HIF-PH/hypoxia-inducible factor prolyl hydroxylase

GSK1278863 is a small-molecule PHI that is taken orally that promotes the production of endogenous EPO and induces efficient erythropoiesis[1]. It has been demonstrated that GSK1278863 raises erythropoietin levels, which raises hemoglobin, hematocrit, and red blood cell counts[2].

GSK1278863 is an orally administered small-molecule PHI, and stimulates endogenous EPO synthesis and induce effective erythropoiesis. GSK1278863 has been shown to increase erythropoietin levels, leading to increases in hemoglobin, hematocrit and red blood cell numbers.

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This study was performed to evaluate the pharmacokinetics (PK), pharmacodynamics (PD) and safety of GSK1278863, a novel prolyl hydroxylase inhibitor, following a single oral administration of GSK1278863 from 10 to 100 mg or placebo in Japanese (n = 19), and 10, 25 and 100 mg in Caucasians (n = 14). Dose-proportional increases were observed in AUCinf of GSK1278863 in both ethnic groups, with a 1.3-1.5-fold higher exposure seen in Japanese relative to Caucasians for all doses. This difference in exposure can be mainly explained by the observed differences in body weights between the two groups. Statistically significant increases in erythropoietin (EPO), vascular endothelial growth factor (VEGF) and reticulocyte counts were observed in Japanese subjects after the 50 and 100 mg dose as compared to placebo. In Caucasians, similar to Japanese, EPO and VEGF levels were observed to be increased in response to the 100 mg dose. Drug-related adverse events, including headache and abdominal pain were reported in 3 Japanese subjects, while headache was reported in 3 Caucasians. In conclusion, GSK1278863 was well tolerated, with dose-proportional increases in exposure observed in both groups. There was no evidence of ethnic differences between Japanese and Caucasian with regard to PK or PD.[2]

Decreased erythropoietin (EPO) production, shortened erythrocyte survival, and other factors reducing the response to EPO contribute to anemia in patients who have a variety of underlying pathologies such as chronic kidney disease. Treatment with recombinant human EPO (rHuEPO) at supraphysiologic concentrations has proven to be efficacious. However, it does not ameliorate the condition in all patients, and it presents its own risks, including cardiovascular complications. The transcription factors hypoxia-inducible factor (HIF) 1α and HIF2α control the physiologic response to hypoxia and invoke a program of increased erythropoiesis. Levels of HIFα are modulated by oxygen tension via the action of a family of HIF-prolyl hydroxylases (PHDs), which tag HIFα for proteasomal degradation. Inhibition of these PHDs simulates conditions of mild hypoxia, leading to a potentially more physiologic erythropoietic response and presenting a potential alternative to high doses of rHuEPO. Here we describe the discovery and characterization of GSK1278863 [2-(1,3-dicyclohexyl-6-hydroxy-2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carboxamido) acetic acid], a pyrimidinetrione-glycinamide low nanomolar inhibitor of PHDs 1-3 that stabilizes HIFα in cell lines, resulting in the production of increased levels of EPO. [3]

In normal mice, a single dose of GSK1278863 induced significant increases in circulating plasma EPO but only minimal increases in plasma vascular endothelial growth factor (VEGF-A) concentrations. GSK1278863 significantly increased reticulocytes and red cell mass parameters in preclinical species after once-daily oral administration and has demonstrated an acceptable nonclinical toxicity profile, supporting continued clinical development. GSK1278863 is currently in phase 3 clinical trials for treatment of anemia in patients with chronic kidney disease.[3]

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10, 25, 50, or 100mg

Clinical trials (A 28-Day, Phase 2A Randomized Trial)

