POS0818 TREATMENT OF POLYMYALGIA RHEUMATICA WITH TOCILIZUMAB: RESULTS OF AN OBSERVATIONAL RETROSPECTIVE MULTICENTER STUDY
Authors: M. Assaraf, B. Chevet, P. Philippe, J. Avouac, M. Delacour, E. Houvenagel, T. Pascart, J. Henry, C. Roux, D. Wendling, J. Paccou, B. Cortet, V. Devauchelle-Pensec, R. M. Flipo
Journal: Annals of the Rheumatic Diseases (2021)

Background: In 2017, TOCILIZUMAB (TCZ) obtained marketing authorization for treatment of giant cell arteritis (GCA); however, this doesn’t extend to polymyalgia rheumatica (PMR) therapy. Based on efficacy data for TCZ in GCA, TCZ is sometimes used as a glucocorticoid (GC) sparing agent when PMR is GC dependent or when a rapid steroid withdraw is needed. Currently, there are no available recommendations on the use of this therapeutic class in for this particular indication. Objectives: Here, we present the results of an observational French multicentric study of patients with PMR treated with TCZ. Methods: Thirteen medical centers were included in this study. The data was collected retrospectively between 2015 and 2020. The minimum duration of treatment was 3 months. Patients were included when receiving TCZ for isolated PMR or associated with a non-active GCA (asymptomatic, no vascular fixation on PET scanner). Results: Overall, 34 patients were included (24 women; mean age 70.1 years (+/-10.3)). At TCZ introduction, patients had been treated with GC for a mean duration of 27,9 months (+/-25.9) and the mean GC dose was 16,8mg/d (+/-10). Fifteen patients (44%) had one or more complications from GC therapy. Another immunosuppressant was added before TCZ treatment for 25 (74%); mostly METHOTREXATE (24/25). TCZ was initiated intravenously at 8mg/kg every 4 weeks for 27 patients (79%) and subcutaneously at 162mg/week for 7 patients (21%). The reasons for TCZ introduction included GC dependence (n=30, 88%), and necessity of quick GC sparing (n=4 patients,12%). Of all patients, 76% (26 patients) had stopped GC treatment definitively, with a mean time of 9,4 (0-32) months. The mean TCZ treatment period was 19,2 months (3-66). Fifteen patients (44%) permanently stopped TCZ at the end of the observation period (8 prolonged remissions;1 myocardial infarction; 1 cutaneous lymphoma; 1 primary failure, 3 lost to follow up). Eighteen patients (60%) benefited from an attempted tapering of TCZ (infusion spacing or dose reduction), 6 attempts (1/3) led to a relapse. 1/2 patients had side effects mostly benign (cytopenia n=6, infections n=5). Conclusion: This is the largest cohort presenting results of the use of TCZ in PMR. Despite the small number of participants, our study suggests TCZ is effective as a GC sparing agent in PMR. As there are no official recommendations of use, indications for TCZ use within this population are no defined. Randomized Controlled Trial would be beneficial to validate these first results. References: [1]Toussirot, « Biothérapies, pseudo- polyarthrite rhizomélique et artérite à cellules géantes État des lieux en 2018 ». [2]Devauchelle-Pensec et al., « Efficacy of First-Line Tocilizumab Therapy in Early Polymyalgia Rheumatica ». [3]Genovese et al., « Longterm Safety and Efficacy of Tocilizumab in Patients with Rheumatoid Arthritis ». [4]Stone et al., « Trial of Tocilizumab in Giant-Cell Arteritis ». Disclosure of Interests: None declared