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715 result(s) for "Prolyl hydroxylase"
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Vadadustat in Patients with Anemia and Non–Dialysis-Dependent CKD
Two randomized, phase 3, open-label noninferiority trials compared vadadustat with darbepoetin alfa in patients with non–dialysis-dependent chronic kidney disease. Vadadustat, as compared with darbepoetin alfa, met the prespecified noninferiority criterion for hematologic efficacy but not for cardiovascular safety.
Safety and Efficacy of Vadadustat for Anemia in Patients Undergoing Dialysis
Two randomized, open-label, noninferiority phase 3 trials compared the prolyl hydroxylase inhibitor vadadustat with darbepoetin alfa in patients with incident or prevalent chronic kidney disease who were undergoing dialysis. Vadadustat was noninferior to darbepoetin alfa with respect to cardiovascular safety and correction and maintenance of hemoglobin concentrations.
Roxadustat: First Global Approval
Roxadustat (Ai Rui Zhuo ® in China) is an orally administered, small molecule hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor that is being developed by FibroGen, in collaboration with Astellas and AstraZeneca, for the treatment of anaemia in patients with dialysis-dependent chronic kidney disease (CKD), non-dialysis-dependent CKD and in patients with myelodysplastic syndromes. The drug reversibly binds to and inhibits HIF-prolyl hydroxylase enzymes that are responsible for the degradation of transcription factors in the HIF family under normal oxygen conditions. Inhibition of these enzymes reduces HIF breakdown and promotes HIF activity, leading to an increase in endogenous erythropoietin production, thereby enhancing erythropoiesis. It also reduces the expression of the peptide hormone hepcidin, improves iron availability and increases haemoglobin levels. HIF regulates the expression of genes in response to reduced oxygen levels, including genes required for erythropoiesis and iron metabolism. Roxadustat is approved in China and is under regulatory review in Japan for the treatment of anaemia in patients with dialysis-dependent CKD. Studies are underway to investigate long-term cardiovascular outcomes with roxadustat versus placebo (for non-dialysis-dependent CKD) or standard of care (for dialysis-dependent CKD). This article summarizes the milestones in the development of roxadustat leading to this first approval.
Phase I Clinical Study of ZYAN1, A Novel Prolyl-Hydroxylase (PHD) Inhibitor to Evaluate the Safety, Tolerability, and Pharmacokinetics Following Oral Administration in Healthy Volunteers
Objective This phase I study of ZYAN1 was conducted to evaluate the safety, tolerability, and pharmacokinetics following oral administration in healthy volunteers. Methods The study was a randomized, double-blind, placebo-controlled phase I study carried out in two parts in addition to a third part involving an open-label study to evaluate the food/sex effect. A total of 100 subjects were enrolled into the study as follows: part I—single-dose study with ZYAN1 10, 25, 50, 100, 150, 200, and 300 mg ( n  = 56); part II—multiple-dose study with every other day dosing of ZYAN1 100, 150, 200, and 300 mg ( n  = 32); and part III—sex and food effect study with ZYAN1 150 mg ( n  = 12; open-label). Results ZYAN1 was well-tolerated after single and multiple oral ascending doses. No drug-related serious adverse events were reported. Following a single ascending dose of ZYAN1, the maximum concentration ( C max ) ranged from 566.47 ± 163.03 to 17,858.33 ± 2899.19 ng/mL and the median time to C max ( t max ) was approximately 2.5 h for the studied 30-fold oral doses of ZYAN1. Regardless of single or multiple doses, mean C max and area under the concentration–time curve from time zero to time t (AUC t ) values generally showed a dose-proportional increase. The mean elimination half-life ( t ½ ) of ZYAN1 ranged from 6.9 to 13 h with negligible accumulation. Following a single dose of ZYAN1, the mean serum erythropoietin (EPO) C max values showed dose response (i.e., 6.6 and 79.9 mIU/L for 10 and 300 mg ZYAN1 doses, respectively), while the time to mean maximal serum EPO concentrations ranged from 10 to 72 h. Conclusion Oral single (10–300 mg) and multiple dosing (100–300 mg) of ZYAN1 in healthy subjects was found to be safe and well-tolerated. With increasing ZYAN1 dose, there was almost a proportional increase in mean C max and AUC t . The mean serum EPO concentrations showed a trend of dose response. Based on the t ½ , pharmacodynamic activity, and lack of drug accumulation, a once every 2 days dosing regimen of ZYAN1 was appropriate for phase II study. Trial Registration: Australian New Zealand Clinical Trials Registry trial ID ACTRN12614001240639.
