Pharmacokinetics and tissue distribution of 3-((5-(6-methylpyridin-2-yl)-4-(quinoxalin-6-yl)-1H-imidazol-2-yl)methyl)benzamide; a novel ALK5 inhibitor and a potential anti-fibrosis drug

The authors investigated the pharmacokinetics and metabolism of 3-((5-(6-methylpyridin-2-yl)-4-(quinoxalin-6-yl)-1H-imidazol-2-yl)methyl)benzamide (IN-1130), a novel ALK5 inhibitor, which suppresses renal and hepatic fibrosis, and also exerts anti-metastatic effects on breast cancer-bearing MMTV-cNeu mice model. Plasma half-lives of orally administered IN-1130 were 62.6 min in mice, 76.6?±?10.6 min in dogs, 156.1?±?19.3 min in rats, and 159.9?±?59.9 min in monkeys. IN-1130 showed a high apparent permeability coefficient (P_app) of (45.0?±?2.3)?×?10^?6 cm s^?1 in in vitro permeability tests in a Caco-2 cell monolayer model. The bioavailability of orally administered IN-1130 was 84.9% in dogs and 34.4% in monkeys (oral dose, 5.5 mg kg^?1), 11.4% in rats and 8.95% in mice (oral dose, 50.3 mg kg^?1), respectively. Orally given IN-1130 was readily distributed into liver, kidneys and lungs. The major metabolite of IN-1130 (M1) was detected in the systemic circulation of rat and mouse and was purified and tentatively identified as 3-((4-(3-hydroxyquinoxaline-6-yl)-5-(6-methylpyridine-2-yl)-1H-imidazol-2-yl)methyl)benzamide or 3-((4-(2-hydroxyquinoxalin-6-yl)-5-(6-methylpyridine-2-yl)-1H-imidazol-2-yl)methyl)benzamide. The highest levels of M1 were found in liver. The results of this study suggest that IN-1130 has the potential to serve as an effective oral anti-fibrotic drug.