Comparative Effectiveness of Tocilizumab and Tumor Necrosis Factor Inhibitors in Takayasu Arteritis: Age‐Related Differences in Treatment Response

OBJECTIVE: Comparative, prospective data on biologics for Takayasu arteritis (TAK) are limited. We compared tumor necrosis factor inhibitors (TNFi) and tocilizumab (TCZ) in a combined cohort, assessed demographic and cytokine influences, and evaluated longitudinal outcomes. METHODS: Clinical response to TNFi or TCZ was assessed in patients with TAK from two independent cohorts. In a subset followed prospectively within a standardized research protocol, physician global assessment (PGA), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and FDG-PET activity were compared pre- and post-treatment. Time to response was analyzed using Kaplan-Meier curves. Cytokine levels were measured with Luminex assays in patients and age-matched healthy controls. RESULTS: Among 151 patients (Cohort A=57; Cohort B=94), 129 received TNFi and 56 received TCZ during follow-up. Clinical response rates were 72.1% for TNFi and 60.7% for TCZ (p = 0.17). In the prospective subset, no significant differences in PGA, CRP, ESR, or FDG-PET outcomes (p > 0.30) were observed. Changing to another TNFi or switching between TNFi or TCZ after treatment failure resulted in clinical response in 31/33 (94%) patients. TNFi responders had younger median age at onset than non-responders (23 vs 33.5 years, p = 0.0039), whereas TCZ responders were older (35 vs 21.5 years, p = 0.0043). Patients with onset <30 years showed elevated IL-6 and TNF versus controls, a pattern not observed in older patients. CONCLUSION: TNFi and TCZ demonstrate similar effectiveness in TAK. These findings support therapeutic switching after treatment failure and suggest that age-related immunologic differences may influence treatment response.