Targeting Janus Kinase (JAK) for Fighting Diseases: The Research of JAK Inhibitor Drugs

Janus Kinase (JAK), a nonreceptor protein tyrosine kinase, has emerged as an excellent target through research and development since its discovery in the 1990s. As novel small-molecule targeted drugs, JAK inhibitor drugs have been successfully used in the treatment of rheumatoid arthritis (RA), myelofibrosis (MF), and ulcerative colitis (UC). With the gradual development of JAK targets in the market, JAK inhibitors have also received considerable feedback in the treatment of autoimmune diseases, such as atopic dermatitis (AD), Crohn's disease (CD), and graft-versus-host disease (GVHD). This article reviews the research progress of JAK inhibitor drugs, focusing on the existing JAK inhibitors in the market and some JAK inhibitors in clinical trials currently. In addition, the synthesis of various types of JAK inhibitors and the effects of different drug structures on drug inhibition and selectivity are summarized.