Biochem/physiol Actions
Orally active, highly potent and selective Syk inhibitor with in vivo efficacy in animal models of thrombosis and B-cell acute lymphoblastic leukemia (B-ALL).
PRT-060318 (PRT318; P142-76) is a highly potent and selective Syk inhibitor (IC50 = 4 nM; much reduced potency against 138 other kinases) that blocks BCR-dependent signaling in chronic lymphocytic leukemia (CCL) cultures (2-3 μM) and specifically inhibits platelets activation via ITAM receptor complex GPVI/FcRγ, but not P2Y1/12 or PAR1, stimulation (IC50 = 2.5 μM; aggregation by 8 ng/mL convulxin). PRT318 demonstrates in vivo efficacy in animal models of thrombosis (30 mg/kg mouse bis p.o.; 5.1675 mg/3.1 mL/kg/rabbit/15 min then 7.33 mg/4.4 mL/kg/h i.v.; 8.90 mg/mL/kg pig/h i.v.) and B-cell acute lymphoblastic leukemia (30 mg /kg bis p.o.; human B-ALL xenograft mice).