Click Chemistry-Based Discovery of [3-Hydroxy-5-(1<i>H</i>‑1,2,3-triazol-4-yl)picolinoyl]glycines as Orally Active Hypoxia-Inducing Factor Prolyl Hydroxylase Inhibitors with Favorable Safety Profiles for the Treatment of Anemia

As a gene associated with anemia, the erythropoiesis gene is physiologically expressed under hypoxia regulated by †hypoxia-inducing factor-α (HIF-α). Thus, stabilizing HIF-α is a potent strategy to stimulate the expression and secretion of erythropoiesis. In this study, we applied click chemistry to the discovery of HIF prolyl hydroxylase 2 (HIF-PHD2) inhibitors for the first time, and a series of triazole compounds showed preferable inhibitory activity in fluorescence polarization assays. Of particular note was the orally active HIF-PHD inhibitor <b>15i</b> (IC₅₀ = 62.23 nM), which was almost ten times more active than the phase III drug <b>FG-4592</b> (IC₅₀ = 591.4 nM). Furthermore, it can upregulate the hemoglobin of cisplatin-induced anemia mice (120 g/L) to normal levels (160 g/L) with no apparent toxicity observed in vivo. These results confirm that triazole compound <b>15i</b> is a promising candidate for the treatment of renal anemia