Revisiting Janus Kinase Inhibitors in Hospitalized COVID-19: Evidence for Baricitinib’s Superiority and the Absence of a Class Effect

Lei Gu,1,* Jing Lin,2,* Jian Yue,3,* Zeyi Liu,1 Jian-an Huang1 1Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China; 2Department of Infectious Diseases, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China; 3The People’s Hospital of Gaozhou, Gaozhou, Guangdong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jian-an Huang, Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China, Email [email protected] Zeyi Liu, Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China, Email [email protected]: Janus kinase (JAK) inhibitors, developed for autoimmune diseases, have been repurposed as potential therapies for severe COVID-19. Growing evidence indicates that their clinical utility is heterogeneous and cannot be generalized as a class effect. In this Perspective, we focus on the clinical evidence base for JAK inhibitors in COVID-19 and emphasize baricitinib as the the only agent with consistent mortality benefit and highlights the need for agent-specific recommendations and individualized treatment strategies.Keywords: janus kinase inhibitors, baricitinib, tofacitinib, ruxolitinib, COVID-19, immunomodulation