REVIEW article

Front. Pharmacol., 29 August 2022

Sec. Renal Pharmacology

Volume 13 - 2022 | https://doi.org/10.3389/fphar.2022.971795

Roxadustat: Not just for anemia

  • 1. Department of Nephrology, The First Hospital of Jilin University, Changchun, Jilin, China

  • 2. Physical Examination Center, The First Hospital of Jilin University, Changchun, Jilin, China

Abstract

Roxadustat is a recently approved hypoxia-inducible factor prolyl hydroxylase inhibitor that has demonstrated favorable safety and efficacy in the treatment of renal anemia. Recent studies found it also has potential for the treatment of other hypoxia-related diseases. Although clinical studies have not yet found significant adverse or off-target effects of roxadustat, clinicians must be vigilant about these possible effects. Hypoxia-inducible factor regulates the expression of many genes and physiological processes in response to a decreased level of oxygen, but its role in the pathogenesis of different diseases is complex and controversial. In addition to increasing the expression of hypoxia-inducible factor, roxadustat also has some effects that may be HIF-independent, indicating some potential off-target effects. This article reviews the pharmacological characteristics of roxadustat, its current status in the treatment of renal anemia, and its possible effects on other pathological mechanisms.

Introduction

Hypoxia-inducible factor (HIF) is a key regulator of the body’s response to hypoxia. This protein is a heterodimer that has an oxygen-sensitive a subunit and a constitutively expressed ß subunit. The prolyl hydroxylase domain (PHD) is an oxygen sensitive enzyme with three subtypes (PHD1, PHD2, and PHD3) that regulates the activity of HIF-α (; ). Under normoxic conditions, PHD catalyzes the degradation of the HIF-α subunit, leading to its inactivation. However, hypoxic conditions inhibit PHD activity, leading to stabilization and accumulation of HIF-α in the cytoplasm (); under these conditions, HIF-α translocates into the nucleus, dimerizes with HIF-β, and activates the transcription of many genes (). In 1992, first discovered that HIF binds to the hypoxia response element (HRE) in the enhancer region of the erythropoietin gene (EPO), and was responsible for the induction of EPO and other oxygen-sensitive genes during hypoxia. To date, three distinct HIF-α subtypes have been identified: HIF-1α, HIF-2α, and HIF-3α. HIF-1α is primarily regulated by PHD2 (), is expressed in almost all cell types, and activates the transcription of many genes, including those that function in iron metabolism, angiogenesis, energy metabolism, mitochondrial metabolism, inflammation, cellulose production, and cell fate (; ). HIF-2α is mainly regulated by PHD1 and PHD3 (; ), is more restricted to specific cell types, such as renal interstitial fibroblast-like cells and endothelial cells, and is a major transcription factor regulating EPO expression and iron transport (). The function of HIF-3α remains uncertain, although some research showed it down-regulated the expression of the other two HIF genes ().

Roxadustat (FG-4592) is an orally bioavailable and reversible hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) that inhibits PHD by mimicking 2-oxoglutarate, one of its substrates (). This drug stabilizes the level of HIF and stimulates erythropoiesis in a dose-dependent manner (). Clinical trials of roxadustat began in November 2005 () and it was first approved in China for treatment of anemia patients receiving hemodialysis or peritoneal dialysis in December 2018 (). In August 2019, roxadustat was approved for the treatment of anemia in Chinese patients with chronic kidney disease (CKD) but not receiving dialysis (). Roxadustat has received increasing attention from researchers and nephrologists in various disciplines since its approval. Studies have shown that roxadustat has similar effects on the three subtypes of proline hydroxylase (PHD1, PHD2, and PHD3) (). In addition to the treatment of renal anemia, roxadustat may also protect against other hypoxia-related diseases, including chronic inflammation, fibrosis, ischemia, and even cancer. In this review, we summarize the pharmacological characteristics of roxadustat and describe recent research that examined its potential for use in pathologies other than renal anemia in an effort to provide an objective, in-depth, and up-to-date understanding of this medication (Figure 1).

FIGURE 1

Pharmacological characteristics of roxadustat

Roxadustat is an oral, potent, and reversible small molecule HIF-PHI whose molecular weight is 352.34 g/mol and chemical formula is C19H16N2O5 (). It is a second-generation HIF-PHI that was synthesized by adding a phenoxy group to carbon-7 of the quinoline core of its precursor, FG-2261 (). Roxadustat has a good pharmacokinetic profile, its solubility depends on pH (), and it is rapidly absorbed in healthy subjects and patients with moderate hepatic impairment. After oral administration, it usually reaches a maximum blood concentration in about 2 h (). The absorption of roxadustat is independent of food (), and body weight, age, gender, race, and drug dose have no significant effects on its pharmacokinetics (). After oral absorption, roxadustat is transported to the liver mainly via phase I oxidation by cytochrome P450 2C8 and phase II glucuronidation by uridine diphosphate glucuronyltransferase (UGT1A9) (). Its elimination half-life is approximately 9.6–16 h in healthy volunteers and approximately 18 h in patients with impaired renal function (; ). Roxadustat is a lipophilic acid, and is therefore tightly bound (approximately 99%) to plasma proteins, and cannot be significantly removed by dialysis (). Because roxadustat is mainly metabolized in the liver, the European Drug Administration suggested the dose should be reduced to half when initially given to patients with moderate liver cirrhosis (Child Pugh B), and that patients with severe liver cirrhosis (Child Pugh C) should not receive roxadustat ().

Patients with CKD typically need to take other drugs to treat the many complications of this disease, and drug interactions should be considered when treating these patients. Lanthanum carbonate, carbon adsorbents, omeprazole, and warfarin have no clinically relevant effects on the pharmacokinetics of roxadustat (; ; ; ). However, phosphorus-lowering drugs, such as calcium acetate and sevelamer, may form insoluble chelates with roxadustat and reduce its absorption (). In addition, roxadustat significantly increases the blood level of statins because it inhibits the pharmacokinetic interaction of organic anion transporting polypeptide 1B1/B3 (OATP1B1/B3) with statins (). Therefore, when statins are co-administered with roxadustat, adverse reactions should be evaluated and the statin dose should be reduced or the interval between the roxadustat doses should be increased. Roxadustat is usually administered 2 to 3 times per week for treatment of anemia in CKD patients, and the plasma levels generally return to very low levels between doses, without significant drug accumulation (). Current clinical studies support its efficacy and safety, but more in-depth and long-term studies are needed, especially before its indications can be expanded.

Effect of roxadustat on anemia

Anemia often accompanies CKD, and is associated with a significantly increased risk of morbidity, mortality, and cardiovascular events (). Previous studies showed that the prevalence of anemia in patients with CKD (15.4%) is twice that of the general population (7.6%), and the prevalence increases as CKD progresses (). Thus, in the United States, the prevalence of anemia is 8.4% in patients with CKD stage 1 and is 53.4% in patients with CKD stage 5 (). In China, more than 90% of the 500,000 patients undergoing dialysis have anemia (). The current treatments for anemia and CKD are generally erythropoietin stimulating agents (ESAs), iron supplements, and blood transfusions. When an ESA is used to treat renal anemia, it can increase the hemoglobin (Hb) level, reduce the need for blood transfusions, and improve quality-of-life, and these drugs have therefore been a key treatment for anemia in patients with CKD since 1989 (). However, treatment with ESAs, especially when aiming to achieve normal levels of Hb, may increase the risk of cardiovascular disease (CVD), myocardial infarction, hypertension, and thromboembolism (; ). Another disadvantage of ESAs is that they are administered intravenously or subcutaneously. Iron therapy may also require injections and hospital visits, and red blood cell transfusions significantly increase the cost of anemia treatment and may lead to infection, allosensitization, and rejection of kidney transplants. All of these factors can affect treatment compliance and outcome in non-hemodialysis and peritoneal dialysis patients who have anemia (; ). In addition, approximately 10% of patients are resistant to ESAs and require higher doses to achieve the recommended Hb target (). However, use of high-dose ESAs appears to increase the risk of adverse cardiovascular effects and mortality (; ). These findings led the US Food and Drug Administration (FDA) to recommend use of the lowest possible dose of an ESA that can achieve an adequate Hb level without the need for transfusions (). Although renal anemia is a serious and widespread problem, many patients with CKD still suffer from anemia due to inadequate treatment. Therefore, a safer and more effective method for treatment of anemia in CKD patients is urgently needed.

