Coming to a hard stop? effect of tapered tocilizumab after weekly tocilizumab cessation for GCA: a multicentre evaluation

Objectives: In England, there is a ‘hard stop’ to weekly tocilizumab (qwTCZ) therapy for GCA; this is currently 12 months but was extended during the COVID-19 pandemic subject to certain criteria for GCA relapse risk. Taking advantage of variation in practice, we aimed to compare outcomes of GCA patients who tapered-TCZ vs those who stopped abruptly (non-taper patients). Methods: Secondary analysis of an English multicentre service evaluation of relapse after stopping qwTCZ for GCA. Time to relapse was compared between taper and non-taper patients. We examined outcomes according to whether they had been ‘adequate responders’ during qwTCZ therapy, defined as those in remission and on ≤5 mg prednisolone at qwTCZ cessation, without relapse whilst taking qwTCZ. Results: We analysed 336 patients from 40 centres. Time to relapse after qwTCZ cessation was significantly longer in adequate responders than non-adequate responders (P ¼ 0.0004). 17.0% (57/336) patients tapered to fortnightly TCZ after qwTCZ cessation, for a median of 6 (IQR 2–13) months. For adequate responders, time to relapse whilst taking tapered-dose TCZ was significantly longer compared with those in the non-taper group (P ¼ 0.0231) based on a relatively small number of flares. There was no difference between the taper and non-tapered groups after tapered-TCZ was stopped (P ¼ 0.8346). In contrast, time to relapse for non-adequate responders was similar in taper patients compared with non-taper patients (P ¼ 0.4892). Conclusion: Tapering TCZ after qwTCZ cessation delayed relapse only during the tapering period, but only in adequate responders to qwTCZ. No lasting benefit was seen after tapering ended.