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Inhibition of the hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) represents a promising strategy for discovering next-generation treatments for renal anemia. We discovered DS44470011 in our previous study, which showed potent in vitro activity and in vivo efficacy based on HIF-PHD inhibition. However, DS44470011 was also found to exert genotoxic effects. By converting the biphenyl structure, which is suspected to be the cause of this genotoxicity, to a 1-phenylpiperidine structure, we were able to avoid genotoxicity and further improve the in vitro activity and in vivo efficacy. Furthermore, through the optimization of pyrimidine derivatives, we discovered DS-1093a, which has a wide safety margin with potent in vitro activity and an optimal pharmacokinetic profile. DS-1093a achieved an increase in hemoglobin levels in an adenine-induced rat model of chronic kidney disease after its continuous administration for 4 days., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Anaemia is a common complication of chronic kidney disease (CKD) and is associated with poor long-term outcomes and quality of life. The use of supplemental iron, erythropoiesis-stimulating agents (ESAs) and blood transfusions has been the mainstay for treatment of anaemia in CKD for more than 3 decades. Despite available treatments, CKD patients with anaemia are undertreated and moderate-severe anaemia remains prevalent in the CKD population. Anaemia has consistently been associated with greater mortality, hospitalization, cardiovascular events and CKD progression in CKD patients, and the risk increases with anaemia severity. Hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) inhibitors have a novel mechanism of action by mimicking the body's response to hypoxia and have emerged as an alternative to ESAs for treatment of anaemia in CKD. Their efficacy in correcting and maintaining haemoglobin has been demonstrated in >30 phase 3 clinical trials. Additionally, HIF activation results in various pleiotropic effects beyond erythropoiesis, with cholesterol reduction and improved iron homeostasis and potential anti-inflammatory effects. The long-term safety of these agents, particularly with respect to cardiovascular and thromboembolic events, and their possible effect on tumour growth needs to be fully elucidated. This article presents in detail the effects of HIF-PH inhibitors, describes their mechanisms of action and pharmacologic properties and discusses their place in the treatment of anaemia in CKD according to the available evidence., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

Neuroinflammation and dysregulated energy metabolism are linked to motor neuron degeneration in amyotrophic lateral sclerosis (ALS). The egl-9 family hypoxia-inducible factor (EGLN) enzymes, also known as prolyl hydroxylase domain (PHD) enzymes, are metabolic sensors regulating cellular inflammation and metabolism. Using an oligonucleotide-based and a genetic approach, we showed that the downregulation of Egln2 protected motor neurons and mitigated the ALS phenotype in two zebrafish models and a mouse model of ALS. Single-nucleus RNA sequencing of the murine spinal cord revealed that the loss of EGLN2 induced an astrocyte-specific downregulation of interferon-stimulated genes, mediated via the stimulator of interferon genes (STING) protein. In addition, we found that the genetic deletion of EGLN2 restored this interferon response in patient induced pluripotent stem cell (iPSC)-derived astrocytes, confirming the link between EGLN2 and astrocytic interferon signaling. In conclusion, we identified EGLN2 as a motor neuron protective target normalizing the astrocytic interferon-dependent inflammatory axis in vivo, as well as in patient-derived cells., Competing Interests: Declaration of interests T.V. is an employee of Bristol-Myers Squibb (Princeton, USA). B.D.S. has been a consultant for Eli Lilly and Company (Indianapolis, USA), Biogen (Cambridge, USA), Janssen Pharmaceutica (Beerse, Belgium), AbbVie, Inc. (North Chicago, USA), and others and is now a consultant for Eisai (Nutley, USA), Remynd (Leuven, Belgium), and Muna Therapeutics (Copenhagen, Denmark). B.D.S. is a scientific founder and stockholder of Muna Therapeutics. P.V.D. has served on advisory boards for Biogen, CSL Behring (King of Prussia, USA), Alexion Pharmaceuticals (Boston, USA), Ferrer (Barcelona, Spain), QurAlis (Cambridge, UK), Cytokinetics (South San Francisco, USA), Argenx (Boston, USA), UCB (Brussels, Belgium), Muna Therapeutics, Alector (South San Francisco, USA), Augustine Therapeutics (Leuven, Belgium), VectorY (Amsterdam, the Netherlands), Zambon (Bresso, Italy), and Amylyx (Cambridge, UK) (paid to institution). P.V.D. has received speaker fees from Biogen and Amylyx (paid to institution). P.V.D. has participated as an investigator in clinical trials on ALS sponsored by Biogen, Cytokinetics, Ferrer, Amylyx, Wave Life Sciences (Cambridge, UK), Corcept Therapeutics (Menlo Park, USA), Transposon Therapeutics (Westport, USA), Sanofi (Paris, France), AB Science (Paris, France), IONIS Pharmaceuticals (Carlsbad, USA), Apellis Pharmaceuticals (Waltham, USA), Alexion Pharmaceuticals, Orphazyme (Copenhagen, Denmark), Orion Pharma (Espoo, Finland), and AL-S Pharma (Schlieren, Switzerland). P.V.D. is supported by the E. von Behring Chair for Neuromuscular and Neurodegenerative Disorders (from CSL Behring, paid to institution). L.V.D.B. is head of the scientific advisory board of Augustine Therapeutics and is part of the investment advisory board of Droia Ventures (Meise, Belgium). L.V.D.B. and B.D.S. are scientific founders of Augustine Therapeutics., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background and Objective: Daprodustat is a first-in-class hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) approved in the USA for treatment of anemia owing to chronic kidney disease (CKD) in dialysis-dependent adults and in Japan for treatment of CKD in dialysis- and non-dialysis dependent adults. This analysis characterized the population pharmacokinetics (PopPK) of daprodustat in adults with CKD and evaluated the influence of intrinsic and extrinsic factors., Methods: This PopPK analysis included data from one phase 2B and four phase 3 studies comprising 707 CKD subjects dose titrated to prespecified target hemoglobin levels with daprodustat doses ranging from 1 to 24 mg once daily and 2 to 48 mg given three times a week (TIW). Model development leveraged a previous phase 1/2 PopPK model. Stepwise covariate analysis included 20 extrinsic and intrinsic factors. Model evaluation used standard goodness-of-fit and visual predictive checks., Results: Daprodustat PopPK was adequately characterized using a three-compartment distribution model with first-order elimination. The absorption phase was described using five transit compartments. Oral clearance and volume of distribution was 24.6 L/h and 26.9 L, respectively. Body weight dependence (with fixed allometric coefficients) of clearance and volume terms was a statistically significant covariate. Concomitant use of clopidogrel (moderate CYP2C8 inhibitor) decreased oral clearance, resulting in higher area under the plasma concentration-time curve (AUC) ratio of 1.59 (90% CI: 1.39-1.82), subjects' dialysis status (non-dialysis versus dialysis) had an effect on absorption, with C max ratio of 1.19 (90% CI: 1.09-1.30). None of the other investigated intrinsic or extrinsic covariates, including concomitant administration with phosphate binders, oral iron and acid reducing agents resulted in a significant change in daprodustat systemic exposure., Conclusion: The PopPK of daprodustat in the CKD population with anemia was adequately characterized. Allometrically-scaled body weight on clearance and volume, dialysis status on absorption and clopidogrel on clearance were statistically significant covariates., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitors are an oral treatment for anemia of chronic kidney disease (CKD). In this systematic review and meta-analysis, we assessed long-term safety of HIF prolyl hydroxylase inhibitors., Methods: We searched MEDLINE, Embase, and Cochrane databases for randomized trials comparing HIF prolyl hydroxylase inhibitors with an erythropoiesis-stimulating agent (ESA) or placebo with greater than or equal to 48 weeks of follow-up. The primary outcome was major adverse cardiovascular event (MACE), defined as a composite of all-cause death, myocardial infarction, or stroke. Treatment effects were pooled using random-effects models., Results: Twenty-five trials involving 26,478 participants were included. Of these, 13 trials enrolled 13,230 participants with dialysis-dependent CKD, and 12 trials enrolled 13,248 participants with nondialysis-dependent CKD. There was no evidence that HIF prolyl hydroxylase inhibitors and ESA had different effects on MACE in people with dialysis-dependent CKD (risk ratio, 0.99; 95% confidence interval [CI], 0.92 to 1.08) or people with nondialysis-dependent CKD (risk ratio, 1.08; 95% CI, 0.95 to 1.22). Similarly, there was no evidence that HIF prolyl hydroxylase inhibitors and placebo had different effects on MACE (risk ratio, 1.10; 95% CI, 0.96 to 1.27) in people with nondialysis-dependent CKD. The lack of difference between HIF prolyl hydroxylase inhibitors and ESA or placebo was observed for individual components of MACE and cardiovascular death. Safety of HIF prolyl hydroxylase inhibitors for other outcomes was comparable with ESA in dialysis-dependent CKD. In nondialysis-dependent CKD, dialysis access thrombosis, venous thromboembolism, infections, and hyperkalemia occurred more frequently with HIF prolyl hydroxylase inhibitors in placebo-controlled trials but not in ESA-controlled trials., Conclusions: There was no evidence of a difference in the long-term cardiovascular safety profile of HIF prolyl hydroxylase inhibitors and ESA in adults with dialysis-dependent CKD and adults with nondialysis-dependent CKD. (PROSPERO registration number, CRD42021278011.).