Three researchers who described the mechanism of HIF in response to hypoxia received the Nobel Prize in 2019 (). Roxadustat, as a novel oral HIF-PHI used for treatment of renal anemia, can regulate many of the pathological responses related to renal anemia. In particular, an intermittent dosing regimen of roxadustat (2 or 3 times per week) induces a transient elevation in endogenous EPO to near the normal physiological range, but below the level achieved by an intravenous ESA (). Roxadustat can also increase Hb to a level similar to that achieved by an ESA without substantially increasing the risk of cardiovascular events (). Another consideration when using an ESA is that iron is required for erythropoiesis (), and hepcidin (a key factor regulating iron homeostasis) increases with inflammation and limits intestinal absorption of iron, potentially causing ESA resistance (; ). Inflammation suppresses the response to an ESA, but the effects of roxadustat on Hb appear to be unaffected by inflammation (; ). Compared with ESAs, roxadustat appears to cause greater suppression of hepcidin (; ). As a likely consequence, roxadustat is effective in some individuals who are relatively resistant to ESAs. Consistent with this view, there is evidence that roxadustat prevents ESA-hyporesponsiveness and anemia in patients with myelodysplastic syndrome (; ). In addition, showed that roxadustat significantly increased the Hb level in patients with renal transplantation anemia without affecting renal function or increasing rejection. In contrast to ESAs, roxadustat is an oral medication, it can be stored at room temperature, and it improves the efficacy of oral iron and reduces the need for intravenous iron. These are clear advantages for patients with CKD, especially those who have anemia and are non-dialysis dependent (NDD) or using peritoneal dialysis.

Many studies have reported the efficacy and safety of roxadustat when used as a treatment for renal anemia. However, there is some evidence that roxadustat can cause a variety of side effects, mainly diarrhea, vomiting, peripheral edema, headache, back pain, fatigue, and hyperkalemia (; ). In addition, HIF functions in the progression of polycystic kidney disease (PKD), and roxadustat may promote the growth of renal cysts (). A case report found that roxadustat reduced the TSH levels in hemodialysis patients, but the mechanism and clinical significance of this effect is unclear (). Another consideration is that different countries have approved different initial doses of roxadustat, and there is also no unified clinical guideline regarding the starting and ending times of treatment. A document released by the U.S. FDA on its official website on 15 July 2021 questioned the cardiovascular safety of roxadustat. In particular, for dialysis dependent (DD) patients, roxadustat had a higher cardiovascular risk than epoetin alfa; for NDD patients, roxadustat had a higher cardiovascular risk than placebo. Therefore, the FDA refused to approve the listing of roxadustat in the United States. Therefore, large, high-quality multinational studies with long-term evaluations are needed to further examine different dosing strategies. In addition to roxadustat, other HIF-PHIs have been used clinically or are undergoing clinical trials for the treatment of CKD-related anemia (; ; ; ; ; ). Although all HIF-PHIs have similar mechanisms of action, their specific effects on cells and preferred targets may differ. This paper summarizes recent research on roxadustat and other HIF-PHIs, and describes their half-lives, targets, indications, and major adverse effects (Table 1).

TABLE 1

MoleculeHalf lifeMain targetIndicationsMajor adverse reactionsSponsorInvestigatinal status
Roxadustat9.6–12 hPHD1-3Dialysis and non-dialysis; CKD anemiaDiarrhea, vomiting, peripheral edema, headache, back pain, fatigue, and hyperkalemiaFibrogenIt is described as a second-generation HIF-PHI, and listed in China in December, 2018 ()
FG-221614 hPHD1-3Anemia including renal anemia, sickle cellemia, chemotherapy-induced anemiaIn 2007, a case of death due to fulminant hepatitis occurred in the course of a phase II study. (The adverse event was later declared to be unrelated to the drug, but no further clinical studies have been reported for FG-2216)FibrogenPhase II ()
Daprodustat4 hPHD1 and PDH3 are preferredChronic renal anemiaRetinal hemorrhage and anaphylaxis, hypertension, increased myocardial infarction and heart failure deterioration events, and showed tumor effects in patients with NDDGlaxoSmithKlineListed in Japan in June 2020 ()
Vadadustat4.5 hPHD3Dialysis and non-dialysis; CKD anemiaGastrointestinal reaction, hypertension, hyperkalemiaAkebia therapeuticsListed in Japan in June 2020 ()
Enarodustat1.4 hPHD1-3Chronic renal anemiaRespiratory tract infection, gastrointestinal reactionJapan Tobacco Inc.Listed in Japan in September 2020 ()
Desidustat6.9–13 hPHD1-3Dialysis and non-dialysis; CKD anemiaDizziness, respiratory infections, and gastrointestinal reactionsZydus CadilaPhase III ()
Molidustat7–13 hPHD1-3, especially PHD3Chronic kidney disease or end-stage; nephropathy-associated anemiaIncreased levels of inflammatory markers CRP, infections and gastrointestinal reactionsBayer health careListed in Japan in January 2021 ()

The PHD inhibitors have been trialled in Humans.

In addition, considering the breadth of biological processes regulated by HIF, roxadustat may have clinical effects beyond the stimulation of erythropoiesis. Another important consideration is that roxadustat was designed as an analogue of 2-oxoglutarate (2-OG) that inhibits 2-OG-dependent dioxygenase (2-OGDD). This enzyme is in a superfamily whose members have a wide range of biological functions. Thus, PHD enzymes may not be the only substrates of roxadustat, and roxadustat (or similar PHD enzyme inhibitors) could possibly inhibit other 2-OGDDs, which may lead to “off-target” effects beyond its effects on HIF and PHD (). For example, collagen prolyl 4-hydroxylase (CP4H) is a type of non-heme iron (II)-containing 2-OGDD (). The PHD and CP4H enzymes are both proline-4-hydroxylases. Roxadustat and CP4H inhibitors are structural analogues, and recent studies found that roxadustat can inhibit the hydroxylation and secretion of complement C1q by acting on CP4H. This suggests that prolonged use of roxadustat for treatment of renal anemia may eventually decrease the level of C1q, which may have detrimental clinical effects (). Mannose-binding lectin (MBL), a serum C-type lectin produced by the liver, plays an important role in the innate immune response by activating the lectin pathway of the complement system and subsequent inflammatory mechanisms (). CP4H mediates the hydroxylation of MBL, and after multiple post-translational modifications, MBL oligomerizes to a high molar weight (HMW) form. found that roxadustat inhibited the proline hydroxylation of MBL and the formation of HMW oligomers by inhibiting the activity of CP4H. This may be considered an off-target effect of certain PHD enzyme inhibitors, including roxadustat, and these effects may be beneficial, neutral, or harmful. Figure 2 compares the effects of roxadustat and ESAs when used for treatment of anemia.

FIGURE 2

Effect of roxadustat on fibrosis

Tissue fibrosis underlies most chronic diseases that have high levels of morbidity and mortality, but treatment of fibrosis remains challenging. Hypoxia is an important microenvironmental factor that promotes the development of tissue fibrosis, and HIF is a major regulator of cellular adaptation to ischemia and hypoxia. Numerous studies confirmed an association of HIF with fibrosis. For example, found that stabilization of HIF prior to the onset of ischemia reduced renal fibrosis and prevented anemia. studied rats with subtotal nephrectomy and found transient activation of HIF-α in the residual kidney during the early postoperative period, and activation of HIF-α during a later stage that reduced tubulointerstitial fibrosis. This suggests that appropriate short-term increases in the level of HIF-α may prevent renal fibrosis. Recently, studied a unilateral renal ischemia-reperfusion injury (IRI) model and reported that roxadustat significantly attenuated renal fibrosis, and that the increase in HIF may have provided this protective effect by maintaining renal function and preventing the transition from AKI to CKD. showed that roxadustat inhibited experimental pulmonary fibrosis by regulating the TGF-β1/Smads signaling pathway in vitro and in vivo. studied a folic acid (FA)-induced AKI model and found that roxadustat pretreatment promoted the regeneration of renal tubular structures 7 days after FA injection. They also found that roxadustat inhibited ferroptosis and inflammation due to activation of Nrf2 by Akt/GSK-3β, thereby inhibiting interstitial fibrosis ().

However, the role of HIF in fibrosis is still controversial, and there is evidence that hyperactivation and prolonged exposure to HIF may actually increase renal fibrosis. For example, studied a 5/6 nephrectomy model (removal of one kidney and 2/3 of the other kidney) and found that VHL deletion led to increased HIF-1α expression and increased renal fibrosis, and that the application of anti-HIF-1α drugs inhibited the progression of renal fibrosis in the unilateral ureteral obstruction (UUO) mouse model. showed that HIF-1α enhanced the epithelial-mesenchymal transition (EMT) in vitro, and that increased expression of HIF-1α was associated with tubulointerstitial damage in patients with CKD. These authors also demonstrated that genetic ablation of HIF-1α from epithelial cells inhibited the development of tubulointerstitial fibrosis in the UUO model. Studies of pulmonary fibrosis reported that HIF-1α activation induced cell proliferation, adhesion, and secretion of extracellular matrix (ECM), and these led to lung inflammation and fibrosis under hypoxic conditions ().

