AB0365 CLINICAL, LABORATORY AND IMAGING OUTCOMES IN TOCILIZUMAB-TREATED PATIENTS WITH LARGE VESSEL-GIANT CELL ARTERITIS ACCORDING TO EARLY ONSET THERAPY
Authors: D. Prieto-Peña, I. Martínez-Rodríguez, B. Atienza-Mateo, O. Cuenca-Vera, F. J. Gomez de la Fuente, A. Sanchez-Salmón, M. A. González-Gay, R. Blanco
Journal: Annals of the Rheumatic Diseases (2021)

Background: Tocilizumab (TCZ) has shown efficacy in large vessel vasculitis (LVV)-Giant Cell Arteritis (LVV-GCA) (1-2 ). 18 F-fluodeoxyglucose positron emission tomography ( 18 F-FDG PET/CT) is useful to assess LVV disease activity (3-5 ). It is unknown if early treatment with TCZ may have an influence on clinical, laboratory and imaging outcomes. Objectives: To assess clinical, laboratory and PET/CT activity improvement in LVV-GCA patients treated with TCZ according to the time from disease diagnosis to TCZ onset. Methods: Comparative single-center study of 30 LVV-GCA patients treated with TCZ who were divided into 2 groups depending on the time of onset of TCZ: a ) early onset (≤ 6 months; n=15) and b ) late onset (&gt; 6 months; n=15). All patients had a baseline and a follow-up PET/CT scan. Complete clinical improvement and normalization of laboratory markers (CRP ≤0.5mg/dL and/or ESR ≤ 20 mm/1 st hour) was assessed. For imaging evaluation, normalization of total visual score (TVS) was considered when TVS = 0 and normalization of semiquantitative activity if the target to background ratio (TBR) at the thoracic aorta was &lt;1.34. Results: 30 patients were included (24 women/6 men); mean age 65.7± 9.8 years. Patients in the TCZ early-onset group were receiving higher doses of prednisone (10.0[5.9-15.0] vs 5.0 [5.0-7.5] mg/day; p&lt; 0.01) and had higher TVS scores (7.0 [4.0-9.0] vs 3.0 [2.0-5.0]; p&lt; 0.01) at baseline (Table 1). Following TCZ initiation, after a mean of 10.8±3.7 months, most patients achieved complete clinical improvement and normalization of ESR and CRP in both groups. Uncoupling with imaging outcomes was observed in both groups. Although non-significant statistical differences were observed, complete TBR normalization (TBR &lt;1.34) and complete TVS normalization (TVS=0) tended to be more frequent in the group of patients who received early-onset TCZ therapy (Figure 1). Table 1. Early-onset TCZ therapy (n= 15) Late-onset TCZ therapy (n=15) p General features Age (years), mean ± SD 65.8 ± 9.9 65.5 ± 10.1 0.94 Sex (female), n (%) 11 (73.3) 13 (86.7) 0.65 GCA evolution before TCZ onset, median [IQR] 2.0 [1.0-5.0] 18.0 [9.0-34.0] &lt; 0.01 Laboratory ESR (mm/1st hour), mean ± SD 34.7 ± 26.3 30.8 ± 28.7 0.70 CRP (mg/dL), median [IQR] 1.1 [0.6-2.3] 0.8 [1.8 -2.5] 0.28 Prednisone dose (mg/day), mean ± SD 10.0 [5.9-15.0] 5.0 [5.0-7.5] 0.01 TCZ therapy Intravenous, n (%) 10 (66.7) 11(73.3) 0.99 Combined with MTX, n(%) 6 (40) 8 (53.3) 0.46 PET /CT activity TBR at thoracic aorta 1.86 ± 0.69 1.54 ± 0.18 0.09 TVS 7.0 [4.0-9.0] 3.0 [2.0-5.0] &lt; 0.01 Complete clinical improvement, n (% ) 13 (86.7) 12 (80) 0.99 Normalization of ESR and CRP, n (% ) 15 (100) 15 (100) 0.99 PET/CT improvement Complete TBR normalization 6 (40) 3 (20) 0.23 Complete TVS normalization 2 (13.3) 1 (6.7) 0.54 CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; TBR: target-to-background ratio. * Normalization of TBR was considered when TBR &lt; 1.34. ** Normalization of TVS was considered when TVS=0. Conclusion: TCZ was effective in patients with LVV-GCA regardless the time from disease diagnosis to TCZ onset. However, complete normalization of vascular activity in PET/CT scans tended to occur more likely in patients who receive early-onset TCZ therapy within the first 6 months of the disease. References: [1]Calderón-Goercke M et al. Semin Arthritis Rheum. 2019; 49:126-135. PMID: 30655091 [2]Prieto Peña D et al. Clin Exp Rheumatol. 2020. PMID: 33253103 [3]González-Gay MA et al. Expert Rev Clin Immunol. 2018; 14:593-605. PMID: 29877748 [4]Martínez-Rodríguez et al. Semin Arthritis Rheum.2018; 47(4): 530-537. PMID: 28967430 [5]Prieto-Peña D et al. Semin Arthritis Rheum. 2019; 48:720-727. PMID: 28967430 Disclosure of Interests: Diana Prieto-Peña Grant/research support from: UCB Pharma, Roche, Sanofi, Pfizer, AbbVie and Lilly, Isabel Martínez-Rodríguez: None declared, Belén Atienza-Mateo: None declared, Oriana Cuenca-Vera: None declared, Francisco Javier Gomez de la Fuente: None declared, Aida Sanchez-Salmón: None declared, Miguel A González-Gay Grant/research support from: Abbvie, MSD, Jansen and Roche and had consultation fees/participation in company sponsored speaker´s bureau from Abbvie, Pfizer, Roche, Sanofi, Lilly, Celgene and MSD, Ricardo Blanco Grant/research support from: Abbvie, MSD and Roche, and had consultation fees/participation in company sponsored speaker´s bureau from Abbvie, Lilly, Pfizer, Roche, Bristol-Myers, Janssen, UCB Pharma and MSD