Aims/hypothesis: Hypoxia-inducible factor prolyl 4-hydroxylase (HIF-P4H) enzymes regulate adaptive cellular responses to low oxygen concentrations. Inhibition of HIF-P4Hs leads to stabilisation of hypoxia-inducible factors (HIFs) and activation of the HIF pathway affecting multiple biological processes to rescue cells from hypoxia. As evidence from animal models suggests that HIF-P4H inhibitors could be used to treat metabolic disorders associated with insulin resistance, we examined whether roxadustat, an HIF-P4H inhibitor approved for the treatment of renal anaemia, would have an effect on glucose metabolism in primary human myotubes., Methods: Primary skeletal muscle cell cultures, established from biopsies of vastus lateralis muscle from men with normal glucose tolerance (NGT) (n=5) or type 2 diabetes (n=8), were treated with roxadustat. Induction of HIF target gene expression was detected with quantitative real-time PCR. Glucose uptake and glycogen synthesis were investigated with radioactive tracers. Glycolysis and mitochondrial respiration rates were measured with a Seahorse analyser., Results: Exposure to roxadustat stabilised nuclear HIF1α protein expression in human myotubes. Treatment with roxadustat led to induction of HIF target gene mRNAs for GLUT1 (also known as SLC2A1), HK2, MCT4 (also known as SLC16A4) and HIF-P4H-2 (also known as PHD2 or EGLN1) in myotubes from donors with NGT, with a blunted response in myotubes from donors with type 2 diabetes. mRNAs for LDHA, PDK1 and GBE1 were induced to a similar degree in myotubes from donors with NGT or type 2 diabetes. Exposure of myotubes to roxadustat led to a 1.4-fold increase in glycolytic rate in myotubes from men with NGT (p=0.0370) and a 1.7-fold increase in myotubes from donors with type 2 diabetes (p=0.0044), with no difference between the groups (p=0.1391). Exposure to roxadustat led to a reduction in basal mitochondrial respiration in both groups (p<0.01). Basal glucose uptake rates were similar in myotubes from donors with NGT (20.2 ± 2.7 pmol mg -1 min -1 ) and type 2 diabetes (25.3 ± 4.4 pmol mg -1 min -1 , p=0.4205). Treatment with roxadustat enhanced insulin-stimulated glucose uptake in myotubes from donors with NGT (1.4-fold vs insulin-only condition, p=0.0023). The basal rate of glucose incorporation into glycogen was lower in myotubes from donors with NGT (233 ± 12.4 nmol g -1 h -1 ) than in myotubes from donors with type 2 diabetes (360 ± 40.3 nmol g -1 h -1 , p=0.0344). Insulin increased glycogen synthesis by 1.9-fold (p=0.0025) in myotubes from donors with NGT, whereas roxadustat did not affect their basal or insulin-stimulated glycogen synthesis. Insulin increased glycogen synthesis by 1.7-fold (p=0.0031) in myotubes from donors with type 2 diabetes. While basal glycogen synthesis was unaffected by roxadustat, pretreatment with roxadustat enhanced insulin-stimulated glycogen synthesis in myotubes from donors with type 2 diabetes (p=0.0345)., Conclusions/interpretation: Roxadustat increases glycolysis and inhibits mitochondrial respiration in primary human myotubes regardless of diabetes status. Roxadustat may also improve insulin action on glycogen synthesis in myotubes from donors with type 2 diabetes., (© 2024. The Author(s).)

Inhibition of the hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) represents a promising strategy for discovering next-generation treatments for renal anemia. We identified a pyrimidine core with HIF-PHD inhibitory activity based on scaffold hopping of FG-2216 using crystal structures of HIF-PHD2 in complex with compound. By optimizing the substituents at the 2- and 6- positions of the pyrimidine core, we discovered DS44470011, which improves the effectiveness of erythropoietin (EPO) release in cells. Oral administration of DS44470011 to cynomolgus monkeys increased plasma EPO levels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This systematic review and meta-analysis were conducted to evaluate the cardiac and kidney-related adverse effects of roxadustat for the treatment of anemia in CKD patients. 18 trials with a total of 8806 participants were identified for analysis. We employed a fixed-effects model for analysis. The pooled result revealed no significant difference in the risk of occurrence of cardiac disorders when comparing CKD patients receiving roxadustat with the placebo (RR = 1.049; CI [0.918 to 1.200]) or ESA (RR = 1.066; CI [0.919 to 1.235]), in both dialysis-dependent (DD) (RR = 1.094; CI [0.925 to 1.293]) or non-dialysis-dependent (NDD) (RR = 1.036; CI [0.916 to 1.171]) CKD patients. No significant difference was observed in the risk of kidney-related adverse events when comparing roxadustat with the placebo (RR = 1.088; CI [0.980 to 1.209]) or ESA (RR = 0.968; CI [0.831 to 1.152]), in DD (RR = 2.649; CI [0.201 to 34.981]) or NDD (RR = 1.053; CI [0.965 to 1.149]) CKD patients. A high risk of hyperkalemia was observed in the roxadustat group in DD (RR = 0.939; CI [0.898 to 0.981]). Incidence of hypertension was higher in the roxadustat for NDD patients (RR = 1.198; CI [1.042 to 1.377]), or compared to the placebo (RR = 1.374; CI [1.153 to 1.638]). In summary, the risk of cardiac or kidney-related events observed in the roxadustat was not significantly increase whether in DD or NDD patients. However, attention must be paid to the occurrence of hyperkalemia for DD patients and hypertension in NDD patients using roxadustat.

Introduction: Erythropoiesis-stimulating agents (ESAs) together with iron supplementation had been the standard treatment for anemia in chronic kidney disease (CKD) for the past decades. Recently, hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) have attracted attention as a novel treatment option., Areas Covered: This review summarizes the effectiveness and the safety of HIF-PHIs based on previous clinical trials and discusses points to consider for their clinical use., Expert Opinion: The results from clinical trials demonstrate that HIF-PHIs are non-inferior to ESAs in terms of the efficacy to maintain or improve blood hemoglobin levels. However, concerns about adverse events including cardiovascular outcomes, thrombotic events, and tumor progression have prevented HIF-PHIs from being widely approved for clinical use. Also, long-term safety has not been demonstrated yet. Practically, HIF-PHIs should be used with caution in patients with a history of thrombosis or active malignancy. Patients without them may be preferable for HIF-PHIs if those are bothered with regular injections of ESAs or are hyporesponsive to ESAs without obvious reasons, provided that the drugs were approved in the country. Even so, clinicians must take caution for signs of adverse events such as heart failure after prescribing the drugs.

Objectives: To compare the efficacy and safety of hypoxia-inducible factor prolyl-hydroxylase inhibitors (HIF-PHis), a novel agent for management of anemia in chronic kidney disease (CKD), between transplant recipients and nontransplant individuals., Methods: A retrospective analysis was conducted on nondialysis-dependent CKD stage 3 to 5 patients treated with the HIF-PHi roxadustat or daprodustat at a single institution. Patients were categorized as kidney transplant recipients (KTRs) and non-KTRs. Efficacy outcomes (hemoglobin and creatinine levels) and safety profiles (rate of adverse events [AEs], descriptions, and discontinuations due to AEs) were assessed 3 months before and 6 months after HIF-PHi initiation within and then between the groups., Results: The study comprised 82 patients (KTR: 43, non-KTR: 39). Median ages significantly differed between the KTR (52.7 years) and non-KTR (82.9 years) groups (P < .001). Roxadustat was predominantly used in the KTR group (88.4%), while daprodustat was used in the non-KTR group (94.9%, P < .001). Both groups exhibited significant increases in Hb levels at 1, 3, and 6 months post-HIF-PHi initiation (P for trend, <.001), with a relative increase in Hb level at 6 months of 16% for KTRs and 13% for non-KTRs. Creatinine levels showed no significant changes over 6 months. Although no difference was observed in drug discontinuation due to AEs, the KTR group experienced a significantly higher rate of thrombotic events (18.6 vs 2.6%, P = .049)., Conclusions: HIF-PHis demonstrate comparable efficacy for managing anemia in CKD, regardless of transplant status. However, heightened vigilance for thrombosis events is necessary during follow-up for KTRs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective We retrospectively compared the dose, cost, and safety of vadadustat and daprodustat for the treatment of renal anemia in patients with chronic kidney diseases who were not undergoing dialysis. Methods The primary outcome of this study was the change in dose and cost from the initiation of vadadustat and daprodustat treatment. The secondary outcome was the drug safety. Patients We treated 30 patients each with the hypoxia-inducible factor prolyl-hydroxylase inhibitors (HIF-PHIs) daprodustat and vadadustat. The hemoglobin (Hb) concentration was targeted at 11-13 g/dL, and transferrin saturation was maintained at ≥20%, as per the 2018 Japanese guidelines for the diagnosis and treatment of chronic kidney disease. Results Hb levels increased from 10.7 to 11.5 g/dL after the first month of daprodustat administration, whereas those for vadadustat patients remained relatively stable, going from 10.7 to 10.6 g/dL. After six months, the Hb level reached 12.1 g/dL and 11.3 g/dL for daprodustat and vadadustat, respectively. The dosage of vadadustat was significantly increased by 46% and 70% after 3 and 12 months, respectively, compared with the initial doses, whereas that of daprodustat did not change substantially. The average cost of vadadustat also increased in the first 3 months and remained over 500 yen/day after 3 months, while that of daprodustat showed little change from the initial cost of 360 yen/day. Conclusion These results suggest that heterogeneity exists in the drug potency and dosage required for treatment between daprodustat and vadadustat. Serious adverse events [death, cardiovascular disease, end stage renal disease (ESRD), and malignancy] occurred in more than 20% of participants with both HIF-PHIs. Further studies are required to confirm the safety of HIF-PHIs.

