2610: Imaging remission in aortitis associated with giant cell arteritis. Multicenter study with tocilizumab in monotherapy and combined therapy

Background/Purpose: Aortitis is a frequent and potential severe complication of giant cell arteritis (GCA)(GCA-aortitis). Tocilizumab (TCZ) was approved for the treatment of GCA, but its efficacy in GCA-aortitis has not been specifically studied in randomized clinical trials. GCA-aortitis may be more refractory to TCZ than classic cranial GCA phenotype.

Our aim was to assess the effectiveness and safety of TCZ in monotherapy (TCZmono) compared to TCZ combined with conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs)(TCZcombo) in GCA-aortitis in clinical practice. To study associative factors associated with imaging remission.

Methods: Comparative multicenter observational study of GCA-aortitis treated with TCZcombo vs TCZmono. Outcomes, at 12 and 24 months, were: clinical, EULAR, and imaging remission (¹⁸F-FDG PET/CT vascular uptake lower than liver uptake), glucocorticoid-sparing effect and safety data. Associative factors associated with imaging remission (multivariable logistic regression) were determined at 24 months.

Results: 196 patients (148 female/48 male) with GCA-aortitis treated with TCZ (136 TCZmono/60 TCZcombo) (Table 1). After 24 months since the initiation of TCZ, imaging remission (50% vs.15.8%; p=0.026) was higher with TCZcombo (Figure). In contrast, there were no differences in EULAR and clinical remission. Prednisone sparing effect was higher in TCZcombo. In addition, a non-statistically lower adverse events rate was observed in TCZcombo (8.7 vs. 13.2 vs. adverse events 100 patients/year; p=0.21). In a multivariable logistic study TCZcombo vs TCZmono increases the imaging remission 5.26-fold (OR 5.26 (95% CI: 1.03-26.85; p=0.046) at 24-month follow-up (Table 2).

Conclusion: In GCA-aortitis, TCZ therapy combined with csDMARDs may be more effective than TCZmono in imaging remission without increasing adverse events.