Sotyktu

Deucravacitinib is a small molecule that selectively inhibits the tyrosine kinase 2 (TYK2) enzyme. Deucravacitinib binds to the regulatory domain of TYK2, stabilising an inhibitory interaction between the regulatory and the catalytic domains of the enzyme. This results in allosteric inhibition of receptor-mediated activation of TYK2 and its downstream functions in cells. TYK2 is a member of the Janus kinase (JAK) family. JAK kinases, including TYK2, function in pairs to mediate Janus kinase-signal transducer and activator of transcription [JAK-STAT] pathways. TYK2 pairs with JAK1 to mediate multiple cytokine pathways and also pairs with JAK2 to transmit signals. The pairing of TYK2 with either JAK1 or JAK2 mediates signalling of a narrower range of cytokines compared with the pairings of JAKs 1/2/3 with each other. The allosteric mechanism of action of deucravacitinib has been shown to inhibit TYK2 with minimal or no inhibition of JAK 1/2/3. TYK2 mediates signalling of interleukin-23 (IL-23) cytokine, interleukin-12 (IL-12) cytokine, and type I interferons (IFN), which are naturally occurring cytokines involved in inflammatory and immune responses. Deucravacitinib inhibits signalling from IL-23, IL-12 and type I IFN and the downstream release of proinflammatory cytokines and chemokines.