% hit sPGA 0/1 at week 16; 87% reached PASI 75, 77% PASI 90, and 43% PASI 100.

Clinical responses were maintained or improved through week 52 in patients on continuous risankizumab. One caveat matters here: the study ran no formal statistical comparisons between treatments, so the numerical edge over ustekinumab — including that PASI 100 gap — can't support firm comparative-efficacy conclusions.

Did itch and quality of life improve too?

Yes. Adolescents in Part 2 showed reductions in itch severity and improvements in Children's Dermatology Life Quality Index (CDLQI) scores at both weeks 16 and 52. That matters in pediatric psoriasis, where visible plaques and persistent itching disrupt sleep, school, social interaction, and emotional well-being — outcomes clinicians often weigh as heavily as lesion counts.

The withdrawal arm told its own story. More than half of adolescents who stopped risankizumab after achieving a response experienced a disease flare, and retreatment restored clinical improvement. The message for practice: sustained dosing, not intermittent courses, looks like the right frame for chronic inflammatory disease in younger patients.

What does this change for pediatric psoriasis care?

Roughly one-third of people with psoriasis develop the disease during childhood, yet kids have fewer approved systemic options than adults. OptIMMize-1 adds to the evidence base for IL-23 inhibition as a long-term systemic approach in this population — an option where choice has historically been thin.

Safety across 52 weeks showed no new overall pattern in children compared with adults. Investigators tracked treatment-emergent adverse events, serious adverse events, discontinuations, and prespecified adverse events of special interest; longer-term monitoring of biologics in children and adolescents remains important.

As more pediatric biologic data accumulate, clinicians should be better positioned to individualize therapy by disease severity, age, symptom burden, and long-term management needs — with risankizumab now carrying 52-week phase 3 evidence behind it.