· Topline results show TREMFYA met the primary and major secondary endpoints of axial involvement in PsA - including spinal pain and stiffness - and demonstrated significant improvement in MRI-confirmed inflammation
· First-ever study to use objective MRI assessments to confirm presence of axial involvement and demonstrate axial inflammation reduction in PsA
Spring House, Pa. (September 25, 2026) - Johnson & Johnson (NYSE: JNJ) today announced that TREMFYA® (guselkumab) met the primary and major secondary endpoints demonstrating both improvement in axial symptoms and reduction in inflammation by MRI assessment in the Phase 4 STAR study evaluating biologic-naïve adults with active psoriatic arthritis and axial involvement (axial PsA). STAR is the first and only dedicated randomized, double-blind, placebo-controlled study of its kind designed to prospectively evaluate an IL-23 inhibitor specifically in patients with axial involvement confirmed by magnetic resonance imaging (MRI).[i] These topline findings represent an important milestone in advancing disease-specific evidence for patients living with axial PsA. Detailed efficacy and safety results, including MRI findings, will be presented at an upcoming scientific congress.
In the STAR study, TREMFYA met the primary endpoint evaluating improvement in a composite patient-reported disease activity score that includes spinal pain, stiffness, fatigue, joint symptoms and areas of tenderness (the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI])a at Week 24 versus placebo. TREMFYA also met major secondary endpoints demonstrating a significant reduction in both axial symptoms, as measured by ASDAS-CRPb, and objective (MRI) inflammation of the sacroiliac joints. The overall safety profile observed in the STAR study was consistent with the established safety profile of TREMFYA in PsA, and no new safety signals were identified.1
“Axial PsA involves inflammation of the spine and sacroiliac joints, often leading to debilitating pain, stiffness, and fatigue. Patients face reduced mobility and a diminished quality of life, underscoring the urgent need for a treatment that helps stop further joint damage and targets the underlying disease,” said David M. Lee, M.D., Ph.D., Global Immunology Therapeutic Area Head, Johnson & Johnson. “As the first Phase 4 study of an IL-23 inhibitor in this patient population, STAR further strengthens the growing body of evidence supporting TREMFYA as a first-line treatment option proven to help stop further joint damage.”
Advancing the evidence in psoriatic arthritis with axial involvement
Axial involvement is a clinical domain of PsA in which inflammation affects the spine and sacroiliac joints.2 It can cause back pain, morning stiffness, fatigue, impaired mobility and reduced physical function, and is associated with poorer quality of life than PsA without axial involvement.3 Axial involvement may affect approximately 5 to 28 percent of patients with early PsA and 25 to 70 percent of those with longer-standing disease.4
Despite advances in treating PsA, axial involvement remains an area of significant unmet need. There are currently no universally accepted classification criteria specific to axial PsA,5 and very few prospective clinical trials have been dedicated specifically to this patient population.
Building on the growing body of evidence supporting TREMFYA in psoriatic arthritis
“Clinical data continue to expand the evidence base for TREMFYA effectiveness across multiple domains of psoriatic arthritis,” said Philip J. Mease, M.D., MACR, FRCP, Director of Rheumatology Research at the Providence Swedish Medical Center and Clinical Professor at the University of Washington School of Medicine in Seattle, WA.c “What makes the STAR study particularly noteworthy is that, for the first time in a prospective, randomized, double-blinded, placebo-controlled PsA study, it evaluates MRI assessments for inclusion and provides a rigorous and objective measure of improvements in inflammation alongside clinical outcomes in axial PsA. Together, these findings contribute to a more comprehensive understanding of disease activity and treatment effects.”
Johnson & Johnson recently received U.S. Food and Drug Administration (FDA) approval of a label expansion for the inhibition of progression of structural joint damage in adults with active PsA, cementing TREMFYA as the only IL-23 inhibitor proven to help stop further joint damage.