Aims: Kidney disease often leads to anemia due to a defect in the renal production of the erythroid growth factor erythropoietin (EPO), which is produced under the positive regulation of hypoxia-inducible transcription factors (HIFs). Chemical compounds that inhibit HIF-prolyl hydroxylases (HIF-PHs), which suppress HIFs, have been developed to reactivate renal EPO production in renal anemia patients. Currently, multiple HIF-PH inhibitors, in addition to conventional recombinant EPO reagents, are used for renal anemia treatment. This study aimed to elucidate the therapeutic mechanisms and drug-specific properties of HIF-PH inhibitors., Methods and Key Findings: Gene expression analyses and mass spectrometry revealed that HIF-PH inhibitors (daprodustat, enarodustat, molidustat, and vadadustat) alter Epo gene expression levels in the kidney and liver in a drug-specific manner, with different pharmacokinetics in the plasma and urine after oral administration to mice. The drug specificity revealed the dominant contribution of EPO induction in the kidneys rather than in the liver to plasma EPO levels after HIF-PH inhibitor administration. We also found that several HIF-PH inhibitors directly induce duodenal gene expression related to iron intake, while these drugs indirectly suppress hepatic hepcidin expression to mobilize stored iron for hemoglobin synthesis through induction of the EPO-erythroferrone axis., Significance: Renal EPO induction is the major target of HIF-PH inhibitors for their therapeutic effects on erythropoiesis. Additionally, the drug-specific properties of HIF-PH inhibitors in EPO induction and iron metabolism have been shown in mice, providing useful information for selecting the proper HIF-PH inhibitor for each renal anemia patient., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Acute myeloid leukemia (AML) is a largely incurable disease, for which new treatments are urgently needed. While leukemogenesis occurs in the hypoxic bone marrow, the therapeutic tractability of the hypoxia-inducible factor (HIF) system remains undefined. Given that inactivation of HIF-1α/HIF-2α promotes AML, a possible clinical strategy is to target the HIF-prolyl hydroxylases (PHDs), which promote HIF-1α/HIF-2α degradation. Here, we reveal that genetic inactivation of Phd1/Phd2 hinders AML initiation and progression, without impacting normal hematopoiesis. We investigated clinically used PHD inhibitors and a new selective PHD inhibitor (IOX5), to stabilize HIF-α in AML cells. PHD inhibition compromises AML in a HIF-1α-dependent manner to disable pro-leukemogenic pathways, re-program metabolism and induce apoptosis, in part via upregulation of BNIP3. Notably, concurrent inhibition of BCL-2 by venetoclax potentiates the anti-leukemic effect of PHD inhibition. Thus, PHD inhibition, with consequent HIF-1α stabilization, is a promising nontoxic strategy for AML, including in combination with venetoclax., (© 2024. The Author(s).)

Inhibition of prolylhydroxylase-2 (PHD-2) in both normoxic and hypoxic cells is a critical component of solid tumours. The present study aimed to identify small molecules with PHD-2 activation potential. Virtually screening 4342 chemical compounds for structural similarity to R59949 and docking with PHD-2. To find the best drug candidate, hits were assessed for drug likeliness, antihypoxic and antineoplastic potential. The selected drug candidate's PHD-2 activation, cytotoxic and apoptotic potentials were assessed using 2-oxoglutarate, MTT, AO/EtBr and JC-1 staining. The drug candidate was also tested for its in-vivo chemopreventive efficacy against DMBA-induced mammary gland cancer alone and in combination with Tirapazamine (TPZ). Virtual screening and 2-oxoglutarate assay showed BBAP-6 as lead compound. BBAP-6 exhibited cytotoxic and apoptotic activity against ER+ MCF-7. In carmine staining and histology, BBAP-6 alone or in combination with TPZ restored normal surface morphology of the mammary gland after DMBA produced malignant alterations. Immunoblotting revealed that BBAP-6 reduced NF-κB expression, activated PHD-2 and induced intrinsic apoptotic pathway. Serum metabolomics conducted with 1H NMR confirmed that BBAP-6 prevented HIF-1α and NF-κB-induced metabolic changes in DMBA mammary gland cancer model. In a nutshell, it can be concluded that BBAP-6 activates PHD-2 and exhibits anticancer potential., (© 2024 John Wiley & Sons Ltd.)

Anemia is a frequent and early chronic kidney disease (CKD) complication. Its management is currently based on oral or intravenous iron supplements, erythropoiesis-stimulating agents, and red blood cell transfusions, when the benefits of transfusion outweigh the risks. Anemia in CKD patients is underdiagnosed and undertreated. Current standard of care is associated with challenges and therefore new treatment approaches have been sought. Hypoxia-inducible factor-prolyl-hydroxylase enzyme inhibitors are a new class of orally administered drugs used to treat anemia associated with CKD. Small-molecule hypoxia-inducible factor-prolyl-hydroxylase inhibitors have a novel mechanism of action that activates the hypoxia-inducible factor (oxygen-sensing) pathway resulting in a coordinated erythropoietic response, leading to increased endogenous erythropoietin production, improved iron absorption and transport, and reduced hepcidin. Roxadustat is the first hypoxia-inducible factor-prolyl-hydroxylase inhibitor approved by the European Medicines Agency (EMA) and reimbursed in Italy by the Italian Medicines Agency (AIFA) for the treatment of adult patients with symptomatic CKD-related anemia. This authorization was based on the outcome of a globally-conducted phase 3 clinical trial program comprising eight pivotal multicenter randomized studies. In the absence of up-to-date guidelines, we performed a critical appraisal of the placement and use of roxadustat in this therapeutic context., (© 2024. The Author(s) under exclusive licence to Italian Society of Nephrology.)

Background: Vadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor developed for treating anemia in chronic kidney disease (CKD). The purpose of this post-hoc analysis was to investigate the factors affecting the responsiveness to vadadustat in anemia patients with nondialysis-dependent (NDD) or hemodialysis-dependent (HDD) CKD in two Japanese phase 3 studies., Methods: Of 151 and 162 patients enrolled in NDD-CKD and HDD-CKD studies, 136 and 140 patients, respectively, were included and divided into subgroups for the analysis. To assess vadadustat responsiveness, the resistance index was defined as the mean body weight-adjusted dose of vadadustat (mg/kg) at weeks 20-24 divided by the mean hemoglobin (g/dL) at weeks 20-24. Multivariate analysis was performed to identify the variables affecting the resistance index., Results: Independent factors identified as determinants for better response to vadadustat were as follows: high baseline hemoglobin, low baseline eGFR, high week-20-24 ferritin, and CKD not caused by autoimmune disease/glomerulonephritis/vasculitis in NDD-CKD; and male sex, high baseline C-reactive protein, and low baseline erythropoiesis-stimulating agent resistance index (ERI) in HDD-CKD., Conclusions: In this post-hoc analysis, several factors were identified as affecting the response to vadadustat. These results may provide useful information leading to an appropriate dose modification for vadadustat., Clinical Trial Registration: NCT03329196 (MT-6548-J01) and NCT03439137 (MT-6548-J03)., (© 2024. The Author(s).)

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are new drugs developed for the treatment of anemia associated with chronic kidney disease (CKD). This class of drugs stimulates endogenous erythropoietin production and, at the same time, improves iron absorption and mobilization of iron stores (less evident with daprodustat, vadadustat and enarodustat). Several studies have been published in the last few years showing that these agents are not inferior to standard therapy in correcting anemia associated with CKD. The efficacy of HIF-PHIs is coupled with a safety profile comparable to that of standard erythropoiesis stimulating agent (ESA) treatment. However, studies with HIF-PHIs were not long enough to definitively exclude the impact of new drugs on adverse events, such as cancer, death and possibly cardiovascular events, that usually occur after a long follow-up period. Kidney Disease: Improving Global Outcomes (KDIGO) recently reported the conclusions of the Controversies Conference on HIF-PHIs held in 2021. The goal of the present position paper endorsed by the Italian Society of Nephrology is to better adapt the conclusions of the latest KDIGO Conference on HIF-PHIs to the Italian context by reviewing the efficacy and safety of HIF-PHIs as well as their use in subpopulations of interest as emerged from more recent publications not discussed during the KDIGO Conference., (© 2024. The Author(s).)

