Outcomes during and after long-term tocilizumab treatment in patients with giant cell arteritis

ObjectiveTo assess outcomes in giant cell arteritis (GCA) patients during and after long-term tocilizumab (TCZ) treatment.MethodsRetrospective analysis of GCA patients treated with TCZ at a single centre (2010-2022). Time to relapse and annualised relapse rate during and after TCZ treatment, prednisone use, and safety were assessed. Relapse was defined as reappearance of any GCA clinical manifestation that required treatment intensification, regardless of C reactive protein levels and erythrocyte sedimentation rate.ResultsSixty-five GCA patients were followed for a mean (SD) of 3.1 (1.6) years. The mean duration of the initial TCZ course was 1.9 (1.1) years. The Kaplan-Meier (KM)-estimated relapse rate at 18 months on TCZ was 15.5%. The first TCZ course was discontinued due to satisfactory remission achievement in 45 (69.2%) patients and adverse events in 6 (9.2%) patients. KM-estimated relapse rate at 18 months after TCZ discontinuation was 47.3%. Compared with patients stopping TCZ at or before 12 months of treatment, the multivariable adjusted HR (95% CI) for relapse in patients on TCZ beyond 12 months was 0.01 (0.00 to 0.28; p=0.005). Thirteen patients received >1 TCZ course. Multivariable adjusted annualised relapse rates (95% CI) in all periods on and off TCZ aggregated were 0.1 (0.1 to 0.2) and 0.4 (0.3 to 0.7), respectively (p=0.0004). Prednisone was discontinued in 76.9% of patients. During the study, 13 serious adverse events occurred in 11 (16.9%) patients.ConclusionLong-term TCZ treatment was associated with remission maintenance in most patients with GCA. The estimated relapse rate by 18 months after TCZ discontinuation was 47.3%.