Systematic Literature Review of Real-World Evidence on Baricitinib for the Treatment of Rheumatoid Arthritis

INTRODUCTION: Baricitinib, an orally available small-molecule inhibitor of Janus kinase (JAK)1 and JAK2, is indicated to treat active moderate-to-severe rheumatoid arthritis (RA). OBJECTIVE: This systematic review described the real-world clinical characteristics of baricitinib-treated patients with RA, prescription patterns, effectiveness, drug persistence, patient-reported outcomes (PROs; physical function, pain, health-related quality of life [HRQoL]), patient global assessment (PGA), and safety of baricitinib. METHODS: A PRISMA systematic review of real-world studies was conducted to identify relevant literature published between January 2016 and September 2022 using MEDLINE®, EMBASE®, and evidence-based medicine review databases. Websites or online repositories of the American College of Rheumatology and the European Alliance of Associations for Rheumatology were searched manually to include relevant abstracts from conferences held between January 2016 and November 2022. RESULTS: A total of 11,472 records were identified by searching online databases. Seventy studies were included in the study, of which 40 were abstracts. Most patients were older (51–71 years), female, and with mean RA duration of 4–19 years. Baricitinib was mostly used after the failure of one or more bDMARDs, and 4 mg dosing was prevalent in patients with RA (range 22–100%). Clinical effectiveness of baricitinib was reported in real-world settings regardless of prior biologic/targeted synthetic disease-modifying antirheumatic drug (DMARD) use and concomitant conventional synthetic DMARD use. Achievement of Clinical Disease Activity Index (CDAI) remission was reported in 8.7–60% of patients at week 12 and CDAI low disease activity (LDA) in 20.2–81.6% at week 24. The proportion of patients attaining Simple Disease Activity Index (SDAI) remission was reported in 12% at week 4 to 45.4% at 24 weeks. Drug persistence was high, similar, or equal to anti-tumor necrosis factor drugs. No new safety signals were identified. CONCLUSION: Baricitinib demonstrated effectiveness in the real-world setting with a consistent safety profile observed in clinical studies. Better persistence rates for baricitinib compared to bDMARDs with improvement in PROs were reported, although baricitinib-treated patients had RA with poor prognostic characteristics.