The role of HIF in promoting the progression of fibrosis appears contrary to its organ-protective role during early kidney injury. These different effects may be explained by differences in the timing of administration and the extent and duration of HIF activation. Activating HIF at an appropriate level and within a well-regulated range may promote cellular adaptation to hypoxia and ischemia, and therefore play a protective role. simulated renal fibrosis in the UUO model and found that a high dose of roxadustat (50 mg/kg/day) significantly increased the expression of pro-fibrotic genes after 3 days, but there was no effect after 7 days. The effect of roxadustat on renal fibrosis may also be dose- and time-dependent, in that it may promote renal fibrosis during the early stage of disease, but this pro-fibrotic effect gradually declines, and there is a protective effect during a later stage (). To date, no clinical trials have reported significant adverse events or significant off-target effects. However, given the role of HIF and roxadustat in fibrosis, it is necessary to consider possible adverse effects by carefully considering the dose and timing of treatment. Figure 3 summarizes the mechanisms by which roxadustat reduces fibrosis.

FIGURE 3

Effect of roxadustat on lipid metabolism

Clinical research showed that roxadustat significantly reduced the level of plasma total cholesterol in patients with CKD due to an increased HIF-mediated degradation of 3-hydroxy-3-methylglutaryl (HMG) -CoA reductase, and that this effect occurred regardless of statin use (). In addition, roxadustat lowered the level of LDL-cholesterol and triglycerides, and increased the ratio of HDL-cholesterol to LDL-cholesterol, and the cholesterol level returned to the pre-treatment level after discontinuation of roxadustat (; ). These are important findings, because reductions in the levels of total cholesterol, LDL-cholesterol, and triglycerides reduce cardiovascular morbidity and mortality (). Therefore, the effects of roxadustat on lipid metabolism may reduce the risk of CKD and CVD. found that roxadustat reduced the abnormal accumulation of lipids in cells and zebrafish that had a deficient ATP7B gene. showed that HIF stabilizers counteracted the altered renal energy metabolism that occurs during diabetic nephropathy by downregulating fatty acid and amino acid metabolism and upregulating glycolysis, effects may inhibit the progression of diabetic kidney disease (DKD).

However, showed that roxadustat reduced fatty acid oxidation in renal tubular epithelial cells, and also inhibited lipid metabolism and caused significant lipid accumulation, alterations that may contribute to renal pathology. suggested that roxadustat promoted the switch from aerobic metabolism to glycolysis by increasing the level of HIF-1α. They concluded that this allowed cells to adapt to hypoxia and reduced the overproduction of mitochondrial reactive oxygen species (ROS), but it may also have increased the accumulation of lipids and lactic acid, thus increasing the risk of renal fibrosis. Acidosis caused by the overproduction of lactic acid leads to the release of intracellular potassium ions, and this may explain the presence of hyperkalemia in some patients taking roxadustat. Thus, roxadustat appears to have complex and diverse effects on lipid metabolism. The effect of roxadustat-mediated alterations of lipid metabolism on patient outcome is a topic that requires further research.

Effect of roxadustat on inflammation

Inflammation is a defense response, but persistent and excessive inflammation occurs in many acute and chronic diseases. Previous studies showed that HIF had anti-inflammatory effects and promoted the resolution of inflammation (). found that early intermittent hypoxia preconditioning of rat skeletal muscle inhibited inflammation and had a protective effect on acute IRI of skeletal muscle. In addition, upregulation of HIF-2α can reduce inflammasome hyperactivation and prevent cell death (). Other research found that roxadustat corrected the inflammatory anemia that was induced in an animal model by peptidoglycan polysaccharide (PG-PS) (). studied an animal model of cisplatin-induced AKI and showed that roxadustat significantly reduced the levels of TNF-α, IL-1β, IL-6, and other inflammatory cytokines due to its effect on HIF. demonstrated that roxadustat significantly reduced inflammation in vivo and in vitro, and reduced acute lung injury in mice caused by sepsis due to its upregulation of HIF-1α and heme oxygenase 1 (HO-1). Another study of a mouse model of dextran sulfate sodium (DSS)-induced colitis showed that activation of HIF-1 had a protective effect, and suggested that PHIs have potential as a novel treatment for inflammatory bowel disease ().

However, there is currently no consensus regarding the anti-inflammatory function of HIF. Previous studies reported a bidirectional interaction between inflammation and hypoxia (). In particular, hypoxia induces and promotes inflammation in a variety of pathological conditions, and inflammatory lesions can also lead to the formation of a severe hypoxic microenvironment. A study that examined an animal model of inflammatory bowel disease reported that the diseased tissue and gut had upregulation of HIF-1α and hypoxia (). Inflammation promotes cellular hypoxia, and IL-1β increases hypoxia and the levels of HIF-1α in human breast cancer cell lines (). studied the CCAAT/enhancer-binding protein delta (CEBPD), which functions in inflammatory responses, and showed that inflammatory cytokines induced the expression of CEBPD, increased the level of HIF-1α, and promoted tubulointerstitial inflammation. There are also disparate findings regarding the regulation of inflammation by roxadustat. Some evidence indicates that roxadustat inhibits cellular and humoral immunity in mixed lymphocyte reactions (). In addition, clinical studies of roxadustat found it was effective in the treatment of renal anemia, but that the incidence of urinary tract infections and pneumonia appeared to be higher in a roxadustat group than a placebo group, suggesting that roxadustat may lead to immunosuppression (; ). Because inflammation underlies so many acute and chronic diseases, more research is needed to clarify the effect of roxadustat on this complex physiological response.

Effect of roxadustat on oxidative stress

Oxidative stress occurs when there is an imbalance between oxidative and antioxidative reactions (), and ROS are responsible for most oxidative stress in biological systems. ROS are mainly derived from the electron transport chain, endoplasmic reticulum, and reduced nicotinamide dinucleotide phosphate (NADPH) oxidases (NOXs) in the mitochondria, and the production and clearance of ROS are tightly controlled by the antioxidant system (). When ROS are at normal physiological concentrations, they can also function as second messengers that induce the activation of various signaling pathways, so an appropriate level of ROS is crucial for allowing cells to engage in normal functions (). However, mitochondrial dysfunction and upregulation of NOXs can cause excessive ROS production and irreversible damage of cells. Therefore, tight regulation of the redox balance is necessary to keep ROS at a suitable concentration.

HIF functions as a key nuclear transcription factor that maintains redox function and oxygen homeostasis (). HIF-1α inhibits ROS formation by inducing the expression of genes that function in antioxidant defense (). Furthermore, upregulation of HIF-1α shifts metabolism from oxidative phosphorylation to glycolysis, and this can change the redox potential and reduce mitochondrial generation of ROS (). For example, a study of hepatocellular carcinoma (HepG2) cells reported that HIF-1α upregulated the thioredoxin (TXN), a common anti-oxidant, and thereby reduced oxidative stress (). However, HIF has broad effects, and the relationship between oxidative stress and HIF-1 may be far more complex. In particular, there may be a positive feedback loop between ROS and HIF-1α, as indicated by a study which showed that an increased level of HIF-1α contributed to the formation of ROS, especially mitochondrial ROS (). There is also evidence that overproduction of ROS during hypoxia increased the activity of HIF-1α via the phosphorylation of PI3K/AKT and ERK (). Excess ROS can also activate the NF/κB and TGF-β signaling pathways, thereby promoting the expression of HIF-1α (). In contrast, ROS can reduce the level of HIF-1α by upregulating PHD2 or supplying oxygen under hypoxic conditions ().

Although current findings suggest the relationship of ROS and HIF is complex, and even differs in different cells and tissues, no clinical studies of roxadustat have reported elevated ROS levels. In fact, there is evidence that roxadustat reduced ROS production and attenuated FA-induced kidney damage (). IRI is the most common cause of acute kidney injury. In particular, during the reperfusion period, abundant ROS are generated due to restoration of the oxygen supply, and this causes cell damage. showed that roxadustat increased the levels of HIF-1α and LDHA in reoxidized cells, but did not affect ROS production. studied the in vitro effects of roxadustat as a treatment for bone fracture and showed that silencing of HIF-1α increased the intracellular concentration of ROS and decreased the survival rate of bone marrow mesenchymal stem cells. Roxadustat also promoted the proliferation and migration of bone marrow mesenchymal stem cells by eliminating ROS, and accelerated fracture healing. studied doxorubicin-induced cardiotoxicity and found that roxadustat reduced oxidative stress in damaged cardiomyocytes by upregulating the expression of HIF-1α and two target genes (SOD2 and Bcl-2), and this ultimately inhibited cardiomyocyte apoptosis and protected cardiac function. Considering that HIF functions in complex networks that are related to the onset and progression of many diseases, and the need to assure safety when administering roxadustat and other drugs, more studies are needed to examine the role of HIF in the pathology of different diseases, and to examine the possible adverse effects of roxadustat treatment. Figure 4 summarizes the mechanisms by which roxadustat reduces oxidative stress.