Absorption, Distribution and Excretion
Daprodustat exposure typically increases dose-proportionately within the therapeutic dose range. Steady-state concentrations are reached within 24 hours after administration. Following oral administration, daprodustat is rapidly absorbed, with a median time to peak concentration (Tmax) of 1 to 4 hours in healthy subjects. The absolute bioavailability of daprodustat is 65%. Co-administration with high-fat or high-calorie foods does not significantly alter daprodustat exposure compared to fasting administration. Seven days after oral administration of radiolabeled daprodustat, 74% of the radioactive material is excreted in feces, and 21% in urine. Approximately 99.5% of the dose is excreted as oxidative metabolites, with the remainder being unmetabolized parent drug. Daprodustat is distributed approximately equally in plasma and blood cells (plasma/blood ratio 1.23). The steady-state volume of distribution in healthy subjects after intravenous administration is 14.3 L. The mean plasma clearance rate is 18.9 L/h, equivalent to a blood clearance rate of 15 L/h, and the liver extraction rate is approximately 18%. Metabolites/Metabolites: In vitro studies show that dapoxetine is primarily metabolized by CYP2C8 (95%), with a smaller contribution from CYP3A4 (5%). After oral or intravenous administration of radiolabeled dapoxetine to healthy adults, approximately 40% of the total circulating radioactivity in plasma is dapoxetine, and the remaining 60% is metabolites. The parent drug is the main circulating component in plasma. Among the six identified dapoxetine metabolites, the major metabolites are M2 (GSK2391220), M3 (GSK2506104), and M13 (GSK2531401), each accounting for more than 10% of the total circulating radioactivity in plasma. In the human body, each metabolite circulates primarily as a single stereoisomer. In vitro and non-clinical studies have shown that these identified metabolites have comparable pharmacological activity to the parent drug. However, the extent of pharmacological action of each metabolite remains unclear.

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Biological Half-Life
The terminal elimination half-life of daprodustat is 1 to 4 hours.

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This study aimed to evaluate the pharmacokinetics (PK), pharmacodynamics (PD), and safety of the novel prolyl hydroxylase inhibitor GSK1278863 after a single oral dose of 10 to 100 mg GSK1278863 or placebo in Japanese (n = 19) and Caucasian (n = 14) subjects. A dose-proportional increase in AUCinf of GSK1278863 was observed in both ethnic populations, with Japanese subjects showing 1.3 to 1.5 times higher exposure than Caucasian subjects at all doses. The difference in exposure between the two groups was primarily attributable to the difference in body weight between the two groups. Compared with the placebo group, Japanese subjects showed statistically significant increases in erythropoietin (EPO), vascular endothelial growth factor (VEGF), and reticulocyte count after receiving 50 mg and 100 mg doses. Similar to the Japanese subjects, Caucasian subjects also showed increased EPO and VEGF levels after receiving 100 mg doses. Three Japanese subjects reported drug-related adverse events, including headache and abdominal pain, while three Caucasian subjects reported headache. In summary, GSK1278863 was well tolerated, and exposure increased proportionally to the dose in both groups. No racial differences were found between Japanese and Caucasian subjects in terms of pharmacokinetics (PK) or pharmacodynamics (PD). [2]

Hepatotoxicity
In an open-label premarketing clinical trial of daprodustat in patients with kidney disease, 1.7% of subjects experienced serum transaminase elevations of 3 times or more above the upper limit of normal (ULN), and 1.1% experienced elevations of 5 times or more above the ULN. However, the incidence of ALT and AST elevations was similar in the placebo and erythropoietin treatment groups. These elevations were generally mild and transient, and no cases of serum transaminase elevations with jaundice due to daprodustat treatment were reported. Since daprodustat was approved and widely used, there have been no published reports of clinically significant liver injury caused by its use. Probability Score: E (Unlikely to cause clinically significant liver injury). Pregnancy and Lactation Effects ◉ Overview of Use During Lactation There is currently no information regarding the use of daprodustat during lactation. Due to its relatively high protein binding rate, the concentration in breast milk may be low. The manufacturer recommends discontinuing breastfeeding during dapoxetine treatment and for one week after the last dose.
◉ Effects on breastfed infants
No published information found as of the revision date.
◉ Effects on lactation and breast milk
No published information found as of the revision date.

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Protein binding
In vitro studies show that dapoxetine has a plasma protein binding rate >99%.

[1]. A Novel Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitor (GSK1278863) for Anemia in CKD: A 28-Day, Phase 2A Randomized Trial. Am J Kidney Dis. 2016 Jun;67(6):861-71.

[2]. Pharmacokinetics, pharmacodynamics and safety of single, oral doses of GSK1278863, a novel HIF-prolyl hydroxylase inhibitor, in healthy Japanese and Caucasian subjects. Drug Metab Pharmacokinet. 2015 Dec;30(6):410-8.

