Influencing factors of clinical efficacy of roxadustat among hemodialysis patients

OBJECTIVE

To explore independent influencing factors for clinical efficacy of roxadustat in hemodialysis patients.

METHODS

Hemodialysis patients treated with roxadustat were enrolled. The plasma trough concentrations of roxadustat were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A multiple logistic regression model was established to determine the factors that affect clinical efficacy of roxadustat in patients undergoing hemodialysis.

RESULTS

A total of 67 hemodialysis patients were enrolled in the study. The results showed that age, blood trough concentration of roxadustat, and baseline hemoglobin (Hb) level were independent factors of clinical efficacy of roxadustat (OR = 1.06, p = .025 for age; OR = 1.001, p = .037 for plasma concentration; and OR = 0.941, p = .003 for baseline Hb), with an AUC score of 0.859.

CONCLUSIONS

Age, blood trough concentration of roxadustat, and baseline Hb level were independent influencing factors of the response to roxadustat in hemodialysis patients.

A retrospective study on the efficacy of Roxadustat in peritoneal dialysis patients with erythropoietin hyporesponsiveness

Background/Aims

Roxadustat, an oral medication for treating renal anemia, is a hypoxia-inducible factor prolyl hydroxylase inhibitor used for regulating iron metabolism and promoting erythropoiesis. To investigate the efficacy and safety of roxadustat in patients undergoing peritoneal dialysis (PD) with erythropoietin hyporesponsiveness.

Methods

Single-center, retrospective study, 81 PD patients (with erythropoietin hyporesponsiveness) were divided into the roxadustat group (n = 61) and erythropoiesis-stimulating agents (ESAs) group (n = 20). Hemoglobin (Hb), total cholesterol, intact parathyroid hormone (iPTH), brain natriuretic peptide (BNP), related indicators of cardiac function and high-sensitivity C-reactive protein (hs-CRP) were collected. Additionally, adverse events were also recorded. The follow-up period was 16 weeks.

Results

The two groups exhibited similar baseline demographic and clinical characteristics. At baseline, the roxadustat group had a mean Hb level of 89.8 ± 18.9 g/L, while the ESAs group had a mean Hb level of 95.2 ± 16.0 g/L. By week 16, the Hb levels had increased to 118 ± 19.8 g/L (p < 0.05) in the roxadustat group and 101 ± 19.3 g/L (p > 0.05) in the ESAs group. The efficacy of roxadustat in improving anemia was not influenced by baseline levels of hs-CRP and iPTH. Cholesterol was decreased in the roxadustat group without statin use. An increase in left ventricular ejection fraction and stabilization of BNP were observed in the roxadustat group.

Conclusions

For PD patients with erythropoietin hyporesponsiveness, roxadustat can significantly improve renal anemia. The efficacy of roxadustat in improving renal anemia was not affected by baseline levels of hs-CRP0 and iPTH.

Risk Factors for Thromboembolic Events in Patients With Dialysis-Dependent CKD: Pooled Analysis of Phase 3 Roxadustat Trials in Japan

INTRODUCTION

Thromboembolic events have occurred in clinical trials of roxadustat. This post hoc analysis explored potential factors related to thromboembolic events in dialysis-dependent patients treated with roxadustat in four phase 3 clinical trials in Japan.

METHODS

Thromboembolic events with onset before and after week 12 were evaluated. Baseline risk factors for thromboembolic events were investigated by Cox regression analyses. Nested case-control analyses using conditional logistic models with matched pairs of case-control data explored relationships between thromboembolic events and laboratory parameters.

RESULTS

Of the 444 patients, 56 thromboembolic events were observed in 44 patients during ≤ 52 weeks of treatment. The proportion of venous and arterial thromboembolic events gradually increased after week 12. Baseline risk factors included hemodialysis (vs peritoneal dialysis), advanced age (≥ 65 years), shorter dialysis vintage (< 4 months), and history of thromboembolism. The absence of concomitant intravenous or oral iron therapy (including ferric citrate) was associated with thromboembolic events before week 12 (hazard ratio 11.25; 95% confidence interval [CI] 3.36-37.71; vs presence). Case-control analysis revealed that low average transferrin saturation (< 10%; unadjusted odds ratio [OR] 6.25; 95% CI 1.52-25.62; vs ≥ 20%), high average transferrin level (≥ 2.5 g/L; unadjusted OR 4.36; 95% CI 1.23-15.39; vs < 2.0 g/L), and high average roxadustat dose (≥ 150 mg; unadjusted OR 5.95; 95% CI 1.07-33.16; vs < 50 mg) over the previous 8 weeks before the event onset were associated with thromboembolic events after week 12. However, adjustment for iron status extinguished the significant relationship between roxadustat dose and events. Multivariate case-control analysis showed that increased transferrin from baseline (≥ 1.0 g/L; adjusted OR 7.85; 95% CI 1.82-33.90; vs < 0.5 g/dL) and decreased mean corpuscular volume (< - 2 fL; adjusted OR 5.55; 95% CI 1.73-17.83; vs ≥ 0 fL) were associated with increased risk of thromboembolic events.

CONCLUSION

In addition to established risk factors, iron deficiency may be related to thromboembolic events. Graphical Abstract available for this article.

TRIAL REGISTRATION

NCT02780726, NCT02952092, NCT02780141, NCT02779764.

Risk Factors for Thromboembolic Events in Patients With Dialysis-Dependent CKD: Pooled Analysis of Four Global Roxadustat Phase 3 Trials

INTRODUCTION

Risk factors for thromboembolic events in patients with dialysis-dependent chronic kidney disease (CKD) receiving roxadustat are unknown. Iron deficiency has been reported as a risk factor for thrombosis in the general population.

METHODS

Thromboembolic events with onset before and after week 12 in patients receiving roxadustat were evaluated in this pooled analysis of four global phase 3 trials, PYRENEES, SIERRAS, HIMALAYAS, and ROCKIES. Baseline risk factors for thromboembolic events were investigated by Cox regression analyses. Nested case-control analyses with matched pairs of case-control data explored the relationship between thromboembolic events and last known laboratory parameters before event onset.

RESULTS

Of 2354 patients, 1026 thromboembolic events were observed in 568 patients. Baseline risk factors found included hemodialysis (vs peritoneal dialysis), advanced age (≥ 65 years), Black race, high high-sensitivity C-reactive protein, and history of thromboembolism, cardiovascular disease, or diabetes. Univariate case-control analyses revealed that high hemoglobin rate of rise (≥ 0.5 g/dL/week; odds ratio [OR] 2.09; 95% confidence interval [CI] 0.98-4.46) showed a trend towards increased risk of thromboembolic events before week 12, and high rate of hemoglobin decline was associated with events after week 12 (< - 0.5 g/dL/week; OR 3.73; 95% CI 1.68-8.27) as compared to stable hemoglobin levels (≥ - 0.1 to < 0.1 g/dL/week). Multivariate case-control analyses showed that low last known hemoglobin level (< 10 g/dL: adjusted OR 1.91; 95% CI 1.04-3.50; vs ≥ 12 g/dL) and low last known transferrin saturation (TSAT < 10%: adjusted OR 3.78; 95% CI 1.71-8.39; vs ≥ 30%) before event onset were associated with events after week 12. In patients with last known TSAT < 30%, higher roxadustat dose was associated with thromboembolic events; however, no association was observed in those with TSAT ≥ 30%.

CONCLUSIONS

Among various risk factors for thromboembolic events, it is reasonable to avoid a rapid increase and decline in hemoglobin levels as well as ensure TSAT ≥ 30%, rather than increasing the roxadustat dose. Graphical Abstract available for this article.

TRIAL REGISTRATION

NCT02278341, NCT02273726, NCT02052310, NCT02174731.

Positive response of a hemodialysis patient with pure red cell aplasia on recombinant human erythropoietin therapy to cyclosporine and Roxadustat

Recombinant human erythropoietin (rHuEPO) is commonly used to treat anemia associated with chronic kidney disease (CKD). EPO-induced Pure Red Cell Aplasia (PRCA) is a rare condition of profound anemia with EPO treatment. Upon finding the development of EPO-induced PRCA, the treatment requires immediate withdrawal of EPO therapy and initiate new treatments with immunosuppression or renal transplantation. Anti-EPO antibody assay is not always positive in EPO-induced PRCA. Here, we report a case on the sudden development of PRCA in a hemodialysis patient receiving EPO and how we treated the condition successfully with cyclosporine and subsequently maintained the hemoglobin with Roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI). Even though the anti-EPO antibody was negative by Enzyme Linked Immunosorbent Assay (ELISA) in our case, the clinical course, the markedly reduced reticulocyte count < 10,000/μL, the bone marrow (BM) biopsy revealing reduced erythroblasts, and its subsequent response to cyclosporine, were similar to EPO-induced PRCA. The clinical picture of EPO-induced PRCA, the limitation of the EPO-neutralizing antibody (Ab) assay, and treatment strategies were discussed.

erythropoietin in non-dialysis CKD with diabetes: a single center propensity score matching analysis

PURPOSE

Renal anemia is a common complication of chronic kidney disease. Currently, recombinant human erythropoietin and roxadustat are the main treatments. In China, diabetic kidney disease is the primary cause of chronic kidney disease. However, high-quality evidence on the efficacy of roxadustat in patients with non-dialysis-dependent chronic kidney disease and diabetes mellitus is scarce. This study aimed to assess the clinical effect of roxadustat in such patients.

METHODS

Patients with non-dialysis-dependent anemia and diabetes mellitus who received roxadustat or recombinant human erythropoietin for ≥ 4 weeks were enrolled. We compared baseline characteristics, including age, gender, hypertension, and hemoglobin level, and then employed a 1:3 ratio propensity score matching. The primary efficacy outcomes were changes in hemoglobin levels. After propensity score matching, 212 patients were analyzed, including the roxadustat (n = 53) and recombinant human erythropoietin (n = 159) groups. Baseline characteristics were comparable, including hemoglobin level, estimated glomerular filtration rate, and glycated hemoglobin A1c (p > 0.05).

