Anti-IL-6 therapy shows promise in GCA Save

The opening day plenary session at ACR 2016 this morning featured John H. Stone, MD, presenting the much anticipated primary endpoint data from GiACTA, the phase III, double-blind, randomized, controlled trial of tocilizumab (TCZ) in patients with giant cell arteritis.

There are several abstracts and presentations on this hot topic this year, but perhaps none as anticipated as these results. GiACTA is now the largest trial looking at treatment of GCA, including 251 patients with either newly diagnosed or relapsing GCA from 76 sites across 14 countries.

There were four treatment groups: 1) placebo + 26-week prednisone taper, 2) placebo + 52 week prednisone taper, 3) TCZ 162 mg weekly + 26-week prednisone taper, and 4) TCZ 162 mg every-other-week + 26 week prednisone taper. The primary endpoint was sustained remission from week 12 to week 52 and adherence to the protocol-defined prednisone taper in group 3 versus group 1. The key secondary endpoint was the same but for group 3 versus group 2. Of note, this is the first trial to use a masked variable-dose glucocorticoid regimen.

What they found was in both placebo groups sustained remission occurred in less than 18% of patients at 52 weeks, compared to 56 % of patients receiving weekly TCZ and 53% receiving every-other week dosing. Time to first flare following clinical remission was significantly later in both study groups compared to placebo.

In summary, TCZ had a significantly steroid-sparing effect in this study.  Important to note is that there were no new safety signals and adverse events, while common, were balanced across all 4 groups. Interestingly there were no bowel perforations reported. As Dr. Stone stated today, it seems “there IS something new in GCA, at last”. Only the primary endpoint data was presented today. The open-label portion will be continuing for at least another year and we all will anxiously await the results.