Upadacitinib Versus Placebo or Adalimumab in Patients With Rheumatoid Arthritis and an Inadequate Response to Methotrexate: Results of a Phase III, Double-Blind, Randomized Controlled Trial.

OBJECTIVE: To evaluate the efficacy, including capacity for inhibition of radiographic progression, and safety of upadacitinib, a JAK1-selective inhibitor, as compared to placebo or adalimumab in patients with rheumatoid arthritis (RA) who have experienced an inadequate response to methotrexate (MTX). METHODS: In total, 1,629 RA patients with an inadequate response to MTX were randomized (2:2:1) to receive upadacitinib (15 mg once daily), placebo, or adalimumab (40 mg every other week) while continuing to take a stable background dose of MTX. The primary end points were achievement of an American College of Rheumatology 20% (ACR20) improvement response and a Disease Activity Score in 28 joints using C-reactive protein level (DAS28-CRP) of <2.6 in the upadacitinib group compared to the placebo group at week 12; inhibition of radiographic progression was evaluated at week 26. The study was also designed and powered to test for the noninferiority and superiority of upadacitinib compared to adalimumab, as measured both clinically and functionally. RESULTS: At week 12, both primary end points were met in patients receiving upadacitinib compared to those receiving placebo (P ≤ 0.001). An ACR20 improvement response was achieved by 71% of patients in the upadacitinib group compared to 36% in the placebo group, and a DAS28-CRP score of