AB0534 EFFICACY OF TOCILIZUMAB IN LARGE-VESSEL GIANT CELL ARTERITIS: A SINGLE-CENTER REAL-LIFE EXPERIENCE
Authors: A. Tomelleri, C. Campochiaro, S. Sartorelli, E. Baldissera, L. Dagna
Journal: Annals of the Rheumatic Diseases (2020)

Background: In a significant proportion of giant cell arteritis (GCA) patients, large vessels (LV) are affected 1 . GiACTA trial showed tocilizumab (TCZ) to be effective for the treatment of GCA 2 but did not differentiate between patients with and without LV involvement and did not evaluate LV-imaging response. Objectives: To assess efficacy of TCZ in LV-GCA, evaluating both clinical symptoms and vascular inflammation on PET scan. Methods: Data from GCA patients followed-up at our Institution between January 2003 and December 2019 were retrospectively collected. Only TCZ-treated patients, with evidence of LV 18F-FDG-uptake at baseline (T0) and who repeated a PET scan after at least 6 months of treatment (T1) were included. All patients received subcutaneous TCZ 162 mg weekly. PET scans were read by 2 physicians blinded with regard to clinical data and to each other’s assessment; vascular inflammation was quantified using the PETVAS score 3 . Clinical symptoms, prednisone (PDN) dosage, and PETVAS score between T0 and T1 were compared. Flares and adverse events were recorded. Non parametric tests were used. Results: 61 TCZ-treated GCA patients were identified. Of these, 28 (45.9%) had evidence of vascular inflammation at T0, and 14 of them (10 female, mean age 66.2±7.4 years) repeated a PET scan during follow-up, after a median of 13 months (IQR, 9.5-17.5). 10 patients started TCZ upon GCA relapse, with a median delay from GCA diagnosis of 7.5 (3-15.8) months; 4 patients were newly diagnosed and started TCZ at diagnosis. At T0, 10 patients had systemic symptoms, 6 patients had cranial symptoms, and 7 had polymyalgia rheumatica (PMR). 12/14 patients were on concomitant steroids, with a median PDN daily dose of 15 (15-25) mg. Erythrocyte sedimentation rate and C-reactive protein levels were respectively 35 (21-39) mm/h and 7.8 (3.2-11) mg/L. Median PETVAS was 7 (3.3-11). At T1, 13/14 patients were asymptomatic; 1 patient had a PMR relapse. No GCA flare was recorded. Median PDN daily dose was 1.25 (0-2.5), p=0.002, and PDN suspension was achieved in 5 patients. Median PETVAS was 0 (0-0.8), p=0.003; only in 1 patient PETVAS increased between T0-T1 (from 2 to 5), in absence of clinical symptoms. This was the patient with the longest delay between diagnosis and TCZ start (124 months) and suspended TCZ for 3 months due to oral aphthosis. No patients had severe infections; 1 patient definitively suspended TCZ at T1 due to severe leukopenia. Conclusion: In LV-GCA patients, TCZ seems to be effective in obtaining clinical remission and in reducing vascular inflammation on PET scan. References: [1]Dejaco C, et al. Nature Reviews Rheumatology (2017) [2]Stone JH, et al. N Engl J Med (2017) [3]Grayson PC, et al. Arthritis Rheumatol (2018) Disclosure of Interests: Alessandro Tomelleri: None declared, Corrado Campochiaro Speakers bureau: Novartis, Pfizer, Roche, GSK, SOBI, Silvia Sartorelli: None declared, Elena Baldissera Speakers bureau: Novartis, Pfizer, Roche, Alpha Sigma, Sanofi, Lorenzo Dagna Grant/research support from: Abbvie, BMS, Celgene, Janssen, MSD, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, SG, SOBI, Consultant of: Abbvie, Amgen, Biogen, BMS, Celltrion, Novartis, Pfizer, Roche, SG, and SOBI