Prolyl hydroxylase domain 2 (PHD2) is an important enzyme in the human body that perceives changes in oxygen concentration and regulates response in hypoxic environments. Evaluation of PHD2 inhibitory activity of natural products is crucial for drug development of hypoxia related diseases. At present, the detection of low concentration of α-ketoglutaric acid (the substrate of PHD2 enzymatic reaction) requires derivatization reactions or sample pretreatment, which undoubtedly increases the workload of PHD2 inhibitory activity evaluation. In this paper, a direct detection approach of α-ketoglutaric acid was established by using the online stacking strategy of capillary electrophoresis to evaluate the PHD2 inhibitory activity of natural products. Under optimized conditions, detection of a single sample can be achieved within 2 min. By calculation, the intraday precision RSD of the apparent electrophoretic mobility and peak areas of α-ketoglutaric acid are 0.92 % and 0.79 %, respectively, and the interday RSD were 1.27 % and 0.96 % respectively. The recoveries of the present approach were 97.9-105.2 %, and the LOQ and LOD were 2.0 μM and 5.0 μM, respectively. Furthermore, this approach was applied for the evaluation of inhibitory activity of PHD2 for 13 natural products, and PHD2 inhibitory activity of salvianolic acid A was firstly reported. The present work not only realizes evaluation of PHD2 inhibitory activity through direct detection of α-ketoglutaric acid, but also provides technical support for the discovery of potential drug molecules in hypoxia related diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Myelodysplastic syndromes is a heterogeneous group of myeloid neoplastic disorders originating from hematopoietic stem cells and manifesting as pathological bone marrow hematopoiesis and a high risk of transformation to acute myeloid leukemia. In low-risk patients, the therapeutic goal is to improve hematopoiesis and quality of life. Roxadustat is the world's first oral small-molecule hypoxia-inducible factor prolyl hydroxylase inhibitor, which, unlike conventional erythropoietin, corrects anemia through various mechanisms. In this study, we retrospectively analyzed the changes in anemia, iron metabolism, lipids and inflammatory indexes in patients with low-risk myelodysplastic syndromes to evaluate its therapeutic efficacy and safety, and to provide theoretical and practical data for the application of roxadustat in myelodysplastic syndromes.

Background: The National Health and Nutrition Examination Survey (NHANES) carried out a survey between 2007-10 and found that as compared to the general population, the prevalence of anemia in chronic kidney disease (CKD) patients was twice high. Daprodustat is an investigational novel drug for the treatment of renal anemia., Objective: The objective of this study is to provide a comprehensive review of chemistry, synthesis, pharmacology, pharmacokinetic, and bioanalytical methods for the analysis of Daprodustat., Methods: To improve understanding, a review was carried out by creating a database of relevant prior research from electronic sources such as ScienceDirect and PubMed. The methodology is shown in the flowchart of the literature selection process., Results: The drug was approved in 2020 for therapeutic purposes in Japan. It is a novel drug approved for the treatment of anemia in chronic kidney disease for oral administration. It is intended for adults who have undergone dialysis for a minimum of four months and are experiencing anemia as a result of chronic kidney disease., Conclusion: This review examines therapeutic, pharmacological, and analytical aspects related to the novel drug Daprodustat., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Since the approval of HIF-PH inhibitors, HIF-PH inhibitors have been used clinically, and many studies and clinical case reports have been reported in Japan. A lot of information has been accumulated on clinical usage. However, HIF-PH inhibitors require careful administration for cancer patients due to their action mechanism through upregulating hypoxia-inducible factors (HIFs) level. In cancer cells, HIFs affect tumor progression and contribute to chemo- and radio-resistance. On the other hand, upregulation of HIFs in immune cells is associated with inflammation and suppress tumor progression. However, these controversial effects are not clear in in vivo model. It is needed to reveal whether upregulating HIFs level is beneficial for cancer therapy or not. We have previously reported that HIF-PH inhibitor treatment in tumor bearing mice model led to reconstitute tumor blood vessel and inhibit tumor growth. In addition, these phenomena were caused by tumor infiltrated macrophages and they altered these phenotypes. In this review, we will describe our findings on the mechanism of tumor growth suppression by HIF-PH inhibitors. We also want to mention the risks and benefits of future HIF-PH inhibitors.

Anemia in chronic kidney disease (CKD) occurs due to insufficient production of erythropoietin to compensate for the decrease in hemoglobin. Anemia in CKD has traditionally been treated with periodic injections of erythropoiesis-stimulating agents (ESAs), which are recombinant human erythropoietin preparations. Although ESA improved anemia in CKD and dramatically improved the quality of life of patients, there are some patients who are hyporesponsive to ESA, and the use of large doses of ESA in these patients may have a negative impact on patient prognosis. Currently, HIF prolyl hydroxylase (HIF-PH) inhibitors have been approved in Japan as a new treatment for anemia in CKD. HIF-PH inhibitors activate HIF and promote the production of endogenous erythropoietin. The 2019 Nobel Prize in Physiology or Medicine was awarded for groundbreaking research that uncovered the HIF pathway. Because HIF-PH inhibitors improve both erythropoietin production and iron metabolism, they are expected to be effective in treating ESA hyporesponsiveness and solve the inconvenience of injectable preparations. On the other hand, its effects are systemic and multifaceted, and long-term effects must be closely monitored.

Background: Erythropoietic effects of molidustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, were previously demonstrated in healthy cats., Objective: To evaluate the safety and erythropoietic effects of daily PO administration of molidustat in anemic cats with chronic kidney disease (CKD)., Animals: Twenty-one client-owned CKD cats (4-17 years old) with anemia., Methods: Multicenter field study; randomized, masked, and placebo-controlled. Cats were treated PO once daily for 28 days with suspensions of control product (CP; n = 6) or 5 mg/kg of molidustat (n = 15). Hematocrit (HCT) was evaluated at weekly intervals. Individual cat treatment success was defined as a ≥4% point increase in HCT compared to baseline., Results: Control group mean HCT remained low throughout the study (20.1%-23.4%). Mean HCT of molidustat-treated cats increased weekly, and a significant increase compared to baseline (23.6%) was first observed on Day 21 (27.3%; P < .001; 95% confidence interval [CI], 1.69-5.67). Compared to CP group, mean HCT was significantly higher on Day 21 (27.3% vs 20.1%; P < .001; 95% CI, 2.91-10.75) but not significantly higher on Day 28 (27.8% vs 23.4%; P = .06; 95% CI, -0.23 to 9.88). The number of individual treatment successes on Day 28 was higher among remaining molidustat-treated cats (7/14) compared to remaining control cats (1/5), but there was no significant difference between groups., Conclusions and Clinical Importance: Daily PO molidustat administration may stimulate a clinically relevant erythropoietic response in anemic cats with CKD. This HIF-PH inhibitor may be an alternative for managing anemia in cats compared to recombinant EPO treatment., (© 2023 Elanco Animal Health. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Immune cells adopt a variety of metabolic states to support their many biological functions, which include fighting pathogens, removing tissue debris, and tissue remodeling. One of the key mediators of these metabolic changes is the transcription factor hypoxia-inducible factor 1α (HIF-1α). Single-cell dynamics have been shown to be an important determinant of cell behavior; however, despite the importance of HIF-1α, little is known about its single-cell dynamics or their effect on metabolism. To address this knowledge gap, here we optimized a HIF-1α fluorescent reporter and applied it to study single-cell dynamics. First, we showed that single cells are likely able to differentiate multiple levels of prolyl hydroxylase inhibition, a marker of metabolic change, via HIF-1α activity. We then applied a physiological stimulus known to trigger metabolic change, interferon-γ, and observed heterogeneous, oscillatory HIF-1α responses in single cells. Finally, we input these dynamics into a mathematical model of HIF-1α-regulated metabolism and discovered a profound difference between cells exhibiting high versus low HIF-1α activation. Specifically, we found cells with high HIF-1α activation are able to meaningfully reduce flux through the tricarboxylic acid cycle and show a notable increase in the NAD + /NADH ratio compared with cells displaying low HIF-1α activation. Altogether, this work demonstrates an optimized reporter for studying HIF-1α in single cells and reveals previously unknown principles of HIF-1α activation., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Hypoxia-inducible factor-prolyl hydroxylase (HIF-PHD) inhibitors are therapeutic agents for renal anemia that work through HIF2-mediated upregulation of erythropoietin (EPO) and have also been reported to suppress renal fibrosis. Group 2 innate lymphoid cells (ILC2s) have been proven to be involved in the pathogenesis of fibrosis in various organs, including the kidney. However, the relationship between the HIF pathway, renal fibrosis, and kidney ILC2s remains unclear. In the present study, we found that HIF activation by HIF-PHD inhibitors suppressed type 2 cytokine production from kidney ILC2s. The enhanced HIF pathway downregulated the IL-33 receptor ST2L on ILC2s, and phosphorylation of downstream p38 MAPK was attenuated. M2 macrophages that promote renal fibrosis were polarized by ILC2 supernatants, but reduced cytokine production from ILC2s treated with HIF-PHD inhibitors suppressed this polarization. Our findings suggest that HIF-PHD inhibitors are potential therapeutic agents for renal fibrosis that are mediated by the alteration of ILC2 function., (© 2023. The Author(s).)

