Pos1424 Tocilizumab in Extracranial Large-Vessel Giant Cell Arteritis and Takayasu Arteritis: Comparative Multicenter Study

Background: Giant Cell Arteritis (GCA) and Takayasu Arteritis (TAK) are two systemic granulomatous vasculitis included in the group of large vessel vasculitis (LVV) Extracranial phenotype is characterized by large vessels (LV-GCA) involvement, mainly aorta or its main branches. Characteristically isolated extracranial LV-GCA phenotype is more like TAK disease. Tocilizumab (TCZ) seems to be an effective therapy for both diseases 1,2. Nevertheless, no comparative studies on the effectiveness and safety of TCZ in GCA and TAK have been performed. Objectives: To compare the effectiveness and safety of TCZ in LV-GCA and TAK. Methods: A comparative observational national, open-label and multicenter study in patients diagnosed with LV-GCA (n=70) and TAK (n=57) patients who had received TCZ therapy. The diagnosis of GCA was made according to the 1990 criteria of the American College of Rheumatology (ACR). Patients with TAK were diagnosed according to the ACR 1990 criteria and/or Ishikawa criteria modified. Most patients were followed for at least 1 year since the TCZ onset. Follow-up visits were arranged at 1, 3, 6 and 12 months after TCZ initiation and outcome variables included: a) clinical remission and laboratory markers improvement; b) imaging improvement; c) GC-sparing effect; and d) safety analysis. Results: At TCZ initiation, TAK patients were younger, mainly female gender, with a longer disease duration, prior exposure to more biologics, and were on higher prednisone doses (Table 1). Although an initial slower clinical remission was observed in TAK patients, similar rates were observed at 12 months. Remission was observed in 35 (75.5%) and 30 (76.9%) LV-GCA and TAK, respectively, while complete imaging remission was achieved in 18.9% and 21.1% (Figure 1A). Similarly, CRP significantly decreased, during follow-up (Figures 1B). In this line, no differences were found in ESR and CRP between both groups in every visit and at the end of follow-up. Prednisone dose in every visit was found to be different between both diseases (Figure 1C). In this regard, TAK patients disclosed higher doses of GC in every visit and at the end of follow-up. In the mixed-models analysis, prednisone dose during follow-up was significantly different between both conditions (pConclusion: In a real-world setting TCZ showed comparable effectiveness in achieving remission and GC-sparing effects in LV-GCA and TAK. A discordance between clinical and imaging activity improvement was observed in both groups. REFERENCES: 1 Loricera J, Blanco R, Hernández JL, Castañeda S, Mera A, Pérez-Pampín E, et al. Tocilizumab in giant cell arteritis: Multicenter open-label study of 22 patients. Semin Arthritis Rheum. 2015;44(6). 2 Prieto-Peña D, Bernabeu P, Vela P, Narváez J, Fernández-López JC, Freire-González M, et al. Tocilizumab in refractory Caucasian Takayasu's arteritis: a multicenter study of 54 patients and literature review. Ther Adv Musculoskelet Dis. 2021;13. Acknowledgements: NIL. Disclosure of Interests: Carmen Lasa-Teja: None declared, Javier Loricera Roche, Novartis, UCB Pharma, MSD, Janssen, Galápagos, Celgene, Astra Zeneca and Grünenthal., Janssen, Abbvie, Roche, Novartis, MSD, UCB Pharma, Celgene, Lilly, Pfizer, Galápagos., Diana Prieto-Peña UCB Pharma, Roche, Sanofi, Pfizer, Janssen, Amgen, AbbVie, Novartis and Lilly., Fernando López-Gutiérrez: None declared, Pilar Bernabéu: None declared, Mercedes Freire González: None declared, Beatriz González-Alvarez: None declared, Roser Solans-Laqué: None declared, Mauricio Minguez Abbvie, Janssen, GSK, Faes Farma and Novartis., Iván Ferraz-Amaro: None declared, Santos Castañeda BMS, Eli-Lilly, MSD, Roche, and UCB, MSD and Pfizer, Ricardo Blanco AbbVie, Pfizer, Roche, Bristol-Myers, Lilly, Galapagos, Novartis, Janssen, GSK, and MSD., AbbVie, MSD, and Roche.