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.