Upadacitinib as monotherapy in patients with active rheumatoid arthritis and inadequate response to methotrexate (SELECT-MONOTHERAPY): a randomised, placebo-controlled, double-blind phase 3 study.

Background: Upadacitinib, an oral Janus kinase (JAK)1-selective inhibitor, showed efficacy in combination with stable background conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) in patients with rheumatoid arthritis who had an inadequate response to DMARDs. We aimed to evaluate the safety and efficacy of upadacitinib monotherapy after switching from methotrexate versus continuing methotrexate in patients with inadequate response to methotrexate.

Methods: SELECT-MONOTHERAPY was conducted at 138 sites in 24 countries. The study enrolled adults (≥18 years) who fulfilled the 2010 American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria for rheumatoid arthritis. Patients with active rheumatoid arthritis despite stable methotrexate were randomly assigned 2:2:1:1 to switch to once-daily monotherapy of of upadacitinib or to continue methotrexate at their existing dose as blinded study drug; starting from week 14, patients assigned to continue methotrexate were switched to 15 mg or 30 mg once-daily upadacitinib per prespecified random assignment at baseline. The primary endpoints in this report are proportion of patients achieving 20% improvement in the ACR criteria (ACR20) at week 14, and proportion achieving low disease activity defined as 28-joint Disease Activity Score using C-reactive protein (DAS28[CRP]) of 3·2 or lower, both with non-responder imputation at week 14. Outcomes were assessed in patients who received at least one dose of study drug. This study is active but not recruiting and is registered with ClinicalTrials.gov, number NCT02706951.

Findings: Patients were screened between Feb 23, 2016, and May 19, 2017 and 648 were randomly assigned to treatment. 598 (92%) completed week 14. At week 14, an ACR20 response was achieved by 89 (41%) of 216 patients (95% CI 35-48) in the continued methotrexate group, 147 (68%) of 217 patients (62-74) receiving upadacitinib 15 mg, and 153 (71%) of 215 patients (65-77) receiving upadacitinib 30 mg (p<0·0001 for both doses vs continued methotrexate). DAS28(CRP) 3·2 or lower was met by 42 (19%) of 216 (95% CI 14-25) in the continued methotrexate group, 97 (45%) of 217 (38-51) receiving upadacitinib 15 mg, and 114 (53%) of 215 (46-60) receiving upadacitinib 30 mg (p<0·0001 for both doses vs continued methotrexate). Adverse events were reported in 102 patients (47%) on continued methotrexate, 103 (47%) on upadacitinib 15 mg, and 105 (49%) on upadacitinib 30 mg. Herpes zoster was reported by one (<1%) patient on continued methotrexate, three (1%) on upadacitinib 15 mg, and six (3%) on upadacitinib 30 mg. Three malignancies (one [<1%] on continued methotrexate, two [1%] on upadacitinib 15 mg), three adjudicated major adverse cardiovascular events (one [<1%] on upadacitinib 15 mg, two [<1%] on upadacitinib 30 mg), one adjudicated pulmonary embolism (<1%; upadacitinib 15 mg), and one death (<1%; upadacitinib 15 mg, haemorrhagic stroke [ruptured aneurysm]) were reported in the study.

Interpretation: Upadacitinib monotherapy showed statistically significant improvements in clinical and functional outcomes versus continuing methotrexate in this methotrexate inadequate-responder population. Safety observations were similar to those in previous upadacitinib rheumatoid arthritis studies.

Funding: AbbVie Inc, USA.