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 subcutaneous tocilizumab (qwTCZ) for patients with relapsing or refractory giant cell arteritis (GCA). During the 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: 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% of 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 = 0.0017); in those not in remission at qwTCZ cessation (P = 0.0036); and in those with large vessel involvement on imaging (P = 0.0296). Age ≥65, 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.