RESULTS

After 4, 12, and 24 weeks of treatment, the median hemoglobin levels in the roxadustat group were 97.5 g/L, 104 g/L, and 106.5 g/L, respectively, significantly surpassing the corresponding levels in the recombinant human erythropoietin group at 91 g/L, 94.5 g/L, and 94.5 g/L (p = 0.002, p = 0.025, p = 0.006, respectively). Additionally, subgroup analysis demonstrated better treatment efficacy of roxadustat patients with elevated high-sensitivity C-reactive protein and low albumin levels.

CONCLUSION

In Chinese patients with anemia and diabetes not on dialysis, roxadustat efficiently and rapidly improved and maintained hemoglobin levels unaffected by elevated high-sensitivity C-reactive protein and low albumin levels.

Hypoxia-inducible Factor Prolyl Hydroxylase Inhibitors and Hypothyroidism: An Analysis of the Japanese Pharmacovigilance Database

BACKGROUND/AIM

Hypothyroidism induced by roxadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, was recently reported; however, information regarding roxadustat-associated hypothyroidism is still lacking. We explored the risk and time to onset of hypothyroidism associated with HIF-PH inhibitors using the Japanese Adverse Drug Event Report (JADER), a pharmacovigilance database.

PATIENTS AND METHODS

The participants of this study were registered in the JADER database between April 2004 and March 2023. The association between HIF-PH inhibitors and hypothyroidism was evaluated using the reporting odds ratio (ROR) and information component (IC). We also calculated the period from the start of drug administration to the onset of hypothyroidism and determined the onset pattern using Weibull distribution.

RESULTS

Roxadustat had positive signals for hypothyroidism among the HIF-PH inhibitors based on the ROR [31.03, 95% confidence interval (CI)=27.81-34.62] and IC (4.51, 95%CI=4.36-4.67) values, and a strong relationship was confirmed. In addition, the median time to roxadustat-associated hypothyroidism onset was 92 days, and over 50% of cases occurred within 100 days of starting treatment. Furthermore, the onset pattern was an early failure type.

CONCLUSION

There is a possible association between roxadustat and hypothyroidism. Therefore, enhanced thyroid function testing within 100 days of treatment initiation may help detect roxadustat-associated hypothyroidism. However, further research is required to confirm these findings, considering study limitations using databases of spontaneous adverse event reports.

Compassionate use of roxadustat for treatment of refractory renal anemia in an infant

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) have played an important role in the treatment of renal anemia in children, but cannot improve hemoglobin to target level in some cases. Roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, can stimulate endogenous erythropoietin production and regulate iron metabolism even in patients with kidney failure. However, roxadustat has not yet been approved for use in children.

CASE-DIAGNOSIS/TREATMENT

We report a case of refractory renal anemia in an 80-day-old boy, who was hyporesponsive to ESAs even in combination with iron supplementation and transfusion. Compassionate use of roxadustat successfully corrected the intractable anemia. Hyperkalemia is a manageable adverse event of concern during follow-up.

CONCLUSION

The successful experience in this case may inform the clinical utility of roxadustat for refractory renal anemia in children, which should be further confirmed by well-designed prospective clinical trials.

Roxadustat ameliorates experimental colitis in mice by regulating macrophage polarization through increasing HIF level

BACKGROUND

Gastro-intestinal (GI) tract inflammation is as a result of inflammatory hypoxia which is also induced by long-standing group of disorders like inflammatory-bowel disease (IBD). Regulation of GI immune homeostasis by macrophage involves hypoxia-inducible factor (HIF). As inhibitor of HIF prolyl hydroxylase, roxadustat (ROX) increases the levels of HIF.

METHODS

We induced experimental colitis (EC) model in mice via dextran-sulfate sodium (DSS) to evaluate ROX role in above-mentioned disease.

RESULTS

ROX ameliorated EC in mice by blocking colonic length shorten and loss of body weight, thereby reducing scores of disease-activity index (DAI) and histopathology. ROX significantly reduced inflammatory cytokines levels, suppressed M1 and increased M2 macrophage polarization in colonic tissues. Besides, ROX blocked declining hematocrit (HCT) level in blood and increased HIF-1-α and HIF-2-α level in colonic tissues. The inhibitor of HIF-1- α, KC7F2 decreased body weight and colonic length in ROX-treated DSS mice. Meanwhile, DAI scores and histopathology in KC7F2 treated DSS mice were markedly higher than that of treatment with ROX alone. KC7F2 treatments also significantly increased inflammatory cytokines levels, respectively promoted and reduced polarization of M1 and M2 macrophages in colonic tissue from ROX treated mice. Further, KC7F2 treatments inhibited ROX induced HCT level increasing in blood and decreased HIF-1-α and HIF-2-α level in colonic tissue.

CONCLUSION

Collectively, we discovered that ROX ameliorated EC in mice by regulating macrophage polarization through promotion of HIF expression.

GENERAL SIGNIFICANCE

Taken together, we developed a new application of ROX, which provides new ideas and a scientific basis for IBD treatment.

Roxadustat and Oral Iron Absorption in Chinese Patients with Anemia of Chronic Kidney Disease: A Randomized, Open-Label, Phase 4 Study (ALTAI)

INTRODUCTION

Anemia of chronic kidney disease (CKD) has a high incidence and is associated with many disease conditions. Iron dysmetabolism is an important contributor to anemia in CKD patients.

METHODS

ALTAI, a randomized, active-controlled, phase 4 trial, investigated the efficacy of roxadustat versus recombinant human erythropoietin (rHuEPO) on gastrointestinal iron absorption in patients with anemia of CKD (stage 4/5). The primary endpoint was change from baseline to day 15 in gastrointestinal iron absorption (serum iron area under the concentration-time curve; AUC0-3h) following single-dose oral iron.

RESULTS

Twenty-five patients with a mean age of 55.1 years were randomized 1:1 to roxadustat (n = 13) or rHuEPO (n = 12). Baseline iron profiles were similar between treatment groups. Change from baseline to day 15 in serum iron AUC0-3h was not statistically significantly different between the roxadustat and rHuEPO groups. Mean (SD) change from baseline in serum iron AUC0-3h was 11.3 (28.2) g × 3 h/dl in the roxadustat group and - 0.3 (9.7) g × 3 h/dl in the rHuEPO group. Roxadustat treatment was associated with decreased hepcidin and also increased transferrin, soluble transferrin receptor, and total iron-binding capacity (TIBC), with nominal significance. The proportion of patients experiencing one or more adverse events was 38.5% when treated with roxadustat and 16.7% with rHuEPO.

CONCLUSIONS

The study showed no significant difference between roxadustat and rHuEPO in iron absorption but was underpowered because of recruitment challenges.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT04655027.

A clinical study on roxadustat for anemia in diabetic nephropathy: a 8-week study

PURPOSE

The development of roxadustat is a standard treatment for renal anemia, and multiple clinical trials have proved its safety and efficacy. However, less information is available from trials of the population with diabetic nephropathy (DN). This study aimed to determine whether roxadustat is effective for treating DN.

METHODS

This was a single-center, retrospective, institutional review board-approved cohort study. The patients with DN were chosen and given roxadustat or erythropoietin (EPO) for 8 weeks. The mean hemoglobin (Hb) level after 8 weeks of treatment served as the primary outcome. Alterations in the iron index and lipid levels were considered secondary objectives. Sub-group analysis was performed to observe the impact of inflammation and glycemic status on Hb.

RESULTS

A total of 80 patients were enrolled, 40 in each group. After 8 weeks of treatment, the Hb levels in the roxadustat group were higher than those in the control group. The number of patients who achieved Hb response was higher in the roxadustat group than in the control group (77.5% versus 27.5%; P < 0.001). In addition to lowering total cholesterol and low-density lipoprotein cholesterol, roxadustat decreased ferritin and elevated total iron-binding capacity. Compared to the control group, roxadustat was more beneficial for patients with an inflammatory condition and poor glycemic control.

CONCLUSIONS

Roxadustat treatment remarkably corrected anemia in patients with DN, and its effectiveness was unaffected by inflammation or glycemic control levels. In addition, roxadustat can also reduce a patient's blood lipid level and enhance the body's use of iron.

CLINICAL TRIAL REGISTRATION

ChiCTR2200057232.

Hair and dietary supplements testing to identify contamination with roxadustat in an adverse analytical finding

Roxadustat is an oral inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase, which increases endogenous erythropoiesis. WADA has included roxadustat and other HIF stabilizers on its list of prohibited substances. We describe here the case of an elite athlete (female, 31 years old, 168 cm and 53 kg) with an adverse analytical finding (AAF) with concentration of roxadustat in her urine at 0.289 ng/mL in the A sample and 0.529 ng/mL in the B sample (83% higher than A). A stability study was carried out, showing total stability of roxadustat at this concentration in urine exposed to light for 50 h, so photoisomerization degradation cannot explain the difference in concentration. Her urine had been completely negative in a control test carried out three days previously, while roxadustat had been shown to be present in urine for at least 20 days after administration of pharmacologically effective doses to an athlete. Hair concentration was 0.39 and 0.35 pg/mg in the segments corresponding to the presumed period of intake, with few adjacent segments also positive (0.29-0.33 pg/mg), likely explained by cosmetic treatments. Concentrations found in a patient treated with a pharmacologically active dose (between 100 and 120 mg 3 days a week) were more than 100 times higher (between 41 and 57 pg/mg). Numerous supplements and pharmaceuticals taken by the athlete were analyzed. Only collagen powder showed the presence of roxadustat, at a very low but highly variable concentration (100 pg/g-1000 pg/g). A female volunteer (58 years old, 169 cm and 65 kg), taking this powder at the same doses as the athlete (10 g of powder 5 times for 6 days) presented 7 roxadustat-positive urine samples (although lower than those observed in the athlete) out of 34 sampled over 7 days, the difference in powder sampling location, age, weight, height, pharmacokinetic parameters variability and level of sporting activity between the athlete and the volunteer probably explaining the difference in concentrations observed. All these results could be consistent with an AAF due to contamination by dietary supplements, which are becoming increasingly common due to the current exposome of athletes in our society.

