Efficacy and safety of filgotinib in patients with active radiographic and nonradiographic axial spondyloarthritis: results from OLINGUITO, a phase 3 trial consisting of 2 randomised, placebo-controlled, double-blind, parallel-group studies

OBJECTIVES: This study aimed to investigate the efficacy and safety of filgotinib, a JAK1 preferential inhibitor, in patients with axial spondyloarthritis (axSpA). METHODS: The phase 3 OLINGUITO trial comprises 2 international, randomised, double-blind, placebo (PBO)-controlled studies. Patients with an established diagnosis of radiographic (r) or nonradiographic (nr) axSpA and an inadequate response/intolerance to ≥2 nonsteroidal anti-inflammatory drugs were randomised 1:1 to filgotinib 200 mg or PBO once daily through week (W) 16 (double-blind period; stratified by high-sensitivity C-reactive protein [hs-CRP] level and prior biologic disease-modifying antirheumatic drug [bDMARD] use). After W16, patients received open-label filgotinib 200 mg through W52; patients ≥65 years and/or with prespecified risk factors received response-based dosing (100 or 200 mg). The primary (Assessment of SpondyloArthritis international Society ≥40% response [ASAS40 response]) and secondary efficacy endpoints were assessed at W16. Efficacy and safety were assessed through W52. RESULTS: At W16, the primary endpoint was met in both studies (ASAS40 response rates: r = axSpA [n = 258], 39.5% filgotinib vs 20.9% PBO [P = .001]; nr-axSpA [n = 237], 34.5% vs 17.8% [P = .003], respectively). ASAS40 improvements, irrespective of hs-CRP level/prior bDMARD use, were observed as early as W1. For secondary endpoints, significant improvements were seen in Axial Spondyloarthritis Disease Activity Score and Spondyloarthritis Research Consortium of Canada magnetic resonance imaging sacroiliac joint inflammation in both studies, and in Bath Ankylosing Spondylitis Functional Index and Ankylosing Spondylitis Quality of Life Questionnaire in patients with r-axSpA. Improvements with filgotinib were maintained/increased further through W52. Overall, 2 cases of myocardial infarction (PBO: n = 1; PBO-filgotinib: n = 1), 3 of herpes zoster (PBO-filgotinib), and 4 of malignancies (excluding nonmelanoma skin cancer; filgotinib: n = 3; PBO-filgotinib: n = 1) occurred. CONCLUSIONS: Across the whole spectrum of axSpA, filgotinib provided rapid and significant patient-relevant improvements in axSpA signs and symptoms and was well tolerated.