TREMFYA (guselkumab) shows clinical and MRI improvement for axial psoriatic arthritis in Phase 4 STAR study

# What the STAR topline results show

Johnson & Johnson announced topline Phase 4 results for the STAR study showing TREMFYA (guselkumab) met its primary and major secondary endpoints in patients with psoriatic arthritis that includes axial involvement. The company reports both patient-reported improvement in axial symptoms and objective reduction in MRI inflammation of the sacroiliac joints at Week 24 versus placebo.

# Why this matters for patients with axial PsA

Axial involvement affects the spine and sacroiliac joints and commonly causes back pain, morning stiffness, fatigue, reduced mobility and lower quality of life compared to PsA without axial disease. Prospective, randomized trials focused on axial PsA have been limited. STAR is notable because it prospectively selected patients using MRI evidence of axial inflammation and then used MRI to measure inflammatory change alongside clinical scores.

# The endpoints and measures used

# Objective MRI assessment

STAR is the first study in psoriatic arthritis to use MRI both to confirm axial involvement for enrollment and to document reduction in axial inflammation. Johnson & Johnson said MRI findings demonstrated a significant reduction in sacroiliac joint inflammation with TREMFYA compared with placebo. The company plans to present detailed MRI and efficacy data at an upcoming scientific congress.

# Safety profile

Johnson & Johnson reported that the overall safety profile in STAR was consistent with the established safety profile of TREMFYA in PsA and that no new safety signals were identified in the topline release.

# Regulatory context and product positioning

The company noted a recent FDA label expansion for TREMFYA for inhibition of progression of structural joint damage in adults with active PsA. Johnson & Johnson describes TREMFYA as the only IL-23 inhibitor proven to inhibit progression of structural joint damage in PsA and as a fully-human, dual-acting monoclonal antibody that blocks IL-23 and binds CD64.

# What remains to see

Topline results give a directional view, but the detailed data set is pending. Expect presentation of full efficacy, safety and MRI analyses at a scientific meeting. Those details will allow clinicians and reviewers to assess effect sizes, responder rates, subgroup outcomes and any laboratory or imaging nuances that matter for clinical decision making.

# Bottom line

The STAR topline announces that TREMFYA demonstrated both symptom improvement on standardized clinical scores and objective reduction in MRI inflammation in patients with axial PsA at Week 24. The findings expand the evidence base for TREMFYA in psoriatic arthritis with axial involvement, with full data due at an upcoming congress.