Safety and Efficacy of Upadacitinib in Patients With Active Ankylosing Spondylitis and an Inadequate Response to Nonsteroidal Antiinflammatory Drug Therapy: One-Year Results of a Double-Blind, Placebo-Controlled Study and Open-Label Extension.

Objective: To report the efficacy and safety of upadacitinib through 1 year in patients with ankylosing spondylitis (AS).

Methods: In the SELECT-AXIS 1 study, adults with active AS and an inadequate response to nonsteroidal antiinflammatory drugs were randomized to receive upadacitinib 15 mg once daily or placebo. At week 14, patients who had been randomized to receive placebo were switched to upadacitinib, and all patients continued in the open-label extension and received upadacitinib up to week 104; interim data up to week 64 are reported herein.

Results: Of 187 patients, 178 completed week 14 on study drug and entered the open-label extension. Similar proportions of patients in either group (continuous upadacitinib or placebo-to-upadacitinib) achieved Assessment of SpondyloArthritis international Society 40% response (ASAS40) or Ankylosing Spondylitis Disease Activity Score (ASDAS) showing low disease activity at week 64: ≥70% of patients achieved these end points based on nonresponder imputation (NRI) and ≥81% based on as-observed analyses. Furthermore, ≥34% (NRI) and ≥39% (as-observed analysis) achieved ASDAS showing inactive disease or ASAS showing partial remission at week 64. Mean changes from baseline (week 0) to week 64 in pain, function, and inflammation showed consistent improvement or sustained maintenance through the study. Among 182 patients receiving upadacitinib (237.6 patient-years), 618 adverse events (260.1 per 100 patient-years) were reported. No serious infections, major adverse cardiovascular events, venous thromboembolic events, gastrointestinal perforation, or deaths were reported.

Conclusion: Upadacitinib 15 mg once daily showed sustained and consistent efficacy over 1 year. Patients who switched from placebo to upadacitinib at week 14 showed similar efficacy versus those who received continuous upadacitinib.