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 generally increases in a dose-proportional manner over the range of therapeutic doses. Steady-state concentrations are achieved within 24 hours of dosing. Following oral administration, daprodustat is readily absorbed with a median time to peak concentration (Tmax) in healthy subjects ranging from one to four hours. The absolute bioavailability of daprodustat is 65%. Administration of daprodustat with a high-fat or high-calorie meal did not significantly alter daprodustat exposure compared to administration in the fasted state.
Within seven days of an oral dose of radiolabeled daprodustat, 74% of the radioactivity was recovered in the feces, and 21% of the radioactivity was recovered in the urine. Approximately 99.5% of the dose was excreted as oxidative metabolites, with the remaining fraction representing the unchanged parent drug.
Daprodustat has an approximately equal distribution between plasma and blood cells (blood:plasma ratio of 1.23). Following intravenous dosing, the volume of distribution at steady-state in healthy subjects is 14.3 L.
Mean clearance from plasma was 18.9 L/h, which correlates to blood clearance of 15 L/h and equates to a hepatic extraction of approximately 18%.

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Metabolism / Metabolites
_In vitro_, daprodustat is primarily metabolized by CYP2C8 (95% contribution), with a minor contribution by CYP3A4 (5%). Following oral or intravenous administration of radiolabeled daprodustat to healthy adults, approximately 40% of the total circulating radioactivity in plasma was daprodustat, and the remaining 60% was metabolites. The parent drug is the principal circulating component in plasma. Of the six metabolites of daprodustat that were characterized, the major metabolites were M2 (GSK2391220), M3 (GSK2506104), and M13 (GSK2531401), with each metabolite accounting for more than 10% of circulating radioactivity in plasma. In humans, each metabolite circulates primarily as a single stereoisomeric form. _In vitro_ and non-clinical studies suggest that these identified metabolites have a comparable pharmacological activity to the parent drug; however, the extent of the pharmacological contribution of each metabolite is unknown.

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Biological Half-Life
The terminal elimination half-life of daprodustat ranges from one to four hours.

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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]

Hepatotoxicity
In the open label prelicensure clinical trials of daprodustat in patients with renal disease, serum aminotransferase elevations 3 times the upper limit of normal (ULN) or above occurred in 1.7% of subjects, and elevations of 5 times ULN or above in 1.1%. However, similar rates of ALT and AST elevations occurred in placebo and erythropoietin treated participants. The elevations were typically mild and transient and there were no instances of serum aminotransferase elevations with jaundice that were attributed to daprodustat therapy. Since approval and more widescale availability of daprodustat, there have been no published reports of clinically apparent liver injury associated with its use.
Likelihood score: E (unlikely cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the use of daprodustat during breastfeeding. Because of relatively high protein binding, the amount in milk is likely to be low. The manufacturer recommends that breastfeeding be discontinued during daprodustat therapy and for one week after the final dose.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
_In vitro_, plasma protein binding of daprodustat is >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 member of the class of barbiturates that is barbituric acid substituted by cyclohexyl groups at positions 1 and 3, and by a (carboxymethyl)aminocarbonyl group at position 5. It is an inhibitor of hypoxia-inducible factor prolyl hydroxylase developed by GlaxoSmithKline for the treatment of anaemia in patients with chronic kidney disease. It has a role as an anti-anaemic agent, an EC 1.14.11.29 (hypoxia-inducible factor-proline dioxygenase) inhibitor and an antiviral agent. It is a member of barbiturates, a secondary carboxamide, a N-acylglycine and an oxo monocarboxylic acid.
Daprodustat is a small-molecule hypoxia-inducible factor (HIF) prolyl hydroxylase (PHD) inhibitor that was developed by GSK. Patients with CKD cannot induce erythropoietin (EPO) production in response to hypoxia or anemia. As a potent inhibitor of PHD1, PHD2 and PHD3 (≥ 1000-fold selectivity), daprodustat stabilizes cellular HIF1α and HIF2α and the induces erythropoiesis. A phase 3 clinical trial (NCT02879305) found that in patients with CKD undergoing dialysis, daprodustat was non-inferior to erythropoiesis-stimulating agents regarding the change in the hemoglobin level from baseline and cardiovascular outcomes. In June 2020, daprodustat was first approved in Japan for the treatment of renal anemia. On October 2022, the FDA Cardiovascular and Renal Drugs Advisory Committee (CRDAC) supported that the benefit of treatment with daprodustat outweighs the risks for adult dialysis patients with anemia of CKD but not for non-dialysis patients with anemia of CKD. On February 1, 2023, daprodustat was fully approved by the FDA as the first oral treatment for anemia caused by chronic kidney disease in patients on dialysis. The drug is currently under EMA review.
Daprodustat is a Hypoxia-inducible Factor Prolyl Hydroxylase Inhibitor. The mechanism of action of daprodustat is as a Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor.
Daprodustat is an orally available small molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase that is used to treat the anemia of chronic renal disease in patients on dialysis. Daprodustat is associated with a low rate of transient and usually mild elevations in serum aminotransferase levels during therapy but has yet to be linked to cases of clinically apparent acute liver injury.