FIGURE 4

Effect of roxadustat on angiogenesis

Blood supplies oxygen and nutrients to cells and tissues, and abnormalities in vascular structure and angiogenesis that lead vascular leakage and reduced blood flow contribute to the pathologies of many disease processes (; ). Therefore, the restoration of vascular function and normalization of angiogenesis may be effective strategies for treatment of different diseases. The main mediator of angiogenesis is vascular endothelial growth factor (VEGF). HIF is a potent stimulator of angiogenesis that coordinates the processes of neovascularization and angiogenesis by targeting VEGF and other pro-angiogenic factors (). In tumors, the inhibition of PHD2 in endothelial cells normalizes tumor vasculature by upregulating HIF, thereby sensitizing tumors to chemotherapy (). Therefore, upregulation of HIF might be an effective strategy for promoting angiogenesis and normalization of blood flow.

A study of diabetic rats reported that roxadustat promoted angiogenesis and wound healing by upregulating the HIF-1α/VEGF/VEGFR2 pathway (). A study of renal IRI in mice reported that roxadustat attenuated renal injury by enhancing renal angiogenesis and tissue repair due to its upregulation of HIF (). A study of neonatal mice found that intraperitoneal roxadustat upregulated the expression of HIF-1α, VEGF, and endothelial NO synthase, promoted alveolar normalization and angiogenesis, and alleviated hyperoxia-induced lung injury (). Another study of roxadustat reported that it significantly upregulated VEGF production in rats and bone marrow mesenchymal stem cells, and also promoted fracture healing (). Two animal studies showed that VEGF promoted neurogenesis and also had antidepressant effects (; ). studied a rat model of depression and showed that roxadustat appeared to reverse depression-like behaviors in rats by activating HIF and its target genes (EPO and VEGF), and it also reduced memory impairment. Studies of preterm infants found that hyperoxia led to downregulation of HIF, and this may have led to attenuated retinal vessel growth and vascular occlusion, leading to retinopathy of prematurity (ROP) (). There is also evidence that the activation of HIF by roxadustat prevented oxygen-induced retinopathy in animal models, suggesting its possible use for prevention of childhood blindness (; ). Another study of ROP found that roxadustat stably increased the expression of glycolysis-related genes by inducing HIF-1α, which improved retinal metabolism and normalized angiogenesis (). An elevated level of HIF-2α contributes to angiogenesis during retinopathy, and roxadustat provides a weak induction of HIF-2α in retinal cells, thus suggesting the safety of this drug for treatment of ROP (). examined a rat subcutaneous cavity model and showed that roxadustat promoted angiogenesis and maturation in vitro and in vivo, suggesting it may be useful during tissue transplantation.

On the other hand, hypoxia is also a key characteristic of the tumor microenvironment, and HIF overexpression occurs in a variety of cancers (). Theoretically, long-term application of a HIF activator could increase the risk for tumorigenesis and diabetic retinopathy. However, no clinical studies of roxadustat have reported that it increased the systemic level of VEGF, increased tumorigenesis or metastasis, or adversely affected diabetic retinal neovascularization (). Considering that roxadustat is an oral medication that is given intermittently, it is likely that a low level of cellular HIF activation is insufficient to increase VEGF expression, but is sufficient to increase erythropoiesis. However, a case report of a patient treated in a phase III clinical trial of roxadustat reported the development of pulmonary arterial hypertension (PAH) (). Although confirmation in additional patients is necessary, stabilization of HIF by roxadustat may possibly contribute to the pathophysiology of PAH.

Furthermore, HIF stabilization may promote wound healing and collateral vessel growth when there is cardiovascular injury (). Some evidence suggests that HIF activation plays a cardioprotective role in myocardial IRI (), although prolonged HIF activation can promote vascular calcification. Vascular calcification is a common complication in CKD patients, and is closely related to their increased risk of cardiovascular complications (). found that HIF and phosphate acted synergistically to promote osteogenic transdifferentiation and calcification of vascular smooth muscle cells, and that roxadustat promoted vascular calcification. This finding suggests that roxadustat may possibly increase the risk for cardiovascular events in CKD patients. However, the potential role of elevated HIF in promoting vascular calcification remains unclear, and this topic should be examined when considering the possible adverse effects of HIF activation and roxadustat. Figure 5 summarizes the mechanisms by which roxadustat promotes angiogenesis and reduces vascular abnormalities in numerous diseases.

FIGURE 5

Conclusion

Roxadustat is a HIF activator that is approved for the clinical treatment of renal anemia in China, the European Union, Japan, South Korea, and Chile. Numerous clinical studies showed that it is safe and effective in maintaining target Hb levels in CKD patients, and it is not significantly affected by inflammatory status. Thus roxadustat, as a new HIF-PHI, is an encouraging new option for the treatment of patients with CKD. In addition to the treatment of anemia in these patients, roxadustat also has potential for reducing tissue and organ fibrosis and inflammation, correcting metabolic disorders, reducing oxidative stress, improving mitochondrial function, and normalizing angiogenesis. Thus, roxadustat may provide benefits beyond reducing anemia. However, recent research has found that roxadustat, like all medications, must be used cautiously because of certain common adverse reactions. In particular, it has the potential to increase the risk of pulmonary hypertension and vascular calcification, and aggravate inflammatory infections. Although roxadustat appeared to cause no obvious off-target effects in clinical trials or clinical applications so far, HIF targets many different genes and has a wide range of effects. It is therefore necessary to strictly control the extent and duration of HIF activation, and to carefully consider the dose and schedule of roxadustat to avoid unexpected side effects caused by the pleiotropic effects of HIF activation.

Statements

Author contributions

XZ contributed to the conception and design of this work, and wrote and revised the manuscript. LJ provided guidance on the organization and content of the manuscript. XW helped in preparation of the figures. ML helped to revise the structure and language of the manuscript. YD provided guidance, edited and revised the manuscript, and is responsible for all aspects of the manuscript. All authors contributed to the manuscript and approved the submitted version.

Funding

This work was supported in part by grants from the Jilin Provincial Department of Finance (JLSWSRCZX 2021-006).

Acknowledgments

We thank Medjaden Inc., for scientific editing of this manuscript.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

  • 1

    AbdelazeemB.AbbasK.ShehataJ.El-ShahatN.BaralN.SavarapuP.et al (2021). The efficacy of roxadustat for the treatment of anemia in dialysis dependent chronic kidney disease patients: An updated systematic review and meta-analysis of randomized clinical trials. Ann. Transl. Med.9 (23), 1714. 10.21037/atm-21-4357

  • 2

    AganiF.PichiuleP.ChavezJ.LaMannaJ. (2000). The role of mitochondria in the regulation of hypoxia-inducible factor 1 expression during hypoxia. J. Biol. Chem.275 (46), 3586335867. 10.1074/jbc.M005643200

  • 3

    AkizawaT.IwasakiM.OtsukaT.ReuschM.MisumiT. (2019). Roxadustat treatment of chronic kidney disease-associated anemia in Japanese patients not on dialysis: A phase 2, randomized, double-blind, placebo-controlled trial. Adv. Ther.36 (6), 14381454. 10.1007/s12325-019-00943-4

  • 4

    AkizawaT.IwasakiM.YamaguchiY.MajikawaY.ReuschM. (2020). Phase 3, randomized, double-blind, active-comparator (darbepoetin alfa) study of oral roxadustat in CKD patients with anemia on hemodialysis in Japan. J. Am. Soc. Nephrol.31 (7), 16281639. 10.1681/ASN.2019060623

  • 5

    AkizawaT.OtsukaT.ReuschM.UenoM. (2020). Intermittent oral dosing of roxadustat in peritoneal dialysis chronic kidney disease patients with anemia: A randomized, phase 3, multicenter, open-label study. Ther. Apher. Dial.24 (2), 115125. 10.1111/1744-9987.12888

  • 6

    AkizawaT.UenoM.ShigaT.ReuschM. (2020). Oral roxadustat three times weekly in ESA-naïve and ESA-converted patients with anemia of chronic kidney disease on hemodialysis: Results from two phase 3 studies. Ther. Apher. Dial.24 (6), 628641. 10.1111/1744-9987.13468

  • 7

    AkizawaT.YamaguchiY.OtsukaT.ReuschM. (2020). A phase 3, multicenter, randomized, two-arm: Open-label study of intermittent oral dosing of roxadustat for the treatment of anemia in Japanese erythropoiesis-stimulating agent-naïve chronic kidney disease patients not on dialysis. Nephron144 (8), 372382. 10.1159/000508100

  • 8

    AppelhoffR.TianY.RavalR.TurleyH.HarrisA.PughC.et al (2004). Differential function of the prolyl hydroxylases PHD1, PHD2, and PHD3 in the regulation of hypoxia-inducible factor. J. Biol. Chem.279 (37), 3845838465. 10.1074/jbc.M406026200

