Objectives: Tocilizumab, an IL-6 inhibitor, has been proven effective in patients with adult-onset Still's disease (AOSD). This study aimed to clarify whether tocilizumab can be discontinued after achieving remission and to identify factors relevant to its successful discontinuation.
Methods: Consecutive patients with AOSD diagnosed according to Yamaguchi's criteria from April 2012 to July 2022, who were treated with tocilizumab, were retrospectively reviewed.
Results: Forty-eight patients with AOSD treated with intravenous tocilizumab, with sufficient information, were included. Thirty-eight patients (79.2%) achieved remission after 6 months of tocilizumab treatment, 12 of whom discontinued tocilizumab during remission. Within 1 year after tocilizumab discontinuation, six patients (50.0%) recurred at a mean of 5.5 months, while the other six (50.0%) remained in remission. Between the non-recurrence and recurrence groups, no difference was found in disease activity at tocilizumab discontinuation (systemic feature score, p = 0.24; ferritin, p = 0.46). While the duration of tocilizumab use was not different (p = 0.32), the interval of tocilizumab administration at tocilizumab discontinuation in the recurrence group was 21 (14-35) days, which tended to be shorter than 35 (28-53) days in the non-recurrence group (p = 0.08). Patients with prednisolone dose < 7 mg/day at last tocilizumab treatment had fewer recurrences than those without (p = 0.001). After recurrence, tocilizumab was resumed in half of the patients, resulting in successful disease control.
Conclusions: The recurrence rate after tocilizumab discontinuation was 50% in 1 year. Patients who remained in remission with a longer interval of tocilizumab administration and lower prednisolone dose were likely to succeed in the withdrawal of tocilizumab.
Keywords: adult-onset Still’s disease; drug withdrawal; remission; tocilizumab.
© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology.