PF-06282999

A potent, highly selective and irreversible inhibitor of myeloperoxidase (MPO) with Kinact/KI of 116000 M-1s-1; displays high selectivity for MPO over TPO and cytochrome P450 isoforms; shows excellent pharmacological and pharmacokinetic profile; orally active. Thrombosis Phase 1 Clinical (In Vitro) :PF-06282999 (Compound 8) is a potent and selective myeloperoxidase inhibitor. The estimated EC50 for total PF-06282999 concentration in plasma is 3.8 μM, which corresponds well with the IC50 value obtained in the human whole blood assay of 1.9 μM. (In Vivo) :PF-06282999 is moderately bound to plasma proteins across preclinical species and humans. The blood/plasma ratios for PF-06282999 are 1.1, 1.1, 0.91, 1.2, and 0.94 in mice, rats, dogs, monkeys, and humans, respectively, suggesting that PF-06282999 is equally distributed into plasma and red blood cells. The in vivo pharmacokinetics of PF-06282999 are examined in greater detail in mice, rats, dogs, and monkeys, wherein it is demonstrated to have low CLp in mice (10.1 mL/min/kg), dogs (3.39 mL/min/kg), monkeys (10.3 mL/min/kg) and moderate CLp in rats (41.8 mL/min/kg) . The terminal plasma elimination half-lives (t1/2) range from 0.75 to 3.3 h in the four species. Approximately 26-32% of the iv dose of PF-06282999 is excreted in the unchanged form in rat, dog, and monkey urine, wherein it is also shown that it is well distributed with steady state distribution volumes (Vdss) ranging from 0.5-2.1 L/kg in mice, rats, dogs, and monkeys. Following oral administration, PF-06282999 is rapidly (Tmax=0.78-1.70 h) and well absorbed in mice, rats, dogs, and monkeys with oral bioavailability values of 100%, 86%, 75%, and 76%, respectively.