Trial of Upadacitinib or Abatacept in Rheumatoid Arthritis.

Background: Upadacitinib is an oral selective Janus kinase inhibitor to treat rheumatoid arthritis. The efficacy and safety of upadacitinib as compared with abatacept, a T-cell costimulation modulator, in patients with rheumatoid arthritis refractory to biologic disease-modifying antirheumatic drugs (DMARDs) are unclear.

Methods: In this 24-week, phase 3, double-blind, controlled trial, we randomly assigned patients in a 1:1 ratio to receive oral upadacitinib (15 mg once daily) or intravenous abatacept, each in combination with stable synthetic DMARDs. The primary end point was the change from baseline in the composite Disease Activity Score for 28 joints based on the C-reactive protein level (DAS28-CRP; range, 0 to 9.4, with higher scores indicating more disease activity) at week 12, assessed for noninferiority. Key secondary end points at week 12 were the superiority of upadacitinib over abatacept in the change from baseline in the DAS28-CRP and the percentage of patients having clinical remission according to a DAS28-CRP of less than 2.6.

Results: A total of 303 patients received upadacitinib, and 309 patients received abatacept. From baseline DAS28-CRP values of 5.70 in the upadacitinib group and 5.88 in the abatacept group, the mean change at week 12 was -2.52 and -2.00, respectively (difference, -0.52 points; 95% confidence interval [CI], -0.69 to -0.35; P<0.001 for noninferiority; P<0.001 for superiority). The percentage of patients having remission was 30.0% with upadacitinib and 13.3% with abatacept (difference, 16.8 percentage points; 95% CI, 10.4 to 23.2; P<0.001 for superiority). During the treatment period, one death, one nonfatal stroke, and two venous thromboembolic events occurred in the upadacitinib group, and more patients in the upadacitinib group than in the abatacept group had elevated hepatic aminotransferase levels.

Conclusions: In patients with rheumatoid arthritis refractory to biologic DMARDs, upadacitinib was superior to abatacept in the change from baseline in the DAS28-CRP and the achievement of remission at week 12 but was associated with more serious adverse events. Longer and larger trials are required in order to determine the effect and safety of upadacitinib in patients with rheumatoid arthritis. (Funded by AbbVie; SELECT-CHOICE Clinicaltrials.gov number, NCT03086343.).