The effect of 0.5 mg/kg (administered orally) of B-P2 (phenyl ester of B) and 0.3 mg/kg (administered orally) of B-P1 (ethyl ester of B) on ex vivo platelet aggregation in PRP upon stimulation with 20 μmol/L ADP (A) and platelet count in whole blood (B) in rhesus monkey 94-R021. The effect of 5 μg/kg IV bolus of A2-L and 20 μg/kg IV bolus of B on ex vivo platelet aggregation in PRP upon stimulation with 20 μmol/L ADP and platelet count in whole blood (C) and number of receptors occupied by B (D) in rhesus monkey 94-R021. (A and B) Inhibition of platelet aggregation by B-P1 (▾) or B-P2 (▴) as measured by a change in light transmittance (PPP 100%) under stirring conditions (1,100 rpm) at 37°C in Biodata Platelet Aggregation Profiler. Platelet count measured in whole blood of rhesus monkey 94-R021 using an automated hematology analyzer (Biochem Immunosystems) upon dosing B-P1 (•) and B-P2 (▪). (C and D) Platelet count measured in whole blood of rhesus monkey 94-R021 using an automated hematology analyzer (Biochem Immunosystems) upon dosing A2-L (•) and B (▪). Inhibition of platelet aggregation by B (▾) or A2-L (⧫) as measured by a change in light transmittance (PPP 100%) under stirring conditions (1,100 rpm) at 37°C in Biodata Platelet Aggregation Profiler. The number of GP IIb/IIIa receptors occupied by B as measured by competition displacement measurements with [¹²⁵I]-L-692,884 (▴).