RT Journal Article
SR Electronic
T1 Metabolites in Safety Testing Assessment in Early Clinical Development: A Case Study with a Glucokinase Activator
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 1926
OP 1939
DO 10.1124/dmd.114.060087
VO 42
IS 11
A1 Sharma, Raman
A1 Litchfield, John
A1 Atkinson, Karen
A1 Eng, Heather
A1 Amin, Neeta B.
A1 Denney, William S.
A1 Pettersen, John C.
A1 Goosen, Theunis C.
A1 Di, Li
A1 Lee, Esther
A1 Pfefferkorn, Jeffrey A.
A1 Dalvie, Deepak K.
A1 Kalgutkar, Amit S.
YR 2014
UL http://dmd.aspetjournals.org/content/42/11/1926.abstract
AB The present article summarizes Metabolites in Safety Testing (MIST) studies on a glucokinase activator, N,N-dimethyl-5-((2-methyl-6-((5-methylpyrazin-2-yl)carbamoyl)benzofuran-4-yl)oxy)pyrimidine-2-carboxamide (PF-04937319), which is under development for the treatment of type 2 diametes mellitus. Metabolic profiling in rat, dog, and human hepatocytes revealed that PF-04937319 is metabolized via oxidative (major) and hydrolytic pathways (minor). N-Demethylation to metabolite M1 [N-methyl-5-((2-methyl-6-((5-methylpyrazin-2-yl)carbamoyl)benzofuran-4-yl)oxy)pyrimidine-2-carboxamide] was the major metabolic fate of PF-04937319 in human (but not rat or dog) hepatocytes, and was catalyzed by CYP3A and CYP2C isoforms. Qualitative examination of circulating metabolites in humans at the 100- and 300-mg doses from a 14-day multiple dose study revealed unchanged parent drug and M1 as principal components. Because M1 accounted for 65% of the drug-related material at steady state, an authentic standard was synthesized and used for comparison of steady-state exposures in humans and the 3-month safety studies in rats and dogs at the no-observed-adverse-effect level. Although circulating levels of M1 were very low in beagle dogs and female rats, adequate coverage was obtained in terms of total maximal plasma concentration (∼7.7× and 1.8×) and area under the plasma concentration-time curve (AUC; 3.6× and 0.8× AUC) relative to the 100- and 300-mg doses, respectively, in male rats. Examination of primary pharmacology revealed M1 was less potent as a glucokinase activator than the parent drug (compound PF-04937319: EC50 = 0.17 μM; M1: EC50 = 4.69 μM). Furthermore, M1 did not inhibit major human P450 enzymes (IC50 > 30 μM), and was negative in the Salmonella Ames assay, with minimal off-target pharmacology, based on CEREP broad ligand profiling. Insights gained from this analysis should lead to a more efficient and focused development plan for fulfilling MIST requirements with PF-04937319.