TREMFYA is the first and only fully-human, dual-acting monoclonal antibody approved to treat PsA that blocks IL-23 while also binding to CD64, a receptor on cells that produce IL-23. IL-23 is a cytokine secreted by activated monocyte/macrophages and dendritic cells that is known to be a driver of immune-mediated diseases including active psoriatic arthritis. Findings are based on in vitro studies. 6,7,8,9,10
Editor’s notes:
a. BASDAI is a validated patient-reported outcome (PRO) originally developed to measure disease activity on a 0 to 10 scale in ankylosing spondylitis (AS), now referred to as radiographic axial spondyloarthritis (r-axSpA).11
b. ASDAS-CRP, or Ankylosing Spondylitis Disease Activity Score with C-Reactive Protein, is a validated, composite index that combines patient-reported symptoms with a laboratory biomarker to objectively measure inflammation and disease severity.12,13
c. Dr. Philip Mease is a paid consultant for Johnson & Johnson. He has not been compensated for any media work.
About the STAR study (NCT04929210)
STAR is a Phase 4, multicenter, randomized, double-blind, placebo-controlled study evaluating TREMFYA in biologic-naïve adults with active psoriatic arthritis (PsA) and axial involvement. Eligible participants had active PsA with objective evidence of axial inflammation confirmed by centrally read MRI and elevated C-reactive protein despite previous treatment with non-biologic disease-modifying antirheumatic drugs (DMARDs), apremilast and/or nonsteroidal anti-inflammatory drugs (NSAIDs).14
The study enrolled 411 participants worldwide and includes a 24-week placebo-controlled treatment period followed by a 24-week active treatment period. The primary endpoint evaluated change from baseline in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) at Week 24. Secondary endpoints include additional assessments of axial symptoms, MRI inflammation, physical function, peripheral musculoskeletal manifestations, skin disease and safety.14
About psoriatic arthritis with axial involvement
Psoriatic arthritis with axial involvement (axial PsA) is a chronic inflammatory condition where psoriatic arthritis affects the spine and sacroiliac joints (connecting the lower spine to the pelvis). It can cause inflammatory back pain, neck stiffness, and reduced mobility, in addition to the joint, skin or nail manifestations commonly associated with PsA.15,16
Despite significant advances in the treatment of psoriatic arthritis, axial involvement remains an area of substantial ongoing need and research.7 While it shares some clinical features with axial spondyloarthritis (axSpA), axial involvement is increasingly recognized as a distinct domain of psoriatic arthritis.4 However, there is currently no universally accepted definition or validated classification criteria specific to PsA with axial involvement, and prospective studies conducted exclusively in patients with axial involvement remain very limited.5
About TREMFYA (guselkumab)
Developed by Johnson & Johnson, TREMFYA is the first approved fully-human, dual-acting monoclonal antibody designed to neutralize inflammation at the cellular source by blocking IL-23 and binding to CD64 (a receptor on cells that produce IL-23). Findings for dual-acting are limited to in vitro studies that demonstrate guselkumab binds to CD64, which is expressed on the surface of IL-23 producing cells in an inflammatory monocyte model. The clinical significance of this finding is not known.
TREMFYA is a prescription medicine approved in the U.S. to treat:
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adults and children six years and older who also weigh at least 40 kg with moderate to severe plaque psoriasis who may benefit from taking injections or pills (systemic therapy) or phototherapy (treatment using ultraviolet or UV light).
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adults and children six years and older who also weigh at least 40 kg with active psoriatic arthritis.
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adults with moderately to severely active ulcerative colitis.
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adults with moderately to severely active Crohn’s disease.
TREMFYA is approved in Europe, Canada, Japan, and a number of other countries for the treatment of adults with moderate-to-severe plaque psoriasis, adults with active psoriatic arthritis, adults with moderate-to-severe Crohn’s disease and adults with moderate-to-severe ulcerative colitis.
The manufacturer for TREMFYA is Janssen Biotech, Inc.
About Johnson & Johnson
At Johnson & Johnson, we believe health is everything. Our strength in healthcare innovation empowers us to build a world where complex diseases are prevented, treated, and cured, where treatments are smarter and less invasive, and solutions are personal. Through our expertise in Innovative Medicine and MedTech, we are uniquely positioned to innovate across the full spectrum of healthcare solutions today to deliver the breakthroughs of tomorrow, and profoundly impact health for humanity.
