Background:

PRT062607 Hydrochloride is a highly selective and novel SYK inhibitor with IC50 value of 1 nM. Spleen tyrosine kinase (SYK) is a cytoplasmic tyrosine kinase and primarily expressed in hematopoietic cells including B-cells.
PRT062607 Hydrochloride is an orally bioavailable SYK inhibitor and its affinity for SYK is at least 80-fold greater than other kinases. In NHL cell lines, PRT062607 Hydrochloride inhibits SYK activation and induces caspase dependent apoptosis. Also, PRT062607 Hydrochloride inhibited SYK and caused apoptosis of the tumor B-cell line [1].
PRT062607 Hydrochloride effectively antagonize CLL cell survival after BCR triggering. Moreover, they inhibit the secretion of the chemokines CCL3 and CCL4 by CLL cells, and leukemia cell transfer toward beneath stromal cells, the tissue homing chemokines CXCL13 and CXCL12 [2].
In a mouse xenograft model, mice dosed with all three concentrations (twice daily with 10, 15, or 20 mg/kg) of  PRT062607 Hydrochloride were protected from Ramos tumor growth [1].
参考文献:
[1]. Spurgeon SE, Coffey G, Fletcher LB, et al. The selective SYK inhibitor P505-15 (PRT062607) inhibits B cell signaling and function in vitro and in vivo and augments the activity of fludarabine in chronic lymphocytic leukemia. J Pharmacol Exp Ther, 2013, 344(2): 378-387.
[2]. Hoellenriegel J, Coffey GP, Sinha U, et al. Selective, novel spleen tyrosine kinase (Syk) inhibitors suppress chronic lymphocytic leukemia B-cell activation and migration. Leukemia, 2012, 26(7): 1576-1583.