Janus Kinase Inhibitors in the Treatment of Rheumatoid Arthritis - A Literature Review

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by persistent joint inflammation, leading to their destruction and deformities. The disease may also manifest with extraarticular symptoms. The pathogenesis of RA is multifactorial, involving genetic, environmental, and immunological factors. Treatment includes disease-modifying antirheumatic drugs, glucocorticosteroids, nonsteroidal anti-inflammatory drugs, biologic TNF-α inhibitors, and janus kinase (JAK) inhibitors. The objective of this study is to present the characteristics of JAK inhibitors, their mechanisms of action, efficacy, and safety. A literature review was conducted using PubMed, Cochrane, Medline, and Google Scholar databases. Data on clinical efficacy, safety profile, and tolerability of tofacitinib, baricitinib, upadacitinib, and filgotinib were collected and analysed. JAK inhibitors block the JAK-STAT pathway, inhibiting pro-inflammatory cytokine signalling. Treatment with tofacitinib, baricitinib, upadacitinib, and filgotinib led to rapid symptom improvement, reduced joint damage, and enhanced quality of life. JAK inhibitors have shown efficacy in patients with methotrexateresistant RA. Adverse effects include infections, gastrointestinal disturbances, and hypercholesterolemia. These drugs can be used as monotherapy or in combination with standard treatment. JAK inhibitors provide an effective and safe alternative for patients with moderate to severe RA who have an inadequate response to other therapies. Treatment with these drugs results in rapid clinical improvement, limits progression of joint damage, and improves patients’ quality of life, representing a modern treat-to-target therapeutic strategy.