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Drug Indication
Daprodustat is a hypoxia-inducible factor prolyl hydroxylase (HIF PH) inhibitor indicated for the treatment of anemia due to chronic kidney disease in adults who have been receiving dialysis for at least four months. The US prescribing information for daprodustat indicates that the drug was not shown to improve quality of life, fatigue, or patient well-being. It is not advised to be used as a substitute for transfusion in patients requiring immediate correction of anemia. It is also not indicated in patients not on dialysis.
Treatment of anaemia due to chronic disorders

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Mechanism of Action
Chronic kidney disease (CKD) is associated with several complications, including anemia. The development of anemia in patients with CKD is mostly due to the kidneys' inability to produce a sufficient amount of erythropoietin (EPO). Daprodustat is a potent reversible inhibitor of hypoxia-inducible factor (HIF)-prolyl hydroxylase (PH) 1, PH2 and PH3, with an IC₅₀ in the low nM range. By inhibiting HIF-PHDs, daprodustat promotes the stabilization and nuclear accumulation of HIF-1α and HIF-2α transcription factors. HIF-α translocates to the nucleus and binds to hypoxia response elements (HREs) on DNA to promote the production of EPO as well as proteins involved in iron uptake, mobilization, and transport. Ultimately, erythropoiesis is increased, iron transport is upregulated, and circulating Hb levels are elevated.

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Pharmacodynamics
Daprodustat is Daprodustat increases endogenous erythropoietin in a dose-dependent manner within six to eight hours after administration. With repeated doses, peak increases in reticulocyte counts occurred in seven to 15 days, with subsequent increases in red blood cell production. New hemoglobin steady-state levels are reached several weeks (approximately four weeks in ESA-users and approximately 16-20 weeks in ESA-non-users) after initial administration. Daprodustat also increased serum transferrin and total iron binding capacity (TIBC) and decreased serum ferritin, transferrin saturation, and hepcidin when administered for 52 weeks in adults on dialysis with anemia due to CKD.

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Background: Anemia associated with chronic kidney disease (CKD) often requires treatment with recombinant human erythropoietin (EPO). Hypoxia-inducible factor-prolyl hydroxylase inhibitors (PHIs) stimulate endogenous EPO synthesis and induce effective erythropoiesis by non-EPO effects. GSK1278863 is an orally administered small-molecule PHI. Study design: Multicenter, single-blind, randomized, placebo-controlled, parallel-group study. Setting & participants: Anemic non-dialysis-dependent patients with CKD stages 3-5 (CKD-3/4/5 group; n=70) and anemic hemodialysis patients with CKD stage 5D (CKD-5D group; n=37). Interventions: Patients with CKD-3/4/5 received placebo or GSK1278863 (10, 25, 50, or 100mg), and patients with CKD-5D received placebo or GSK1278863 (10 or 25mg) once daily for 28 days. Outcomes & measurements: Primary pharmacokinetic and pharmacodynamic (increase and response rates in achieving the target hemoglobin [Hb] concentration, plasma EPO concentrations, reticulocyte count, and others]) and safety and tolerability end points were obtained. Results: Both CKD-3/4/5 and CKD-5D populations showed a dose-dependent increase in EPO concentrations and consequent increases in reticulocytes and Hb levels. Percentages of GSK1278863 participants with an Hb level increase > 1.0g/dL (CKD-3/4/5) and >0.5g/dL (CKD-5D) were 63% to 91% and 71% to 89%, respectively. Per-protocol-defined criteria, high rate of increase in Hb level, or high absolute Hb value was the main cause for withdrawal (CKD-3/4/5, 30%; CKD-5D, 22%). A dose-dependent decrease in hepcidin levels and increase in total and unsaturated iron binding were observed in all GSK1278863-treated patients. Limitations: Sparse pharmacokinetic sampling may have limited covariate characterization. EPO concentrations at the last pharmacodynamic sample (5-6 hours) postdose may not represent peak concentrations, which occurred 8 to 10 hours postdose in previous studies. Patients were not stratified by diabetes status, potentially confounding vascular endothelial growth factor and glucose analyses. Conclusions: GSK1278863 induced an effective EPO response and stimulated non-EPO mechanisms for erythropoiesis in anemic non-dialysis-dependent and dialysis-dependent patients with CKD. Keywords: Erythropoietin (EPO); chronic kidney disease (CKD); dialysis; dosing; erythropoiesis-stimulating agent (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.)