Pharmacological inhibition of prolyl-4-hydroxylase domain (PHD) enzymes stabilizes hypoxia-inducible factors (HIFs), transcription factors that activate target genes that, among others, increase erythropoietin (EPO) synthesis, resulting in the production of new red blood cells (RBCs). Herein, we summarize the preclinical characteristics of the small molecule HIF prolyl-4-hydroxylase inhibitor vadadustat (AKB-6548), which is in development for the treatment of anemia in patients with chronic kidney disease (CKD). Vadadustat inhibits the enzyme activity of all three human PHD isozymes, PHD1, PHD2, and PHD3, with similar low nanomolar inhibitory constant values. PHD enzyme inhibition by vadadustat is competitive with endogenous cofactor 2-oxoglutarate and is insensitive to free iron concentration. In the human hepatocellular carcinoma cell line (Hep 3B) and human umbilical vein endothelial cells, PHD inhibition by vadadustat leads to the time- and concentration-dependent stabilization of HIF-1 α and HIF-2 α In Hep 3B cells, this in turn results in the synthesis and secretion of EPO; vascular endothelial growth factor is not measured at detectable levels. A single oral dose of vadadustat in rats potently increases circulating levels of EPO, and daily oral dosing for 14 days increases RBC indices in healthy rats and in the 5/6 nephrectomy model of CKD. In mice and dogs, once-daily repeat oral dosing increases hemoglobin and hematocrit. Vadadustat has a relatively short half-life in all nonclinical species evaluated and does not accumulate when administered as a single bolus dose (oral or intravenous) or upon repeat oral dosing. The pharmacological profile of vadadustat supports continued development for treatment of renal anemia. SIGNIFICANCE STATEMENT: Vadadustat (AKB-6548) is an orally bioavailable small molecule prolyl-4-hydroxylase inhibitor in development for anemia of chronic kidney disease. It is an equipotent inhibitor of the three human prolyl-4-hydroxylase domain isoforms, which activates erythropoiesis through stabilization of hypoxia-inducible factor (HIF)-1 α and HIF-2 α , increasing production of erythropoietin, without detectable stimulation of vascular endothelial growth factor., (Copyright © 2022 The Author(s).)

Prolyl hydroxylase 2 (PHD2) is a key regulatory enzyme responsible for the degradation of hypoxia-inducible factor-α (HIF-α). Pharmacological inhibition of PHD2 stabilizes HIF-α and induces the production of endogenous erythropoietin (EPO), which is regarded as a promising strategy for the treatment of renal anemia. To date, a series of PHD2 inhibitors have been approved or advanced into clinical studies. In this study, we developed a new type of PHD2 inhibitors with the tetrahydropyridin-4-ylpicolinoylglycine scaffold by using a scaffold hopping strategy. Among them, compound 25 showed potent inhibition toward PHD2 with an IC 50 of 6.55 ± 0.41 nM. Furthermore, compound 25 upregulated reticulocytes in C57BL/6 mice. The subacute toxicological assay demonstrated 25 has no obvious toxicity in vivo. Overall, compound 25 is a promising candidate for the treatment of renal anemia., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Hypoxia-inducible factor (HIF) prolyl 4-hydroxylases (HIF-P4Hs 1-3) are druggable targets in renal anemia, where pan-HIF-P4H inhibitors induce an erythropoietic response. Preclinical data suggest that HIF-P4Hs could also be therapeutic targets for treating metabolic dysfunction, although the contributions of HIF-P4H isoenzymes in various tissues to the metabolic phenotype are inadequately understood. Here, we used mouse lines that were gene-deficient for HIF-P4Hs 1 to 3 and two preclinical pan-HIF-P4H inhibitors to study the contributions of these isoenzymes to the anthropometric and metabolic outcome and HIF response. We show both inhibitors induced a HIF response in wildtype white adipose tissue (WAT), liver, and skeletal muscle and alleviated metabolic dysfunction during a 6-week treatment period, but they did not alter healthy metabolism. Our data indicate that HIF-P4H-1 contributed especially to skeletal muscle and WAT metabolism and that its loss lowered body weight and serum cholesterol levels upon aging. In addition, we found HIF-P4H-3 had effects on the liver and WAT and its loss increased body weight, adiposity, liver weight and triglyceride levels, WAT inflammation, and cholesterol levels and resulted in hyperglycemia and insulin resistance, especially during aging. Finally, we demonstrate HIF-P4H-2 affected all tissues studied; its inhibition lowered body and liver weight and serum cholesterol levels and improved glucose tolerance. We found very few HIF target metabolic mRNAs were regulated by the inhibition of three isoenzymes, thus suggesting a potential for selective therapeutic tractability. Altogether, these data provide specifications for the future development of HIF-P4H inhibitors for the treatment of metabolic diseases., Competing Interests: Conflict of interest G. W. is an employee and shareholder of FibroGen, Inc, which develops HIF-P4H inhibitors as therapeutics. J. M. owns equity in the company, which supports her research., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Competing Interests: MT has received honoraria (unrelated to anaemia or HIF-PHIs) from AstraZeneca for lectures on the future of nephrology. RT is a paid standing member of the US FDA Cardiovascular and Renal Drugs Advisory Committee, which reviewed the application for roxadustat, and is a paid consultant to Fresenius Medical Care North America, unrelated to the topic of this Comment.

The respiratory epithelium provides a first line of defense against pathogens. Hypoxia-inducible factor (HIF)1α is a transcription factor which is stabilized in hypoxic conditions through the inhibition of prolyl-hydroxylase (PHD)2, the enzyme that marks HIF1α for degradation. Here, we studied the impact of HIF1α stabilization on the response of primary human bronchial epithelial (HBE) cells to the bacterial component, flagellin. The treatment of flagellin-stimulated HBE cells with the PHD2 inhibitor IOX2 resulted in strongly increased HIF1α expression. IOX2 enhanced the flagellin-induced expression of the genes encoding the enzymes involved in glycolysis, which was associated with the intracellular accumulation of pyruvate. An untargeted pathway analysis of RNA sequencing data demonstrated the strong inhibitory effects of IOX2 toward key innate immune pathways related to cytokine and mitogen-activated kinase signaling cascades in flagellin-stimulated HBE cells. Likewise, the cell-cell junction organization pathway was amongst the top pathways downregulated by IOX2 in flagellin-stimulated HBE cells, which included the genes encoding claudins and cadherins. This IOX2 effect was corroborated by an impaired barrier function, as measured by dextran permeability. These results provide a first insight into the effects associated with HIF1α stabilization in the respiratory epithelium, suggesting that HIF1α impacts properties that are key to maintaining homeostasis upon stimulation with a relevant bacterial agonist.

Background: Daprodustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor. In patients with chronic kidney disease (CKD) who are not undergoing dialysis, the efficacy and safety of daprodustat, as compared with the conventional erythropoiesis-stimulating agent darbepoetin alfa, are unknown., Methods: In this randomized, open-label, phase 3 trial with blinded adjudication of cardiovascular outcomes, we compared daprodustat with darbepoetin alfa for the treatment of anemia in patients with CKD who were not undergoing dialysis. The primary outcomes were the mean change in the hemoglobin level from baseline to weeks 28 through 52 and the first occurrence of a major adverse cardiovascular event (MACE; a composite of death from any cause, nonfatal myocardial infarction, or nonfatal stroke)., Results: Overall, 3872 patients were randomly assigned to receive daprodustat or darbepoetin alfa. The mean (±SD) baseline hemoglobin levels were similar in the two groups. The mean (±SE) change in the hemoglobin level from baseline to weeks 28 through 52 was 0.74±0.02 g per deciliter in the daprodustat group and 0.66±0.02 g per deciliter in the darbepoetin alfa group (difference, 0.08 g per deciliter; 95% confidence interval [CI], 0.03 to 0.13), which met the prespecified noninferiority margin of -0.75 g per deciliter. During a median follow-up of 1.9 years, a first MACE occurred in 378 of 1937 patients (19.5%) in the daprodustat group and in 371 of 1935 patients (19.2%) in the darbepoetin alfa group (hazard ratio, 1.03; 95% CI, 0.89 to 1.19), which met the prespecified noninferiority margin of 1.25. The percentages of patients with adverse events were similar in the two groups., Conclusions: Among patients with CKD and anemia who were not undergoing dialysis, daprodustat was noninferior to darbepoetin alfa with respect to the change in the hemoglobin level from baseline and with respect to cardiovascular outcomes. (Funded by GlaxoSmithKline; ASCEND-ND ClinicalTrials.gov number, NCT02876835.)., (Copyright © 2021 Massachusetts Medical Society.)

