WASHINGTON, DC — At the 2016 ACR/ARHP Annual Meeting, researchers from Genentech presented positive data from the GIACTA study that evaluated Actemra (tocilizumab) in patients with giant cell arteritis (GCA).
For patients with GCA, treatment has been limited to high-dose steroids to quickly reduce inflammation and prevent serious complications, explained Sandra Horning, MD, chief medical officer and head of Global Product Development. Treatment with steroids, however, often fail to manage disease in the long-term and can lead to severe adverse effects.
GiACTA is a Phase 3, global, randomized, double-blind, placebo-controlled trial assessing the safety and efficacy of Actemra as a new treatment for GCA (n=251) with blinded glucocorticoid regimens of variable dose and duration. The study was conducted in over 76 sites.
Study patients were randomized 1:1:2:1 to the following 4 groups:
- A: short-course prednisone (26-week prednisone taper + weekly subcutaneous [SC] placebo)
- B: long-course prednisone (52-week prednisone taper + weekly SC placebo)
- C: weekly SC Actemra 162mg + 26-week prednisone taper
- D: every other week SC Actemra 162mg + 26-week prednisone taper
“Sustained remission was defined at Week 52 as the absence of flare and normalization of C-reactive protein after Week 12, combined with adherence to the protocol-defined prednisone taper,” described study author John H. Stone, from Massachusetts General Hospital Rheumatology Unit, Harvard Medical School, Boston, MA.
The primary and key secondary endpoint was the proportion of patients in sustained remission comparing groups C and D (Actemra groups) with A (short-course prednisone) and B (long-course prednisone), respectively.
When Actemra was combined with a 6-month steroid taper regimen, it significantly increased the proportion of patients obtaining sustained remission at 1 year (56% [weekly Actemra] and 53.1% [every other week Actemra])compared to patients who were given the short-course prednisone alone (14%)(P<0.0001).
The percentage of patients in sustained remission in each Actemra group was also higher than that of patients in the long-course prednisone group (17.6%; P≤0.0002)
In addition, treatment with Actemra also significantly decreased cumulative steroid exposure in both Actemra groups vs. the long-course prednisone group.
In general, Actemra plus a 26-week prednisone taper proved superior to both short- and long-course prednisone tapers in achieving sustained remission at 52 weeks, the authors concluded.
No new safety signals were observed and these results remained consistent with Actemra’s established safety profile in RA.
The open-label extension study for GIACTA 104 weeks is still ongoing and will seek to quantify the drug’s long-term safety and maintenance of efficacy beyond 1 year, as well as any potential long-term steroid-sparing effects.
Actemra is the first humanized interleukin-6 (IL-6) receptor antagonist currently approved for the treatment of adults with moderately to severely active rheumatoid arthritis (RA) who have used 1 or more disease-modifying antirheumatic drugs (DMARDs), such as methotrexate (MTX), that did not provide enough relief.