Impact of C-reactive protein on the effect of Roxadustat for the treatment of anemia in chronic kidney disease: a systematic review of randomized controlled trials

BACKGROUND

Chronic inflammation, reflected by an increased blood C-reactive protein (CRP) level, is common in patients with chronic kidney disease (CKD) and is involved in the development of renal anemia. This systematic review aims to investigate the impacts of CRP on the efficacy of hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) in the treatment of renal anemia in patients with CKD.

METHODS

We conducted a comprehensive search of electronic databases including Pubmed, Web of Science, Embase, Cochrane Library, CNKI, Wanfang, and the International Clinical Trials Registry Platform (ICTRP), from their inception to May 19, 2022. We systematically reviewed evidence from randomized controlled trials using HIF-PHIs for renal anemia treatment. The mean difference (MD) in changes in hemoglobin concentration (∆Hb) before and after treatment served as the meta-analysis outcome, utilizing a random-effects model. We compared groups with CRP levels greater than or equal to the upper limit of normal (ULN) and less than the ULN. Additionally, further analysis was conducted in the CRP ≥ ULN group comparing HIF-PHIs and erythropoiesis-stimulating agents (ESA).

RESULTS

A total of 7 studies from 6 publications were included in the analysis. In the comparison between the CRP ≥ ULN group and the CRP < ULN group, 524 patients from 4 studies were incorporated into the analysis. All patients received roxadustat as the primary intervention. The pooled results revealed no significant difference in ΔHb between patients with CRP ≥ ULN and CRP < ULN at baseline (Mean Difference: 0.00, 95% Confidence Interval: -0.32 to 0.33, P = 0.99). Moreover, within the CRP ≥ ULN group, three studies involving 1399 patients compared the efficacy of roxadustat and erythropoiesis-stimulating agents (ESAs). The results indicated no significant difference in ΔHb between patients treated with ESAs and HIF-PHIs (Mean Difference: 0.24, 95% Confidence Interval: -0.08 to 0.56, P = 0.14). In terms of medication dosage, an increase in ESA dose over time was observed across various studies, particularly evident in the CRP ≥ ULN group, while the dose of roxadustat remains constant over time and is not influenced by the baseline levels of CRP.

CONCLUSIONS

Our systematic review demonstrates that roxadustat exhibits similar efficacy across different CRP levels. Moreover, within the CRP ≥ ULN group, roxadustat can maintain efficacy comparable to ESA without the necessity for dose escalation.

TRIAL REGISTRATION

CRD42023396704.

Roxadustat for Patients with Posttransplant Anemia: A Narrative Review

Background

Hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) are novel oral agents used for renal anemia treatment. Roxadustat, a first-in-class HIF-PHI used for treating anemia in chronic kidney disease patients, has been approved in China, Japan, South Korea, Chile, and Europe. Roxadustat is involved in HIF degradation, which can stimulate endogenous erythropoietin (EPO) production and improve iron utilization. Besides, roxadustat can promote dietary iron uptake and transport. In comparison with traditional erythropoiesis-stimulating agent treatment, it might reduce cardiovascular risk and mortality as it causes only a slight increase in the plasma EPO level. Phase II and III clinical trial reports have shown that roxadustat is effective for treating chronic kidney disease patients. The role of roxadustat in kidney transplant recipients (KTRs) needs to be examined as patients with chronic kidney disease are different from those receiving renal transplants.

Summary

Clinical trials have demonstrated that roxadustat effectively increases and maintains hemoglobin levels in patients with dialysis-dependent and non-dialysis-dependent chronic kidney disease by stimulating endogenous EPO production and optimizing iron utilization. Roxadustat has recently been used effectively to treat patients with EPO-resistant anemia. It has also been used for treating patients with posttransplant anemia (PTA), which is a prognostic factor for mortality in KTRs with an iron deficiency and impaired glomerular filtration rate. Here, we examined the findings of four studies in a narrative review and discussed our perspectives regarding this field of study.

Key Messages

Roxadustat significantly improves hemoglobin levels without affecting renal function in KTRs with PTA. It also enhances iron utilization by decreasing ferritin and hepcidin levels and increasing total iron binding capacity, transferrin, and serum iron levels. Roxadustat ameliorates anemia and inflammation, and might have reno-protective effects in KTRs.

Investigating the therapeutic effects and mechanisms of Roxadustat on peritoneal fibrosis Based on the TGF-β/Smad pathway

Peritoneal fibrosis (PF) is particularly common in individuals undergoing peritoneal dialysis (PD). Fibrosis of the parenchymal tissue typically progresses slowly. Therefore, preventing and reducing the advancement of fibrosis is crucial for effective patient treatment. Roxadustat is a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI), primarily used to treat and improve renal anemia. Recent studies have found that HIF-1α possesses antioxidant activity and exerts a certain protective effect in ischemic heart disease and spinal cord injury, while it can also delay the progression of pulmonary and renal fibrosis. This study establishes the mice model through intraperitoneal injection of 4.25 % peritoneal dialysate fluid (PDF) and explores the therapeutic effects of Roxadustat by inducing TGF-β1-mediated epithelial-mesenchymal transition (EMT) in Met-5A cells. The aim is to investigate the protective role and mechanisms of Roxadustat against PD-related PF. We observed thicker peritoneal tissue and reduced permeability in animals with PD-related PF samples. This was accompanied by heightened inflammation, which Roxadustat alleviated by lowering the levels of inflammatory cytokines (IL-6, TNF-α). Furthermore, Roxadustat inhibited EMT in PF mice and TGF-β1-induced Met-5A cells, as evidenced by decreased expression of fibrotic markers, such as fibronectin, collagen I, and α-SMA, alongside an elevation in the expression of the epithelial marker, E-cadherin. Roxadustat also significantly decreased the expression of TGF-β1 and the phosphorylation of p-Smad2 and p-Smad3. In conclusion, Roxadustat ameliorates peritoneal fibrosis through the TGF-β/Smad pathway.

A novel scenario in the therapeutic management of anemia of chronic kidney disease: placement and use of roxadustat

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.

Hypoxia-inducible factor stabilisation-related lncRNAs in retinopathy of prematurity

Long non-coding RNAs (lncRNAs) play an important role in the response to many diseases. The previous study reported the transcriptomes of mice that were cured of oxygen-induced retinopathy (OIR, retinopathy of prematurity (ROP) model) by hypoxia-inducible factor (HIF) stabilisation via HIF prolyl hydroxylase inhibition using the isoquinolone Roxadustat or the 2-oxoglutarateanalog dimethyloxalylglycine (DMOG). However, there is little understanding of how those genes are regulated. In the present study, 6918 known lncRNAs and 3654 novel lncRNAs were obtained, and a series of differentially expressed lncRNAs (DELncRNAs) were also identified. By cis- and trans-regulation analyses, the target genes of DELncRNAs were predicted. Functional analysis demonstrated that multiple genes were involved in the MAPK signalling pathway, adipocytokine signalling pathway was regulated by the DELncRNAs. By HIF-pathway analysis, two lncRNAs Gm12758 and Gm15283 were found that can regulate the HIF-pathway by targeting the Vegfa, Pgk1, Pfkl, Eno1, Eno1b and Aldoa genes. In conclusion, the present study provided a series of lncRNAs for further understanding and protecting the extremely premature infant from oxygen toxicity.

Thyroid function analysis after roxadustat or erythropoietin treatment in patients with renal anemia: a cohort study

PURPOSE

This cohort study was designed to explore whether roxadustat or erythropoietin could affect thyroid function in patients with renal anemia.

METHODS

The study involved 110 patients with renal anemia. Thyroid profile and baseline investigations were carried out for each patient. The patients were divided into two groups: 60 patients taking erythropoietin served as the control group (rHuEPO group) and 50 patients using roxadustat served as the experimental group (roxadustat group).

RESULTS

The results indicated that there were no significant differences in serum total thyroxine (TT4), total triiodothyronine (TT3), free triiodothyronine (FT3), free thyroxine (FT4) or thyroid stimulating hormone (TSH) between the two groups at baseline. After treatment, TSH, FT3, and FT4 were significantly lower in the roxadustat group than in the rHuEPO group (p < 0.05). After adjusting for age, sex, dialysis modality, thyroid nodules and causes of kidney disease, Cox regression showed that roxadustat was an independent influencing factor on thyroid dysfunction (HR 3.37; 95% CI 1.94-5.87; p < 0.001). After 12 months of follow-up, the incidence of thyroid dysfunction was higher in the roxadustat group than in the rHuEPO group (log-rank p < 0.001).

CONCLUSION

Roxadustat may lead to a higher risk of thyroid dysfunction, including low TSH, FT3 and FT4, than rHuEPO in patients with renal anemia.

