JAK inhibitors in areas outside of inflammatory arthritis: focus on connective tissue diseases.

Abstract

Janus kinase (JAK) inhibitors have emerged as a transformative therapeutic class across autoimmune diseases by targeting multiple cytokine networks implicated in inflammation and fibrosis. Beyond inflammatory arthritis, increasing evidence supports their potential efficacy in connective tissue diseases such as idiopathic inflammatory myopathies, systemic sclerosis, primary Sjögren's disease, and systemic lupus erythematosus. Through modulation of type I/II interferon and interleukin signaling, JAK inhibition exerts broad anti-inflammatory and antifibrotic effects, translating into clinical improvements in cutaneous, articular, and pulmonary domains. Early clinical trials and real-world data confirm meaningful responses in refractory disease, though randomized evidence remains limited. Overall, JAK inhibitors represent a promising, mechanistically grounded option for systemic autoimmune diseases, with ongoing studies expected to refine selectivity, indications, and long-term safety profiles.