Trial results for guselkumab (Tremfya) in active psoriatic arthritis were posted on ClinicalTrials.gov on 2025-12-08. The Phase 3 study demonstrated that 63.0% of participants receiving guselkumab 100 mg q8w achieved an ACR20 response at Week 24, compared to 35.9% in the placebo group.
Background
Guselkumab is being investigated for the treatment of active psoriatic arthritis (PsA) in participants who have had an inadequate response or intolerance to one prior anti-tumor necrosis factor (TNF) alpha agent. Psoriatic arthritis is a chronic inflammatory disease affecting the joints and skin, often associated with psoriasis.
Trial design
This Phase 3 study (NCT04936308) enrolled 453 participants with active Psoriatic Arthritis who had an inadequate response or intolerance to a prior anti-TNF alpha agent. The trial's purpose was to evaluate the efficacy of guselkumab treatment by assessing the reduction in signs and symptoms of PsA. Participants were randomized to receive guselkumab 100 mg every 8 weeks (q8w), guselkumab 100 mg every 4 weeks (q4w), or placebo followed by guselkumab 100 mg.
Key results
Results from the study at Week 24 demonstrated improvements across several key efficacy measures:
- Percentage of Participants Who Achieved an American College of Rheumatology (ACR) 20 Response:
- 63.0% for guselkumab 100 mg q8w.
- 60.9% for guselkumab 100 mg q4w.
- 35.9% for placebo.
- Percentage of Participants Who Achieved a Psoriasis Response of Investigator's Global Assessment (IGA) Psoriasis Score of 0 or 1 and >=2 Grade Reduction From Baseline (among participants with >=3% Body Surface Area (BSA) psoriatic involvement):
- 60.7% for guselkumab 100 mg q8w.
- 56.8% for guselkumab 100 mg q4w.
- 18.8% for placebo.
- Percentage of Participants Who Achieved Psoriasis Area and Severity Index (PASI) 90 Response (among participants with >=3% BSA psoriatic involvement and an IGA score of >=2 (Mild) at Baseline):
- 47.6% for guselkumab 100 mg q8w.
- 54.9% for guselkumab 100 mg q4w.
- 12.5% for placebo.
- Change From Baseline in Health Assessment Questionnaire Disability Index (HAQ-DI) Score:
- -0.3955 (least squares mean) for guselkumab 100 mg q8w.
- -0.4159 (least squares mean) for guselkumab 100 mg q4w.
- -0.2359 (least squares mean) for placebo.
What this means
The trial results indicate that guselkumab, at both 100 mg q8w and 100 mg q4w dosing regimens, demonstrated superior efficacy compared to placebo in reducing the signs and symptoms of active psoriatic arthritis. The higher rates of ACR20, IGA psoriasis response, and PASI 90 response, along with greater improvements in HAQ-DI scores, suggest a clinically meaningful benefit for patients who have not adequately responded to or tolerated prior anti-TNF alpha agents.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT04936308, titled "Guselkumab in Active Psoriatic Arthritis Participants With Inadequate Response/Intolerance to One Prior Anti-TNF Alpha Agent," were posted on 2025-12-08 on clinicaltrials.gov.