CS-2524

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 μM) does not interfere with other serpin/serine protease systems. TM5275 at concentrations of 20 and 100 μM 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. Cell viability at 72 h treatment is decreased with 70-100 μM TM5275 in ES-2 and JHOC-9 cells. From 48 h up to 96 h, cell growth is suppressed with 100 μM TM5275. Active PAI-1 in cell culture media is significantly decreased in cells treated with 100 μM TM5275 compared to control treatment. TM5275 is suggested to exert anti-proliferative effects in ovarian cancer with high PAI-1 expression.

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 μM 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).