Evolving Strategies in the Treatment of Anaemia in Chronic Kidney Disease: The HIF-Prolyl Hydroxylase Inhibitors
Chronic kidney disease (CKD) affects approximately 10% of the worldwide population; anaemia is a frequent complication. Inadequate erythropoietin production and absolute or functional iron deficiency are the major causes. Accordingly, the current treatment is based on iron and erythropoiesis stimulating agents (ESAs). Available therapy has dramatically improved the management of anaemia and the quality of life. However, safety concerns were raised over ESA use, especially when aiming to reach near-to-normal haemoglobin levels with high doses. Moreover, many patients show hypo-responsiveness to ESA. Hypoxia-inducible factor (HIF) prolyl hydroxylase domain (PHD) inhibitors (HIF-PHIs) were developed for the oral treatment of anaemia in CKD to overcome these concerns. They simulate the body's exposure to moderate hypoxia, stimulating the production of endogenous erythropoietin. Some molecules are already approved for clinical use in some countries. Data from clinical trials showed non-inferiority in anaemia correction compared to ESA or superiority for placebo. Hypoxia-inducible factor-prolyl hydroxylase domain inhibitors may also have additional advantages in inflamed patients, improving iron utilisation and mobilisation and decreasing LDL-cholesterol. Overall, non-inferiority was also shown in major cardiovascular events, except for one molecule in the non-dialysis population. This was an unexpected finding, considering the lower erythropoietin levels reached using these drugs due to their peculiar mechanism of action. More data and longer follow-ups are necessary to better clarifying safety issues and further investigate the variety of pathways activated by HIF, which could have either positive or negative effects and could differentiate HIF-PHIs from ESAs.
Integrated Population Pharmacokinetics of Daprodustat in Patients with Chronic Kidney Disease with Anemia
Background and Objective Daprodustat is a first-in-class hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) approved in the USA for treatment of anemia owing to chronic kidney disease (CKD) in dialysis-dependent adults and in Japan for treatment of CKD in dialysis- and non-dialysis dependent adults. This analysis characterized the population pharmacokinetics (PopPK) of daprodustat in adults with CKD and evaluated the influence of intrinsic and extrinsic factors. Methods This PopPK analysis included data from one phase 2B and four phase 3 studies comprising 707 CKD subjects dose titrated to prespecified target hemoglobin levels with daprodustat doses ranging from 1 to 24 mg once daily and 2 to 48 mg given three times a week (TIW). Model development leveraged a previous phase 1/2 PopPK model. Stepwise covariate analysis included 20 extrinsic and intrinsic factors. Model evaluation used standard goodness-of-fit and visual predictive checks. Results Daprodustat PopPK was adequately characterized using a three-compartment distribution model with first-order elimination. The absorption phase was described using five transit compartments. Oral clearance and volume of distribution was 24.6 L/h and 26.9 L, respectively. Body weight dependence (with fixed allometric coefficients) of clearance and volume terms was a statistically significant covariate. Concomitant use of clopidogrel (moderate CYP2C8 inhibitor) decreased oral clearance, resulting in higher area under the plasma concentration-time curve (AUC) ratio of 1.59 (90% CI: 1.39–1.82), subjects’ dialysis status (non-dialysis versus dialysis) had an effect on absorption, with C max ratio of 1.19 (90% CI: 1.09–1.30). None of the other investigated intrinsic or extrinsic covariates, including concomitant administration with phosphate binders, oral iron and acid reducing agents resulted in a significant change in daprodustat systemic exposure. Conclusion The PopPK of daprodustat in the CKD population with anemia was adequately characterized. Allometrically-scaled body weight on clearance and volume, dialysis status on absorption and clopidogrel on clearance were statistically significant covariates.
Dynamics of Prolyl Hydroxylases Levels During Disease Progression in Experimental Colitis
AbstractHypoxia inducible factor (HIF)-prolyl hydroxylase (PHD) inhibitors are shown to be protective in several models of inflammatory bowel disease (IBD). However, these non-selective inhibitors are known to inhibit all the three isoforms of PHD, i.e. PHD-1, PHD-2 and PHD-3. In the present report, we investigated the associated changes in levels of PHDs during the development and recovery of chemically induced colitis in mice. The results indicated that in the experimental model of murine colitis, levels of both, PHD-1 and PHD-2 were found to be increased with the progression of the disease; however, the level of PHD-3 remained the same in group of healthy controls and mice with colitis. Thus, the findings advocated that inhibitors, which inhibited all three isoforms of PHD could not be ideal therapeutics for IBD since PHD-3 is required for normal gut function. Hence, this necessitates the development of new compounds capable of selectively inhibiting PHD-1 and PHD-2 for effective treatment of IBD.
