Tocilizumab for the treatment of giant cell arteritis: Efficacy and safety analysis from the giacta trial

Background: Giant cell arteritis (GCA) is a vasculitis of medium and large vessels. Neurological manifestations include headache, vision loss, and stroke. GiACTA is a randomized, double‐blind, placebo‐controlled trial evaluating the efficacy and safety of tocilizumab (TCZ), an IL‐6 recep‐tor‐a inhibitor, in GCA patients (Unizony SH et al. Int J Rheumatol. 2013;2013:912562). Methods: Patients aged >50 years with active GCA were randomly assigned 1:1:2:1 to short‐course (PBO 1 26) or long‐course (PBO152) prednisone (26‐week or 52‐week prednisone taper1weekly subcutaneous [SC] placebo, respectively) or weekly (TCZ‐QW) or every‐other‐week (TCZ‐Q2W) SC TCZ 162 mg126‐week prednisone taper. Primary and key secondary end points were the proportions of patients in sustained remission, comparing TCZ groups with PBO 1 26 and PBO 1 52, respectively (significance level, 0.005). Subgroup analysis was performed according to disease‐onset status (new‐onset vs relapsing GCA) to evaluate time to flare. Results: Randomization included 251 patients, 119 (47%) with new‐onset and 132 (53%) with relapsing GCA. At baseline, new‐onset localized headache and polymyalgia rheumatica (PMR) symptoms were each reported in approximately two‐thirds of patients, and jaw claudication, scalp tenderness, and temporal artery tenderness were each reported in approximately one‐third of patients. In the TCZ‐QW and TCZ‐Q2W groups, 56.0% and 53.1% of patients, respectively, achieved sustained remission compared with 14.0% in the PBO 1 26 group (both p<0.0001) and 17.6% in the PBO 1 52 group (both p<0.0002). Patients with relapsing disease were in relapse‐free remission longer and thus had lower risk for flare (hazard ratio) versus placebo when treated with TCZ‐QW than with TCZ‐Q2W Hazard ratio (99% CI) for flare in relapsing patients was 0.23 (0.09‐0.61) for TCZ‐QW and 0.42 (0.14‐1.28) for TCZ‐Q2W versus PBO126 and 0.36 (0.13‐1.00) for TCZ‐QW and 0.67 (0.21‐2.10) for TCZ‐Q2W versus PBO152. Among 109 patients who experienced GCA flare, approximately two‐thirds had cranial signs and symptoms at flare presentation whereas approximately half had PMR symptoms. Adverse events (AEs) were similar across the treatment groups. Serious AEs were reported in 15.0% of TCZ‐QW, 14.3% of TCZ‐Q2W, 22.0% of PBO 1 26, and 25.5% of PBO 1 52 patients. Serious AE rates were similar between patients with new‐onset and relapsing GCA. No patients experienced vision loss. Conclusions: TCZ126‐week prednisone taper was superior to PBO 1 26 and PBO 1 52 tapers in achieving sustained remission at 52 weeks. The higher relapse‐free survival rate of patients with relapsing GCA treated with TCZ‐QW may influence treatment decisions in clinical practice. Disclosure: Do you (or your spouse/partner) have any relevant financial relationships (currently or within the past 12 months) with any commercial interests? Salary‐employee.