Background: Among patients with chronic kidney disease (CKD), the use of recombinant human erythropoietin and its derivatives for the treatment of anemia has been linked to a possibly increased risk of stroke, myocardial infarction, and other adverse events. Several trials have suggested that hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitors (PHIs) are as effective as erythropoiesis-stimulating agents (ESAs) in increasing hemoglobin levels., Methods: In this randomized, open-label, phase 3 trial, we assigned patients with CKD who were undergoing dialysis and who had a hemoglobin level of 8.0 to 11.5 g per deciliter to receive an oral HIF-PHI (daprodustat) or an injectable ESA (epoetin alfa if they were receiving hemodialysis or darbepoetin alfa if they were receiving peritoneal dialysis). The two primary outcomes were the mean change in the hemoglobin level from baseline to weeks 28 through 52 (noninferiority margin, -0.75 g per deciliter) and the first occurrence of a major adverse cardiovascular event (a composite of death from any cause, nonfatal myocardial infarction, or nonfatal stroke), with a noninferiority margin of 1.25., Results: A total of 2964 patients underwent randomization. The mean (±SD) baseline hemoglobin level was 10.4±1.0 g per deciliter overall. The mean (±SE) change in the hemoglobin level from baseline to weeks 28 through 52 was 0.28±0.02 g per deciliter in the daprodustat group and 0.10±0.02 g per deciliter in the ESA group (difference, 0.18 g per deciliter; 95% confidence interval [CI], 0.12 to 0.24), which met the prespecified noninferiority margin of -0.75 g per deciliter. During a median follow-up of 2.5 years, a major adverse cardiovascular event occurred in 374 of 1487 patients (25.2%) in the daprodustat group and in 394 of 1477 (26.7%) in the ESA group (hazard ratio, 0.93; 95% CI, 0.81 to 1.07), which also met the prespecified noninferiority margin for daprodustat. The percentages of patients with other adverse events were similar in the two groups., Conclusions: Among patients with CKD undergoing dialysis, daprodustat was noninferior to ESAs regarding the change in the hemoglobin level from baseline and cardiovascular outcomes. (Funded by GlaxoSmithKline; ASCEND-D ClinicalTrials.gov number, NCT02879305.)., (Copyright © 2021 Massachusetts Medical Society.)

Anemia is a common feature and complication of chronic kidney disease (CKD). Erythropoiesis-stimulating agents (ESAs) and recombinant human erythropoietin have been used widely in renal anemia treatment. Recently, hypoxia-inducible factor-prolyl hydroxylase domain inhibitors (HIF-PHIs) that may improve the treatment of renal anemia patients were launched. Previous studies indicated that HIF-PHIs may decrease hepcidin levels and modulate iron metabolism, thereby increasing total iron-binding capacity and reducing the need for iron supplementation. Furthermore, HIF-PHIs can reduce inflammation and oxidative stress in CKD. Recombinant erythropoietin has become a routine treatment for patients with CKD and end-stage renal disease with relatively few adverse effects. However, higher doses of recombinant erythropoietin have been demonstrated to be an independent predictor of mortality in patients under hemodialysis. Phase III clinical trials of HIF-PHIs in patients with anemia and dialysis-dependent CKD have shown their efficacy and safety in both non-dialysis and dialysis CKD patients. However, HIFα binds to specific hypoxia-response elements in the vascular endothelial growth factor or retinoic acid-related orphan receptor gamma t (RORγt) promoter, which may be involved in the progression of cancer, psoriasis, and rheumatoid arthritis. In this paper, we have summarized the mechanism, clinical application, and clinical trials of HIF-PHIs in the treatment of renal anemia and aimed to provide an overview of the new drugs in clinical practice, as well as reconsider the advantages and disadvantages of HIF-PHIs and ESAs. Presently, there are not enough clinical studies examining the effects of long-term administration of HIF-PHIs. Therefore, further studies will be needed., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Hypoxia-induced inflammation is the critical pathological feature of acute kidney injury (AKI). Activation of hypoxia-inducible factor (HIF) signaling is considered as a central mechanism of body adapting to hypoxia. Hypoxia-inducible factor prolyl hydroxylase inhibitor FG-4592 (Roxadustat) is a first-in-class HIF stabilizer for the treatment of patients with renal anemia. The current study aimed to investigate whether FG-4592 could protect against ischemia/reperfusion (I/R)-induced kidney injury via inhibiting inflammation. Here, efficacy of FG-4592 was evaluated in a mice model of I/R-induced AKI. Interestingly, improved renal function and renal tubular injuries, combined with reduced kidney injury molecule-1 were observed in the mice with FG-4592 administration. Meanwhile, inflammation responses in FG-4592-treated mice were also strikingly attenuated, as evidenced by the decreased infiltration of macrophages and neutrophils and down-regulated expression of inflammatory cytokines. In vitro , FG-4592 treatment significantly protected the tubular epithelial cells against hypoxia-induced injury, with suppressed inflammation and cell injuries. In summary, FG-4592 treatment could protect against the I/R-induced kidney injury possibly through diminishing tubular cells injuries and suppression of sequence inflammatory responses. Thus, our findings definitely offered a clinical potential approach in treating AKI.

The proline hydroxylase domain-containing enzymes (PHDs) acts as cellular oxygen sensors, inducing a series of responses to hypoxia, especially during the regulation of metabolism and energy homeostasis. The increase of Ca 2+ in cardiomyocytes, induced by the opening of PHD signaling pathway, is the key initiation signal necessary for the PHD-mediated regulation of the energy metabolism pathway, but the underlying molecular mechanism remains incompletely understood. This study used PHD inhibitors (PHIs) and PHD2-specific RNA interference (PHD2shRNA) to inhibit PHD signals in cardiomyocytes to explore whether transient receptor potential ankyrin 1 (TRPA1) is involved in the regulation of calcium ion influx in the PHD activation pathway associated with to AMP-activated protein kinase (AMPK). The Fluo-3AM probe was used to measure changes in free intracellular calcium ion concentrations, and Western blot analysis was used to detect the levels of phosphorylated (P)-AMPK, TRPA1, and P-Ca 2+ /calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) levels. The PHI-mediated inhibition of PHD resulted in an increase in free Ca 2+ fluorescence in cardiomyocytes, which activated AMPK, TRPA1, and CaMKⅡ. The TRPA1 inhibitor HC030031, the CaMKII inhibitor KN93, and a ryanodine inhibitor (Ryanodine) were all able to inhibit the PHI-induced increase in intracellular Ca 2+ and AMPK activation. Both PHIs and PHD2shRNA were able to effectively activate CaMKII and TRPA1. However, an inositol 1,4,5-triphosphate receptor (IP3R) inhibitor and the protein kinase A (PKA) inhibitor H89 did not significantly inhibit the PHI-induced increase in intracellular Ca 2+ and AMPK activation. These results indicated that PHD might activate the CaMKⅡ pathway through the TRPA1 ion channel, inducing the release of calcium from the sarcoplasmic reticulum through ryanodine receptor 2 (RyR2), activating AMPK to initiate the protective effects of hypoxia in cardiomyocytes., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Periodontal defect regeneration in severe periodontitis remains a challenging task in clinic owing to poor survival of seed cells caused by the remaining oxidative stress microenvironment. Recently, the reduction of prolyl hydroxylase domain-containing protein 2 (PHD2), a primary cellular oxygen sensor, has shown an incredible extensive effect on skeletal muscle tissue regeneration by improving cell resistance to reactive oxygen species, whereas its role in periodontal defect repair is unclear. Here, through lentivirus vector-mediated RNA interference, the PHD2 gene in human periodontal ligament cells (hPDLCs) is silenced, leading to hypoxia-inducible factor-1α stabilization in normoxia. In vitro, PHD2 silencing not only exhibited a satisfactory effect on cell proliferation, but also induced distinguished osteogenic differentiation of hPDLCs. Real-time polymerase chain reaction and Western blotting revealed significant up-regulation of osteocalcin, alkaline phosphatase (ALP), runt-related transcription factor 2, and collagen type I (COL I). Under oxidative stress conditions, COL I and ALP expression levels, suppressed by 100 μM H 2 O 2 , were elevated by PHD2-gene-silencing in hPDLCs. In vivo, periodontal fenestration defects were established in 18 female Sprague-Dawley rats aged 6 wk old, followed by implantation of PHD2 silencing hPDLCs in situ for 21 d. Persistent and stable silencing of PHD2 in hPDLCs promoted better new bone formation according to microcomputed tomography 3D reconstruction and related bone parameter analysis. This work demonstrates the therapeutic efficiency of PHD2 gene interference in osteogenic differentiation and periodontal defect repair for highly efficient periodontal regeneration., (©2021 Society for Leukocyte Biology.)

Inhibition of hypoxia-inducible factor-prolyl hydroxylase (PHD) has been shown to protect against various kidney diseases. However, there are controversial reports on the effect of PHD inhibition in renoprotection. The present study determined whether delivery of PHD2 small interfering RNA (siRNA) using an siRNA carrier, folic acid (FA)-decorated polyamidoamine dendrimer generation 5 (G5-FA), would mainly target kidneys and protect against renal ischemia/reperfusion injury (I/R). The renal I/R was generated by clipping the renal pedicle for 30 minutes in uninephrectomized mice. Mice were sacrificed 48 hours after I/R. Normal saline or G5-FA complexed with control or PHD2 siRNA was injected via tail vein 24 hours before ischemia. After the injection of near-infrared fluorescent dye-labeled G5-FA, the fluorescence was mainly detected in kidneys but not in other organs. The reduction of PHD2 mRNA and protein was only observed in kidneys but not in other organs after injection of PHD2-siRNA-G5-FA complex. The injection of PHD2-siRNA-G5-FA significantly alleviated renal I/R injury, as shown by the inhibition of increases in serum creatinine and blood urea nitrogen, the blockade of increases in kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin, and the improvement of histologic damage compared with mice treated with control siRNA. PHD2 siRNA can be delivered specifically into kidneys using G5-FA, and that local knockdown of PHD2 gene expression within the kidney alleviates renal I/R injury. Therefore, G5-FA is an efficient siRNA carrier to deliver siRNA into the kidney, and that local inhibition of PHD2 within the kidney may be a potential strategy for the management of acute I/R injury. SIGNIFICANCE STATEMENT: Folic acid (FA)-decorated polyamidoamine dendrimer generation 5 (G5-FA) was demonstrated to be an effective carrier to deliver small interfering RNA (siRNA) into kidneys. Delivery of prolyl hydroxylase domain protein 2 siRNA with G5-FA effectively protected the kidneys against the acute renal ischemia/reperfusion injury., (Copyright © 2021 by The American Society for Pharmacology and Experimental Therapeutics.)

