Upadacitinib in patients from China, Brazil, and South Korea with rheumatoid arthritis and an inadequate response to conventional therapy

AIM: This study assessed the efficacy and safety of upadacitinib (UPA), in combination with conventional synthetic disease‐modifying antirheumatic drugs (csDMARDs), in Chinese, Brazilian, and South Korean patients with active rheumatoid arthritis (RA) and an inadequate response (IR) to csDMARDs. METHODS: Patients on stable csDMARDs were randomized (1:1) to once‐daily UPA 15 mg or matching placebo (PBO) for a 12‐week, double‐blind period. The primary endpoint was the proportion of patients achieving ≥20% improvement in American College of Rheumatology criteria (ACR20) at week 12. RESULTS: In total, 338 patients were randomized and treated, of whom 310 (91.7%) completed the double‐blind phase. The study met the primary endpoint of ACR20 at week 12 for UPA 15 mg vs PBO (71.6% vs 31.4%, P < .001), with a treatment difference observed as early as week 1. All ranked and other key secondary endpoints, including more stringent responses such as ACR50, ACR70 (≥50%/70% improvement in ACR criteria), and Disease Activity Score in 28 joints using C‐reactive protein <2.6, were met for UPA 15 mg vs PBO. The incidence of serious infections (2.4% vs 0.6%) and herpes zoster (HZ: 1.8% vs 0.6%) was higher with UPA 15 mg vs PBO. There was one case of venous thromboembolism reported in the UPA group. CONCLUSION: UPA 15 mg in combination with csDMARDs demonstrated clinical and functional improvement and an acceptable safety profile over 12 weeks among patients from China, Brazil, and South Korea who had moderately to severely active RA and an IR to csDMARDs.