TM5275 sodium is a plasminogen activator inhibitor (PAI-1) with an IC50 of 6.95 uM.
Docking studies shows that TM5275 binds to strand 4 of the A β-sheet (s4A) position of PAI-1. TM5275 is a selective PAI-1 and (up to 100 uM) does not interfere with other serpin/serine protease systems[1]. TM5275 at concentrations of 20 and 100 uM significantly prolongs the retention of tPA-GFP on VECs by inhibiting tPA-GFP-PAI-1 high-molecular-weight complex formation. TM5275 enhances the time-dependent accumulation of plasminogen as well as the dissolution of fibrin clots on and around the tPA-GFP-expressing cells[2]. Cell viability at 72 h treatment is decreased with 70-100 uM TM5275 in ES-2 and JHOC-9 cells. From 48 h up to 96 h, cell growth is suppressed with 100 uM TM5275. Active PAI-1 in cell culture media is significantly decreased in cells treated with 100 uM TM5275 compared to control treatment. TM5275 is suggested to exert anti-proliferative effects in ovarian cancer with high PAI-1 expression[3].
TM5275 exhibits a favorable pharmacokinetics profile and very low toxicity to mice and rats. In rat thrombosis models. Blood clot weights are significantly lower in rats administered 10 and 50 mg/kg of TM5275 (60.9±3.0 and 56.8±2.8 mg, respectively) than in vehicle-treated rats (72.5±2.0 mg). The antithrombotic effectiveness of TM5275 (50 mg/kg) is equivalent to that of ticlopidine (500 mg/kg), a reference antithrombotic compound. Plasma concentration of TM5275 reaches 17.5±5.2 uM after a dose of 10 mg/kg. TM5275 (5 mg/kg) combined with tPA (0.3 mg/kg) significantly enhances the antithrombotic effect of tPA (0.3 mg/kg) alone and provides a benefit similar to that of a high tPA dose (3 mg/kg)[1].
References:
[1]. Izuhara Y, et al. A novel inhibitor of plasminogen activator inhibitor-1 provides antithrombotic benefits devoid of bleeding effect in nonhuman primates. J Cereb Blood Flow Metab. 2010 May;30(5):904-12.
[2]. Yasui H, et al. TM5275 prolongs secreted tissue plasminogen activator retention and enhances fibrinolysis on vascular endothelial cells. Thromb Res. 2013 Jul;132(1):100-5.
[3]. Mashiko S, et al. Inhibition of plasminogen activator inhibitor-1 is a potential therapeutic strategy in ovarian cancer. Cancer Biol Ther. 2015;16(2):253-60.