An agent-to-agent real life comparison study of tocilizumab versus abatacept in giant cell arteritis

The present study aimed at evaluating the efficacy of abatacept (ABA) compared to tocilizumab (TCZ), assumed as a gold standard biologic treatment in the management of patients with giant cell arteritis (GCA).

Thirty-three biospy-proven GCA consecutive patients were prospectively collected. Odd patients (from 1 to 33) were assigned to TCZ, given either intravenously (IV 8 mg/kg/month), #8 cases, or subcutaneously (SC 162 mg/week) #9, based on patient's preference. ABA was administered subcutaneously at the dose of 125 mg/week in 16 even patients (from 2 to 32). Biological therapies were prescribed in addition to oral prednisone.

A single biologic agent was administered in 28 patients out of 33 (85%) (8 TCZ IV, 9 TCZ SC and 16 ABA). Five patients (15%) needed a therapeutic switch (one patient from TCZ to ABA, and 4 patients from ABA to TCZ). Among the TCZ IV group, all patients experienced a response (57% complete response and 43% partial response). Among the TCZ SC group, 7 experienced a clinical response (complete in 67% and partial in 16%). Among the ABA group, 10 patients (62%) achieved either complete (5 patients) or partial (5) response, respectively. After 12 months of therapy, 100% of patients in TCZ groups, both IV and SC, and 7 (43%) of ABA group were receiving doses of oral prednisone not exceeding 7.5 mg/day as maintenance.

Both TCZ and ABA can be proposed as an effective therapeutic option in GCA with relevant inflammatory symptoms. ABA can be considered in the patient with absolute or relative or contraindications to TCZ.