Tocilizumab in refractory giant cell arteritis. Monotherapy versus combined therapy with conventional immunosuppressive drugs. Observational multicenter study of 134 patients

Objective: To compare the efficacy and safety of TCZ in monotherapy (TCZMONO) vs. combined with conventional immunosuppressive drugs (TCZCOMBO) in Giant Cell Arteritis (GCA) in a clinical practice scenario. Methods: Multicenter study of 134 patients with refractory GCA. Patients on TCZMONO (n = 82) were compared with those on TCZCOMBO (n = 52). Drugs were methotrexate (MTX) (n = 48), azathioprine (n = 3), and leflunomide (n = 1). The main outcomes were: prolonged remission (normalization of clinical and laboratory parameters for at least 6 months) and the number of relapses. Results: Patients on TCZCOMBO were younger (68.8 ± 8.0 vs 71.2 ± 9.0 years; p = 0.04), with a trend to a longer GCA duration (median [IQR],18.5 [6.25–34.0] vs. 13.0 [7.75–33.5] months; p = 0.333), higher C-reactive protein (CRP) levels (2.1[1–4.7] vs 1.2 [0.2–2.4] mg/dL; p = 0.003), and more prevalence of extra-cranial large-vessel vasculitis (LVV) (57% vs. 34.1%; p = 0.007). In both groups, rapid and sustained improvement was observed. Despite the longer GCA duration, and the higher CRP levels and prevalence of LVV in the TCZCOMBO, the improvement was similar in both groups at 12 months. Moreover, in the TCZCOMBO group, prolonged remission was significantly higher at 12-month. Relapses and serious adverse events were similar in both groups. Conclusion: In clinical practice, TCZ in monotherapy or combined with conventional immunosuppressive agents is effective and safe in patients with GCA. Nevertheless, the addition of immunosuppressive drugs, usually MTX, seems to allow a higher rate of prolonged remission, even in patients with a longer GCA duration, more extra-cranial LVV involvement, and higher acute-phase reactants. © 2021 Elsevier Inc.