Tocilizumab bests steroid in GiACTA: RA drug also works for GCA
Tocilizumab, an old drug approved for rheumatoid arthritis (RA), also works well for giant-cell arteritis (GCA), the phase III GiACTA* study has shown.
The interleukin-6 inhibitor tocilizumab outperformed steroid in patients with GCA, scoring another US FDA nod in May 2017, this time for the treatment of adults with GCA.
“The trial is the first to demonstrate beyond any doubt that an alternative to chronic, unending steroid treatment exists,” said lead author Dr John Stone from the Rheumatology Unit, Massachusetts General Hospital in Massachusetts, US. “One of the most surprising findings [of GiACTA] was just how poorly the traditional, steroid-only regimens worked. These results are likely to have an immediate, sustained impact on the lives of hundreds of thousands of patients [with GCA] across the world.”
Patients with GCA have very limited treatment options. High doses of glucocorticoids – primarily prednisone – have been the mainstay of treatment but are not without attendant adverse effects such as hypertension, diabetes, cataracts, and fractures when given on long courses. This puts clinicians under pressure to gradually taper glucocorticoids. Tapering though also comes with risks, including rebound GCA, stroke, and visual loss.
Findings from the GiACTA study however showed that tocilizumab improved relapse rates during glucocorticoid tapering in GCA. In this trial of 251 patients randomized to subcutaneous tocilizumab 162 mg (weekly or every other week) combined with a 26-week prednisone taper vs placebo with a prednisone taper for 26 or 52 weeks, a greater percentage of patients on tocilizumab and prednisone regimens achieved sustained remission from week 12 through week 52 vs those on placebo with prednisone. [N Engl J Med 2017;377:317-328]
Sustained remission was defined in the study as the absence of GCA symptoms, normalization of inflammatory lab tests, and tapering of prednisone.
At 52 weeks, more than half of the patients receiving tocilizumab had sustained remission (56 and 53 percent for tocilizumab weekly and every other week, respectively vs 14 and 18 percent for placebo and prednisone for 26 weeks and 52 weeks, respectively; p<0.001). Fewer patients in the tocilizumab groups experienced symptom exacerbations during the treatment period compared with the placebo and prednisone groups.
Total prednisone dose was also lower in the tocilizumab vs the placebo group (1862 mg in the tocilizumab group vs 3296 mg in the placebo group for the 26-week taper regimen (p<0.001) and 3818 mg with placebo for the 52-week taper regimen (p<0.001)).
“The findings demonstrate quite clearly the powerful steroid-sparing effects of tocilizumab,” said Stone. “Tocilizumab allowed for the reduction of prednisone, resulting in reduced steroid-related symptoms and with the added benefit of sustained disease remission.”
Patients with GCA should receive this drug early in their treatment course for any delay would simply extend the time they must remain on steroids, he added.