Further support for tocilizumab use in giant cell arteritis
medwireNews: More than a third of patients with giant cell arteritis remission who discontinue tocilizumab treatment after 1 year remain in clinical remission for a further 2 years, suggest follow-up results from the GiACTA trial.
Moreover, use of the interleukin-6 receptor inhibitor is associated with a reduction in glucocorticoid exposure over 3 years, and restarting tocilizumab restores clinical remission among patients who experience disease flare, said John Stone (Massachusetts General Hospital, Boston, USA), who presented the findings at the EULAR 2019 congress in Madrid, Spain.
Stone explained that at the end of the 1-year randomized treatment period, participants who were in clinical remission stopped receiving blinded tocilizumab or placebo injections, and went on to receive no treatment, open-label tocilizumab, and/or glucocorticoids at the investigator’s discretion.
At the time of entry into the open-label phase, 73% of the 81 patients in clinical remission were receiving no treatment after stopping tocilizumab, and 42% of these 59 patients remained in treatment-free remission 2 years later.
Stone said that patients originally assigned to tocilizumab in the randomized part of the trial had higher rates of treatment-free remission at the end of the open-label period compared with those originally assigned to placebo, with rates of 65% versus 45% at the 3-year follow-up.
The presenter emphasized that “tocilizumab randomization at the very beginning of the trial had a profound effect on cumulative glucocorticoid use over the entire 3 years of the trial.” Indeed, median cumulative glucocorticoid doses were approximately 2000 mg for participants originally assigned to tocilizumab, compared with around 4000 mg for those given placebo in the randomized part of the trial.
Among the 89 patients who experienced a disease flare in the open-label part of the study, the majority (53%) had received no treatment prior to the flare, while 37% had been taking glucocorticoids only, 9% glucocorticoids plus tocilizumab, and 1% tocilizumab only.
Stone reported that the flares tended to be resolved more quickly among patients who received tocilizumab-based treatment for the flare. For example, for the patients assigned to tocilizumab once weekly in the randomized part of the trial, the median duration of flare was 15.0 days for those treated with tocilizumab for the flare, 8.5 days for those given tocilizumab plus glucocorticoids, and 37.5 days for those given glucocorticoids only.
He said that no new safety signals emerged in the second part of the GiACTA trial, and “there was a trend towards fewer adverse events” among patients who had received tocilizumab at some point in the trial compared with those never given tocilizumab, at rates of 538.3 and 636.3 per 100 person–years, respectively.
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