GiACTA

Population

• 251 patients with giant-cell arteritis.

Intervention

Subcutaneous tocilizumab 162 mg weekly or every other week, each combined with a 26-week prednisone taper.

Comparator

Placebo combined with a prednisone taper over 26 weeks (primary comparison) or 52 weeks (key secondary comparison).

Key results

• Sustained remission at week 52 occurred in 56% with weekly tocilizumab and 53% with every-other-week tocilizumab, versus 14% with placebo plus a 26-week taper and 18% with placebo plus a 52-week taper (P<0.001 for either active treatment versus placebo).
• The key secondary comparison versus the 52-week placebo taper also favored tocilizumab (same remission rates; P<0.001).
• The cumulative median prednisone dose over 52 weeks was 1862 mg in each tocilizumab group, versus 3296 mg with the 26-week placebo taper and 3818 mg with the 52-week placebo taper (P<0.001 for both comparisons).

Harms

• Serious adverse events occurred in 15% with weekly tocilizumab, 14% with every-other-week tocilizumab, 22% with the 26-week placebo taper, and 25% with the 52-week placebo taper.
• Anterior ischemic optic neuropathy developed in one patient in the every-other-week tocilizumab group.

Practice impact

• Use subcutaneous tocilizumab 162 mg weekly or every other week with a 26-week prednisone taper to increase sustained glucocorticoid-free remission and lower cumulative prednisone.

Applicability

• Most applicable to patients with giant-cell arteritis in whom a 26-week or 52-week prednisone taper is being planned.

Limitations

• No odds ratio, risk ratio, or confidence interval was reported for the primary remission comparison.
• Per-arm randomized Ns are not given beyond the 2:1:1:1 assignment of 251 patients.
• The authors stated that longer follow-up is necessary to determine durability of remission and safety.

Common misinterpretations

• This is not a trial of tocilizumab without glucocorticoids; both tocilizumab arms used a 26-week prednisone taper.
• Superiority for sustained remission does not mean serious adverse events were higher with prednisone alone in a statistically tested comparison; only the rates are reported.