Tocilizumab Is Effective to Treat GCA

New results reveal that the interleukin (IL)-6 receptor alpha inhibitor tocilizumab helps sustain glucocorticoid-free remission in patients with GCA. John H. Stone, MD, MPH, director of Clinical Rheumatology at the Massachusetts General Hospital in Boston, and colleagues compared weekly or bi-weekly treatment with tocilizumab in combination with a 26-week prednisone taper with either a 26-week or 52-week prednisone tapering plus placebo. The results of the one-year trial were published July 27 in The New England Journal of Medicine.^1,2.

The researchers randomly assigned 251 patients with active GCA to one of two groups that received different doses of tocilizumab administered subcutaneously in combination with a 26-week prednisone taper (n=150). Patients were also assigned to one of two groups that received placebo and prednisone with the prednisone tapered over 26 weeks (n=50) or 52 weeks (n=51).

Both regimens—weekly and bi-weekly tocilizumab—in combination with a prednisone taper over 26 weeks were superior to placebo plus a prednisone taper of 26 weeks or 52 weeks. Specifically, approximately 50% of the patents treated with tocilizumab achieved prednisone-free remission when compared with approximately 15% of those in the placebo groups.

The investigators also found that only one quarter of patients treated with tocilizumab experienced flares compared with 68% of patients in the placebo group who underwent a 26-week taper and 49% of patients in the placebo group who underwent a 52-week taper. The investigators used this data to calculate a hazard ratio for flare of 0.23 (99% confidence interval [CI], 0.11 to 0.46) in the group that received tocilizumab weekly relative to those who received placebo and had a 26-week taper and 0.28 (99% CI, 0.12 to 0.66) in the group that received tocilizumab bi-weekly relative to those who received placebo and had a 26-week taper (P<0.001 for both comparisons).

Tocilizumab treatment was also associated with a reduction in the cumulative prednisone dose over the 52-week trial period. Specifically, the cumulative median prednisone dose over the 52-week period was 1,862 mg in each tocilizumab group, 3,296 mg in the placebo group that underwent the 26-week taper (P<0.001) and 3,818 in the placebo group that underwent the 52-week taper (P<0.001). Moreover, post hoc analyses revealed that 23% of patients who received tocilizumab weekly received open-label prednisone as escape therapy compared with 33% in the group that received tocilizumab every other week, 74% in the placebo group that underwent the 26-week taper and 55% in the placebo group that underwent the 52-week taper.