XL-784

XL-784 is a selective matrix metalloproteinases (MMP) inhibitor, with IC₅₀s of ~1900, 0.81, 120, 10.8, 18, 0.56 nM for MMP-1，MMP-2，MMP-3，MMP-8，MMP-9，MMP-13，respectively. IC50 & Target:MMP^[1]. In Vitro: XL-784 is a highly potent, low-molecular-weight (1,122 g/mol) inhibitor of MMPs that has very limited aqueous solubility (20 μg/mL). XL-784 potently inhibits MMP-2, MMP-13, and ADAM10 [TNF-α-converting enzyme (TACE)] activity in vitro, with IC₅₀ values in the range of 1-2 nM. XL-784 also inhibits MMP-9 (IC₅₀ ~20 nM) activity and ADAM17 (IC₅₀ ~70 nM) also known as TACE. However, it exhibits low potency for inhibition of MMP-1 (IC₅₀ ~2,000 nM)^[1]. In Vivo: All mice tolerate the treatments similarly. Control mice all developed aneurysms with a mean %△AD of 158.5%±4.3%. Treatment with all doses of XL-784 and doxycycline are effective in inhibiting aortic dilatation. There is a clear dose-response relationship between XL-784 and reductions in aortic dilatation at harvest (50 mg/kg 140.4% ±3.2%; 125 mg/kg 129.3% ±5.1%; 250 mg/kg 119.2%±3.5%; all Ps<0.01 compared to control). This continues with the higher doses (375 mg/kg 88.6%±4.4%; 500 mg/kg 76.0%±3.5%). The highest 2 doses of XL-784 tested are more effective than doxycycline (112.2%±2.0%, P<0.05) in inhibiting maximal dilatation of the aorta after elastase perfusion^[2].