Daprodustat is a barbiturate drug with barbituric acid substituted with cyclohexyl groups at positions 1 and 3, and with a (carboxymethyl)aminocarbonyl group at position 5. It is a hypoxia-inducible factor prolyl hydroxylase inhibitor developed by GlaxoSmithKline (GSK) for the treatment of anemia in patients with chronic kidney disease. It has dual effects as an anti-anemic agent, an EC 1.14.11.29 (hypoxia-inducible factor-prolyl dioxygenase) inhibitor, and an antiviral agent. It belongs to the barbiturate, secondary amide, N-acylglycine, and oxomonocarboxylic acid class of compounds. Daprodustat is a small molecule hypoxia-inducible factor (HIF) prolyl hydroxylase (PHD) inhibitor developed by GlaxoSmithKline. Patients with chronic kidney disease (CKD) are unable to induce erythropoietin (EPO) production under hypoxic or anemic conditions. Dapresstat is a potent PHD1, PHD2, and PHD3 inhibitor (≥1000-fold selectivity) that stabilizes intracellular HIF1α and HIF2α, thereby inducing erythropoiesis. A phase 3 clinical trial (NCT02879305) found that in CKD patients undergoing dialysis, dapresstat was non-inferior to erythropoietic drugs in terms of changes in hemoglobin levels from baseline and cardiovascular outcomes. In June 2020, dapresstat was first approved in Japan for the treatment of renal anemia. In October 2022, the FDA's Cardiovascular and Renal Drugs Advisory Committee (CRDAC) concluded that the benefits of dapresstat treatment outweighed the risks for adult dialysis patients with anemia due to chronic kidney disease (CKD); however, the same conclusion was not reached for non-dialysis patients with anemia due to CKD. On February 1, 2023, the FDA officially approved dapresstat for the treatment of anemia caused by chronic kidney disease in dialysis patients, becoming the first oral treatment option. Currently, this drug is under review by the European Medicines Agency (EMA). Daprestat is a hypoxia-inducible factor prolyl hydroxylase inhibitor. Daprestat's mechanism of action is the inhibition of hypoxia-inducible factor prolyl hydroxylase. Daprestat is an oral, small-molecule hypoxia-inducible factor prolyl hydroxylase inhibitor used to treat anemia in dialysis patients with chronic kidney disease. The incidence of transient and usually mild elevations in serum transaminase levels during daprestat treatment is low, but it has not been found to be associated with clinically significant cases of acute liver injury. Drug Indications Daprestat is a hypoxia-inducible factor prolyl hydroxylase (HIFPH) inhibitor indicated for the treatment of anemia in adults with chronic kidney disease undergoing dialysis for at least four months. Prescribing information for daprestat in the United States indicates that this drug has not been shown to improve quality of life, fatigue, or patient health. It is not recommended for use as a transfusion replacement therapy in patients requiring immediate correction of anemia. It is also not recommended for use in patients not undergoing dialysis.
Treatment of Anemia Caused by Chronic Disease

Mechanism of Action

Chronic kidney disease (CKD) is associated with a variety of complications, including anemia. Anemia in CKD patients is primarily attributed to the kidneys' inability to produce sufficient erythropoietin (EPO). Daprestat is a potent, reversible inhibitor of hypoxia-inducible factor (HIF)-prolyl hydroxylase (PH) 1, PH2, and PH3 with an IC50 value in the low nanomolar range. Daprestat promotes the stabilization and nuclear accumulation of HIF-1α and HIF-2α transcription factors by inhibiting HIF-PHD. HIF-α translocates to the nucleus and binds to hypoxia-responsive elements (HREs) on DNA, thereby promoting the production of EPO and proteins involved in iron uptake, mobilization, and transport. Ultimately, erythropoiesis increases, iron transport is upregulated, and circulating hemoglobin levels rise.

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Pharmacodynamics
Daprodustat increases endogenous erythropoietin in a dose-dependent manner within 6 to 8 hours after administration. Following repeated dosing, reticulocyte counts peak within 7 to 15 days, followed by increased erythropoiesis. New hemoglobin homeostasis is achieved within weeks of the first dose (approximately 4 weeks for ESA users and 16–20 weeks for non-ESA users). In adult patients with chronic kidney disease (CKD) and anemia undergoing dialysis, 52 weeks of daprodustat treatment increased serum transferrin and total iron-binding capacity (TIBC) and decreased serum ferritin, transferrin saturation, and hepcidin levels.

