Metabolites in Safety Testing Assessment in Early Clinical Development: A Case Study with a Glucokinase Activator
作者:Raman Sharma、John Litchfield、Karen Atkinson、Heather Eng、Neeta B. Amin、William S. Denney、John C. Pettersen、Theunis C. Goosen、Li Di、Esther Lee、Jeffrey A. Pfefferkorn、Deepak K. Dalvie、Amit S. Kalgutkar
DOI:10.1124/dmd.114.060087
日期:2014.11
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 μ M; M1: EC50 = 4.69 μ M). Furthermore, M1 did not inhibit major human P450 enzymes (IC50 > 30 μ M), 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.
本文总结了关于一种葡萄糖激酶激活剂 N,N-二甲基-5-((2-甲基-6-((5-甲基吡嗪-2-基)氨基)苯并呋喃-4-基)氧)pyrimidine-2-羧酰胺(PF-04937319)的代谢物安全性测试(MIST)研究,该药物正在开发用于治疗2型糖尿病。对大鼠、犬和人类肝细胞的代谢谱分析显示,PF-04937319通过氧化(主要)和水解(次要)途径代谢。N-去甲基化生成代谢物M1(N-甲基-5-((2-甲基-6-((5-甲基吡嗪-2-基)氨基)苯并呋喃-4-基)氧)pyrimidine-2-羧酰胺)是PF-04937319在人体肝细胞中的主要代谢去向(而在大鼠或犬肝细胞中则不是),由CYP3A和CYP2C亚型催化。对人类在14天多剂量研究中100mg和300mg剂量下的循环代谢物的定性分析显示,未改变的母药和M1是主要成分。由于M1在稳态时占药物相关物质的65%,因此合成了一个真实标准并用于人类和在无观察到不良反应水平下的大鼠和犬的3个月安全性研究中稳态暴露的比较。尽管在比格犬和雌性大鼠中M1的循环水平非常低,但在雄性大鼠中的总最大血浆浓度(约7.7倍和1.8倍)及血浆浓度-时间曲线下面积(AUC;3.6倍和0.8倍AUC)相对于100mg和300mg剂量仍获得了足够的覆盖。对主要药理学的检查显示M1作为葡萄糖激酶激活剂的效能低于母药(化合物PF-04937319: EC50 = 0.17 μM; M1: EC50 = 4.69 μM)。此外,M1不抑制主要人类P450酶(IC50 > 30 μM),在Salmonella Ames试验中呈阴性,基于CEREP的广谱配体配置分析显示其具有最小的非靶向药理学。从该分析中获得的见解应能指导PF-04937319的MIST要求的更有效和更有针对性的开发计划。