Comparison of treatment of severe rheumatoid arthritis patients with biological agents and JAK-STAT inhibitors. An extension study.

Introduction: This study compared treatment with biologic agents and Janus kinase inhibitors (JAKi) in combination with methotrexate (MTX) for rheumatoid arthritis (RA) in a real-world setting at a large center in Poland. There is a persistent shortage of such studies, and illustrating the switching of medications in search of a suitable way of treatment for a given patient is a crucial step towards future personalized therapy.

Aim of the study: This study is an extension of the initial work published in 2022 in Reumatologia, with the addition of an analysis of patients treated with upadacitinib. The study compared the effectiveness and side effects after treatment of biological disease modifying antirheumatic drugs (bDMARDs) and targeted synthetic DMARDs (tsDMARDs) in combination with MTX.

Materials and methods: A total of 130 patients with active severe RA (Disease Activity Score for 28 joints based on the erythrocyte sedimentation rate [DAS28(ESR)] value > 5.1) were treated at the Rheumatologic Outpatients Department of the Central Clinical Hospital of the Ministry of the Interior and Administration, Warsaw, Poland between January 2010 and September 2021. All patients were treated with MTX 25 mg per week. They were divided into two groups: group I (80 patients) treated with biologic agents, and group II (50 patients) treated with JAKi. Assessment of DAS28(ESR) and Simplified Disease Activity Index (SDAI) and analysis of Boolean criteria for remission were performed. Remission or low disease activity, switching between drugs and adverse events were assessed and compared between studied groups.

Results: Patients treated with tsDMARDs had previously used a higher number of conventional synthetic DMARDs (csDMARDs) and bDMARDs compared to those treated with bDMARDs. However, they achieved lower SDAI and assessment of disease activity using Visual Analogue Scale (VAS) values, and a higher proportion of patients achieved Boolean criteria for remission after treatment.

Conclusions: The results of treatment with JAKi were successful, but the potential side effects indicate that this treatment may not be equally suitable for all RA patients.