  • 9

    Aranda-RiveraA.Cruz-GregorioA.Aparicio-TrejoO.Ortega-LozanoA.Pedraza-ChaverriJ. (2021). Redox signaling pathways in unilateral ureteral obstruction (UUO)-induced renal fibrosis. Free Radic. Biol. Med.172, 6581. 10.1016/j.freeradbiomed.2021.05.034

  • 10

    BarrattJ.SulowiczW.SchömigM.EspositoC.ReuschM.YoungJ.et al (2021). Efficacy and cardiovascular safety of roxadustat in dialysis-dependent chronic kidney disease: Pooled analysis of four phase 3 studies. Adv. Ther.38 (10), 53455360. 10.1007/s12325-021-01903-7

  • 11

    BeckerK.SaadM. (2017). A new approach to the management of anemia in CKD patients: A review on roxadustat. Adv. Ther.34 (4), 848853. 10.1007/s12325-017-0508-9

  • 12

    BesarabA.ChernyavskayaE.MotylevI.ShutovE.KumbarL.GurevichK.et al (2016). Roxadustat (FG-4592): Correction of anemia in incident dialysis patients. J. Am. Soc. Nephrol.27 (4), 12251233. 10.1681/ASN.2015030241

  • 13

    BesarabA.ProvenzanoR.HertelJ.ZabanehR.KlausS.LeeT.et al (2015). Randomized placebo-controlled dose-ranging and pharmacodynamics study of roxadustat (FG-4592) to treat anemia in nondialysis-dependent chronic kidney disease (NDD-CKD) patients. Nephrol. Dial. Transplant.30 (10), 16651673. 10.1093/ndt/gfv302

  • 14

    BeuckS.SchänzerW.ThevisM. (2012). Hypoxia-inducible factor stabilizers and other small-molecule erythropoiesis-stimulating agents in current and preventive doping analysis. Drug Test. Anal.4 (11), 830845. 10.1002/dta.390

  • 15

    BhuteV. J.HarteJ.HoughtonJ. W.MaxwellP. H. (2020). Mannose binding lectin is hydroxylated by collagen prolyl-4-hydroxylase and inhibited by some PHD inhibitors. Kidney3601 (6), 447457. 10.34067/KID.0000092020

  • 16

    BradburyB.CritchlowC.WeirM.StewartR.KrishnanM.HakimR. (2009). Impact of elevated C-reactive protein levels on erythropoiesis- stimulating agent (ESA) dose and responsiveness in hemodialysis patients. Nephrol. Dial. Transplant.24 (3), 919925. 10.1093/ndt/gfn543

  • 17

    ChangW.LoY.GaoZ.WuS. (2019). Evidence for the capability of roxadustat (FG-4592), an oral HIF prolyl-hydroxylase inhibitor, to perturb membrane ionic currents: An unidentified yet important action. Int. J. Mol. Sci.20 (23), E6027. 10.3390/ijms20236027

  • 18

    ChenC.YanS.QiuS.GengZ.WangZ. (2021). HIF/Ca2+/NO/ROS is critical in roxadustat treating bone fracture by stimulating the proliferation and migration of BMSCs.Life Sci.264, 118684. 10.1016/j.lfs.2020.118684

  • 19

    ChenN.HaoC.LiuB.LinH.WangC.XingC.et al (2019). Roxadustat treatment for anemia in patients undergoing long-term dialysis. N. Engl. J. Med.381 (11), 10111022. 10.1056/NEJMoa1901713

  • 20

    ChenN.HaoC.PengX.LinH.YinA.HaoL.et al (2019). Roxadustat for anemia in patients with kidney disease not receiving dialysis. N. Engl. J. Med.381 (11), 10011010. 10.1056/NEJMoa1813599

  • 21

    ChenN.QianJ.ChenJ.YuX.MeiC.HaoC.et al (2017). Phase 2 studies of oral hypoxia-inducible factor prolyl hydroxylase inhibitor FG-4592 for treatment of anemia in China. Nephrol. Dial. Transplant.32 (8), 13731386. 10.1093/ndt/gfx011

  • 22

    ChenR.LaiU.ZhuL.SinghA.AhmedM.ForsythN. (2018). Reactive oxygen species formation in the brain at different oxygen levels: The role of hypoxia inducible factors. Front. Cell Dev. Biol.6, 132. 10.3389/fcell.2018.00132

  • 23

    ChengW.LiuX.ZhangL.GuoX.WangF.ZhangY.et al (2019). Chronic intermittent hypobaric hypoxia attenuates skeletal muscle ischemia-reperfusion injury in mice. Life Sci.231, 116533. 10.1016/j.lfs.2019.06.008

  • 24

    CioffiC.LiuX.KosinskiP.GarayM.BowenB. (2003). Differential regulation of HIF-1 alpha prolyl-4-hydroxylase genes by hypoxia in human cardiovascular cells. Biochem. Biophys. Res. Commun.303 (3), 947953. 10.1016/s0006-291x(03)00453-4

  • 25

    CumminsE.SeeballuckF.KeelyS.ManganN.CallananJ.FallonP.et al (2008). The hydroxylase inhibitor dimethyloxalylglycine is protective in a murine model of colitis. Gastroenterology134 (1), 156165. 10.1053/j.gastro.2007.10.012

  • 26

    CygulskaK.Wejner-MikP.PlewkaM.FigielŁ.ChrzanowskiŁ.KasprzakJ. (2019). Roxadustat: Another drug that causes pulmonary hypertension? Report of first human case. Pol. Arch. Intern. Med.129 (5), 344345. 10.20452/pamw.4445

  • 27

    CzockD.KellerF. (2022). Clinical pharmacokinetics and pharmacodynamics of roxadustat. Clin. Pharmacokinet.61 (3), 347362. 10.1007/s40262-021-01095-x

  • 28

    Del BalzoU.SignoreP.WalkinshawG.SeeleyT.BrennerM.WangQ.et al (2020). Nonclinical characterization of the hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat, a novel treatment of anemia of chronic kidney disease. J. Pharmacol. Exp. Ther.374 (2), 342353. 10.1124/jpet.120.265181

  • 29

    Del VecchioL.LocatelliF. (2018). Roxadustat in the treatment of anaemia in chronic kidney disease. Expert Opin. Investig. Drugs27 (1), 125133. 10.1080/13543784.2018.1417386

  • 30

    DeyamaS.BangE.WohlebE.LiX.KatoT.GerhardD.et al (2019). Role of neuronal VEGF signaling in the prefrontal cortex in the rapid antidepressant effects of ketamine. Am. J. Psychiatry176 (5), 388400. 10.1176/appi.ajp.2018.17121368

  • 31

    DhillonS. (2020). Daprodustat: First approval. Drugs80 (14), 14911497. 10.1007/s40265-020-01384-y

  • 32

    DhillonS. (2022). Desidustat: First approval. Drugs1, 16. 10.1007/s40265-022-01744-w

  • 33

    DhillonS. (2019). Roxadustat: First global approval. Drugs79 (5), 563572. 10.1007/s40265-019-01077-1

  • 34

    EleftheriadisT.PissasG.FilippidisG.LiakopoulosV.StefanidisI. (2021). Reoxygenation induces reactive oxygen species production and ferroptosis in renal tubular epithelial cells by activating aryl hydrocarbon receptor. Mol. Med. Rep.23 (1), 41. 10.3892/mmr.2020.11679

  • 35

    EleftheriadisT.PissasG.MavropoulosA.NikolaouE.FilippidisG.LiakopoulosV.et al (2020). In mixed lymphocyte reaction, the hypoxia-inducible factor prolyl-hydroxylase inhibitor roxadustat suppresses cellular and humoral alloimmunity.Arch. Immunol. Ther. Exp.68 (6), 31. 10.1007/s00005-020-00596-0

  • 36

    FandreyJ. (2004). Oxygen-dependent and tissue-specific regulation of erythropoietin gene expression. Am. J. Physiol. Regul. Integr. Comp. Physiol.286 (6), R977R988. 10.1152/ajpregu.00577.2003

  • 37

    FiggW.McDonoughM.ChowdhuryR.NakashimaY.ZhangZ.Holt-MartynJ.et al (2021). Structural basis of prolyl hydroxylase domain inhibition by molidustat. ChemMedChem16 (13), 20822088. 10.1002/cmdc.202100133

  • 38

    FlightM. (2013). Deal watch: AstraZeneca bets on FibroGen's anaemia drug. Nat. Rev. Drug Discov.12 (10), 730. 10.1038/nrd4135

