Glucocorticoid Dosages and Acute-Phase Reactant Levels at Giant Cell Arteritis Flare in a Randomized Trial of Tocilizumab

OBJECTIVE: To evaluate glucocorticoid doses and serological findings in patients with giant cell arteritis (GCA) flares.

METHODS: Patients with GCA were randomly assigned to receive double-blind dosing with subcutaneous tocilizumab (TCZ) 162 mg weekly plus 26-week prednisone (TCZ-QW+Pred-26), every-other-week TCZ plus 26-week prednisone (TCZ-Q2W+Pred-26), placebo plus 26-week prednisone (PBO+Pred-26), or placebo plus 52-week prednisone (PBO+Pred-52). Outcomes were prednisone dose, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR) at the time of flare and remission during 52 weeks.

RESULTS: One hundred patients received TCZ-QW+Pred-26, 49 received TCZ-Q2W+Pred-26, 50 received PBO+Pred-26, and 51 received PBO+Pred-52. Among 149 TCZ-treated patients, 36 (24%) experienced flare, 23 (64%) of whom were still receiving prednisone (median dose, 2.0 mg/day). Among 101 PBO+Pred-treated patients, 59 (58%) experienced flare, 45 (76%) of whom were receiving prednisone (median dose, 5.0 mg/day). Many flares occurred while patients were taking more than 10 mg/day prednisone: 9 (25%) in the TCZ groups and 13 (22.0%) in the placebo groups. Thirty-three flares (92%) in TCZ-treated groups and 20 (34%) in PBO+Pred-treated groups occurred with normal CRP. More than half the PBO+Pred-treated patients had elevated CRP without flare. Benefits of the combination of TCZ plus prednisone over prednisone alone for remission induction were apparent by 8 weeks.

CONCLUSION: Most GCA flares occurred while patients were still receiving prednisone. Acute-phase reactants were not reliable indicators of flare in patients treated with TCZ plus prednisone or with prednisone alone. The addition of TCZ to prednisone facilitates earlier GCA control. This article is protected by copyright. All rights reserved.