Johnson & Johnson Reports TREMFYA Axial PsA Study Data

Spring House, Pennsylvania, September 25, 2026

TREMFYA Demonstrates Improvement in Axial Symptoms

The STAR study (NCT04929210) evaluated TREMFYA in adults with active PsA and objective evidence of axial inflammation confirmed through centrally read magnetic resonance imaging (MRI). The trial included a 24-week placebo-controlled treatment period followed by a 24-week active-treatment period. The primary endpoint assessed change from baseline at Week 24 in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), a patient-reported measure that incorporates spinal pain, stiffness, fatigue, joint symptoms, and areas of tenderness. Johnson & Johnson reported that TREMFYA achieved a statistically significant improvement in the primary endpoint compared with placebo. The company also reported positive results for major secondary endpoints. TREMFYA produced significant reductions in axial symptoms measured by ASDAS-CRP, while MRI assessments demonstrated a reduction in sacroiliac-joint inflammation. The combination of patient-reported outcomes and objective imaging provides clinical and radiographic measures of treatment response in axial PsA. Full efficacy and safety findings, including detailed MRI results, are expected to be presented at a future scientific congress.

MRI Provides Objective Evidence of Inflammation

A central feature of the STAR study is its use of MRI to confirm axial involvement at enrollment and assess changes in inflammation during treatment. Axial PsA involves inflammation affecting the spine and sacroiliac joints, and patients may experience inflammatory back pain, morning stiffness, fatigue, impaired mobility, and reduced physical function. The condition can occur alongside the skin, nail, and peripheral joint manifestations associated with PsA. Johnson & Johnson described STAR as the first dedicated randomized, double-blind, placebo-controlled study of an IL-23 inhibitor specifically designed for patients with axial PsA and MRI-confirmed axial inflammation. The company said the study addresses an area where prospective clinical research has historically been limited. The use of centrally read MRI assessments also provides an objective method for evaluating inflammatory changes alongside patient-reported measures of disease activity.

TREMFYA Adds Evidence Across Psoriatic Arthritis

TREMFYA (guselkumab) is a fully human monoclonal antibody that targets the IL-23 pathway and is approved in the United States for several inflammatory diseases, including active PsA, plaque psoriasis, ulcerative colitis, and Crohn’s disease. The medicine is also approved in multiple other countries for indications including psoriasis and PsA. In PsA, guselkumab has been evaluated across several disease domains, including peripheral joint symptoms, skin manifestations, enthesitis, dactylitis, and structural joint damage. The latest STAR findings add clinical evidence specifically addressing axial symptoms and inflammation in PsA. Johnson & Johnson reported that the overall safety profile observed in STAR was consistent with the established safety profile of TREMFYA in PsA, with no new safety signals identified. The results come after Johnson & Johnson received a recent U.S. FDA label expansion for TREMFYA covering inhibition of progression of structural joint damage in adults with active PsA.

The company continues to evaluate guselkumab across different manifestations of inflammatory disease, while the STAR findings contribute additional data concerning axial involvement. For patients with axial psoriatic arthritis, the findings provide additional clinical evidence on the potential role of IL-23 inhibition in addressing both symptoms and objectively measured inflammation. However, the September 25 announcement contains topline results, with detailed efficacy, safety, and MRI findings expected at a future scientific congress. Further peer-reviewed reporting and regulatory interpretation will provide additional context for the results.

Source: Johnson & Johnson press release