CP-673451S1536

CP 673451 is a selective inhibitor of PDGFRα/β with IC50 of 10 nM/1 nM, exhibits >450-fold selectivity over other angiogenic receptors. In glioblastoma tumors, CP-673451 (33 mg/kg) provides >50% inhibition of PDGFR-β receptor for 4 hours corresponding to an EC50 of 120 ng/mL in plasma at C_max. In a sponge angiogenesis model, CP-673451 inhibits 70% of PDGF-BB-stimulated angiogenesis at a dose of 3 mg/kg (q.d. ×5, p.o., corresponding to 5.5 ng/mL at C_max).^[1] CP-673451 decreases cell proliferation rate through mechanisms involving reduced phosphorylation of GSK-3α and GSK-3β. In both RD and RUCH2 cultures, CP-673451 impairs rhabdosphere-forming capacity and cell differentiation, causes increased senescence. ^[2]