Upadacitinib in active ankylosing spondylitis: results of the 2-year, double-blind, placebo-controlled SELECT-AXIS 1 study and open-label extension

Introduction Long-term safety and efficacy of upadacitinib in patients with active ankylosing spondylitis (AS) has not been previously reported. Methods In SELECT-AXIS 1, patients receiving placebo were switched to upadacitinib 15 mg once daily at week 14 while patients initially randomised to upadacitinib continued their regimen through week 104. Efficacy was assessed using as-observed (AO) and non-responder imputation (NRI). Results Of 187 patients randomised, 144 patients (77%) completed week 104. Among patients receiving continuous upadacitinib, 85.9% (AO) and 65.6% (NRI) achieved Assessment of SpondyloArthritis international Society 40 response (ASAS40) at week 104. Similar magnitude of ASAS40 responses were observed among patients who switched from placebo to upadacitinib (88.7% and 63.8%, respectively). The mean change from baseline to week 104 in Spondyloarthritis Research Consortium of Canada MRI spine and sacroiliac joint inflammation scores were -7.3 and -5.3, respectively, in the continuous upadacitinib group and -7.9 and -4.9 in the placebo-to-upadacitinib switch group. The mean (95% CI) change from baseline to week 104 in the modified Stoke Ankylosing Spondylitis Spine Score was 0.7 (0.3, 1.1) in the total group. Adverse event rate was 242.7/100 patient-years. No serious infections, adjudicated major adverse cardiovascular events, lymphoma, non-melanoma skin cancer, or gastrointestinal perforations were observed. Conclusions Upadacitinib 15 mg once daily showed sustained and consistent efficacy over 2 years for ASAS40 and other clinically relevant endpoints. A low rate of radiographic progression was observed and no new safety findings were observed.