Johnson & Johnson: TREMFYA first IL‑23 inhibitor to show spinal pain and stiffness benefit in axial PsA STAR study

Study results

TREMFYA (guselkumab) met the primary endpoint in the Phase 4 STAR study, showing improvement in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) at Week 24 versus placebo in biologic‑naïve adults with active psoriatic arthritis and MRI‑confirmed axial involvement. Major secondary endpoints were also met, including significant reduction in axial symptoms as measured by ASDAS‑CRP and objective reduction of sacroiliac joint inflammation on MRI.

Study design

STAR is a randomized, double‑blind, placebo‑controlled, multicenter Phase 4 trial that enrolled 411 participants worldwide. Eligible patients had active PsA with centrally read MRI evidence of axial inflammation and elevated C‑reactive protein despite prior non‑biologic DMARDs, apremilast and/or NSAIDs. The trial included a 24‑week placebo‑controlled period followed by a 24‑week active treatment period.

Clinical context

Axial involvement affects the spine and sacroiliac joints and can cause back pain, stiffness, fatigue and impaired mobility; it represents an unmet need within PsA with few prospective trials dedicated to this domain. Johnson & Johnson notes these topline STAR findings build on existing TREMFYA evidence, including a recent FDA label expansion for inhibition of progression of structural joint damage in active PsA.

Safety and next steps

The overall safety profile observed in STAR was consistent with the established TREMFYA profile and no new safety signals were identified. Detailed efficacy, safety and MRI findings will be presented at an upcoming scientific congress.