Real-world Risk of Relapse of Giant Cell Arteritis Treated With Tocilizurnab: A Retrospective Analysis of 43 Patients

Objective. Tocilizurnab (TCZ), an interleukin 6 (IL-6) receptor antagonist, is approved for giant cell arteritis (GCA) as a cortisone-sparing strategy and in refractory patients. This study assessed the real-world efficacy, safety, and long-term outcomes of patients with GCA treated with TCZ. Methods. We conducted a multicenter retrospective observational study at 3 French centers. All patients aged >= 50 years who met the American College of Rheumatology (AC R) criteria, and had received at least 1 dose of TCZ were included. Relapse was defined by therapeutic escalation, such as increased doses of corti-costeroids (CS), resumption of CS after weaning, or introduction or intensification of adjuvant therapy. Results. Between 2013 and 2019, 43 patients were included. Patients were followed up for a median 511 days between GCA diagnosis and inclusion, with 34/43 (79%) patients experiencing relapses. At inclusion, median age was 77 years, and median dose of CS was 15 mg/day. After inclusion, the mean cumulative dose of CS was 2.1 g/year vs 9.4 g/year before inclusion (P < 2 x 10(-7)), with 12/43 (28%) patients experiencing relapses on TCZ. Among 29 patients undergoing TCZ discontinuation, 18 (62%) experienced relapses. Factors associated with relapse after inclusion were introduction of TCZ > 6 months after diagnosis (P = 0.005), absence of ischemic signs at diagnosis (P = 0.006), relapse rate > 0.8/year (P = 0.03), and absence of CS tapering <= 5 mg/day (P = 0.03) before inclusion. Serious adverse events occurred in 18/43 patients (42%), including 4 deaths. Conclusion. Our results confirm the effectiveness of TCZ for CS sparing, but after discontinuation of treatment, TCZ allows for a prolonged remission in < 50% of patients. Attention must be paid to the tolerance of this long-term treatment in this elderly, heavily treated refractory population.

Automated summary

This study evaluated the real-world effectiveness, safety, and long-term outcomes of TCZ treatment in patients with giant cell arteritis. Results showed TCZ was effective in reducing corticosteroid use, but less than 50% of patients maintained long-term remission after discontinuation. Factors associated with relapse included delayed initiation of TCZ treatment after diagnosis and insufficient tapering of corticosteroids before inclusion.