Tocilizumab, an interleukin-6 receptor alpha inhibitor, is a newly approved medication for the treatment of giant cell arteritis. In this phase 3 clinical trial, the authors studied the effect of tocilizumab on the rate of relapse of giant cell arteritis during glucocorticoid tapering.
Study design
Conducted at 76 sites in 14 countries, the trial included 251 patients randomized to 4 arms: subcutaneous tocilizumab weekly or every 2 weeks in combination with a 6-month daily oral prednisone taper, or placebo with a 6- or 12-month prednisone taper.
Outcomes
At 1 year, 56% of weekly patients and 53% of biweekly patients achieved sustained remission, compared with 14% and 18% of 6- and 12-month steroid-only patients, respectively (P<0.001 for both active treatments vs. placebo).
The rates of adverse events did not differ across trial groups.
Limitations
The study did not address any ophthalmic manifestations of giant cell arteritis except the mention of 1 patient who developed anterior ischemic optic neuropathy in one of the tocilizumab treatment groups.
Clinical significance
The authors concluded that tocilizumab, received weekly or every other week, combined with a 6-month prednisone taper, was superior to either placebo arms in achieving sustained glucocorticoid-free remission in patients with giant cell arteritis. A 2-year, open-label, follow-up phase of this clinical trial is ongoing, which will provide additional information regarding the safety and efficacy of tocilizumab beyond 52 weeks of treatment.