Safety and effectiveness of baricitinib for rheumatoid arthritis in Japanese clinical practice: 24-week results of all-case post-marketing surveillance

Abstract

Objectives: To assess the safety and effectiveness of baricitinib treatment for rheumatoid arthritis (RA) in real-world clinical practice.

Methods: This ongoing all-case post-marketing surveillance study (starting September 2017) includes all patients with RA treated with baricitinib in Japan. Safety and effectiveness (disease activity) were assessed for 24 weeks.

Results: Safety analyses to February 2021 included 4731 patients (initial baricitinib dose: 4 mg/day, n = 3058; 2 mg/day, n = 1661; other, n = 12); 1059 (22.38%) were ≥75 years and 3362 (71.06%) previously received biologic therapy. The overall observational period was 1863.14 patient-years; 1174 (24.82%) patients discontinued baricitinib before Week 24, mostly for lack of effectiveness (n = 478; 10.10%). Adverse events occurred in 1271 (26.87%) patients [serious: 203 (4.29%); death: 18 (0.38%)]. The incidence of herpes zoster, hepatic function disorder, and serious infection was 3.09%, 2.77%, and 1.90%, respectively. Malignancy occurred in 17 patients (0.36%) and major adverse cardiovascular events in seven patients (0.15%). Among patients with effectiveness data, at least 26.57% (Boolean) achieved remission at Week 24.

Conclusions: This large nationwide surveillance study evaluated the safety and effectiveness of 24 weeks of baricitinib for RA in real-world clinical practice. Continued surveillance of long-term safety is ongoing.

Keywords: Janus kinase inhibitors; Post-marketing surveillance; Rheumatoid arthritis; baricitinib; safety.