Results from a Phase 3 trial investigating guselkumab for moderate-to-severe plaque and/or scalp psoriasis in skin of color participants were posted on 2026-06-24. The study demonstrated that 74.0% of participants with plaque psoriasis achieved an Investigator's Global Assessment (IGA) score of cleared or minimal at Week 16, and 68.4% of participants with scalp psoriasis achieved a Scalp Specific (ss)-IGA score of absence or very mild disease.
Background
The study focused on guselkumab for the treatment of moderate-to-severe plaque and/or scalp psoriasis in skin of color participants. This trial aimed to evaluate the efficacy of guselkumab treatment versus placebo by assessing improvements in the signs and symptoms of psoriasis in this specific population.
Trial design
This was a Phase 3 trial (NCT05272150) that enrolled 211 participants. The study included skin of color participants with predominant moderate-to-severe body psoriasis (Cohort A) or predominant moderate-to-severe scalp psoriasis (Cohort B). Participants were randomized to receive either guselkumab 100 mg or placebo, with placebo participants later receiving guselkumab. The primary objective was to evaluate the efficacy of guselkumab versus placebo in improving the signs and symptoms of psoriasis at Week 16.
Key results
The trial reported significant improvements in both plaque and scalp psoriasis for participants treated with guselkumab at Week 16. Key measurements and analyses include:
- Cohort A (Plaque Psoriasis):
- Investigator's Global Assessment (IGA) score of cleared (0) or minimal (1) at Week 16: 74.0% for guselkumab vs 0% for placebo. The adjusted treatment difference was 74.1% (95% CI: 64.4% to 83.7%; p=0.001).
- Psoriasis Area Severity Index (PASI) 90 Response at Week 16: 57.1% for guselkumab vs 3.8% for placebo. The adjusted treatment difference was 53.3% (95% CI: 40.1% to 66.6%; p=0.001).
- IGA score of cleared (0) at Week 16: 32.5% for guselkumab vs 0% for placebo. The adjusted treatment difference was 32.5% (95% CI: 22.1% to 42.9%; p=0.001).
- PASI 100 Response at Week 16: 29.9% for guselkumab vs 0% for placebo. The adjusted treatment difference was 29.9% (95% CI: 19.7% to 40.1%; p=0.002).
- Cohort B (Scalp Psoriasis):
- Scalp Specific (ss)-IGA score of absence of disease (0) or very mild disease (1) at Week 16: 68.4% for guselkumab vs 11.5% for placebo. The adjusted treatment difference was 56.7% (95% CI: 40.9% to 72.5%; p=0.001).
- Psoriasis Scalp Severity Index (PSSI) 90 Response at Week 16: 65.8% for guselkumab vs 3.8% for placebo. The adjusted treatment difference was 61.9% (95% CI: 48.9% to 74.8%; p=0.001).
What this means
The results from this Phase 3 trial indicate that guselkumab demonstrates significant efficacy in treating moderate-to-severe plaque and scalp psoriasis in skin of color participants. The substantial differences observed in IGA 0/1, PASI 90, ss-IGA 0/1, and PSSI 90 response rates between the guselkumab and placebo groups suggest a clinically meaningful benefit. These findings are particularly important for addressing health disparities and ensuring effective treatment options for diverse patient populations affected by psoriasis.
Source
The trial results were posted on 2026-06-24 on ClinicalTrials.gov, an official database of clinical studies. The full details are available on clinicaltrials.gov under the identifier NCT05272150.