What happened when prednisone was stopped?
In the absence of a direct comparison group (since the extension wasn’t a randomized, controlled part of the trial), the best comparison to that is what happens when prednisone is stopped, he noted.
“And we did that experiment in part 1” of the trial, he said. Overall, 68% of patients in the prednisone/placebo groups flared in 1-year of follow-up, and most of those did so even before they stopped prednisone. In the group that received placebo plus a 52-week prednisone taper, 49% of patients flared and “every single one of those patients flared before they got off prednisone,” he said.
“So in that context, 2 years of treatment-free remission following weekly tocilizumab discontinuation seems very good,” he added.
Of the patients who flared in part 2 of the trial, 11 whose investigator elected to treat them with only tocilizumab reentered remission in a median of 15.8 days, 13 treated with tocilizumab and glucocorticoids reentered remission in a median of 8.5 days (1 didn’t reenter remission at all), and 15 treated with only glucocorticoids reentered remission in a median of 38 days.
“There are a number of biases in these data, but they do point out the fact that some patients can be treated with tocilizumab alone,” Dr. Stone said. “I would be very careful doing that.”
The trial was not powered for the comparison of weekly versus biweekly dosing, he said. However, “multiple lines of investigation and analysis support the idea that weekly tocilizumab is more effective at controlling disease,” he added. But “if you want to be assured that you are doing everything you can to control the disease, weekly tocilizumab would be better than every-other-week tocilizumab,” he said.
GiACTA was funded by Roche. Dr. Stone reported research grants from Roche/Genentech and consulting fees from Chugal, Roche/Genentech, and Xencor.
SOURCE: Stone J et al. Arthritis Rheumatol. 2019;71(suppl 10), .