  • 39

    Groenendaal-van de MeentD.AdelM.NoukensJ.RijndersS.Krebs-BrownA.MatevaL.et al (2016). Effect of moderate hepatic impairment on the pharmacokinetics and pharmacodynamics of roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor. Clin. Drug Investig.36 (9), 743751. 10.1007/s40261-016-0422-y

  • 40

    Groenendaal-van de MeentD.den AdelM.KerbuschV.van DijkJ.ShibataT.KatoK.et al (2022). Effect of roxadustat on the pharmacokinetics of simvastatin, rosuvastatin, and atorvastatin in healthy subjects: Results from 3 phase 1, open-label, 1-sequence, crossover studies. Clin. Pharmacol. Drug Dev.11 (4), 486501. 10.1002/cpdd.1076

  • 41

    Groenendaal-van de MeentD.den AdelM.RijndersS.Krebs-BrownA.KerbuschV.GolorG.et al (2016). The hypoxia-inducible factor prolyl-hydroxylase inhibitor roxadustat (FG-4592) and warfarin in healthy volunteers: A pharmacokinetic and pharmacodynamic drug-drug interaction study. Clin. Ther.38 (4), 918928. 10.1016/j.clinthera.2016.02.010

  • 42

    Groenendaal-van de MeentD.den AdelM.van DijkJ.Barroso-FernandezB.El GaltaR.GolorG.et al (2018). Effect of multiple doses of omeprazole on the pharmacokinetics, safety, and tolerability of roxadustat in healthy subjects. Eur. J. Drug Metab. Pharmacokinet.43 (6), 685692. 10.1007/s13318-018-0480-z

  • 43

    Groenendaal-van de MeentD.KerbuschV.Barroso-FernandezB.den AdelM.van DijkJ.GolorG.et al (2021). Effect of the phosphate binders sevelamer carbonate and calcium acetate on the pharmacokinetics of roxadustat after concomitant or time-separated administration in healthy individuals. Clin. Ther.43 (6), 10791091. 10.1016/j.clinthera.2021.03.025

  • 44

    Groenendaal-van de MeentD.KerbuschV.KasperaR.Barroso-FernandezB.GallettiP.KleinG.et al (2021). Effect of kidney function and dialysis on the pharmacokinetics and pharmacodynamics of roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor. Eur. J. Drug Metab. Pharmacokinet.46 (1), 141153. 10.1007/s13318-020-00658-w

  • 45

    GrzeszczakW.SzczyraD.ŚnitM. (2021). Whether prolyl hydroxylase blocker-roxadustat-in the treatment of anemia in patients with chronic kidney disease is the future?Int. J. Environ. Res. Public Health18 (4), 1612. 10.3390/ijerph18041612

  • 46

    HaaseV. (2013). Regulation of erythropoiesis by hypoxia-inducible factors. Blood Rev.27 (1), 4153. 10.1016/j.blre.2012.12.003

  • 47

    HanF.WuG.HanS.LiZ.JiaY.BaiL.et al (2020). Hypoxia-inducible factor prolyl-hydroxylase inhibitor roxadustat (FG-4592) alleviates sepsis-induced acute lung injury. Respir. Physiol. Neurobiol.281, 103506. 10.1016/j.resp.2020.103506

  • 48

    HaraS.HamadaJ.KobayashiC.KondoY.ImuraN. (2001). Expression and characterization of hypoxia-inducible factor (HIF)-3alpha in human kidney: Suppression of HIF-mediated gene expression by HIF-3alpha. Biochem. Biophys. Res. Commun.287 (4), 808813. 10.1006/bbrc.2001.5659

  • 49

    HartnettM.PennJ. (2012). Mechanisms and management of retinopathy of prematurity. N. Engl. J. Med.367 (26), 25152526. 10.1056/NEJMra1208129

  • 50

    HasegawaS.TanakaT.SaitoT.FukuiK.WakashimaT.SusakiE.et al (2020). The oral hypoxia-inducible factor prolyl hydroxylase inhibitor enarodustat counteracts alterations in renal energy metabolism in the early stages of diabetic kidney disease. Kidney Int.97 (5), 934950. 10.1016/j.kint.2019.12.007

  • 51

    HigginsD.KimuraK.BernhardtW.ShrimankerN.AkaiY.HohensteinB.et al (2007). Hypoxia promotes fibrogenesis in vivo via HIF-1 stimulation of epithelial-to-mesenchymal transition. J. Clin. Invest.117 (12), 38103820. 10.1172/JCI30487

  • 52

    HoppeG.BolokY.McCollumL.ZhangJ.SearsJ. (2020). Rank order of small molecule induced hypoxiamimesis to prevent retinopathy of prematurity. Front. Cell Dev. Biol.8, 488. 10.3389/fcell.2020.00488

  • 53

    HoppeG.YoonS.GopalanB.SavageA.BrownR.CaseK.et al (2016). Comparative systems pharmacology of HIF stabilization in the prevention of retinopathy of prematurity. Proc. Natl. Acad. Sci. U. S. A.113 (18), E2516E2525. 10.1073/pnas.1523005113

  • 54

    HuangH.WangX.ZhangX.WangH.JiangW. (2020). Roxadustat attenuates experimental pulmonary fibrosis in vitro and in vivo. Toxicol. Lett.331, 112121. 10.1016/j.toxlet.2020.06.009

  • 55

    HuangL.ChouH.ChenC. (2021). Roxadustat attenuates hyperoxia-induced lung injury by upregulating proangiogenic factors in newborn mice. Pediatr. Neonatol.62 (4), 369378. 10.1016/j.pedneo.2021.03.012

  • 56

    JathoA.ZiesenissA.Brechtel-CurthK.GuoJ.BökerK.SalinasG.et al (2022). The hifα-stabilizing drug roxadustat increases the number of renal epo-producing sca-1+ cells.Cells11 (4), 753. 10.3390/cells11040753

  • 57

    JinK.ZhuY.SunY.MaoX.XieL.GreenbergD. (2002). Vascular endothelial growth factor (VEGF) stimulates neurogenesis in vitro and in vivo. Proc. Natl. Acad. Sci. U. S. A.99 (18), 1194611950. 10.1073/pnas.182296499

  • 58

    JoharapurkarA.PandyaV.PatelV.DesaiR.JainM. (2018). Prolyl hydroxylase inhibitors: A breakthrough in the therapy of anemia associated with chronic diseases. J. Med. Chem.61 (16), 69646982. 10.1021/acs.jmedchem.7b01686

  • 59

    KabeiK.TateishiY.NozakiM.TanakaM.ShiotaM.Osada-OkaM.et al (2018). Role of hypoxia-inducible factor-1 in the development of renal fibrosis in mouse obstructed kidney: Special references to HIF-1 dependent gene expression of profibrogenic molecules. J. Pharmacol. Sci.136 (1), 3138. 10.1016/j.jphs.2017.12.004

  • 60

    KabeiK.TateishiY.ShiotaM.Osada-OkaM.NishideS.UchidaJ.et al (2020). Effects of orally active hypoxia inducible factor alpha prolyl hydroxylase inhibitor, FG4592 on renal fibrogenic potential in mouse unilateral ureteral obstruction model. J. Pharmacol. Sci.142 (3), 93100. 10.1016/j.jphs.2019.12.002

  • 61

    KapitsinouP.JaffeJ.MichaelM.SwanC.DuffyK.Erickson-MillerC.et al (2012). Preischemic targeting of HIF prolyl hydroxylation inhibits fibrosis associated with acute kidney injury. Am. J. Physiol. Ren. Physiol.302 (9), 11721179. 10.1152/ajprenal.00667.2011

  • 62

    KaplanJ. (2019). Roxadustat and anemia of chronic kidney disease. N. Engl. J. Med.381 (11), 10701072. 10.1056/NEJMe1908978

  • 63

    KaplanJ. (2020). Roxadustat for anemia in patients with chronic kidney disease. Reply.N. Engl. J. Med.383 (1), e3. 10.1056/NEJMc1913712

  • 64

    KarhausenJ.FurutaG.TomaszewskiJ.JohnsonR.ColganS.HaaseV. (2004). Epithelial hypoxia-inducible factor-1 is protective in murine experimental colitis. J. Clin. Invest.114 (8), 10981106. 10.1172/JCI21086

  • 65

    KassimatisT.GoldsmithD. (2014). Statins in chronic kidney disease and kidney transplantation. Pharmacol. Res.88, 6273. 10.1016/j.phrs.2014.06.011

  • 66

    KerberE.PadbergC.KollN.SchuetzholdV.FandreyJ.WinningS. (2020). The importance of hypoxia-inducible factors (HIF-1 and HIF-2) for the pathophysiology of inflammatory bowel disease. Int. J. Mol. Sci.21 (22), E8551. 10.3390/ijms21228551

  • 67

    KiersH.SchefferG.van der HoevenJ.EltzschigH.PickkersP.KoxM. (2016). Immunologic consequences of hypoxia during critical illness. Anesthesiology125 (1), 237249. 10.1097/ALN.0000000000001163

