Tocilizumab for the treatment of large‐vessel vasculitis (giant cell arteritis, Takayasu arteritis) and polymyalgia rheumatica

Abstract

Objective The interleukin‐6 pathway is up‐regulated in giant cell arteritis (GCA), Takayasu arteritis (TA), and polymyalgia rheumatica (PMR). We retrospectively assessed the outcomes of 10 patients with relapsing/refractory GCA, TA, or PMR treated with tocilizumab (TCZ). Methods Patients with GCA (n = 7), TA (n = 2), and PMR (n = 1) received TCZ. Seven subjects had failed at least 1 second‐line agent. The outcomes evaluated were symptoms of disease activity, inflammatory markers, ability to taper glucocorticoids, and cross‐sectional imaging when indicated clinically. Results The mean followup time of this cohort since diagnosis was 27 months (range 16–60 months). The patients were treated with TCZ for a mean period of 7.8 months (range 4–12 months). Before TCZ therapy, the patients experienced an average of 2.4 flares/year. All patients entered and maintained clinical remission during TCZ therapy. The mean daily prednisone dosages before and after TCZ initiation were 20.8 mg/day (range 7–34.3 mg/day) and 4.1 mg/day (range 0–10.7 mg/day), respectively (P = 0.0001). The mean erythrocyte sedimentation rate declined from 41.5 mm/hour (range 11–68 mm/hour) to 7 mm/hour (range 2.2–11.3 mm/hour; P = 0.0001). The adverse effects of TCZ included mild neutropenia (n = 4) and transaminitis (n = 4). One patient flared 2 months after TCZ discontinuation. An autopsy on 1 patient who died from a postoperative myocardial infarction following elective surgery revealed persistent vasculitis of large and medium‐sized arteries. Conclusion TCZ therapy led to clinical and serologic improvement in patients with refractory/relapsing GCA, TA, or PMR. The demonstration of persistent large‐vessel vasculitis at autopsy of 1 patient who had shown a substantial response requires close scrutiny in larger studies.