Washington, DC—Tocilizumab treatment weekly or every other week for 52 weeks with a 26-week prednisone taper was superior to a short and long course of tapered prednisone treatment in patients with giant cell arteritis (GCA). Tocilizumab was also corticosteroid-sparing. These results from the randomized, double-blind, placebo-controlled GiACTA trial were reported at the 2016 Annual Meeting of the American College of Rheumatology. The study met all primary and secondary end points.
“This represents a milestone in the treatment of this debilitating and difficult-to-treat disease. There is a new treatment for GCA at last. Tocilizumab has a powerful steroid-sparing effect. The era of unending glucocorticoid treatment with no viable alternative is over,” stated lead investigator John H. Stone, MD, Rheumatologist, Massachusetts General Hospital, Harvard Medical School, Boston.
Tocilizumab is an FDA-approved interleukin-6 receptor-α inhibitor indicated for the treatment of patients with rheumatoid arthritis and juvenile idiopathic arthritis.
“GCA is a chronic, often devastating, difficult-to-manage disease, and it is difficult to study in clinical trials. At least 10% of patients with GCA lose their vision, and the long-term morbidity of glucocorticoid treatment—the only treatment thus far for this disease—is substantial. For more than 65 years, no true steroid-sparing treatment has been proven effective,” Dr Stone told attendees.
“Treatment to date for GCA has been limited to high-dose steroids to rapidly control inflammation and prevent serious complications. However, steroid treatment often fails to control disease in the long-term, and can be associated with severe side effects. If approved, tocilizumab could have the potential to fundamentally change the way people with GCA are treated,” stated Sandra Horning, MD, Chief Medical Officer, Genentech, Portola Valley, CA.
Patients were randomized as follows: group 1, prednisone with a 6-month taper until week 52 and no other therapy; group 2, prednisone with 52 weeks of taper; group 3, weekly tocilizumab injections plus the same steroid taper as group 1; group 4, tocilizumab every other week with the same steroid taper as group 1.
At the meeting, Dr Stone presented 52-week results for the primary end point of sustained remission from weeks 12 to 52 for tocilizumab versus a prednisone 26-week taper. The study is continuing as open-label for another year.
At 52 weeks, sustained remission was achieved in 56% of patients receiving weekly tocilizumab (n = 100 patients) versus 14% receiving short-course prednisone (n = 50 patients; P <.0001), and 53.1% for patients receiving tocilizumab every other week versus 14% for those receiving short-course prednisone (P = .0002). The rate of sustained remission at 52 weeks was 17.6% for the long-course prednisone group (n = 51 patients).
The same pattern was evident for time to first flare following clinical remission, with the best results in groups 3 and 4—the 2 tocilizumab groups. The weekly tocilizumab group had sustained response following the cessation of prednisone, but the every-other-week tocilizumab group had a drop-off after stopping prednisone. More flares were seen in groups 1 and 2.
Flares were defined as recurrence of GCA signs or symptoms, an increased erythrocyte sedimentation rate >30 mm/h attributed to GCA, or 2 consecutive C-reactive protein elevations, and were treated with an increase in prednisone dose. The cumulative dose of prednisone was cut in half in both tocilizumab arms compared with the long-course prednisone treatment arm.
“The reduction in prednisone use in patients taking tocilizumab was clinically significant,” Dr Stone commented.
On the 36-Item Short Form Health Survey, tocilizumab improved quality of life, whereas quality of life declined in both prednisone taper groups.
No new safety signals attributed to tocilizumab were reported during the trial. No cases of vision loss and no deaths occurred. Two malignancies were reported in the prednisone groups.