  • 68

    KimuraK.IwanoM.HigginsD.YamaguchiY.NakataniK.HaradaK.et al (2008). Stable expression of HIF-1alpha in tubular epithelial cells promotes interstitial fibrosis. Am. J. Physiol. Ren. Physiol.295 (4), F1023F1029. 10.1152/ajprenal.90209.2008

  • 69

    KiriakidisS.HoerS. S.BurrowsN.BiddlecomeG.KhanM. N.ThinnesC. C.et al (2017). Complement C1q is hydroxylated by collagen prolyl 4 hydroxylase and is sensitive to off-target inhibition by prolyl hydroxylase domain inhibitors that stabilize hypoxia-inducible factor. Kidney Int.92 (4), 900908. 10.1016/j.kint.2017.03.008

  • 70

    KoshikawaN.HayashiJ.NakagawaraA.TakenagaK. (2009). Reactive oxygen species-generating mitochondrial DNA mutation up-regulates hypoxia-inducible factor-1alpha gene transcription via phosphatidylinositol 3-kinase-Akt/protein kinase C/histone deacetylase pathway. J. Biol. Chem.284 (48), 3318533194. 10.1074/jbc.M109.054221

  • 71

    KoyamaS.MatsunagaS.ImanishiM.MaekawaY.KitanoH.TakeuchiH.et al (2017). Tumour blood vessel normalisation by prolyl hydroxylase inhibitor repaired sensitivity to chemotherapy in a tumour mouse model. Sci. Rep.7, 45621. 10.1038/srep45621

  • 72

    LeeB.GhodeP.OngD. (2019). Redox regulation of cell state and fate. Redox Biol.25, 101056. 10.1016/j.redox.2018.11.014

  • 73

    LiG.ZhaoM.ChengX.ZhaoT.FengZ.ZhaoY.et al (2020). FG-4592 improves depressive-like behaviors through HIF-1-Mediated neurogenesis and synapse plasticity in rats. Neurotherapeutics17 (2), 664675. 10.1007/s13311-019-00807-3

  • 74

    LiJ.MaK.WangL.QiH.LvJ.RaoY.et al (2021). Efficacy and safety of roxadustat in the treatment of renal allograft anemia patients: A case series. Ann. Palliat. Med.10 (11), 1185911867. 10.21037/apm-21-2916

  • 75

    LiW.DuanA.XingY.XuL.YangJ. (2021). Transcription-based multidimensional regulation of fatty acid metabolism by HIF1α in renal tubules. Front. Cell Dev. Biol.9, 690079. 10.3389/fcell.2021.690079

  • 76

    LiW.ZhaoY.FuP. (2017). Hypoxia induced factor in chronic kidney disease: Friend or foe?Front. Med.4, 259. 10.3389/fmed.2017.00259

  • 77

    LiX.CuiX.ChenY.WuT.XuH.YinH.et al (2018). Therapeutic potential of a prolyl hydroxylase inhibitor FG-4592 for Parkinson's diseases in vitro and in vivo: Regulation of redox biology and mitochondrial function.Front. Aging Neurosci.10, 121. 10.3389/fnagi.2018.00121

  • 78

    LiX.JiangB.ZouY.ZhangJ.FuY.ZhaiRoxadustatX. F. G. (2021). Roxadustat (FG-4592) facilitates recovery from renal damage by ameliorating mitochondrial dysfunction induced by folic acid.Front. Pharmacol.12, 788977. 10.3389/fphar.2021.788977

  • 79

    LiX.ZhangX.XiaJ.ZhangL.ChenB.LianG.et al (2021). Macrophage HIF-2α suppresses NLRP3 inflammasome activation and alleviates insulin resistance. Cell Rep.36 (8), 109607. 10.1016/j.celrep.2021.109607

  • 80

    LiX.ZouY.XingJ.FuY. Y.WangK. Y.WanP. Z.et al (2020). βPretreatment with roxadustat (FG-4592) attenuates folic acid-induced kidney injury through antiferroptosis via akt/GSK-3/nrf2 pathway. Oxid. Med. Cell. Longev.2020, 6286984. 10.1155/2020/6286984

  • 81

    LiZ.TuY.LiuB. (2020). Treatment of renal anemia with roxadustat: Advantages and achievement. Kidney Dis.6 (2), 6573. 10.1159/000504850

  • 82

    LiuF.WangJ.YeQ.FuH.MaoJ. (2021). Roxadustat for renal anemia in ESRD from PKD patients: Is it safe enough?J. Am. Soc. Nephrol.32, 1005. 10.1681/ASN.2020111664

  • 83

    LiuH.ZhuH.LiT.ZhangP.WangN.SunX. (2016). Prolyl-4-Hydroxylases inhibitor stabilizes HIF-1α and increases mitophagy to reduce cell death after experimental retinal detachment. Invest. Ophthalmol. Vis. Sci.57 (4), 18071815. 10.1167/iovs.15-18066

  • 84

    LiuJ.HouW.GuanT.TangL.ZhuX.LiY.et al (2018). Slit2/Robo1 signaling is involved in angiogenesis of glomerular endothelial cells exposed to a diabetic-like environment. Angiogenesis21 (2), 237249. 10.1007/s10456-017-9592-3

  • 85

    LiuJ.ZhangA.HaydenJ.BhagavathulaA.AlshehhiF.RinaldiG.et al (2020). Roxadustat (FG-4592) treatment for anemia in dialysis-dependent (DD) and not dialysis-dependent (NDD) chronic kidney disease patients: A systematic review and meta-analysis. Pharmacol. Res.155, 104747. 10.1016/j.phrs.2020.104747

  • 86

    LocatelliF.FishbaneS.BlockG.MacdougallI. (2017). Targeting hypoxia-inducible factors for the treatment of anemia in chronic kidney disease patients. Am. J. Nephrol.45 (3), 187199. 10.1159/000455166

  • 87

    LongG.ChenH.WuM.LiY.GaoL.HuangS.et al (2020). Antianemia drug roxadustat (FG-4592) protects against doxorubicin-induced cardiotoxicity by targeting antiapoptotic and antioxidative pathways. Front. Pharmacol.11, 1191. 10.3389/fphar.2020.01191

  • 88

    MarkhamA. (2021). Enarodustat: First approval. Drugs81 (1), 169174. 10.1007/s40265-020-01444-3

  • 89

    MarkhamA. (2020). Vadadustat: First approval. Drugs80 (13), 13651371. 10.1007/s40265-020-01383-z

  • 90

    MiX.LiZ.YanJ.LiY.ZhengJ.ZhuangZ.et al (2020). Activation of HIF-1 signaling ameliorates liver steatosis in zebrafish atp7b deficiency (Wilson's disease) models. Biochim. Biophys. Acta. Mol. Basis Dis.1866 (10), 165842. 10.1016/j.bbadis.2020.165842

  • 91

    MokasS.LarivièreR.LamaliceL.GobeilS.CornfieldD.AgharaziiM.et al (2016). Hypoxia-inducible factor-1 plays a role in phosphate-induced vascular smooth muscle cell calcification. Kidney Int.90 (3), 598609. 10.1016/j.kint.2016.05.020

  • 92

    MyllyharjuJ. (2013). Prolyl 4-hydroxylases, master regulators of the hypoxia response. Acta Physiol.208 (2), 148165. 10.1111/apha.12096

  • 93

    NakhoulG.SimonJ. (2016). Anemia of chronic kidney disease: Treat it, but not too aggressively. Cleve. Clin. J. Med.83 (8), 613624. 10.3949/ccjm.83a.15065

  • 94

    NaldiniA.FilippiI.MigliettaD.MoschettaM.GiavazziR.CarraroF. (2010)., 46. Oxford, England, 34003408. 10.1016/j.ejca.2010.07.044Interleukin-1β regulates the migratory potential of MDAMB231 breast cancer cells through the hypoxia-inducible factor-1αEur. J. Cancer18

  • 95

    NishideS.UchidaJ.MatsunagaS.TokudomeK.YamaguchiT.KabeiK.et al (2020). Prolyl-hydroxylase inhibitors reconstitute tumor blood vessels in mice. J. Pharmacol. Sci.143 (2), 122126. 10.1016/j.jphs.2020.02.010

  • 96

    OgawaC.TsuchiyaK.TomosugiN.MaedaK. (2020). A hypoxia-inducible factor stabilizer improves hematopoiesis and iron metabolism early after administration to treat anemia in hemodialysis patients. Int. J. Mol. Sci.21 (19), E7153. 10.3390/ijms21197153

  • 97

    ParisiS.FinelliC.FazioA.De StefanoA.MongiorgiS.RattiS.et al (2021). Clinical and molecular insights in erythropoiesis regulation of signal transduction pathways in myelodysplastic syndromes and β-thalassemia. Int. J. Mol. Sci.22 (2), E827. 10.3390/ijms22020827

