Relapse after cessation of weekly tocilizumab for giant cell arteritis: a multicentre service evaluation in England

Objectives: The National Health Service in England funds 12 months of weekly s.c. tocilizumab (qwTCZ) for patients with relapsing or refractory GCA. During the coronavirus disease 2019 (COVID-19) pandemic, some patients were allowed longer treatment. We sought to describe what happened to patients after cessation of qwTCZ. Methods: Multicentre service evaluation of relapse after stopping qwTCZ for GCA. The log-rank test was used to identify significant differences in time to relapse. Results: A total of 336 GCA patients were analysed from 40 centres, treated with qwTCZ for a median [interquartile range (IQR)] of 12 (12–17) months. At time of stopping qwTCZ, median (IQR) prednisolone dose was 2 (0–5) mg/day. By 6, 12 and 24 months after stopping qwTCZ, 21.4%, 35.4% and 48.6%, respectively, had relapsed, requiring an increase in prednisolone dose to a median (IQR) of 20 (10–40) mg/day. 33.6% relapsers had a major relapse as defined by EULAR. Time to relapse was shorter in those that had previously also relapsed during qwTCZ treatment (P ¼ 0.0017), in those not in remission at qwTCZ cessation (P ¼ 0.0036) and in those with large vessel involvement on imaging (P ¼ 0.0296). Age ≥65 years, gender, GCA-related sight loss, qwTCZ treatment duration, TCZ taper, prednisolone dosing and conventional synthetic DMARD use were not associated with time to relapse. Conclusion: Up to half our patients with GCA relapsed after stopping qwTCZ, often requiring a substantial increase in prednisolone dose. One-third of relapsers had a major relapse. Extended use of TCZ or repeat treatment for relapse should be considered for these patients.