Smolen JS, et al. - In patients with inadequate response to methotrexate, researchers tested the safety and effectiveness of upadacitinib monotherapy after switching from methotrexate vs continuing methotrexate. For this randomized, placebo-controlled, double-blind, phase 3 study, patients with active rheumatoid arthritis despite stable methotrexate were randomized in a 2:2:1:1 ratio to switch to once-daily upadacitinib monotherapy or to continue methotrexate as blinded study drug at their existing dose; patients assigned to continue methotrexate were switched to 15-mg or 30-mg once-daily upadacitinib per prespecified random assignment at baseline starting at week 14. In this methotrexate inadequate-responder population, upadacitinib monotherapy exhibited statistically significant improvements in clinical and functional outcomes vs continuing methotrexate. Safety observations were similar to previous studies of upadacitinib rheumatoid arthritis.