Cerdulatinib is a novel, dual spleen tyrosine kinase (Syk) and janus kinase (JAK) inhibitor.  It preferentially inhibits JAK1 and JAK3 dependent cytokine mediated signaling and functional responses in various cell types. IL2 mediated STAT5 Y694 is inhibited with an IC₅₀ of 0.27 μM, while IL4 mediated signaling to STAT6 Y641 and functional responses in B cells and monocytes, namely CD69, CD25, and CD23 up-regulation, are inhibited with IC₅₀’s within the range of 0.11 μM to 0.57 μM.