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Background: Chronic kidney disease (CKD)-related anemia often requires treatment with recombinant human erythropoietin (EPO). Hypoxia-inducible factor-prolyl hydroxylase inhibitors (PHIs) stimulate endogenous EPO synthesis and induce effective erythropoiesis through non-EPO effects. GSK1278863 is an oral small molecule erythropoietin (PHI). Study Design: Multicenter, single-blind, randomized, placebo-controlled, parallel-group study. Study Participants and Location: Chronic kidney disease (CKD) stage 3-5 patients with anemia who were not dialysis-dependent (CKD-3/4/5 group; n=70) and CKD stage 5D patients with anemia undergoing hemodialysis (CKD-5D group; n=37). Intervention: CKD-3/4/5 patients received either placebo or GSK1278863 (10, 25, 50, or 100 mg) once daily, while CKD-5D patients received either placebo or GSK1278863 (10 or 25 mg) once daily for 28 days. Primary outcome measures and methods: Primary pharmacokinetic and pharmacodynamic endpoints (rate of increase in target hemoglobin [Hb] concentration and response rate, plasma erythropoietin [EPO] concentration, reticulocyte count, etc.) as well as safety and tolerability endpoints. Results: Both CKD-3/4/5 and CKD-5D populations showed a dose-dependent increase in EPO concentration, which subsequently led to increased reticulocyte and Hb levels. In the GSK1278863 study, the proportions of subjects with Hb levels >1.0 g/dL (CKD-3/4/5) and >0.5 g/dL (CKD-5D) were 63%–91% and 71%–89%, respectively. According to the protocol-defined criteria, excessively rapid increase in Hb levels or excessively high absolute Hb values were the main reasons for subject withdrawal (30% in CKD-3/4/5; 22% in CKD-5D). A dose-dependent decrease in hepcidin levels and a dose-dependent increase in total iron-binding capacity and unsaturated iron-binding capacity were observed in all patients treated with GSK1278863. Limitations: Sparse pharmacokinetic sampling may have limited the characterization of covariates. EPO concentrations at the last post-dose pharmacodynamic sampling (5–6 hours) may not represent peak concentrations, as previous studies have shown peak concentrations occur 8–10 hours post-dose. Patients were not stratified by diabetes status, which may have confounded vascular endothelial growth factor and glucose analysis results. Conclusion: GSK1278863 induces a robust EPO response and stimulates non-EPO erythropoiesis mechanisms in both dialysis-dependent and dialysis-dependent patients with chronic kidney disease and anemia. Keywords: erythropoietin (EPO); chronic kidney disease (CKD); dialysis; dosage; erythropoietin (ESA); hemoglobin; hemoglobin response rate; hepcidin; hypoxia-inducible factor (HIF); pharmacodynamics; pharmacokinetics; phase II; prolyl hydroxylase inhibitor (PHI); randomized controlled trial (RCT); reticulocyte count. [1]

C19H27N3O6

393.43

393.189

C, 58.00; H, 6.92; N, 10.68; O, 24.40

960539-70-2

91617630

White to off-white solid

1.4±0.1 g/cm3

1.580

0.86

2

6

5

28

627

0

O=C(CNC(C1C(=O)N(C2CCCCC2)C(=O)N(C2CCCCC2)C1=O)=O)O

RUEYEZADQJCKGV-UHFFFAOYSA-N

InChI=1S/C19H27N3O6/c23-14(24)11-20-16(25)15-17(26)21(12-7-3-1-4-8-12)19(28)22(18(15)27)13-9-5-2-6-10-13/h12-13,15H,1-11H2,(H,20,25)(H,23,24)

(1,3-dicyclohexyl-2,4,6-trioxohexahydropyrimidine-5-carbonyl)glycine

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.35 mM) (saturation unknown) in 5% DMSO + 40% PEG300 + 5% Tween80 + 50% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (6.35 mM) (saturation unknown) in 5% DMSO + 95% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)