Hypoxia-inducible factor prolyl hydroxylase domain 2 (PHD2) is an important oxygen sensor in animals. By using the CO-releasing molecule-2 (CORM-2) as an in situ CO donor, we demonstrate that CO is an inhibitor of PHD2. This report provides further evidence about the emerging role of CO in oxygen sensing and homeostasis., (© 2021 Wiley-VCH GmbH.)

Prolyl hydroxylase (PH) enzymes control the degradation of hypoxia-inducible factor (HIF), a transcription factor known to regulate erythropoiesis, angiogenesis, glucose metabolism, cell proliferation, and apoptosis. HIF-PH inhibitors (HIF-PHIs) correct anemia in patients with renal disease and in animal models of anemia and kidney disease. However, the effects of HIF-PHIs on comorbidities associated with kidney disease remain largely unknown. We evaluated the effects of the HIF-PHI FG-2216 in obese ZSF1 (Ob-ZSF1) rats, an established model of kidney failure with metabolic syndrome. Following unilateral nephrectomy (Nx) at 8 weeks of age, rats were treated with 40 mg/kg FG-2216 or vehicle by oral gavage three times per week for up to 18 weeks. FG-2216 corrected blood hemoglobin levels and improved kidney function and histopathology in Nx-Ob-ZSF1 rats by increasing the glomerular filtration rate, decreasing proteinuria, and reducing peritubular fibrosis, tubular damage, glomerulosclerosis and mesangial expansion. FG-2216 increased renal glucose excretion and decreased body weight, fat pad weight, and serum cholesterol in Nx-Ob-ZSF1 rats. Additionally, FG-2216 corrected hypertension, improved diastolic and systolic heart function, and reduced cardiac hypertrophy and fibrosis. In conclusion, the HIF-PHI FG-2216 improved renal and cardiovascular outcomes, and reduced obesity in a rat model of kidney disease with metabolic syndrome. Thus, in addition to correcting anemia, HIF-PHIs may provide renal and cardiac protection to patients suffering from kidney disease with metabolic syndrome., Competing Interests: FibroGen, Inc. is developing HIF-PHIs for the treatment of anemia. P.E.S., G.G., Z. W., W. Z., A.L., and U. d. B. are employees, and/or stock owners of FibroGen Inc. The funder provided support in the form of salaries but did not play any additional role. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background and Objectives: We evaluated the efficacy and cardiovascular safety of roxadustat versus placebo by analyzing data pooled from three phase 3 studies of roxadustat in patients with non-dialysis-dependent CKD and CKD-related anemia., Design, Setting, Participants, & Measurements: In the three phase 3, double-blind studies of roxadustat versus placebo evaluating the treatment of CKD-related anemia in patients not requiring dialysis, the primary efficacy end point was mean change from baseline in hemoglobin averaged over weeks 28-52, regardless of rescue therapy. The primary cardiovascular safety end point was a composite measure of major adverse cardiovascular events (MACE; all-cause mortality, myocardial infarction, stroke). MACE plus (MACE+; MACE plus unstable angina and heart failure requiring hospitalization) and all-cause mortality were key secondary safety end points. These safety end points were adjudicated., Results: A total of 4277 patients with non-dialysis-dependent CKD were randomized (roxadustat, n =2391; placebo, n =1886). Baseline characteristics were comparable between groups; the mean (SD) hemoglobin was 9.1 (0.7) g/dl and mean eGFR was 20 (12) ml/min per 1.73 m 2 . Patients treated with roxadustat versus those treated with placebo showed a mean change from baseline in hemoglobin averaged over weeks 28-52, regardless of rescue therapy, of 1.9 versus 0.2 g/dl, a treatment difference of 1.7 (95% confidence interval [95% CI], 1.7 to 1.8). Roxadustat reduced the need for red blood cell transfusion in the first 52 weeks versus placebo (6.1 versus 20.4 per 100 patient-exposure years, respectively; hazard ratio [HR], 0.26; 95% CI, 0.21 to 0.32). There were no increased risks of MACE (HR, 1.10; 95% CI, 0.96 to 1.27), MACE+ (HR, 1.07; 95% CI, 0.94 to 1.21), all-cause mortality (HR, 1.08; 95% CI, 0.93 to 1.26), or individual MACE+ components in patients treated with roxadustat versus those treated with placebo., Conclusions: Roxadustat was more effective than placebo at increasing hemoglobin in patients with non-dialysis-dependent CKD and anemia, while decreasing transfusion rate and being noninferior to placebo with respect to risk of MACE., Clinical Trial Registry Name and Registration Number: A Study of FG-4592 for the Treatment of Anemia in Chronic Kidney Disease Patients Not Receiving Dialysis, NCT01750190; Roxadustat in the Treatment of Anemia in Chronic Kidney Disease Patients Not Requiring Dialysis (ALPS), NCT01887600; Safety and Efficacy Study of Roxadustat to Treat Anemia in Patients With Chronic Kidney Disease (CKD), Not on Dialysis, NCT02174627., (Copyright © 2021 by the American Society of Nephrology.)

What Is Known and Objective: Previous studies based on small-sample clinical data proved that short-term use of hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitors increased haemoglobin levels in anaemic patients with chronic kidney disease (CKD). However, these studies reached conflicting conclusions on iron parameters and adverse event profiles. Our meta-analysis aimed to evaluate the long-term efficacy and safety of HIF-PHD inhibitors in renal anaemia., Methods: Randomized controlled trials comparing treatment with HIF-PHD inhibitors versus placebo or erythropoiesis-stimulating agents (ESAs) were thoroughly searched in the PubMed, Embase, Cochrane Library and international clinical trial registries. Meta-analysis was performed on main outcomes with random effects models., Results and Discussion: A total of 30 studies comprising 13,146 patients were included. The HIF-PHD inhibitors used included roxadustat, daprodustat, vadadustat, molidustat, desidustat and enarodustat. HIF-PHD inhibitors significantly increased haemoglobin levels in comparison with placebo [weighted mean difference (WMD) 1.53, 95% confidence interval (CI) 1.39 to 1.67] or ESAs (WMD 0.13, 95% CI 0.03 to 0.22). Hepcidin, ferritin and serum iron levels were decreased, while total iron binding capacity and transferrin levels were increased in the HIF-PHD inhibitor group versus those in placebo or ESAs group. Additionally, HIF-PHD inhibitors medication was associated with cholesterol-lowering effects. As for safety, the risk of serious adverse events in the HIF-PHD inhibitor group was increased in comparison with placebo group [risk ratio (RR) 1.07, 95% CI 1.01 to 1.13], but comparable to the ESAs group (RR 1.02, 95% CI 0.94 to 1.10). Compared with placebo, the agents increased the risk of diarrhoea (1.21, 1.00 to 1.47), nausea (1.46, 1.09 to 1.97), oedema peripheral (1.32, 1.01 to 1.59), hyperkalemia (1.27, 1.05 to 1.54) and hypertension (1.34, 1.02 to 1.76). Compared with ESAs, the drugs increased the risk of vomiting (1.30, 1.02 to 1.65), headache (1.27, 1.05 to 1.53) and thrombosis events (1.31, 1.05 to 1.63)., What Is New and Conclusion: HIF-PHD inhibitors treatment effectively increased haemoglobin levels and promoted iron utilization in anaemic patients with CKD, and they were well tolerated for long-term use. In order to avoid unfavourable effects of excessive iron consumption, it was appropriate to administer HIF-PHD inhibitors in combination with iron supplements for long-term treatment., (© 2021 John Wiley & Sons Ltd.)

