A multicentre, large-scale, observational study of tocilizumab in patients with giant cell arteritis in Japan.

Objectives: In clinical trials, tocilizumab (TCZ) is efficacious in patients with giant cell arteritis (GCA). This study evaluated the real-world tolerability and effectiveness of TCZ in Japanese patients with GCA.

Methods: In this multicentre, prospective, Phase 4, large-scale, observational study, patients with GCA (with no TCZ treatment 6 months before the study) were recruited from 71 centres across Japan. Patients received subcutaneous TCZ 162 mg weekly (observation period, 52 weeks).

Results: Of the 117 patients [female, 70.1%; mean age, 74.2 years; mean disease duration, 1.4 years; treated for new-onset GCA, 71.8%; presence of large-vessel lesions (LVLs), 61.5%; previous immunosuppressant use, 28.2%; glucocorticoids at baseline, 95.7% (mean: 22.4 mg/day)], 38.5% reported adverse events. The most common adverse events of special interest were neutropaenia and leukopaenia (7.7%), followed by serious infection (6.0%). The relapse-free proportion was 85.0%; relapse after remission, 6.0%; and no remission, 9.0%. At the last observation, 94.2% of relapse-free patients received a concomitant glucocorticoid dose of <10 mg/day. Fatigue, headache, neck pain, and absence of LVLs were positively associated with the relapse.

Conclusions: TCZ was effective and well tolerated in Japanese patients with GCA and may be an effective treatment option combined with glucocorticoids.