A multicentre, large-scale, observational study of tocilizumab in patients with Takayasu arteritis in Japan: The ACTEMRA® (ACT)-Bridge study

Objectives We evaluated the real-world tolerability and effectiveness of tocilizumab in Japanese patients with Takayasu arteritis (TAK). Methods Patients with TAK who had not received tocilizumab in the previous 6 months were enrolled in ACTEMRA® (ACT)-Bridge, a phase 4, observational study, from 66 Japanese institutions (enrolment period, September 2017 to September 2020) and received weekly subcutaneous tocilizumab 162 mg (observation period, 52 weeks). Results Among 120 patients included (mean age, 38.4 years; mean disease duration, 7.7 years; treated for relapse, 50.8%; previous immunosuppressant use, 57.5%; glucocorticoid use at baseline, 97.5%), 49 (40.8%) reported adverse events. The most common adverse event of special interest was serious infection (7.5%). Relapse was observed in 24 (20.0%) patients (0.8%, 2.5%, and 16.7% reporting ≥3, 2, and 1 relapses, respectively). The reasons for diagnosing relapse included chest and back pain (45.8%), neck pain (25.0%), fatigue (16.7%), fever and headache (12.5% each), abnormal imaging findings (50.0%), and elevated inflammatory markers (16.7%). At the last observation, 83.0% of relapse-free patients recorded a concomitant glucocorticoid dose (prednisolone equivalent) Conclusions This study demonstrated the effectiveness of tocilizumab in patients with TAK, with no new safety concerns. Tocilizumab plus glucocorticoids may be considered a treatment option for TAK.