Effect of Moderate Hepatic Impairment on the Pharmacokinetics and Pharmacodynamics of Roxadustat, an Oral Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor
Background and Objective Roxadustat is a hypoxia-inducible factor prolyl hydroxylase inhibitor in phase III development for the treatment of anaemia associated with chronic kidney disease. This study evaluated the effects of moderate hepatic impairment on roxadustat pharmacokinetics, pharmacodynamics and tolerability. Methods This was an open-label study in which eight subjects with moderate hepatic impairment (liver cirrhosis Child–Pugh score 7–9) and eight subjects with normal hepatic function (matched for body mass index, age and sex) received a single oral 100 mg roxadustat dose under fasted conditions. Blood samples were collected until 144 h post-dose in subjects with moderate hepatic impairment and until 96 h post-dose in subjects with normal hepatic function. Results In subjects with moderate hepatic impairment, area under the concentration–time curve (AUC) from the time of drug administration to infinity (AUC ∞ ) and observed maximum concentration ( C max ) were 23 % higher [geometric least-squares mean ratio (GMR) 123 %; 90 % CI 86.1–175] and 16 % lower (GMR 83.6 %; 90 % CI 67.5–104), respectively, than in subjects with normal hepatic function. Mean terminal half-life ( t ½ ) appeared to be longer (17.7 vs. 12.8 h) in subjects with moderate hepatic impairment, however intersubject variability on apparent total systemic clearance after single oral dosing (CL/ F ), apparent volume of distribution at equilibrium after oral administration ( V z / F ) and t ½ was approximately twofold higher. Erythropoietin (EPO) baseline-corrected AUC from administration to the last measurable EPO concentration (AUC E,last ) and maximum effect ( E max ) were 31 % (GMR 68.95 %; 90 % CI 29.29–162.29) and 48 % (GMR 52.29 %; 90 % CI 28.95–94.46) lower, respectively, than in subjects with normal hepatic function. The single oral roxadustat dose was generally well tolerated. Conclusions This study demonstrated the effect of moderate hepatic impairment on the pharmacokinetics and pharmacodynamics of roxadustat relative to subjects with normal hepatic function. These differences are not expected to be of clinical significance.
Protein Hydroxylation by Hypoxia-Inducible Factor (HIF) Hydroxylases: Unique or Ubiquitous?
All metazoans that utilize molecular oxygen (O2) for metabolic purposes have the capacity to adapt to hypoxia, the condition that arises when O2 demand exceeds supply. This is mediated through activation of the hypoxia-inducible factor (HIF) pathway. At physiological oxygen levels (normoxia), HIF-prolyl hydroxylases (PHDs) hydroxylate proline residues on HIF-α subunits leading to their destabilization by promoting ubiquitination by the von-Hippel Lindau (VHL) ubiquitin ligase and subsequent proteasomal degradation. HIF-α transactivation is also repressed in an O2-dependent way due to asparaginyl hydroxylation by the factor-inhibiting HIF (FIH). In hypoxia, the O2-dependent hydroxylation of HIF-α subunits by PHDs and FIH is reduced, resulting in HIF-α accumulation, dimerization with HIF-β and migration into the nucleus to induce an adaptive transcriptional response. Although HIFs are the canonical substrates for PHD- and FIH-mediated protein hydroxylation, increasing evidence indicates that these hydroxylases may also have alternative targets. In addition to PHD-conferred alterations in protein stability, there is now evidence that hydroxylation can affect protein activity and protein/protein interactions for alternative substrates. PHDs can be pharmacologically inhibited by a new class of drugs termed prolyl hydroxylase inhibitors which have recently been approved for the treatment of anemia associated with chronic kidney disease. The identification of alternative targets of HIF hydroxylases is important in order to fully elucidate the pharmacology of hydroxylase inhibitors (PHI). Despite significant technical advances, screening, detection and verification of alternative functional targets for PHDs and FIH remain challenging. In this review, we discuss recently proposed non-HIF targets for PHDs and FIH and provide an overview of the techniques used to identify these.
Hypoxia and hypoxia-inducible factors in diabetes and its complications
Hypoxia-inducible factors (HIFs) are the key regulators of oxygen homeostasis in response to hypoxia. In diabetes, multiple tissues are hypoxic but adaptive responses to hypoxia are impaired due to insufficient activation of HIF signalling, which results from inhibition of HIF-1α stability and function due to hyperglycaemia and elevated fatty acid levels. In this review, we will summarise and discuss current findings about the regulation of HIF signalling in diabetes and the pathogenic roles of hypoxia and dysregulated HIF signalling in the development of diabetes and its complications. The therapeutic potential of targeting HIF signalling for the prevention and treatment of diabetes and related complications is also discussed.