The effects of prolyl hydroxylase inhibition during and post, hypoxia, oxygen glucose deprivation and oxidative stress, in isolated rat hippocampal slices

The contributions of hypoxia and oxidative stress to the pathophysiology of acute ischemic stroke are well established and can lead to disruptions in synaptic signaling. Hypoxia and oxidative stress lead to the neurotoxic overproduction of reactive oxygen species (ROS) and the stabilization of hypoxia inducible factors (HIF). Compounds such as prolyl-4-hydroxylase domain enzyme inhibitors (PHDIs) have been shown to have a preconditioning and neuroprotective effect against ischemic insults such as hypoxia, anoxia, oxygen glucose deprivation (OGD) or H2O2. Therefore, this study explored the effects of two PHDIs, JNJ-42041935 (10 µM) and roxadustat (100 µM) on cell viability using organotypic hippocampal slice cultures. We also assessed the effects of these compounds on synaptic transmission during and post hypoxia, OGD and H2O2 application in isolated rat hippocampal slices using field recording electrophysiological techniques and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit trafficking using immunohistochemistry. Our organotypic data demonstrated a protective role for both inhibitors, where slices had significantly less cell death post anoxia and OGD compared to controls. We also report a distinct modulatory role for both JNJ-42041935 and roxadustat on fEPSP slope post hypoxia and OGD but not H2O2. In addition, we report that application of roxadustat impaired long-term potentiation, but only when applied post-hypoxia. This inhibitory effect was not reversed with co-application of the cyclin-dependent kinase 5 (CDK-5) inhibitor, roscovitine (10 µM), suggesting a CDK-5 independent synaptic AMPAR trafficking mechanism. Both hypoxia and OGD induced a reduction in synaptic AMPA GluA2 subunits, the OGD effect being reversed by prior treatment with both JNJ-42041935 and roxadustat. These results suggest an important role for PHDs in synaptic signaling and plasticity during episodes of ischemic stress.

The efficacy and safety of roxadustat for anemia in patients with dialysis-dependent chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

This meta-analysis aims to assess the efficacy and safety of roxadustat in treating anemia patients with dialysis-dependent (DD) chronic kidney disease (CKD).

METHODS

We comprehensively searched 5 databases for randomized controlled trials (RCTs) investigating roxadustat for anemia in DD-CKD patients. RevMan 5.0 was used to extract and synthesize data for meta-analysis.

RESULTS

Ten different RCTs (9 studies) and 5698 DD-CKD patients with anemia were included. Our findings revealed that when compared to the erythropoiesis-stimulating agents (ESAs) group, the roxadustat group showed increased hemoglobin levels [MD (Mean Difference) 0.25 g/dL (95%CI 0.14 g/dL to 0.36 g/dL), p < 0.00001] and improved iron-utilization by increasing serum iron [MD 1.85 µmol/L], total iron binding capacity [MD 35.73 µg/dL], transferrin saturation [MD 1.19%], and transferrin level [MD 0.40 g/L]. In addition, we found that roxadustat significantly decreased the low-density lipoprotein-cholesterol [MD -0.39 mmol/L] and total cholesterol [MD -0.6 mmol/L]. In patients with a C-reactive protein level that exceeds the upper limit of the normal range, hemoglobin levels were higher for roxadustat than for ESAs [MD 0.39 g/dL]. Treatment-emergent adverse events, treatment-emergent serious adverse events, and major adverse cardiovascular events were not significantly different between the two groups.

CONCLUSIONS

The hemoglobin levels of DD-CKD patients were significantly increased and not affected by the inflammatory state after roxadustat treatment. Roxadustat also improved iron utilization, and it was not associated with higher treatment-emergent adverse events, treatment-emergent serious adverse events, and major adverse cardiovascular events when compared to ESAs.

[New Therapeutic Strategies in the Treatment of CKD Anemia: Hypoxia-Induced Factor Prolyl-Hydroxylase Inhibitors]

The link between chronic renal failure and anemia has been known for more than 180 years, negatively impacting the quality of life, cardiovascular risk, mortality, and morbidity of patients with chronic kidney disease (CKD). Traditionally, the management of anemia in CKD has been based on the use of replacement martial therapy, vitamin therapy, and the use of erythropoiesis-stimulating agents (ESAs). In recent years, alongside these consolidated therapies, new molecules known as hypoxia-induced factor prolyl-hydroxylase inhibitors (HIF-PHIs) have appeared. The mechanism of action is expressed through an increased transcriptional activity of the HIF gene with increased erythropoietin production. The drugs currently produced are roxadustat, daprodustat, vadadustat, molidustat, desidustat, and enarodustat; among these only roxadustat is currently approved and usable in Italy. The possibility of oral intake, pleiotropic activity on martial and lipidic metabolism, and the non-inferiority compared to erythropoietins make these drugs a valid alternative to the treatment of anemia associated with chronic kidney disease in the nephrologist practice.

Evaluating the effect of Roxadustat on ventricular repolarization in patients undergoing peritoneal dialysis

BACKGROUND

Roxadustat is a novel oral medication used to treat anemia in CKD patients. Several studies have shown that Roxadustat can alleviate anemia in CKD patients by increasing hemoglobin levels and regulating iron metabolism. We aimed to evaluate the effect of Roxadustat on ventricular repolarization in PD patients. This study may provide a new integrated approach to the assessment and treatment of CKD.

METHODS

The present prospective cohort study enrolled 65 CKD patients who were treated with Roxadustat and 31 CKD patients who received conventional therapy between January 2021 and June 2022. All patients were examined for ECG in the absence of clinical symptoms and compared the ECG indicators. Demographic and clinical data of all patients were collected. All data used SPSS 18.0 for statistical analyses.

RESULTS

The T peak-to-end (Tpe) of PD patients in the Roxadustat group was remarkably slower than that of patients in the conventional group. Additionally, the Tpe/QT ratio in the conventional group was significantly elevated than that in the Roxadustat group. The results of logistic regression analysis showed that Tpe (95%CI 1.191 ~ 2.141, P = 0.002) and Roxadustat treatment (95%CI 1.357 ~ 42.121, P = 0.021) were the risk factors of PD patients with high Tp-e/QT ratio.

CONCLUSION

In summary, we found that Roxadustat could improve ventricular repolarization in peritoneal dialysis patients, which indicated a potential cardiovascular protective effect of Roxadustat. This study might provide a new integrated approach to the assessment and treatment of CKD.

Structural characterization and in silico toxicity prediction of degradation impurities of roxadustat

Roxadustat is the first drug approved for anemia due to chronic kidney disease. Drug degradation profile is very crucial for assessing the quality and safety of the drug substances and their formulations. Forced degradation studies are conducted for quick prediction of drug degradation products. Forced degradation of roxadustat was carried out as per ICH guidelines, and nine degradation products (DPs) were observed. These DPs (DP-1 to DP-9) were separated using the reverse phase HPLC gradient method with an XBridge column (250 mm × 4.6 mm, 5 µm). The mobile phase consisted of 0.1% formic acid (solvent A) and acetonitrile (solvent B) at a flow rate of 1.0 ml/min. The chemical structures of all the DPs were proposed by using LC-Q-TOF/MS. DP-4 and DP-5, the two major degradation impurities, were isolated, and NMR was used to confirm their chemical structures. Based on our experiments, the roxadustat was found stable to thermal degradation in solid state and oxidative conditions. However, it was unstable in acidic, basic, and photolytic conditions. A very remarkable observation was made about DP-4 impurity. DP-4 was generated as a common degradation impurity in alkaline hydrolysis, neutral hydrolysis as well as photolysis conditions. DP-4 has a similar molecular mass to roxadustat but is structurally different. DP-4 is chemically, (1a-methyl-6-oxo-3-phenoxy-1,1a,6,6a-tetrahydroindeno [1,2-b] aziridine-6a-carbonyl) glycine. In silico toxicity study was conducted using Dereck software to gain the best knowledge of the drug and its degradation products towards carcinogenicity, mutagenicity, teratogenicity, and skin sensitivity. A further study using molecular docking confirmed the potential interaction of DPs with proteins responsible for toxicity. DP-4 shows a toxicity alert due to the presence of aziridine moiety.

Safety and effectiveness of recombinant human erythropoietin coupled with different doses of Roxadustat for treatment of renal anemia in patients on maintenance hemodialysis

OBJECTIVE

To investigate the safety and efficacy of recombinant human erythropoietin (rHuEPO) in combination with different doses of Roxadustat in treating renal anemia in patients on maintenance hemodialysis.

METHODS

Eighty patients with renal anemia on maintenance hemodialysis treated in Shuyang Hospital of Traditional Chinese Medicine from January 2020 to December 2021 were selected as study subjects, and they were divided into a study group (n=40, high-dose Roxadustat + rHuEPO therapy) and a control group (Con) (n=40, low-dose Roxadustat + rHuEPO therapy) in accordance with different therapies. The effects of anemia therapy, changes in anemia indicators (hemoglobin (Hb), hematocrit (Hct)), changes in iron metabolism indicators (transferrin saturation (TSAT), serum ferritin (SF)), changes in oxidative stress indicators Malondialdehyde (MDA), Superoxide Dismutase (SOD), and changes in microinflammatory indicators IL6, CRP were compared between the two groups. The occurrences of adverse effects during therapy were counted and compared between the two groups.

RESULTS

The therapy efficiency of the study group was 97.50% (39/40), which was higher than 85.00% (34/40) in the control group (P=0.048). The contents of Hb, Hct, TSAT, and SF were higher in the study group than the Con after therapy (all P<0.001 or P=0.001). The contents of MDA, IL6, and CRP were significantly lower in the study group than the Con after therapy (all P<0.001). The occurrence of adverse effects was 10.00% in the study group, which was higher than 5.00% in the Con, but the difference was not significant (P=0.396).

CONCLUSION

The combination of rHuEPO and high-dose Roxadustat (120 mg/time) has a better effect on improving anemia symptoms in maintenance hemodialysis patients than in those who take low dose Roxadustat (100 mg/time). It can significantly improve anemia and iron metabolism indicators and alleviate patients' inflammation and oxidative stress levels.

Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitor Improves Leukocyte Energy Metabolism in Hereditary Hemorrhagic Telangiectasia

The interplay between hypoxia-inducible factors (HIFs) and transforming growth factor beta (TGF-β) is critical for both inflammation and angiogenesis. In hereditary hemorrhagic telangiectasia (HHT), we have previously observed that impairment of the TGF-β pathway is associated with downregulation of HIF-1α. HIF-1α accumulation is mandatory in situations of altered energy demand, such as during infection or hypoxia, by adjusting cell metabolism. Leukocytes undergo a HIF-1α-dependent switch from aerobic mitochondrial respiration to anaerobic glycolysis (glycolytic switch) after stimulation and during differentiation. We postulate that the decreased HIF-1α accumulation in HHT leads to a clinically observed immunodeficiency in these patients. Examination of HIF-1α and its target genes in freshly isolated peripheral blood mononuclear cells (PBMCs) from HHT patients revealed decreased gene expression and protein levels of HIF-1α and HIF-1α-regulated glycolytic enzymes. Treatment of these cells with the HIF-prolyl hydroxylase inhibitor, Roxadustat, rescued their ability to accumulate HIF-1α protein. Functional analysis of metabolic flux using a Seahorse FX extracellular flux analyzer showed that the extracellular acidification rate (indicator of glycolytic turnover) after Roxadustat treatment was comparable to non-HHT controls, while oxygen consumption (indicator of mitochondrial respiration) was slightly reduced. HIF stabilization may be a potential therapeutic target in HHT patients suffering from infections.

Roxadustat alleviates the inflammatory status in patients receiving maintenance hemodialysis with erythropoiesis-stimulating agent resistance by increasing the short-chain fatty acids producing gut bacteria

BACKGROUND

Hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) have improved the treatment of renal anemia, especially in patients resistant to erythropoiesis-stimulating agents (ESAs). HIF facilitates maintain gut microbiota homeostasis, which plays an important role in inflammation and iron metabolism, which are in turn key factors affecting ESA resistance. The current study aimed to investigate the effects of roxadustat on inflammation and iron metabolism and on the gut microbiota in patients with ESA resistance.

METHODS

We conducted a self-controlled, single-center study including 30 patients with ESA resistance undergoing maintenance hemodialysis. All patients received roxadustat without iron agents for renal anemia. Hemoglobin and inflammatory factors were monitored. Fecal samples were collected before and after 3 months' administration and the gut microbiota were analyzed by 16S ribosomal RNA gene sequencing.

RESULTS

Hemoglobin levels increased after treatment with roxadustat for 3 months (P < 0.05). Gut microbiota diversity and abundance also changed, with increases in short-chain fatty acid (SCFA)-producing bacteria (Acidaminococcaceae, Butyricicoccus, Ruminococcus bicirculans, Ruminococcus bromii, Bifidobacterium dentium, Eubacterium hallii) (P < 0.05). Serum SCFA levels also increased (P < 0.05). Inflammatory factors, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α, interferon-γ, and endotoxin gradually decreased (P < 0.05). Serum hepcidin, ferritin, and total and unsaturated iron-binding capacities decreased (P < 0.05), while soluble transferrin receptor levels increased at each time point (P < 0.05). There were no significant differences in serum iron and transferrin saturation at each time point. The abundance of Alistipes shahii was significantly negatively correlated with IL-6 and TNF-α (P < 0.05).

CONCLUSIONS

Roxadustat alleviated renal anemia in patients with ESA resistance by decreasing inflammatory factors and hepcidin levels and improving iron utilization. These effects were at least partly mediated by improved diversity and abundance of SCFA-producing gut bacteria, probably via activation of HIF.

A critical review of Roxadustat formulations, solid state studies, and analytical methodology

This review aims to collate information about the analytical methodologies, bioanalytical methodologies, pharmaceutical formulations, solid-state studies, and the current and future market scenario for a relatively new class of drugs, Roxadustat. Roxadustat is a hypoxia-inducible factor propyl hydroxylase inhibitor that significantly increases blood hemoglobin via the action of transcriptional activator HIF. As the molecule has a promising role in stimulating erythropoiesis, it is considered an ideal therapeutic agent for patients with anemia. In the current review, an attempt has been made to compile the pharmacological, pharmacokinetic, and pharmacodynamic characteristics of Roxadustat and systematically present product development data. This drug has several polymorphs of cocrystal, co-former, and salt, which have been explained in detail in the current work. The comprehensive review summarizes all the chromatographic methods and is presented in table form. This review has extensively covered Liquid chromatography-tandem mass spectrometry methods used to analyze Roxadustat in the biological matrix. The literature needs more data on forced degradation study, impurity profiling, gas chromatography, analytical methods for assay, dissolution, and different formulation aspects of Roxadustat.

First detection/quantification of roxadustat in hair with a new liquid chromatography with tandem mass spectrometry method: application to a treated patient

Roxadustat is an oral inhibitor of hypoxia-inducible factor prolyl hydroxylase which increases erythropoiesis. It can therefore be used as a doping agent. No data are available on how to measure roxadustat in hair and on the concentration found in treated patients. The aim of this study was to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of roxadustat in hair and to apply it to a chronically treated patient. After decontamination with dichloromethane, testosterone-D3 used as an internal standard and phosphate buffer pH 5.0 were added to 20 mg of hair and incubated for 10 min at 95°C. Four ml of dichloromethane were used for extraction and reconstituted into the mobile phase, 10 µl were injected into the chromatographic system. The method was linear in the range 0.5-200 pg/mg, accurate and precise (evaluated at 3 levels) and was successfully applied to measure roxadustat in a brown-haired patient treated pharmacologically with 100-120 mg 3 days a week. Results were stable between 41 and 57 pg/mg in the 6 proximal 1 cm segments. This first method describing the measurement of roxadustat in hair appears to be suitable for the quantification of this compound in clinical or doping control cases.

Roxadustat and its failure: A comparative dynamic study

Roxadustat, a small-molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase domain 2 (HIF-PHD2) has been recently overruled by the American Food and Drug Administration (FDA) in Phase 3 clinical trials. This study provides insights into the dynamics of Roxadustat with PHD2 and proposes two FDA-approved drugs; Pemetrexed and Valrubicin to treat chronic kidney disease (CKD). Role of chemical scaffolds such as synthetic pyrimidine-based antifolate is found critical for PHD2 inhibitory activity, which is concurrent with the experimental findings for stimulating Endogenous erythropoietin (EPO) gene expression. Furthermore, Fe⁺² and Mn⁺² in solution are essential for imparting structural stability to the screened carboxylic and non-carboxylic acid drugs. Comparative analysis of FDA-approved drugs namely, Roxadustat, two-hit carboxylic, and non-carboxylic-acid type compounds (Pemetrexed and Valrubicin), as well as the control ligands (KU1 and 4JR), unveil structural dynamics of Roxadustat and its failure. However, the proposed FDA compounds, Pemetrexed and Valrubicin, used to treat mesothelioma, non-small cell lung cancer, and bladder cancer should be subjected to in vitro analysis for renal anemia.

Safety of Roxadustat Versus Erythropoiesis-Stimulating Agents in Patients with Anemia of Non-dialysis-Dependent or Incident-to-Dialysis Chronic Kidney Disease: Pooled Analysis of Four Phase 3 Studies

INTRODUCTION

This study was conducted to elucidate the safety of roxadustat, an oral medication, in patients with non-dialysis-dependent (NDD) or incident dialysis dialysis-dependent (ID-DD) chronic kidney disease (CKD).

METHODS

Safety results from four phase 3, randomized, open-label studies comparing roxadustat to an erythropoiesis-stimulating agent (ESA) in men and women with NDD or ID-DD CKD with anemia were pooled and evaluated. Endpoints were time to major adverse cardiovascular event (MACE; myocardial infarction, stroke, and all-cause mortality) and MACE+ (MACE plus congestive heart failure or unstable angina requiring hospitalization), all-cause mortality, and treatment-emergent adverse events (TEAEs). MACE and MACE+ were evaluated for non-inferiority at 1.8- and 1.3-margins using hazard ratios (HRs) and 95% confidence intervals (CIs). TEAEs were descriptively summarized.

RESULTS

In total, 2142 patients were evaluated (1083 roxadustat; 1059 ESA). Roxadustat was comparable to ESA for risk of MACE (HR 0.79, 95% CI 0.61-1.02), MACE+ (HR 0.78, 95% CI 0.62-0.98), and all-cause mortality (HR 0.78, 95% CI 0.57-1.05). TEAEs were comparable between roxadustat and ESA groups, including any TEAE [incidence rate per 100 (IR/100) patient-exposure years 56.1 vs. 53.5], TEAEs leading to study drug discontinuation (IR/100 patient-exposure years 6.7 vs. 5.1), and TEAEs leading to death (IR/100 patient-exposure years 6.9 vs. 7.4).

CONCLUSION

There was no evidence of increased risk of cardiovascular events or mortality with roxadustat compared with ESA in patients with anemia who have NDD or ID-DD CKD. Although TEAEs occurred commonly in both the roxadustat and ESA groups, patients infrequently discontinued the study drug because of an adverse event.

CLINICAL TRIAL REGISTRATION NUMBERS

DOLOMITES, 1517-CL-0610 [NCT02021318]; HIMALAYAS, FGCL-4592-063 [NCT02052310]; SIERRAS, FGCL-4592-064 [NCT02273726]; and ROCKIES, D5740C00002 [NCT02174731].

Roxadustat protect mice from DSS-induced colitis in vivo by up-regulation of TLR4

BACKGROUND

The incidence of inflammatory bowel disease (IBD) is growing in the population. At present, the etiology of inflammatory bowel disease remains unclear, and there is no effective and low-toxic therapeutic drug. The role of the PHD-HIF pathway in relieving DSS-induced colitis is gradually being explored.

METHODS

Wild-type C57BL/6 mice were used as a model of DSS-induced colitis to explore the important role of Roxadustat in alleviating DSS-induced colitis. High-throughput RNA-Seq and qRT-PCR methods were used to screen and verify the key differential genes in the colon of mice between normal saline (NS) and Roxadustat groups.

