A new multicentre Dutch trial has found that starting treatment for psoriatic arthritis (PsA) with the IL-17A inhibitor secukinumab, a biologic, does not lead to significantly better outcomes at six months compared with a conventional step-up, methotrexate-based approach, despite using a rigorous treat-to-target strategy in both groups.
The STAMP trial (Intensive biological DMARD-first strategy versus standard step-up care in psoriatic arthritis) enrolled 120 newly diagnosed, DMARD-naive adults with active PsA across 12 hospitals in the Netherlands. All participants met Classification Criteria for Psoriatic Arthritis (CASPAR criteria) and had at least two swollen joints at baseline.
Patients were randomised 1:1 to receive either early intensive therapy, secukinumab 300 mg every four weeks plus methotrexate 15 mg weekly, or standard of care, beginning with methotrexate alone, escalated up to 25 mg at six weeks. Both groups followed treat-to-target principles, with treatment adjusted every three months if minimal disease activity (MDA) was not achieved. Patients in the secukinumab arm who failed to reach targets were switched sequentially to one, then two TNF inhibitors, and ultimately apremilast if needed. All participants also received a single 80 mg intramuscular methylprednisolone injection at baseline.
Do Patients with Psoriatic Arthritis Benefit from Early IL-17A Inhibition?
The trial’s primary endpoint, ACR50 at six months, was not met. ACR50 responses occurred in 42% of the early-secukinumab group and 35% of the standard-care group, a difference that was not statistically significant (RR 1.19; p=0.45). By 12 months, both treatment strategies led to comparable clinical improvements, with roughly half of all participants achieving ACR50, suggesting that treat-to-target itself may be the critical driver of outcomes rather than initial drug choice.
Safety profiles were similar across groups. Adverse events occurred in about half of participants in each arm, and serious adverse events were reported in 10% of the secukinumab group and 8% of the standard-care group. No deaths occurred.
How the STAMP Trial May Shape Future Psoriatic Arthritis Guidelines
The investigators conclude that while early biologic therapy is safe and effective, it does not provide a statistically meaningful advantage over a conventional treat-to-target methotrexate-first approach in newly diagnosed PsA. The findings reinforce the value of structured, goal-directed care and suggest that many patients can achieve meaningful disease control without immediate biologic therapy.
Reference
Koc GH et al. Intensive biological DMARD-first strategy versus standard step-up care in psoriatic arthritis (STAMP): 1-year results from a multicentre, open-label, randomised controlled trial comparing two treat-to-target strategies. Lancet Rheumatol. 2025; DOI: 10.1016/S2665-9913(25)00223-1
