Definition

An orally bioavailable pan-inhibitor of the Janus associated-kinases (JAKs), with potential immunomodulatory and anti-inflammatory activities. Upon oral administration, lorpucitinib works in the gastrointestinal (GI) tract where it targets, binds to and inhibits the activity of the JAKs, thereby disrupting JAK-signal transducer and activator of transcription (STAT) signaling pathways and the phosphorylation of STAT proteins. This may inhibit the release of pro-inflammatory cytokines and chemokines, reducing inflammatory responses and preventing inflammation-induced damage. The Janus kinase family of non-receptor tyrosine kinases, which includes tyrosine-protein kinase JAK1 (Janus kinase 1; JAK1), tyrosine-protein kinase JAK2 (Janus kinase 2; JAK2), tyrosine-protein kinase JAK3 (Janus kinase 3; JAK3) and non-receptor tyrosine-protein kinase TYK2 (tyrosine kinase 2), plays a key role in cytokine signaling and inflammaton.