Comparative Effectiveness and Safety of Peficitinib and Abatacept for Rheumatoid Arthritis: A Multicenter, Inverse Probability Weighting Analysis.

Objectives: To examine the real-world effectiveness and safety of peficitinib (PEF) and abatacept (ABT) in patients with rheumatoid arthritis (RA).

Methods: In this multicenter, retrospective cohort study, we examined patients who were administered PEF or ABT between July 2019 and July 2022. The primary endpoint was the one-year retention rate of PEF or ABT. The primary analyses were performed using treatment persistence, disease activity measurements, and safety parameters. The inverse probability of treatment weighting (IPTW) was used to adjust for confounding variables.

Results: A total of 219 patients were enrolled, with 64 receiving PEF and 155 receiving ABT. The one-year retention rates were 42.8% in the PEF group and 61.0% in the ABT group after IPTW (p = 0.0083). Two years following the initiation of treatment, the mean CDAI and SDAI showed comparable improvement in both groups after IPTW. Treatment discontinuation occurred primarily because of an inadequate therapeutic response (PEF: 41.3%, ABT: 28.1%) and adverse reactions (PEF: 11.1%, ABT: 3.8%).

Conclusions: PEF treatment resulted in lower retention rates compared with ABT, whereas both medications demonstrated effectiveness in controlling disease activity for patients who were able to continue treatment. Our findings contribute to informed decision-making in RA treatment in actual clinical practice.