TP0463518, a novel inhibitor for hypoxia-inducible factor prolyl hydroxylases, increases erythropoietin in rodents and monkeys with a good pharmacokinetics-pharmacodynamics correlation

Hypoxia-inducible factor prolyl hydroxylases (PHDs) inhibitor stabilizes hypoxia inducible factor alpha, which increases erythropoietin (EPO) expression via the hypoxia response element. Therefore, PHDs inhibitors have been developed as novel therapeutic agents for anemia. Here, we characterize the in vitro and in vivo pharmacological profiles of TP0463518, 2-[[1-[[6-(4-chlorophenoxy)pyridin-3-yl]methyl]-4-hydroxy-6-oxo-2,3-dihydropyridine-5-carbonyl]amino]acetic acid, a novel potent PHDs inhibitor. TP0463518 competitively inhibited human PHD2 with a Ki value of 5.3 nM. TP0463518 also inhibited human PHD1/3 with IC₅₀ values of 18 and 63 nM as well as monkey PHD2 with an IC₅₀ value of 22 nM. In normal mice and rats, TP0463518 significantly increased the serum EPO levels at doses of 5 and 20 mg/kg, respectively. The correlation factors for serum EPO and the serum TP0463518 levels were 0.95 in mice and 0.92 in rats. TP0463518 also increased the serum EPO level in 5/6 nephrectomized chronic kidney disease model rats at a dose of 10 mg/kg, with a correlation factor for serum EPO and the serum TP0463518 levels of 0.82. Finally, the effect of TP0463518 in monkeys was investigated. TP0463518 was promptly removed with a half-life of 5.2 h and increased the area under the curve (AUC) of EPO at a dose of 5 mg/kg. The EPO and TP0463518 levels were also correlated. These results suggest that TP0463518 induces endogenous EPO with a strong pharmacokinetic-pharmacodynamic correlation and may contribute to desirable hemoglobin control in patients with renal anemia.