FRI0215 RESPONSE TO TOCILIZUMAB IN LARGE VESSEL VASCULITIS ACCORDING TO THE EXTENT OF BASELINE 18F-FDG VASCULAR UPTAKE
Authors: D. Prieto-Peña, M. Calderón-Goercke, I. Martínez-Rodríguez, J. I. Banzo, P. Vicente-Gómez, J. García-Fernández, M. A. González-Gay, R. Blanco
Journal: Annals of the Rheumatic Diseases (2020)

Background: 18 F-FDG PET/CT is useful to establish the presence and extent of large vessel vasculitis (LVV) (1-2). Early therapy is needed to prevent severe complications.Tocilizumab (TCZ) has shown efficacy in LVV (3-5). However, it is unknown if the extent of FDG vascular uptake may influence on clinical response to TCZ Objectives: To assess the correlation of the extent of baseline FDG vascular uptake in PET/CT scan with clinical response to TCZ in patients with LVV. Methods: Single center study of patients with LVV treated with TCZ who were divided into 2 groups depending on the extent of vascular uptake in baseline PET/CT scan: a ) 1-2 affected areas b ) ≥affected 3 areas. Vascular uptake was qualitatively assessed by two experienced nuclear medicine physicians in five areas (supraaortic trunks, thoracic aorta, abdominal aorta, iliac and femorotibial arteries). We assessed clinical improvement (no improvement/partial/complete), normalization of CRP (≤0.5mg/dL) and/or ESR (≤ 20 mm/1 st h) and reduction of prednisone dose (mg/day). Results: 30 patients (24 w/6 m); mean age 65.3±10.6 yrs. In baseline PET/CT, vascular uptake was observed in 1 or 2 areas (n=13) and in ≥3 areas (n=17). There was a trend to higher ESR/CRP and shorter evolution of clinical symptoms before TCZ onset in patients with ≥3 affected areas (TABLE 1). Clinical/serological evolution and reduction of prednisone dose is shown in TABLE 2. No statistical differences were found. However, patients with ≥ 3 affected areas tended to experience a slower clinical response. TABLE 1. 1-2 vascular affected areas (n=13) ≥3 vascular affected areas (n=17) P Demographic data Age, mean ± SD 66.0 ± 10.8 64.8 ± 10.7 0.77 Sex (women), n (% ) 11 (84.6) 13 (76.5) 0.67 Evolution time before TCZ (months), median [IQR] 26.0 [3.5-34.0] 5.0 [1.5-10.0] 0.02 Laboratory markers ESR (mm/1st h), mean ± SD 30.0 ± 27.3 34.8 ± 27.6 0.64 CRP (mg/dL), mean ± SD 1.3 ± 1.2 1.8 ± 1.7 0.28 Previous treatment Prednisone dose (mg/day), mean ± SD 9.4 ± 6.2 7.9 ± 6.9 0.53 TCZ therapy Intravenous, n (% ) 10 (76.9) 11 (64.7) 0.47 Combined with MTX, n (% ) 6 (46.2) 8 (47.1) 0.96 TABLE 2. 1-2 vascular affected areas (n=13) ≥ 3 vascular affected areas (n=17) P Complete clinical improvement, n/N (% ) 6 m 11/13 (84.6) 12/17 (70.6) 0.43 12 m 12/13 (92.3) 13/17 (76.5) 0.36 18 m 10/11 (90.9) 11/12 (91.7) 0.99 24 m 8/8 (100) 9/10 (90.0) 0.99 Normalization of ESR and/or CRP, n/N (% ) 6 m 13/13 (100) 16/17 (94.1) 0.99 12 m 13/13 (100) 16/17 (94.1) 0.99 18 m 11/11 (100) 11/12 (91.7) 0.99 24 m 8/8 (100) 10/10 (100) 0.99 Dose of Prednisone (mg/day), median [IQR] 6 m 5.0 [1.3-5.0] 5.0 [0.0-5.0] 0.98 12 m 2.5 [0.0-3.8] 0.0 [0.0-5.0] 0.97 18 m 0.0 [0.0-2.5] 0.0 [0.0-1.9] 0.72 24 m 0.0 [0.0- 2.2] 0.0 [0.0-2.5] 0.77 Conclusion: TCZ therapy was effective in patients with LVV regardless the extent of FDG vascular uptake in baseline PET/CT scan. However, a trend to a slower clinical response was observed in patients with ≥3 affected areas. References: [1]Martínez-Rodríguez et al. (18)F-FDG PET/CT in the follow-up of large-vessel vasculitis: A study of 37 consecutive patients. Semin Arthritis Rheum.2018 Feb;47(4):530-537. doi: 10.1016/j.semarthrit.2017.08.009. [2]Loricera et al. Non-infectious aortitis: a report of 32 cases from a single tertiary centre in a 4-year period and literature review. Clin Exp Rheumatol. 2015 Mar-Apr; 33(2 Suppl 89): S-19-31 [3]Calderón-Goercke M et al. Tocilizumab in giant cell arteritis. Observational, open-label multicenter study of 134 patients in clinical practice. Semin Arthritis Rheum. 2019 Aug; 49(1):126-135. doi: 10.1016/j.semarthrit.2019.01.003 [4]González-Gay MA et al. Current and emerging diagnosis tools and therapeutics for giant cell arteritis. Expert Rev Clin Immunol. 2018 Jul;14(7):593-605. doi: 10.1080/1744666X.2018.1485491. [5]Loricera et al. Tocilizumab in patients with Takayasu arteritis: a retrospective study and literature review. Clin Exp Rheumatol. 2016 May-Jun;34(3 Suppl 97): S44-53. Disclosure of Interests: D. Prieto-Peña: None declared, Monica Calderón-Goercke: None declared, Isabel Martínez-Rodríguez: None declared, Jose Ignacio Banzo: None declared, Patricia Vicente-Gómez: None declared, Javier García-Fernández: None declared, Miguel A González-Gay Grant/research support from: Pfizer, Abbvie, MSD, Speakers bureau: Pfizer, Abbvie, MSD, Ricardo Blanco Grant/research support from: AbbVie, MSD, Roche, Consultant of: Abbvie, Eli Lilly, Pfizer, Roche, Bristol-Myers, Janssen, UCB Pharma and MSD, Speakers bureau: Abbvie, Eli Lilly, Pfizer, Roche, Bristol-Myers, Janssen, UCB Pharma. MSD