Ruxolitinib Phosphate is the phosphate salt form of ruxolitinib (sc-364729). Mouse models have shown it to be a potent and selective Janus kinase (JAK1, IC50 = 5.9 nM and JAK2, IC50 = 5.7 nM) inhibitor. Ruxolitinib has also been shown to suppress interleukin-6 signaling (IC50 = 281 nM) and proliferation of JAK2V617F+ Ba/F3 cells (IC50 = 127 nM). Ruxolitinib significantly reduced splenomegaly and circulating levels of inflammatory cytokines and selectively eliminated neoplastic cells in mouse models of JAK2V617F+ myeloproliferative neoplasm, prolonging their survival without myelosuppressive or immunosuppressive effects.
Further studies of Ruxolitinib have demonstrated its ability to inhibit phosphorylated signal transducer and activator of transcription 3 (STAT3)