PF-05175157

The in vitro metabolism of PF-05175157 is evaluated in microsomes from rat, dog, and human hepatocytes. PF-05175157 is not metabolized in rat, dog, or human microsomes. PF-05175157 is also stable in human hepatocyte incubations, but is minimally metabolized by recombinant human CYP3A4 and CYP3A5, suggesting it is a substrate for CYP3A4 and CYP3A5. PF-05175157 inhibits formation of malonyl-CoA in a concentration-dependent manner with a potency (EC50 = 30 nM) in rat hepatocytes consistent with its potency against rat ACC1 (24 nM).^[1]

On the day of the study, media was aspirated and cells are treated with fresh MCM media containing DMSO vehicle or varying concentrations of PF-05175157 as indicated. Compound was initially dissolved in DMSO and subsequently diluted 1:100 in MCM.After 5 h at 37 °C, incubation media is removed and the experiment is terminated by washing the cells with ice cold PBS.

In vivo, the plasma clearance of PF-05175157 is low following intravenous (iv) administration (1 mg/kg) to rats, dogs, and monkeys. Oral (po) administration (3 mg/kg) to rats and dogs showed bioavailability of 40% and 54%, respectively, consistent with the low microsomal clearance and good solubility at low pH. The bioavailability following a 50 mg/kg oral dose in rats was 106%, suggesting saturation of clearance. Formation of the direct product of ACC, malonyl-CoA, in the skeletal muscle and liver of lean Sprague Dawley rats is assessed 1 h following an acute oral dose of PF-05175157, showing concentration-dependent reductions in both skeletal muscle and liver malonyl-CoA. At the nadir, quadriceps and liver malonyl-CoA levels are reduced by 76% and 89%, respectively. ^[1]