Background & Aims: Hypoxia inducible factors (HIFs) are a hallmark of inflammation and are key regulators of hepatic immunity and metabolism, yet their role in HBV replication is poorly defined. HBV replicates in hepatocytes within the liver, a naturally hypoxic organ, however most studies of viral replication are performed under conditions of atmospheric oxygen, where HIFs are inactive. We therefore investigated the role of HIFs in regulating HBV replication., Methods: Using cell culture, animal models, human tissue and pharmacological agents inhibiting the HIF-prolyl hydroxylases, we investigated the impact of hypoxia on the HBV life cycle., Results: Culturing liver cell-based model systems under low oxygen uncovered a new role for HIFs in binding HBV DNA and activating the basal core promoter, leading to increased pre-genomic RNA and de novo HBV particle secretion. The presence of hypoxia responsive elements among all primate members of the hepadnaviridae highlights an evolutionary conserved role for HIFs in regulating this virus family., Conclusions: Identifying a role for this conserved oxygen sensor in regulating HBV transcription suggests that this virus has evolved to exploit the HIF signaling pathway to persist in the low oxygen environment of the liver. Our studies show the importance of considering oxygen availability when studying HBV-host interactions and provide innovative routes to better understand and target chronic HBV infection., Lay Summary: Viral replication in host cells is defined by the cellular microenvironment and one key factor is local oxygen tension. Hepatitis B virus (HBV) replicates in the liver, a naturally hypoxic organ. Hypoxia inducible factors (HIFs) are the major sensors of low oxygen; herein, we identify a new role for these factors in regulating HBV replication, revealing new therapeutic targets., Competing Interests: Conflict of interest None of the authors have any conflict of interest. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2021 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Hypoxia-inducible factor (HIF) stabilizer belongs to a novel class of pharmacologically active substances, which are capable of inducing the endogenous erythropoietic system. The transcriptional activator HIF has been shown to significantly increase blood hemoglobin and is well set for the treatment of anemia resulting from chronic kidney disease. This research work reports a comprehensive study of the most popular HIF stabilizer roxadustat and its metabolites in thoroughbred horse urine after oral administration. The plausible structures of the detected metabolites were postulated using liquid chromatography-high-resolution mass spectrometry. Under the experimental condition 13 metabolites (7 phase I, 1 phase II, and 5 conjugates of phase I metabolism) were positively detected (M1-M13). The major phase I metabolites identified were formed by hydroxylation. Dealkylated and hydrolyzed phase I metabolites were also observed in this study. In phase II, a glucuronic acid conjugate of roxadustat was detected as the major metabolite. The sulfonic acid conjugates were observed to be formed from phase I metabolites. The characterized in vivo metabolites can potentially serve as target analytes for doping control analysis; hence, the result is an important tool for assessing its use and abuse in competitive sport., (© 2021 John Wiley & Sons, Ltd.)

Purpose: HIF-PHI (hypoxia-inducible factor prolyl hydroxylase inhibitor) was developed to improve renal anemia. This study was to evaluate the efficiency and safety of HIF-PHI in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD)., Methods: The literature was extracted from PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, and the Wanfang database. Statistical tests and forest plots were depicted by Review Manager Version 5.3. The primary outcome was a change in hemoglobin level from baseline (ΔHb). Secondary outcomes were changes in ferritin (ΔFerritin), hepcidin (ΔHepcidin), and transferrin saturation from baseline (ΔTSAT), and adverse events (AEs). This study is registered with PROSPERO (registration number CRD42020199656)., Results: Ten trials were included. The results showed that HIF-PHI improved the ΔHb [SMD 3.03 (95% CI 2.10, 3.96), P < 0.00001] in NDD patients. HIF-PHI reduced hepcidin levels in the NDD patients [SMD - 1.44 (95% CI - 2.19-0.70), P = 0.0002]. ΔFerritin values were reduced significantly in the HIF-PHI group [SMD - 1.08 (95% CI - 1.63-0.53), P = 0.0001]. However, ΔTSAT values showed no significant difference in the HIF-PHI group compared to the placebo group [SMD - 0.23 (95% CI - 0.66-0.21), P = 0.31]. In the safety assessment, HIF-PHI did not increase adverse events significantly [RR 0.98 (95% CI 0.88-1.10), P = 0.74]., Conclusion: HIF-PHI improves renal anemia and iron utilization disorder in NDD-CKD patients, without significantly more adverse events.

Prolyl hydroxylase (PHD) enzymes play a critical role in the cellular responses to hypoxia through their regulation of the hypoxia inducible factor α (HIF-α) transcription factors. PHD inhibitors show promise for the treatment of diseases including anaemia, cardiovascular disease and stroke. In this work, a pharmacophore-based virtual high throughput screen was used to identify novel potential inhibitors of human PHD2. Two moderately potent new inhibitors were discovered, with IC 50 values of 4 μM and 23 μM respectively. Cell-based studies demonstrate that these compounds exhibit protective activity in neuroblastoma cells, suggesting that they have the potential to be developed into clinically useful neuroprotective agents., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Anemia with inflammation-induced defective iron utilization is a pathological condition observed in patients suffering from chronic kidney disease (CKD) or chronic inflammatory disease. There is no reasonable treatment for these conditions, because the effects of erythropoiesis stimulating agents (ESAs) or iron supplementation in the treatment of anemia are insufficient. JTZ-951 (enarodustat) has been characterized as a novel, orally bioavailable inhibitor of hypoxia-inducible factor prolyl hydroxylase (HIF-PH), and has been developed as a novel therapeutic agent for anemia with CKD. In this study, the effects of JTZ-951 on iron utilization during erythropoiesis and on anemia of inflammation were compared with those of recombinant human erythropoietin (rHuEPO) using normal rat and rat model of anemia of inflammation. In normal rats, under conditions in which JTZ-951 and rHuEPO showed similar erythropoietic effect, repeated doses of JTZ-951 induced erythropoiesis while retaining the hemoglobin content in red blood cells, while administration of rHuEPO resulted in decrease in some erythrocyte-related parameters. As for iron-related parameters during erythropoiesis, JTZ-951 exhibited more efficient iron utilization compared to rHuEPO. A single dose of JTZ-951 resulted in decrease in hepcidin expression observed within 24 h after administration, but a single dose of rHuEPO did not. In a rat model of anemia of inflammation (also known as a model with functional iron-deficiency), JTZ-951 showed erythropoietic effect, in contrast with rHuEPO. These results suggest that, unlike rHuEPO, JTZ-951 stimulates erythropoiesis by increasing iron utilization, and improves anemia of inflammation., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: To meta-statistically compare the efficiency of hypoxia-induced factor prolyl hydroxylase inhibitor on hemoglobin, ferritin, hepcidin rate, and adverse events., Methods: A systematic identification of literature was performed according to PRISMA guidelines on 4 academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL. A meta-analysis evaluating the influence of hypoxia-induced factors was performed for patients undergoing/not undergoing hemodialysis. The analysis evaluated the efficacy of hypoxia-induced factors on hemoglobin, ferritin, hepcidin rate, and the number of adverse events., Results: Out of 1052 records, 15 articles including 2045 patients (mean age 62.1 ± 5.4 years) were included in this review. The systematic review presents a 1a level of evidence supporting the use of hypoxia-induced factor for mediating anemia in patients with chronic kidney disease. The meta-analysis reveals medium to large beneficial effects of the hypoxia-induced factor on hemoglobin rate for patients receiving (0.72) and not receiving (1.04) hemodialysis. Moreover, the administration of hypoxia-induced factors was reported to reduce ferritin rate and the hepcidin rate, and the number of adverse events in patients with chronic kidney disease., Conclusion: The current meta-analysis recommends the use of hypoxia-induced factor prolyl hydroxylase inhibitor for managing anemia in chronic kidney disease.

Background: Current anemia therapies for patients with non-dialysis-dependent CKD may require injection and medical visits. Roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor, stimulates erythropoiesis and improves iron homeostasis., Methods: In this double-blind phase 3 study, we randomized patients with non-dialysis-dependent CKD stages 3-5 and hemoglobin <10.0 g/dl (1:1) to thrice-weekly 70-mg oral roxadustat or placebo. Doses were titrated throughout the study based on hemoglobin levels. The primary efficacy end point was mean change from baseline in hemoglobin averaged over weeks 28-52 versus placebo, irrespective of rescue therapy use. We assessed patients for adverse events., Results: The study included 2781 patients, 1393 who received roxadustat and 1388 who received placebo. Mean baseline hemoglobin was 9.1 g/dl for both groups. The mean change in hemoglobin from baseline was 1.75 g/dl (95% confidence interval [95% CI], 1.68 to 1.81) with roxadustat versus 0.40 g/dl (95% CI, 0.33 to 0.47) with placebo, ( P <0.001). Among 411 patients with baseline elevated high-sensitivity C-reactive protein, mean change in hemoglobin from baseline was 1.75 g/dl (95% CI, 1.58 to 1.92) with roxadustat versus 0.62 g/dl (95% CI, 0.44 to 0.80) with placebo, ( P <0.001). Roxadustat reduced the risk of red blood cell transfusion by 63% (hazard ratio, 0.37; 95% CI, 0.30 to 0.44). The most common adverse events with roxadustat and placebo, respectively, were ESKD (21.0% versus 20.5%), urinary tract infection (12.8% versus 8.0%), pneumonia (11.9% versus 9.4%), and hypertension (11.5% versus 9.1%)., Conclusions: Roxadustat effectively increased hemoglobin in patients with non-dialysis-dependent CKD and reduced the need for red blood cell transfusion, with an adverse event profile comparable to that of placebo., Clinical Trial Registry Name and Registration Number: Safety and Efficacy Study of Roxadustat to Treat Anemia in Patients With CKD, Not on Dialysis, NCT02174627., (Copyright © 2021 by the American Society of Nephrology.)