P210 Tocilizumab versus prednisolone only treatment for giant cell arteritis: an observational study

Abstract

Abstract Background/Aims Giant cell arteritis (GCA) is a medical emergency that requires prolonged high dose glucocorticoids (GC). Tocilizumab (TCZ) is currently approved for GCA in combination with GC tapering for those at high risk of glucocorticoid toxicity, who relapse or have refractory disease. The aim is to evaluate indications and characteristics of patients who were started on TCZ and to assess the rate of relapse and steroid tapering for patients on TCZ compared with an age matched prednisolone (PDN) only treated control group (CTRL). Methods Retrospective review of electronic patient health record data of patients who were diagnosed and treated for GCA in a single rheumatology centre from January 2017- July 2020. All patients were initially treated with high dose PDN (40-60 mg/day) with subsequent steroid tapering with or without TCZ (162 mg/week). Results We included 36 GCA patients who were treated with TCZ+PDN and 26 patients with PDN only. Mean age of patients started on TCZ was 69.3±6.8, 81% were female. There was no significant demographic difference to the CTRL group.The most common reason for starting TCZ (50%) was a GCA relapse requiring uptitration of PDN. 13 patients (36%) started TCZ as they had developed significant steroid side effects including steroid-induced diabetes, hypertension and osteoporosis related fragility fractures. Almost one fifth of patients (19.4%) who were started on TCZ had imaging evidence of large vessel involvement.The mean PDN dose of patients who started TCZ was 26.6±13.1 mg/day. Patients who started TCZ were able to approximately half the PDN dose every 3 months. The average daily PDN dose was 11.3±7.0 mg after 3 months, 6.0±4.3 mg after 6 months, and 3.3±4.7 mg after 12 months of starting TCZ. When compared with the CTRL group (4%), significantly more TCZ patients (41.7%) were able to reduce the PDN dose to a low dose (0-5 mg) after 6 months treatment (p = 0.001).During the course of treatment more CTRL patients (34.6%) relapsed than patients receiving TCZ (11.1% vs CTRL, p = 0.013). The majority of TCZ patients (88.9%) stayed in remission and 2 (5.6%) patients completed 12 months treatment and have ceased therapy. 4 (11.1%) patients stopped Tocilizumab due to side effects (diarrhoea, diverticulitis, scalp irritation) and 2 stopped due to concerns over long term risks. Conclusion Our real-world study shows that TCZ is predominantly initiated in those who relapse or develop GC related side effects. Patients who received TCZ were able to half their PDN dose every 3 months and had lower 6 and 12-month PDN requirements compared to those on PDN solely. The relapse rate was significantly higher in the PDN only treated group than in the TCZ group. TCZ is a good option as steroid sparing agent for the treatment of GCA. Disclosure H. Preston: None. O. Cronin: None. B. Kuske: None. N.D. McKay: None. B. Hauser: Honoraria; Dr Hauser has received speaker fees from Roche.