FRI0412 SPINAL AND SACROILIAC JOINTS INFLAMMATION IN PATIENTS WITH RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS TREATED WITH NETAKIMAB – 16-WEEKS RESULTS OF MULTICENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED PHASE III ASTERA STUDY

Background Efficacy and safety of netakimab (NTK), a humanized anti-interleukin 17A antibody, have been previously established in two phase 2 clinical trials in patients with radiographic axial spondyloarthritis (r-axSpA)1 and psoriasis2. ASTERA is a randomized, double-blind, placebo (PBO)-controlled phase III trial, aimed to demonstrate efficacy and safety of NTK in subjects with r-axSpA (NCT03447704). Objectives To evaluate the effect of NTK on inflammation in spine and sacroiliac joints (SIJ) at Week (Wk) 16 in ongoing ASTERA study in patients with active r-axSpA. Methods 228 eligible adults with active r-axSpA were randomized into 2 study arms (1:1) to receive 120 mg of NTK or PBO, administered as SC injections at Wk 0, 1, 2 and then q2wk through Wk 16. After Wk 16 all patients will start to receive NTK up to week 52. Inflammation in spine and SIJ was assessed with magnetic resonance imaging (MRI) at baseline and Wk 16. The following scoring methods were used: the Berlin spine score (derived from Ankylosing Spondylitis Spine MRI Activity (ASspi-MRI-a) Score for spine assessment and the SPARCC score for SIJ assessment. All images were evaluated by central reader, blinded to treatment. Results Both arms were comparable in the Berlin spine score (4.18 ± 4.58 in NTK arm vs. 4.19 ± 4.32 in PBO arm) and the SPARCC score (5.67 ± 8.33 in NTK arm vs. 5.23 ± 7.86 in PBO arm) at baseline (p≥0.05). Data analysis at Wk16 revealed that NTK arm achieved significant decline in bone marrow edema in direct comparison with PBO arm: by Wk 16 the mean change from baseline in the Berlin spine score was -2.16 ± 2.87 in NTK arm vs. -0.30 ± 1.55 in PBO arm (p Conclusion: the treatment with NTK at a dose 120 mg leads to improvement in spine and SIJ inflammation in patients with active r-axSpA by Wk16, as compared with PBO. References [1] Mazurov V, Erdes S, Kunder E, et al.: OP0028|Efficacy and safety of BCD-085, a novel il-17 inhibitor, in ankylosing spondylitis. Results of phase 2 clinical study. Ann Rheum Dis2018; 77: A64. [2] Samtsov A, Khairutdinov V, Bakulev A, et al.: Efficacy and Safety of BCD-085, a Novel Interleukin-17 Inhibitor. Results of Phase II Clinical Trial in Patients with Moderate-to-Severe Plaque Psoriasis. Vestn Dermatol Venerol 2017; 0(5):52-63. Disclosure of Interests Alexander Smirnov: None declared, Inna Gaydukova Grant/research support from: JSC BIOCAD, Speakers bureau: paiment from Pfizer, Novartis, Abbvie, Biocad, Selgene, MSD, Sanofy does not exceed 10 000 euros, V Mazurov Grant/research support from: JSC BIOCAD, Shandor Erdes Grant/research support from: JSC BIOCAD, Speakers bureau: JSC BIOCAD, Tatiana Dubinina: None declared, Olga Nesmeyanova Grant/research support from: JSC BIOCAD, Elena Ilivanova Grant/research support from: JSC BIOCAD, Alena Kundzer: None declared, Nikolaj Soroka: None declared, Anna Eremeeva Grant/research support from: JSC BIOCAD, Ekaterina Chernyaeva Employee of: JSC BIOCAD, Roman Ivanov Employee of: JSC BIOCAD