To evaluate efficacy, including inhibition of radiographic progression, and safety of upadacitinib, a JAK1-selective inhibitor, vs placebo and adalimumab in patients with rheumatoid arthritis and an inadequate response to methotrexate.
1629 patients with inadequate response to methotrexate were randomized (2:2:1) to once-daily upadacitinib 15mg, placebo, or adalimumab 40mg, on stable background methotrexate. Primary endpoints were ACR20 and DAS28CRP<2.6 versus placebo at Week12; inhibition of radiographic progression was evaluated at Week26. The study was designed and powered to test for non-inferiority and superiority of upadacitinib versus adalimumab clinically and functionally.
At Week12, both primary endpoints were met for upadacitinib versus placebo (p≤0.001). ACR20 was achieved by 71% versus 36%, and DAS28CRP<2.6 by 29% versus 6%. Upadacitinib was superior to adalimumab for ACR50, DAS28CRP≤3.2, ΔPain and ΔHAQ-DI. At Week26, more patients on upadacitinib vs placebo or adalimumab achieved low disease activity or remission (p≤0.001). Radiographic progression was less and observed in fewer patients receiving upadacitinib versus placebo (p≤0.001). Up to Week26, adverse events (AEs) including serious infections were comparable for upadacitinib and adalimumab. The proportions of patients with serious AEs and AEs leading to discontinuation were highest for adalimumab; the proportion with herpes zoster and CPK elevations was highest for upadacitinib. Three malignancies, five MACE, and four deaths were reported, none on upadacitinib. Six venous thromboembolic events were reported [placebo, one; upadacitinib, two; adalimumab, three].
Upadacitinib was superior to placebo and adalimumab for improving signs, symptoms and physical function in RA patients on background methotrexate, and significantly inhibited radiographic progression versus placebo, while the overall safety profile was generally similar to adalimumab, except for higher rates of herpes zoster and CPK elevations on upadacitinib.