Ustekinumab for refractory giant cell arteritis: A prospective 52-week trial

Objectives: Giant cell arteritis (GCA) is the most common form of systemic vasculitis. Glucocorticoids are an effective treatment but have significant adverse events and relapses are common. Interleukins 12 (IL-12) and 23 (IL-23) stimulate T_H1 and T_H17 responses and are implicated in the pathogenesis of GCA. The aim of this study was to evaluate the efficacy and safety of IL-12/23 blockade with ustekinumab in GCA.

Methods: We performed a prospective open label study of ustekinumab in patients with refractory GCA. Ustekinumab 90mg was administered subcutaneously every 12 weeks. The primary outcome was the comparison of the median glucocorticoid dose prior to commencement of ustekinumab and at 52 weeks. Secondary outcomes included physician assessed relapse, acute phase reactants, and imaging assessment of large vessel vasculitis (LVV).

Results: Twenty-five GCA patients received ustekinumab. All patients had failed to taper glucocorticoids despite addition of a median of 1 other immunosuppressive agent. At week 52, median (IQR) daily prednisolone dose decreased from 20 (15, 25)mg to 5 (2.5, 5)mg (p < 0.001). Six patients (24%) stopped prednisolone completely. No patient experienced a relapse of GCA while receiving ustekinumab. Median (IQR) CRP decreased significantly from 12.9 (5.3, 42) to 6 (2.6, 12.5)mg/L (p = 0.006). CT angiography demonstrated improvement of LVV in all patients studied. No unexpected adverse events were observed with ustekinumab.

Conclusions: Ustekinumab may be effective for the treatment of GCA and warrants further assessment in a randomized controlled trial.