RESULTS

Roxadustat could alleviate DSS-induced colitis. Compared with the mice in the NS group, TLR4 were significantly up-regulated in the Roxadustat group. TLR4 KO mice were used to verify the role of TLR4 in the alleviation of DSS-induced colitis by Roxadustat.

CONCLUSION

Roxadustat has a repairing effect on DSS-induced colitis, and may alleviate DSS-induced colitis by targeting the TLR4 pathway and promote intestinal stem cell proliferation.

The role of roxadustat in chronic kidney disease patients complicated with anemia

The incidence of chronic kidney disease (CKD) is increasing worldwide and the current prevalence rate is 13.4%. There are > 120 million CKD patients in China and this number is expected to increase. One of the main abnormalities in patients with CKD and kidney impairment is decreased synthesis of erythropoietin (EPO), which causes anemia and affects iron metabolism. The probability of developing is higher in anemia patients with CKD than in the general population, and the incidence increases as kidney function decreases. Deficient EPO production by the kidney is the most important cause of renal anemia. Notably, anemia in patients with CKD has multiple causes, such as bleeding caused by platelet dysfunction, iron deficiency due to digestive and absorption disorders of the gastrointestinal tract, and shorter red blood cell life. Anemia is also a leading cause of hospitalization in patients with CKD. A new oral medication to treat renal anemia, the hypoxia-inducible factor prolyl hydroxylase inhibitor called roxadustat (FG-4592), regulates iron metabolism and promotes erythropoiesis. This drug has a therapeutic effect on patients with CKD. Roxadustat showed advantages over EPO in clinical experiments. This review summarizes the mechanisms of action, clinical applications, effectiveness, and safety of roxadustat.

Development of 3D-Bioprinted Colitis-Mimicking Model to Assess Epithelial Barrier Function Using Albumin Nano-Encapsulated Anti-Inflammatory Drugs

Physiological barrier function is very difficult to replicate in vitro. This situation leads to poor prediction of candidate drugs in the drug development process due to the lack of preclinical modelling for intestinal function. By using 3D bioprinting, we generated a colitis-like condition model that can evaluate the barrier function of albumin nanoencapsulated anti-inflammatory drugs. Histological characterization demonstrated the manifestation of the disease in 3D-bioprinted Caco-2 and HT-29 constructs. A comparison of proliferation rates in 2D monolayer and 3D-bioprinted models was also carried out. This model is compatible with currently available preclinical assays and can be implemented as an effective tool for efficacy and toxicity prediction in drug development.

Novel function of Roxadustat (FG-4592) as an anti-shock drug in sepsis by regulating mitochondrial oxidative stress and energy metabolism

BACKGROUND

Septic shock is a serious clinical syndrome leading to high mortality. A new anti-anemia drug Roxadustat (FG-4592) protected against cardiac injury and hypertension. However, its effect and mechanism on shock and cardiac dysfunction induced by sepsis require to be investigated.

METHODS

C57BL/6j mice received FG-4592 (10 mg/kg/day) by i.p injection, followed by lipopolysaccharide (LPS) or cecal ligation and puncture (CLP) treatment. Mortality and shock status were monitored during the experiment. Cardiac function was assessed using echocardiography and serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) assay. TEM, COX-SDH staining and ATP production were used to evaluate mitochondrial function. A non-targeted metabolomic analysis was performed to evaluate the metabolic disorders.

RESULTS

Both pre- and post-treatment of FG-4592 could improve the survival rate in LPS- and CLP-induced sepsis mice with a better effect in pre-treated animals. Meanwhile, FG-4592 improved systolic blood pressure and body temperature drop in septic mice along with alleviated cardiac dysfunction (as shown by the restoration of decreased LVEF and LVFS and increased LDH and CK-MB) and inflammation. Interestingly, we observed that FG-4592 improved mitochondrial oxidative stress possibly by upregulating the anti-oxidative enzymes of SOD2 and HO-1. Furthermore, FG-4592 improved the energy supply and glycerophospholipid metabolism in cardiomyocytes, possibly through upregulating the HIF-1α-targeted genes of LDHA and PDK1 in glycolysis and CHK-α, respectively.

CONCLUSIONS

FG-4592 protected against mortality and shock in septic animals possibly by antagonizing mitochondrial oxidative stress and metabolic disorders.

GENERAL SIGNIFICANCE

This study provides a potential of FG-4592 as a novel drug for treating septic shock.

Roxadustat improves renal osteodystrophy by dual regulation of bone remodeling

PURPOSE

Renal osteodystrophy (ROD), a component of chronic kidney disease-mineral and bone disorder (CKD-MBD) can lead to bone loss increasing fracture risks in CKD patients. Therefore, it is important to prevent and treat ROD. Activation of hypoxia-inducible factor-1α (HIF-1α) signaling was reported to prevent osteoporotic bone loss. Roxadustat, which is used to treat renal anemia in the clinic, is a novel HIF stabilizer. In our study, we aimed to investigate the effects of roxadustat on ROD.

METHODS

We established an adenine-induced CKD rat model. Roxadustat was administered intragastrically to normal and CKD rats for 4 weeks. Hemoglobin concentrations and serum biochemical parameters were tested, and bone histomorphometric analysis was performed.

RESULTS

CKD rats exhibited impaired renal function with anemia, secondary hyperparathyroidism and high-turnover ROD-induced significant bone loss. Roxadustat ameliorated renal anemia and attenuated the extreme increase in intact parathyroid hormone (iPTH) and fibroblast growth factor 23 (FGF23) in CKD rats. Bone histomorphometric analysis showed that roxadustat significantly alleviated bone loss and bone microarchitecture deterioration in CKD rats by increasing osteoblast activity and inhibiting osteoclast activity. We did not find that roxadustat had significant effects on bone metabolism in normal rats.

CONCLUSION

Roxadustat can improve ROD via dual regulation of bone remodeling. The use of roxadustat may be a promising strategy to treat osteoporotic bone disorders, such as ROD.

Response to roxadustat in a patient undergoing long-term dialysis and allergic to erythropoiesis-stimulating agents: A case report

BACKGROUND

Hypoxia-inducible factor prolyl hydroxylase inhibitor is a new class of drugs for treating renal anemia. It is a second-generation hypoxia-inducible factor prolyl hydroxylase-2 (PHD2) inhibitor. Roxadustat can effectively increase hemoglobin in patients with dialysis-dependent chronic kidney disease, with an adverse events profile comparable to that of epoetin alfa. We administered roxadustat to a maintenance hemodialysis patient who was allergic to erythropoiesis-stimulating agents (ESAs) and depended on blood transfusion for five years. After applying Roxadustat, the patient’s anemia improved significantly.

CASE SUMMARY

A 77-year-old Chinese man had type 2 diabetes for 16 years, underwent maintenance hemodialysis for five years, and had fatigue for five years. Laboratory tests showed severe anemia (hemoglobin concentration of 42 g/L). The patient was administered a subcutaneous injection of ESAs before dialysis. He suffered an allergic shock immediately and fainted. His blood pressure dropped to undetectable levels. He was not administered ESAs henceforth. The patient was prescribed iron supplements and received blood transfusions occasionally for five years. His hemoglobin concentration ranged from 42-68 g/L. After taking six weeks of oral roxadustat three times weekly (100 mg TIW), the patient’s hemoglobin concentration increased significantly, and his symptoms decreased. We adjusted the doses of roxadustat, and the hemoglobin concentration was maintained between 97 and 126 g/L.

CONCLUSION

Oral roxadustat is effective in treating anemia in maintenance hemodialysis patients who cannot be administered ESAs.

Effect of Roxadustat versus erythropoietin (EPO) for treating anemia in patients with diabetic kidney disease: a retrospective cohort study

Background

Renal anemia of diabetic kidney disease (DKD) shows higher incidence rate, earlier onset and higher severity than other chronic kidney disease (CKD). Roxadustat, an oral hypoxia-inducible factor-prolyl hydroxylase inhibitor, improves CKD anemia. This retrospective cohort study evaluates if Roxadustat could effectively treat DKD anemia.

Methods

DKD anemia patients treated with either Roxadustat or erythropoietin (EPO) for 3 months in two hospitals were enrolled. EPO group were matched 1:1 to Roxadustat group based on age, gender and baseline Hb. Baseline data include age, sex, dialysis, height, weight, hemoglobin (Hb), hematocrit (Hct), serum albumin (ALB), serum creatinine (Scr), eGFR, C-reactive protein (CRP), and intact parathyroid hormone (iPTH). Primary and secondary outcomes were change of Hb (ΔHb) and Hct (ΔHct), Hb response rate and Hb qualified rate. Sensitivity analyses were performed and the effect size were calculated.

Results

No significant differences were observed in body mass index (BMI), Scr, eGFR, Hct, CRP, and dialysis between the 2 groups (61 subjects each). ALB, iPTH, and DKD stage differed between the 2 groups. After 3-month treatment, Roxadustat significantly increased patients' Hb and Hct. Although ΔHb and ΔHct of the Roxadustat group was higher than those of EPO group, difference in the least-square mean changes (95% CI) were 4.9 (-2.4, 12.1) and 1.2 (-1.1, 3.4), while Cohen's d were 0.18 and 0.14, suggesting that Roxadustat's ability to increase Hb within 3-month was similar to EPO. 78.7% and 54.1% of the patients responded to anti-anemia therapy in the Roxadustat and EPO group, respectively. Logistic regression analysis showed the Hb response rate of Roxadustat was 3.30 (1.20, 9.94) times higher than that of EPO. Subgroup analysis suggested that Roxadustat might have better efficacy in treating patients in the advanced stage, with high CRP and iPTH, and low ALB levels.

Conclusions

In DKD patients, Roxadustat improves renal anemia. Effect of Roxadustat is similar to that of EPO.

