908802-63-1Relevant articles and documents
Non-peptide GPIIb/IIIa inhibitors. 20. Centrally constrained thienothiophene α-sulfonamides are potent, long acting in vivo inhibitors of platelet aggregation
Egbertson, Melissa S.,Cook, Jacquelynn J.,Bednar, Bohumil,Prugh, John D.,Bednar, Rodney A.,Gaul, Stanley L.,Gould, Robert J.,Hartman, George D.,Homnick, Carl F.,Holahan, Marie A.,Libby, Laura A.,Lynch Jr., Joseph J.,Lynch, Robert J.,Sitko, Gary R.,Stranieri, Maria T.,Vassallo, Laura M.
, p. 2409 - 2421 (2007/10/03)
The synthesis and pharmacology of 4, a potent thienothiophene non- peptide fibrinogen receptor antagonist, are reported. Compound 4 inhibited the aggregation of human gel-filtered platelets with an IC50 of 8 nM and demonstrated an 8-fold improvement in affinity for isolated GPIIb/IIIa receptors over analogues possessing an isoindolinone backbone. Flow cytometry studies revealed that the binding of 4 to resting platelets is a diffusion- controlled process (k(on) = 3.3 x 106 M-1 s-1) and that 4 binds to dog and human platelets with comparable affinity (K(d) = 0.04 and 0.07 nM, respectively). Ex vivo platelet aggregation in dogs was completely inhibited by an iv dose of 5 mg/kg, and an oral dose of 50-90 mg/kg followed by low daily doses of 10 mg/kg was sufficient to maintain ~80% inhibition of ex vivo platelet aggregation over several days. Inhibition of ADP-induced platelet aggregation in anesthetized dogs at 77 ± 7% resulted in a moderate 2.5-fold increase in bleeding time, while complete inhibition (100%) resulted in an approximately 10-min bleeding time. Additional doses were required to increase the bleeding time to the maximum time allowed in the protocol (15 min), thus indicating a potentially useful and safe separation of efficacy and bleeding time.