1 Data on file.
2 Poddubnyy D, Jadon DR, Van den Bosch F, Mease PJ, Gladman DD. Axial involvement in psoriatic arthritis: an update for rheumatologists. Semin Arthritis Rheum. 2021;51(4):880-887. Accessed July 2026.
3 Mease PJ, Palmer JB, Liu M, et al. Influence of Axial Involvement on Clinical Characteristics of Psoriatic Arthritis: Analysis from the Corrona Psoriatic Arthritis/Spondyloarthritis Registry. The Journal of Rheumatology. 2018;45(10):1389-1396.
https://www.jrheum.org/content/45/10/1389. Accessed July 2026.
4 Feld J, Chandran V, Haroon N, Inman R, Gladman DD. Axial disease in psoriatic arthritis and ankylosing spondylitis: a critical comparison. Nature Reviews Rheumatology. 2018;14(6):363–371. doi:10.1038/s41584-018-0006-8.
5 Helliwell PS. Axial involvement in psoriatic arthritis: is it unique? Rheumatology. 2024;63(Supplement_2):ii15-ii19. doi:10.1093/rheumatology/keae558. Accessed July 2026.
6 Atreya R, Abreu MT, Krueger JG, et al. Guselkumab, an IL-23p19 subunit-specific monoclonal antibody, binds CD64+ myeloid cells and potentially neutralizes IL-23 produced from the same cells. Poster presented at: 18th Congress of the European Crohn’s and Colitis Organization (ECCO); March 1-4, 2023; Copenhagen, Denmark. Poster P504.
7 Kreuger JG, Eyerich K, Kuchroo VK. Il-23 past, present, and future: a roadmap to advancing IL-23 science and therapy. Front Immunol. 2024; 15:1331217. doi:10.3389/fimmu.2024.1331217.
8 TREMFYA® [Prescribing Information]. Horsham, PA: Janssen Biotech, Inc.
9 Skyrizi® [Prescribing Information]. North Chicago, IL: AbbVie, Inc.
10 Omvoh™ [Prescribing Information]. Indianapolis, IN: Eli Lilly and Company.
11 Garrett S, Jenkinson T, Kennedy LG, Whitelock H, Gaisford P, Calin A. A new approach to defining disease status in ankylosing spondylitis: the Bath Ankylosing Spondylitis Disease Activity Index. J Rheumatol. 1994;21(12):2286-2291.
12 van der Heijde D, Lie E, Kvien TK, et al. ASDAS, a highly discriminatory ASAS-endorsed disease activity score in patients with ankylosing spondylitis. Annals of the Rheumatic Diseases. 2009;68(12):1811-1818. doi:10.1136/ard.2008.094870.
13 Eder L et al. Is ASDAS better than BASDAI as a measure of disease activity in axial psoriatic arthritis?. Ann Rheum Dis. 2010;69(12):2160-2164. doi:10.1136/ard.2010.129726
14 ClinicalTrials.gov. A Study of Guselkumab Administered Subcutaneously in Bio-naive Participants With Active Psoriatic Arthritis Axial Disease (STAR). Identifier: NCT04929210. Available at: https://clinicaltrials.gov/study/NCT04929210. Accessed September 2026.
15 Lopez-Medina C, Ziade N. Axial Disease in Psoriatic Arthritis: how can we Define it, and does it have an Impact on Treatment? Mediterranean Journal of Rheumatology. 2022;33(Suppl 1):142-149. doi:10.31138/mjr.33.1.142. PMID: 36127925; PMCID: PMC9450188. Accessed August 2026.
16 Gottlieb AB, Merola JF. Axial psoriatic arthritis: An update for dermatologists. Journal of the American Academy of Dermatology. 2021;84(1):92-101. doi:10.1016/j.jaad.2020.05.089. PMID: 32747079. Access August 2026.