Strike First: TNFi vs. Step-Up Therapy in Early Peripheral SpA Save

The approach to the treatment of peripheral spondyloarthritis (SpA) has been the same for a long time. The guidelines recommend starting with NSAIDs, escalate to conventional synthetic DMARDs, typically sulfasalazine or methotrexate and reserve biologics for patients who fail those. It is a logical, cost-conscious, stepwise strategy. 

According to a new phase 3 trial presented at EULAR 2026 in London (Abstract OP0107), there may be a different way to approach this. The SPARTACUS trial asks the question: in newly diagnosed patients with early active peripheral SpA, does immediate biological therapy outperform the standard step-up approach? 

SPARTACUS enrolled 97 patients with newly diagnosed pSpA fulfilling ASAS classification criteria, with a symptom duration of no more than one year. All patients had at least one active manifestation at baseline; arthritis was present in 97%, enthesitis in 68%, and dactylitis in 34%. Nearly half (49%) had documented psoriasis. Baseline disease was active: mean tender joint count of 5, swollen joint count of 4, SPARCC enthesitis index of 1.5, CRP of 25 mg/L. Mean symptom duration was approximately 6 months.

Patients were randomised 1:1 to first-line Golimumab 50 mg subcutaneously every 4 weeks (TNFi induction arm) or to oral Methotrexate 15 mg weekly, escalated to 20 mg at Week 4 if tolerated (csDMARD step-up arm). At Week 12, patients whose symptoms remained unacceptable received add-on Sulfasalazine 2 g/day. The primary endpoint was clinical remission at 24 weeks, defined as complete absence of arthritis, dactylitis, and enthesitis. Sustained clinical remission, maintained remission across multiple assessments,  was a key secondary endpoint.

At Week 24, clinical remission was achieved by 60% of patients in the TNFi induction arm compared with just 33% in the csDMARD step-up group. The difference of 28 percentage points was statistically significant (p = 0.003), with an odds ratio of 3.1 (95% CI 1.4 – 7.3; p = 0.006) in favour of early biologic therapy. The superiority margin was clearly exceeded. Sustained clinical remission, the more stringent measure requiring maintained disease absence at Week 24,was achieved by 42% of TNFi-treated patients versus only 18% in the step-up group, a difference of 23 percentage points (p = 0.006). Patient-reported outcomes uniformly favoured Golimumab, with significant reductions in global disease activity and pain scores.

SPARTACUS was designed explicitly to extend the findings of the earlier CRESPA trial, which demonstrated that first-line TNFi therapy in pSpA could induce drug-free remission but only in patients with symptom duration of less than three months, a very narrow window rarely achievable in routine practice. SPARTACUS broadens the eligible window to one year, and replaces a placebo comparator with an active csDMARD arm, making the comparison far more clinically relevant. The investigators frame the results within the concept of a 'therapeutic window' for pSpA: a period early in disease during which the immune pathology is most modifiable and during which intensive intervention may translate into not merely better short-term disease control, but potentially lasting drug-free remission. Whether the 24-week advantage translates into such durable outcomes will be the central question as longer-term SPARTACUS data emerge.

The key caveats are modest sample size (97 patients) and the 24-week horizon long enough to show a remission difference, but not long enough to address durability, structural outcomes, or the critical question of whether early TNFi therapy can eventually be stopped. The longer-term SPARTACUS data, when they arrive, will be essential information. 

For now, the 24-week results make a compelling case that, in newly diagnosed patients with active pSpA, reaching for a biologic sooner rather than later may be a more effective strategy.