Comparison of risk of peritoneal dialysis-associated peritonitis between roxadustat and recombinant human erythropoietin in peritoneal dialysis patients: a retrospective comparative cohort study

Background

Roxadustat and recombinant human erythropoietin (rhuEPO) have been approved for the treatment of renal anemia in patients undergoing dialysis. The comparison of risk of peritoneal dialysis (PD)-associated peritonitis between roxadustat and rhuEPO in PD patients remains uncertain. We aimed to compare the risk of PD-associated peritonitis between roxadustat and rhuEPO and examine possible modifiers for the comparison in PD patients.

Methods

A total of 437 PD patients with renal anemia (defined as hemoglobin ≤10.0 g/dL) from 4 centers were selected. Participants were scheduled for follow-up every 1-3 months at each center. We compared differences in baseline characteristics by medication group and 1:1 matching group based on propensity scores. PD-associated peritonitis was defined according to the International Society for Peritoneal Dialysis guidelines. Univariable and multivariable Cox proportional hazard analyses were performed to compare the risk of PD-associated peritonitis between roxadustat and rhuEPO in PD patients. Propensity score matching method was used to examine the robustness of results.

Results

A total of 437 participants, including 291 in roxadustat group and 146 in rhuEPO group, were included in the current study, respectively. During a median follow-up of 13.0 (25th-75th, 10.0-15.0) months, PD-associated peritonitis occurred in 68 patients, including 26 of 291 (0.10 episodes per patient-year) patients in the roxadustat group and 42 of 146 (0.27 episodes per patient-year) patients in the rhuEPO group. Overall, compared to patients in the rhuEPO group, the roxadustat group (hazard ratio, 0.345; 95% confidence interval: 0.202-0.589) was associated with a lower risk of PD-associated peritonitis with adjustment of use of roxadustat medication, age, sex, hypertension status, diabetes status, dialysis vintage, serum potassium, hemoglobin, and albumin. Furthermore, the results were consistent with the propensity score analysis. None of the variables, including age, sex, body mass index, PD vintage, presence of residual renal function, hemoglobin, albumin, serum potassium, and C-reactive protein levels, significantly modified the associations.

Conclusions

Our study demonstrated that compared with rhuEPO, roxadustat may reduce the risk of PD-associated peritonitis in PD patients, highlighting the importance of roxadustat for the prevention of PD-associated peritonitis in PD patients.

Comparison of efficacy of roxadustat and erythropoietin for the treatment of renal anemia in patients with chronic kidney disease: a retrospective study

Background

Renal anemia is a common complication in patients with end-stage renal disease (ESRD). Both roxadustat and recombinant human erythropoietin (rhEPO) are alternative option for patients with renal anemia. However, the adverse events of rhEPO limited the wide use of it and the concrete difference of real clinical efficacy of rhEPO and roxadustat was still uncertain. This study aimed to assess the clinical efficacy of roxadustat for improving renal anemia in patients with chronic kidney disease.

Methods

A retrospective cohort study of 790 consecutive patients with renal anemia treated with roxadustat and rhEPO was conducted at the Zhejiang Provincial People's Hospital. Patients were classified into two groups: roxadustat (n=95) and rhEPO (n=695). Baseline characteristics were compared in two groups. After propensity-score matching at a 1:3 ratio, we compared the efficacy of roxadustat and rhEPO in improving anemia, mainly using the Mann-Whitney U test. The follow-up period lasted 24 weeks.

Results

The baseline characteristics were comparable between the two groups after propensity-score matching. There were no significant differences in the hemoglobin levels and estimated glomerular filtration rates (eGFRs) of the two groups before roxadustat or rhEPO treatment (P>0.05). The hemoglobin level after 4 weeks of treatment was 96 g/L in the roxadustat group, and the increase from baseline was 10 g/L; in the rhEPO group, these values were 87 and 6 g/L, respectively (P<0.001). After 12 weeks of treatment, the hemoglobin level and change from baseline were 105 and 15 g/L in the roxadustat group and 94 and 11 g/L in the rhEPO group, respectively (P<0.001). Similar results were observed after 24 weeks of treatment; the hemoglobin level and change from baseline were 105 and 17 g/L in the roxadustat group and 97 and 14 g/L in the rhEPO group (P=0.001).

Conclusions

This retrospective study demonstrated that orally administered roxadustat improved hemoglobin levels more than rhEPO in patients with CKD and anemia.

Roxadustat regulates iron metabolism in dialysis-dependent and non-dialysis-dependent chronic kidney disease patients: A meta-analysis

BACKGROUND/PURPOSE

The effect of roxadustat on iron homeostasis in patients with chronic kidney disease (CKD) is unclear. This study aimed to evaluate the efficacy of roxadustat for the treatment of iron metabolism disorders in dialysis-dependent (DD) and non-dialysis-dependent (NDD) CKD patients.

METHODS

We searched the PubMed, Embase, China National Knowledge Internet and Web of Science databases for randomized controlled trials (RCTs). The primary outcomes were changes in serum iron, total iron binding capacity (TIBC), transferrin saturation (TSAT), ferritin, transferrin, and hepcidin. The secondary outcomes included the changes in hemoglobin (Hb) and the incidences of adverse events (AEs) and severe adverse events (SAEs).

RESULTS

Twelve RCTs comprising 4976 participants were included. Compared to the control group, increases in the serum iron (SMD = 0.21, 95% CI: 0.15 to 0.27, P < 0.00001), TIBC (SMD = 1.02, 95% CI: 0.82 to 1.22, P < 0.00001) and transferrin levels (WMD = 0.55, 95% CI: 0.41 to 0.69, P < 0.00001) were found in the roxadustat group. Compared to the control group, decreases in the ferritin levels (WMD = -37.82, 95% CI: -59.89 to -15.74, P = 0.0008) and hepcidin levels (WMD = -24.04, 95% CI: -36.28 to -11.79, P = 0.0001) were observed in the roxadustat group. The meta-analysis showed that roxadustat significantly increases Hb levels (WMD = 0.77, 95% CI: 0.42 to 1.12, P < 0.0001). The incidences of AEs and SAEs in the roxadustat group was significantly higher than that in the control group (RR = 1.03, 95% CI: 1.00 to 1.07, P = 0.04; RR = 1.08, 95% CI: 1.00 to 1.15, P = 0.04).

CONCLUSION

Our findings suggest that roxadustat could effectively improve iron metabolism in patients with CKD.

Roxadustat for treatment of anemia in a cancer patient with end-stage renal disease: A case report

BACKGROUND

Most cancer patients are accompanied by anemia, which will be more serious when combined with end-stage renal disease (ESRD). At present, cancer-related anemia and renal anemia treatments mainly include erythropoiesis-stimulating agents (ESAs), iron supplementation, and blood transfusion, but their effects are often poor with several safety concerns. We have used roxadustat to treat anemia in a cancer patient with ESRD and achieved a successful outcome for the first time.

CASE SUMMARY

A 64-year-old man was diagnosed with right renal cancer (clear cell renal cell carcinoma). He did not receive surgery or radiotherapy before admission. He was treated with oral soltan (sunitinib malate) on April 18, 2017. During oral chemotherapy, he had numerous complications, including anemia, hypertension, thyroid hypofunction, skin pigment loss, and renal function deterioration. At last, he progressed to ESRD and began hemodialysis treatment. We initially treated the patient with high-dose ESAs, iron supplementation, adequate dialysis, and even blood transfusion, but his anemia did not improve. Roxadustat is a newly developed drug for renal anemia treatment, but not for cancer-related anemia, let alone to treat anemia in cancer patients with ESRD. We prescribed oral roxadustat to the patient. After a period, his hemoglobin gradually increased. He did not have obvious discomfort symptoms, and his tumor did not progress significantly.

CONCLUSION

Oral roxadustat could achieve good results in treating anemia in cancer patients with ESRD.

Label-free quantitative proteomic analysis of serum exosomes from patients of renal anemia: The Good and the Bad of Roxadustat

BACKGROUND

Roxadustat is a new oral anti-renal anemia medication that works by stabilizing hypoxia-inducible factor (HIF) which can activate the expression of more than 100 genes in addition to genes related to anemia. However, the more potential molecular targets of roxadustat are not completely clear. Therefore, it is essential to further reveal its molecular targets to guide its clinical applications.

METHODS

We performed label-free quantification and LC-MS/MS to study the proteomic alterations in serum exosome of renal anemia patients before and after roxadustat therapy. Results were validated by PRM.

RESULTS

A total of 30 proteins were significantly changed after treatment with roxadustat. Among these proteins, 18 proteins were up-regulated (and 12 were down-regulated). The results are statistically significant (P < 0.05). Then, we validated the result by PRM, the results confirmed that TFRC, HSPA8, ITGB3, COL1A2, and YWHAZ were markedly upregulated, while ITIH2 and CFH were significantly downregulated upon treatment with roxadustat.

CONCLUSIONS

TFRC and HSPA8 could be an important target of the action of roxadustat, and roxadustat may increase cardiovascular risk through its influence on platelet activation. Our results provide a theoretical basis for its wider clinical application and preventing expected side effects.

Cyclic thrombocytopenia related to erythropoietin-dependent anti-platelet anti-GPIV/IIIb antibody in hemodialysis

We describe herein the case of a 65-year-old patient on chronic hemodialysis with a medical history of idiopathic thrombocytopenia who experienced numerous episodes of severe thrombocytopenia with no specific diagnosis. Further analysis of the evolution of the platelet count showed that cyclic thrombocytopenia occurred after each injection of recombinant erythropoietin (rHu-EPO). Exploration of the involved mechanisms revealed the presence of a rHu-EPO-dependent anti-GPIV/IIIb antibody associated with a significant increase in GPIV/IIIb expression on her platelets after the addition of rHu-EPO. EPO was discontinued and the patient was treated with roxadustat with favorable results on her hemoglobin and platelet counts.

