pai-039 and Coronary-Thrombosis

We tested a novel, orally active inhibitor of plasminogen activator inhibitor-1 (PAI-1) in a canine model of electrolytic injury. Dogs received by oral gavage either vehicle (control) or the PAI-1 inhibitor PAI-039 [{1-benzyl-5-[4-(trifluoromethoxy)phenyl]-1H-indol-3-yl}(oxo)acetic acid] (1, 3, and 10 mg/kg) and were subjected to electrolytic injury of the coronary artery. PAI-039 caused prolongation in time to coronary occlusion (control, 31.7 +/- 6.3 min; 3 mg/kg PAI-039, 66.0 +/- 6.4 min; 10 mg/kg, 56.7 +/- 7.4 min; n = 5-6; p < 0.05) and a reduced thrombus weight (control, 7.6 +/- 1.5 mg; 10 mg/kg PAI-039, 3.6 +/- 1.0 mg; p < 0.05). Although occlusive thrombosis was observed across all groups based upon the absence of measurable blood flow, a high incidence (>60%) of spontaneous reperfusion occurred only in those groups receiving PAI-039. Spontaneous reperfusion in the 10 mg/kg PAI-039 group accounted for total blood flow (area under the curve of coronary blood flow) of 99.6 +/- 11.7 ml after initial thrombotic occlusion (p < 0.05 compared with control). Plasma PAI-1 activity was reduced in all drug-treated groups (percentage of reduction in activity p < 0.05; 10 mg/kg PAI-039), whereas ADP-, 9,11-dideoxy-11alpha,9alpha-epoxymethanoprostaglandin F(2alpha) (U46619)-, and collagen-induced platelet aggregation, as well as template bleeding and prothrombin time, remained unaffected by PAI-039. Ex vivo clot lysis analysis revealed normal clot formation but accelerated clot lysis in PAI-039-treated groups. The pharmacokinetic profile of PAI-039 indicated an oral bioavailability of 43 +/- 15.3% and a plasma half-life of 6.2 +/- 1.3 h. In conclusion, PAI-039 is an orally active prothrombolytic drug that inhibits PAI-1 and accelerates fibrinolysis while maintaining normal coagulation in a model of coronary occlusion.

Topics: Acetates; Animals; Bleeding Time; Blood Pressure; Coronary Circulation; Coronary Thrombosis; Dogs; Endpoint Determination; Fibrinolysis; Fibrinolytic Agents; Heart Rate; Hemostasis; Indoleacetic Acids; Indoles; Partial Thromboplastin Time; Plasminogen Activator Inhibitor 1; Platelet Aggregation; Ventricular Remodeling

Indole oxoacetic acid derivatives were prepared and evaluated for in vitro binding to and inactivation of human plasminogen activator inhibitor-1 (PAI-1). SAR based on biochemical, physiological, and pharmacokinetic attributes led to identification of tiplaxtinin as the optimal selective PAI-1 inhibitor. Tiplaxtinin exhibited in vivo oral efficacy in two different models of acute arterial thrombosis. The remarkable preclinical safety and metabolic stability profiles of tiplaxtinin led to advancing the compound to clinical trials.

Topics: Administration, Oral; Animals; Biological Availability; Carotid Artery Thrombosis; Coronary Thrombosis; Dogs; Drug Design; Drug Evaluation, Preclinical; Humans; Indoleacetic Acids; Indoles; Plasminogen Activator Inhibitor 1; Rats; Serine Proteinase Inhibitors; Structure-Activity Relationship