CHICAGO — In patients with axial spondyloarthritis (axSpA) who do not respond to an initial TNF inhibitor, switching to an interleukin (IL)-17 inhibitor was not superior to trying a second TNF inhibitor, according to a prospective, randomized, open-label trial presented at American College of Rheumatology (ACR) 2025 Annual Meeting.

“These findings directly inform treatment sequencing after TNF inhibitor failure and provide valuable evidence to guide individualized, shared decision-making in axial spondyloarthritis management,” Hubert Marotte, MD, PhD, of Université Jean Monnet, Centre Hospitalier Universitaire de Saint-Étienne, Saint-Étienne, France, and colleagues wrote.

Laura Pina Vegas, MD, PhD, an associate professor of medicine at Hôpital Henri-Mondor in Créteil, France, told Medscape Medical News that she found the data interesting because “for the first time, we have real-life data on a therapeutic strategy for axial spondyloarthritis.” Data from observational cohort studies have been available, but it is particularly helpful now to have randomized study data showing that there are no notable differences between the effectiveness of the two classes of drugs, she said.

“Now we don’t have any [reason] to choose one molecule over the other, and we can choose differently depending on the patient’s comorbidities,” Pina Vegas said.

The study enrolled 300 adults with active axSpA from 31 centers in France and Monaco who had an inadequate response to an initial anti-TNF agent. All participants had a score > 4 on the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) or > 3.5 on the Ankylosing Spondylitis Disease Activity Score (ASDAS), and all had been on a stable dose of conventional synthetic disease-modifying antirheumatic drugs, oral corticosteroids, and/or nonsteroidal anti-inflammatory drugs for at least 1 month.

Nearly half of the participants were men (49.3%), with an average age of 45 years. More than half were HLA-B27 positive (59.1%) and had been diagnosed on average 7 years earlier. Participants included 42% with nonradiographic axSpA and 58% with ankylosing spondylitis. At baseline, they had an average BASDAI score of 6.1, an average ASDAS score of 3.2, and an average Bath Ankylosing Spondylitis Functional Index of 4.4.

Participants had been on their first TNF inhibitor for an average of 32.5 months, with 28.3% experiencing a primary nonresponse, 64% a secondary nonresponse, and 7.7% having difficulties with side effects. About half had previously taken adalimumab (51.3%). Other drugs taken included etanercept (22.3%), golimumab (13.7%), certolizumab pegol (7%), and infliximab (5.7%).

One group of 158 participants was randomly assigned to receive an IL-17 inhibitor, either secukinumab (77.6%) or ixekizumab (22.4%). The other 142 participants received a secondary TNF inhibitor, including adalimumab (36.6%), etanercept (25.4%), golimumab (22.5%), certolizumab pegol (14.8%), and infliximab (0.7%).

At 24 weeks, there was no significant difference in the groups’ odds of not responding to the second drug based on 40% improvement in Assessment in SpondyloArthritis international Society response criteria (ASAS40; adjusted odds ratio [aOR], 0.96; 95% CI, 0.68-1.34). The average ASDAS decreased to 2.5 in both groups.

There also were no significant differences for the secondary endpoints of ASAS40 at 12 or 52 weeks or ASAS20 at 12, 24, or 52 weeks. Similarly, partial remission rates and ASDAS-C-reactive protein (CRP) improvement did not differ significantly between the groups at 12, 24, or 52 weeks.

“Some trends were observed according to the cause of failure of the first TNFi in favor of IL-17i in case of primary nonresponse (OR, 0.69; 95% CI, 0.27-1.76) and in favor of another TNFi in case of side effect (OR, 1.49; 95% CI, 0.42-5.32),” the authors reported. “In case of skin psoriasis, HLA B27 negative status, or low CRP (< 5 mg/L), a trend in favor of IL-17i [was] also observed.”

The research did not note external funding, and Marotte had no disclosures. Pina Vegas reported receiving travel support from UCB and AbbVie.

Tara Haelle is a science/health journalist based in Dallas.