Roxadustat promotes osteoblast differentiation and prevents estrogen deficiency-induced bone loss by stabilizing HIF-1α and activating the Wnt/β-catenin signaling pathway

Background

Osteoporosis is a very common skeletal disorder that increases the risk of fractures. However, the treatment of osteoporosis is challenging. Hypoxia-inducible factor-1α (HIF-1α) plays an important role in bone metabolism. Roxadustat is a novel HIF stabilizer, and its effects on bone metabolism remain unknown. This study aimed to investigate the effects of roxadustat on osteoblast differentiation and bone remodeling in an ovariectomized (OVX) rat model.

Methods

In vitro, primary mouse calvarial osteoblasts were treated with roxadustat. Alkaline phosphatase (ALP) activity and extracellular matrix mineralization were assessed. The mRNA and protein expression levels of osteogenic markers were detected. The effects of roxadustat on the HIF-1α and Wnt/β-catenin pathways were evaluated. Furthermore, osteoblast differentiation was assessed again after HIF-1α expression knockdown or inhibition of the Wnt/β-catenin pathway. In vivo, roxadustat was administered orally to OVX rats for 12 weeks. Then, bone histomorphometric analysis was performed. The protein expression levels of the osteogenic markers HIF-1α and β-catenin in bone tissue were detected.

Results

In vitro, roxadustat significantly increased ALP staining intensity, enhanced matrix mineralization and upregulated the expression of osteogenic markers at the mRNA and protein levels in osteoblasts compared with the control group. Roxadustat activated the HIF-1α and Wnt/β-catenin pathways. HIF-1α knockdown or Wnt/β-catenin pathway inhibition significantly attenuated roxadustat-promoted osteoblast differentiation. In vivo, roxadustat administration improved bone microarchitecture deterioration and alleviated bone loss in OVX rats by promoting bone formation and inhibiting bone resorption. Roxadustat upregulated the protein expression levels of the osteogenic markers, HIF-1α and β-catenin in the bone tissue of OVX rats.

Conclusion

Roxadustat promoted osteoblast differentiation and prevented bone loss in OVX rats. The use of roxadustat may be a new promising strategy to treat osteoporosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03162-w.

Efficacy of Roxadustat on anemia and residual renal function in patients new to peritoneal dialysis

Background

Both early correction of anemia and preserving residual renal function (RRF) are reported to improve patient survival. The aim of this study was to explore the efficacy and safety of Roxadustat for treatment of renal anemia in patients new to peritoneal dialysis (PD) and to assess its impact on RRF.

Methods

A retrospective analysis was performed on 60 initial peritoneal dialysis (PD) patients with renal anemia. Twenty-eight cases were treated with Roxadustat (Roxadustat group) and 32 with recombinant human erythropoietin (control group). Clinical characteristics, hemoglobin (Hb), C-reactive protein, blood lipids, iron metabolism, dialysis adequacy and RRF of the two groups were evaluated and adverse events were recorded. All patients were followed up for at least 40 weeks.

Results

After 40 weeks of treatment, mean Hb levels were significantly higher from baseline values in both groups, the mean Hb change in Roxadustat group was higher than control group (3.46 ± 1.59 g/dL vs. 2.28 ± 2.27 g/dL, p < 0.05). At 40 weeks, 92.9% patients met the target level of Hb in Roxadustat group and 84.4% in control group. Total iron binding was higher and ferritin was lower in Roxadustat group from baseline values and Roxadustat-induced Hb increases were independent of baseline C-reactive protein levels and history of rhuEPO administration. RRF decreased over time in both groups, the mean RRF change was lower in Roxadustat group than control group (1.15 ± 1.66 mL/min/1.73 m² vs. 2.31 ± 1.46 mL/min/1.73 m², p < 0.01). Compared with control group, patients in Roxadustat group had higher levels of total iron binding, 24 h urine volume, total weekly Ccr, and lower systolic pressure, ferritin, C-reactive protein, total cholesterol, LDL. No serious adverse reactions occurred in either group.

Conclusion

In patients new to PD, Roxadustat effectively and safely improved renal anemia and delay the decline of RRF.

Effects of Roxadustat on Erythropoietin Production in the Rat Body

Anemia is a major complication of chronic renal failure. To treat this anemia, prolylhydroxylase domain enzyme (PHD) inhibitors as well as erythropoiesis-stimulating agents (ESAs) have been used. Although PHD inhibitors rapidly stimulate erythropoietin (Epo) production, the precise sites of Epo production following the administration of these drugs have not been identified. We developed a novel method for the detection of the Epo protein that employs deglycosylation-coupled Western blotting. With protein deglycosylation, tissue Epo contents can be quantified over an extremely wide range. Using this method, we examined the effects of the PHD inhibitor, Roxadustat (ROX), and severe hypoxia on Epo production in various tissues in rats. We observed that ROX increased Epo mRNA expression in both the kidneys and liver. However, Epo protein was detected in the kidneys but not in the liver. Epo protein was also detected in the salivary glands, spleen, epididymis and ovaries. However, both PHD inhibitors (ROX) and severe hypoxia increased the Epo protein abundance only in the kidneys. These data show that, while Epo is produced in many tissues, PHD inhibitors as well as severe hypoxia regulate Epo production only in the kidneys.

The Effect of Roxadustat on Transfusion-Dependent Myelodysplastic Syndrome Complicated by Chronic Kidney Disease

Haematopoietic insufficiency is the treatment target of lower-risk myelodysplastic syndrome (MDS). Although erythropoiesis-stimulating agents (ESAs) are generally effective for treating anaemia, resistance can develop. Hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) improves renal anaemia by promoting endogenous erythropoietin production and normalizing iron metabolism. HIF-PH inhibitors could be used to treat MDS, but their efficacy and safety have not been studied. A 78-year-old female patient with essential thrombocythemia gradually developed anaemia and was diagnosed with therapy-related MDS 4 years later. The anaemia temporarily improved with ESAs, but the patient became transfusion dependent. At the same time, anaemia and chronic renal failure due to nephrosclerosis progressed, and the patient was diagnosed with MDS with renal anaemia. After switching from ESAs to roxadustat, an HIF-PH inhibitor, anaemia improved, and the patient was no longer transfusion dependent. No progression of the underlying disease or any adverse events was observed 4 months after initiating roxadustat.

Efficacy and safety of roxadustat in the treatment of renal allograft anemia patients: a case series

BACKGROUND

To observe the efficacy and safety of roxadustat, an inhibitor of proline hydroxylase, in renal allograft anemia patients.

METHODS

This prospective study collected the clinical data of renal transplant patients treated with roxadustat for anemia at the Kidney Disease Center of the First Affiliated Hospital of Zhejiang University from April to August 2020. The patients were followed up every 2 weeks, and the changes in their hemoglobin index and any adverse reactions were recorded during 10 weeks of treatment. The efficacy of roxadustat for treatment of anemia after kidney transplantation was analyzed by comparing the change and increase in average hemoglobin levels before and after treatment. Rates of treatment response and achievement of the standard hemoglobin level were statistically analyzed. In addition, any potential adverse events and the glomerular filtration rate were recorded for 10 weeks to assess the safety of roxadustat in renal allograft anemia patients.

RESULTS

After 10 weeks of roxadustat treatment, the mean hemoglobin level was 10.4±3.9 g/dL, which was significantly higher than at baseline. Over the entire period, treatment was observed to have a therapeutic effect at weeks 2-4, with mean hemoglobin levels increasing as treatment time increased. At the 10-week endpoint, the percentage of patients reaching the standard hemoglobin level and exhibiting a response to treatment was 52.4% and 71.4%, respectively. During the treatment, there was no rejection, and the glomerular filtration rate was stable. Only one person showed symptoms of fatigue, and there were no other obvious adverse reactions reported.

CONCLUSIONS

Roxadustat significantly improves hemoglobin levels and can be safely used in renal transplant anemia patients.

Roxadustat for dialysis patients with erythropoietin hypo-responsiveness: a single-center, prospective investigation

Dialysis patients with erythropoietin hypo-responsiveness suffered from refractory anemia. Roxadustat reversibly binds and inhibits hypoxia-inducible factor-prolyl hydroxylase (HIF-PHD), resulting in increased endogenous EPO which stimulates erythropoiesis, theoretically has an advantage over exogenous EPO in anti-anemia therapy. From September 2019 to October 2020, 32 dialysis patients with hypo-responsiveness to erythropoietin were evaluated. During the 24-week follow-up period, all patients were taken off erythropoietin and switched to roxadustat. Dosage adjustments were administrated according to the fluctuation of hemoglobin level during the treatment. Parameters about anemia, iron metabolism and biochemical indexes were collected, and adverse events were recorded. A total of 31 patients completed the clinical observation, with varying degrees of malnutrition-inflammation. Post treatment, the levels of transferrin and total iron-binding capacity were increased, while that of transferrin saturation and cholesterol decreased. 15 cases (accounting for 48.39%, designated as fulfilled group) met the target level of hemoglobin, while 16 cases (51.61%, non-fulfilled group) did not. The baseline conditions of the above two groups were compared. The levels of hypersensitive C-reactive protein, interleukin-6 and serum ferritin in the non-fulfilled group were higher than those in the fulfilled group, and the levels of residual renal function, serum albumin, iron, transferrin and total iron-binding capacity were lower than those in the fulfilled group. Linear regression analysis showed that increase of HsCRP had a negative effect on the improvement of Hb. One case of adverse reaction grade 3 and four cases of grade 2 occurred throughout the study, yet all were relieved after therapy. Significant anti-anemia effects could be achieved in most patients with erythropoietin hypo-responsiveness after treatment with roxadustat, accompanied by relatively mild and rare adverse reactions. The malnutrition-inflammation states of patients may interfere with the anti-anemia effect of roxadustat, and iron utilization is more important than iron storage in anemia improvement.