  • 98

    PodkowińskaA.FormanowiczD. (2020). Chronic kidney disease as oxidative stress- and inflammatory-mediated cardiovascular disease. Antioxidants (Basel, Switz.9 (8), E752. 10.3390/antiox9080752

  • 99

    ProvenzanoR.TumlinJ.ZabanehR.ChouJ.HemmerichS.NeffT.et al (2020). Oral hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat (FG-4592) for treatment of anemia in chronic kidney disease: A placebo-controlled study of pharmacokinetic and pharmacodynamic profiles in hemodialysis patients. J. Clin. Pharmacol.60 (11), 14321440. 10.1002/jcph.1648

  • 100

    RekićD.Kerbusch-HerbenV.NågårdM.ChouJ.HuangJ.BradleyC.et al (2021). Pharmacokinetics of roxadustat: A population analysis of 2855 dialysis- and non-dialysis-dependent patients with chronic kidney disease. Clin. Pharmacokinet.60 (6), 759773. 10.1007/s40262-020-00974-z

  • 101

    SanghaniN.HaaseV. (2019). Hypoxia-inducible factor Activators in renal anemia: Current clinical experience. Adv. Chronic Kidney Dis.26 (4), 253266. 10.1053/j.ackd.2019.04.004

  • 102

    SemenzaG. (2012). Hypoxia-inducible factors in physiology and medicine. Cell148 (3), 399408. 10.1016/j.cell.2012.01.021

  • 103

    ShibataT.NomuraY.TakadaA.AokiS.KatashimaM.MurakamiH. (2018). Evaluation of the effect of lanthanum carbonate hydrate on the pharmacokinetics of roxadustat in non-elderly healthy adult male subjects. J. Clin. Pharm. Ther.43 (5), 633639. 10.1111/jcpt.12729

  • 104

    ShibataT.NomuraY.TakadaA.UenoM.KatashimaM.YazawaR.et al (2019). Evaluation of food and spherical carbon adsorbent effects on the pharmacokinetics of roxadustat in healthy nonelderly adult male Japanese subjects. Clin. Pharmacol. Drug Dev.8 (3), 304313. 10.1002/cpdd.597

  • 105

    SinghA.SzczechL.TangK.BarnhartH.SappS.WolfsonM.et al (2006). Correction of anemia with epoetin alfa in chronic kidney disease. N. Engl. J. Med.355 (20), 20852098. 10.1056/NEJMoa065485

  • 106

    StaufferM.FanT. (2014). Prevalence of anemia in chronic kidney disease in the United States. PloS one9 (1), e84943. 10.1371/journal.pone.0084943

  • 107

    TalksK.TurleyH.GatterK.MaxwellP.PughC.RatcliffeP.et al (2000). The expression and distribution of the hypoxia-inducible factors HIF-1alpha and HIF-2alpha in normal human tissues, cancers, and tumor-associated macrophages. Am. J. Pathol.157 (2), 411421. 10.1016/s0002-9440(10)64554-3

  • 108

    TokuyamaA.KadoyaH.ObataA.ObataT.SasakiT.KashiharaN. (2021). Roxadustat and thyroid-stimulating hormone suppression. Clin. Kidney J.14 (5), 14721474. 10.1093/ckj/sfab007

  • 109

    VastaJ. D.RainesR. T. (2016). Human collagen prolyl 4-hydroxylase is activated by ligands for its iron center. Biochemistry55 (23), 32243233. 10.1021/acs.biochem.6b00251

  • 110

    VissersM. C.KuiperC.DachsG. U. (2014). Regulation of the 2-oxoglutarate-dependent dioxygenases and implications for cancer. Biochem. Soc. Trans.42 (4), 945951. 10.1042/BST20140118

  • 111

    WangG.JiangB.RueE.SemenzaG. (1995). Hypoxia-inducible factor 1 is a basic-helix-loop-helix-PAS heterodimer regulated by cellular O2 tension. Proc. Natl. Acad. Sci. U. S. A.92 (12), 55105514. 10.1073/pnas.92.12.5510

  • 112

    WilsonJ.ShakirD.BatieM.FrostM.RochaS. (2020). Oxygen-sensing mechanisms in cells. FEBS J.287 (18), 38883906. 10.1111/febs.15374

  • 113

    WuM.ChenW.MiaoM.JinQ.ZhangS.BaiM.et al (2021). Anti-anemia drug FG4592 retards the AKI-to-CKD transition by improving vascular regeneration and antioxidative capability. Clin. Sci.135 (14), 17071726. 10.1042/CS20210100

  • 114

    WuM.WangF.YangJ.LiP.YanD.YangY.et al (2020). The responses of the gut microbiota to MBL deficiency. Mol. Immunol.122, 99108. 10.1016/j.molimm.2020.03.008

  • 115

    YamaguchiJ.TanakaT.EtoN.NangakuM. (2015). Inflammation and hypoxia linked to renal injury by CCAAT/enhancer-binding protein δ. Kidney Int.88 (2), 262275. 10.1038/ki.2015.21

  • 116

    YangY.YuX.ZhangY.DingG.ZhuC.HuangS.et al (2018). Hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat (FG-4592) protects against cisplatin-induced acute kidney injury. Clin. Sci.132 (7), 825838. 10.1042/CS20171625

  • 117

    YuW.LiX.YuanF. (2020). Roxadustat for treatment of erythropoietin-hyporesponsive anemia in a hemodialysis patient: A case report. World J. Clin. Cases8 (23), 60486055. 10.12998/wjcc.v8.i23.6048

  • 118

    YuX.FangY.DingX.LiuH.ZhuJ.ZouJ.et al (2012). Transient hypoxia-inducible factor activation in rat renal ablation and reduced fibrosis with L-mimosine. Nephrol. Carlt. Vic.17 (1), 5867. 10.1111/j.1440-1797.2011.01498.x

  • 119

    ZhangH.XuR.WangZ. (2021). Contribution of oxidative stress to HIF-1-Mediated profibrotic changes during the kidney damage. Oxid. Med. Cell. Longev.2021, 6114132. 10.1155/2021/6114132

  • 120

    ZhangL.HouJ.LiJ.SuS.XueS. (2021). Roxadustat for the treatment of anemia in patients with chronic kidney diseases: A meta-analysis. Aging13 (13), 1791417929. 10.18632/aging.203143

  • 121

    ZhangY.RenS.XueH.WangA.ZouY.CaiY.et al (2021). Roxadustat in treating anemia in dialysis patients (ROAD): Protocol and rationale of a multicenter prospective observational cohort study. BMC Nephrol.22 (1), 28. 10.1186/s12882-021-02229-w

  • 122

    ZhaoL.LiW.ZhouY.ZhangY.HuangS.XuX.et al (2015). The overexpression and nuclear translocation of Trx-1 during hypoxia confers on HepG2 cells resistance to DDP, and GL-V9 reverses the resistance by suppressing the Trx-1/Ref-1 axis. Free Radic. Biol. Med.82, 2941. 10.1016/j.freeradbiomed.2015.01.014

  • 123

    ZhouM.HouJ.LiY.MouS.WangZ.HorchR.et al (2019). The pro-angiogenic role of hypoxia inducible factor stabilizer FG-4592 and its application in an in vivo tissue engineering chamber model. Sci. Rep.9 (1), 6035. 10.1038/s41598-019-41924-5

  • 124

    ZhuK.ReiserJ. (2021). ALKBH1 reduces DNA N6-methyladenine to allow for vascular calcification in chronic kidney disease. J. Clin. Invest.131 (14), 150966. 10.1172/JCI150966

  • 125

    ZhuY.WangY.JiaY.XuJ.ChaiY. (2019). Roxadustat promotes angiogenesis through HIF-1α/VEGF/VEGFR2 signaling and accelerates cutaneous wound healing in diabetic rats. Wound Repair Regen.27 (4), 324334. 10.1111/wrr.12708

Summary

Keywords

roxadustat, hypoxia-inducible factor, renal anemia, fibrosis, metabolism, inflammation, oxidative stress, angiogenesis

Citation

Zhu X, Jiang L, Wei X, Long M and Du Y (2022) Roxadustat: Not just for anemia. Front. Pharmacol. 13:971795. doi: 10.3389/fphar.2022.971795

Received

17 June 2022

Accepted

12 August 2022

Published

29 August 2022

Volume

13 - 2022

Edited by

Norberto Perico, Mario Negri Pharmacological Research Institute (IRCCS), Italy

Reviewed by

Patrick Maxwell, University of Cambridge, United Kingdom

Mostafa Eltobgy, The Ohio State University, United States

Updates

Copyright

*Correspondence: Yujun Du,

This article was submitted to Renal Pharmacology, a section of the journal Frontiers in Pharmacology

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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