Molecular pharmacology of the mineralocorticoid receptor: prospects for novel therapeutics

Renoprotective Effects of Mineralocorticoid Receptor Antagonists Against Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a growing epidemic worldwide and a leading cause of end-stage kidney disease. Mineralocorticoid receptor (MR) blockade using Finerenone is a recently approved therapeutic approach to slow down the progression of DKD in patients with type 2 diabetes in addition to other therapies such as angiotensin-II converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), sodium-glucose co-transporter 2 (SGLT2) inhibitors, and glucagon-like peptide 1 (GLP-1) analogs. This review elaborates on the pathophysiologic pathways activated by aldosterone (the human mineralocorticoid) in DKD, the pharmacology of three different generations of mineralocorticoid receptor antagonists (MRAs), specifically, spironolactone, eplerenone, and finerenone, and the mechanisms by which these MRAs elicit their protective effects on the kidney under diabetic settings.

Gene expression analysis to identify mechanisms underlying improvement of myocardial fibrosis by finerenone in SHR

Both spironolactone and finerenone treatments significantly reduced SBP and there was no statistical difference in their antihypertensive effects. The differences in body weight (at the end of 1/2/3/4 week) to pre-dose body weight ratio and heart rate (at the end of 1/2/3/4 week) to pre-dose heart rate ratio were not statistically significant in the vehicle, spironolactone, finerenone, and control groups.There was no statistically significant difference in mortality among the vehicle, spironolactone, and finerenone groups. The relative heart mass, ANP, BNP, CVF, Col I, TGF-β, and Casp-3 were gradually decreased in vehicle group, spironolactone group, and finerenone group. Among them, BNP, CVF, TGF-β, and Casp-3 were significantly decreased in the finerenone group compared with the vehicle group. HE and Masson staining showed that the cardiomyocytes of rats in the vehicle group and spironolactone group were disorganized, with cell hypertrophy, significantly enlarged cell gaps and a large amount of collagen deposition, whereas the cardiomyocytes of rats in the finerenone group and the control group were more neatly arranged, with smaller cell gaps and a small amount of collagen tissue deposition. RNA sequencing (RNA-seq) showed that there was a total of 119 differentially expressed genes (DEGs) between finerenone treatment and vehicle treatment. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the signaling pathways involved were mainly in drug metabolism-cytochrome P450, chemical carcinogenesis, IL-17 signaling pathway, axon guidance, and hematopoietic cell lineage. Protein-protein interaction (PPI) analysis showed that the core genes were Oaslf, Nos2, LOC687780, Rhobtb1, Ephb3, and Rps27a.

Current Landscape of Therapeutics for the Management of Hypertension - A Review

Hypertension is a critical health problem. It is also the primary reason for coronary heart disease, stroke, and renal vascular disease. The use of herbal drugs in the management of any disease is increasing. They are considered the best immune booster to fight against several types of diseases. To date, the demand for herbal drugs has been increasing because of their excellent properties. This review highlights antihypertensive drugs, polyphenols, and synbiotics for managing hypertension. Evidence is mounting in favour of more aggressive blood pressure control with reduced adverse effects, especially for specific patient populations. This review aimed to present contemporary viewpoints and novel treatment options, including cutting-edge technological applications and emerging interventional and pharmaceutical therapies, as well as key concerns arising from several years of research and epidemiological observations related to the management of hypertension.

Molecular pharmacology of mineralocorticoid receptor antagonists: The role of co-regulators

Mineralocorticoid receptor (MR) antagonists have shown remarkable benefits in the treatment of cardiovascular disease. However, their underutilization in clinical practice may be attributed to concerns regarding the risk of hyperkalemia. An ideal selective MR modulator would inhibit the detrimental effects of MR in non-epithelial cells of the cardiovascular system while sparing its physiological function in kidney epithelial cells, thereby reducing the risk of adverse events. To address this issue, a new generation of non-steroidal MR antagonists, including esaxereneone, balcinrenone, ocedurenone, and finerenone, has been developed with distinct molecular structures and pharmacology. They share a mechanism of action that is different from the previously developed steroidal MR antagonists, leading to altered co-regulator interaction, potentially involving conformational changes of the receptor. Interfering with MR co-regulator interaction or the co-regulator itself may enable selective targeting of downstream signaling cascades and - in the long term - lead to more personalized medicine. In this review article, we summarize what is currently known about the mechanisms of action of the different MR antagonists with a focus on MR co-factor interaction and what may be inferred from this for future developments.

Aldosterone Antagonism Is More Effective at Reducing Blood Pressure and Excessive Renal ENaC Activity in AngII-Infused Female Rats Than in Males

BACKGROUND

AngII (angiotensin II)-dependent hypertension causes comparable elevations of blood pressure (BP), aldosterone levels, and renal ENaC (epithelial Na+ channel) activity in male and female rodents. Mineralocorticoid receptor (MR) antagonism has a limited antihypertensive effect associated with insufficient suppression of renal ENaC in male rodents with AngII-hypertension. While MR blockade effectively reduces BP in female mice with salt-sensitive and leptin-induced hypertension, MR antagonism has not been studied in female rodents with AngII-hypertension. We hypothesize that overstimulation of renal MR signaling drives redundant ENaC-mediated Na+ reabsorption and BP increase in female rats with AngII-hypertension.

METHODS

We employ a combination of physiological, pharmacological, biochemical, and biophysical approaches to compare the effect of MR inhibitors on BP and ENaC activity in AngII-infused male and female Sprague Dawley rats.

RESULTS

MR blockade markedly attenuates AngII-hypertension in female rats but has only a marginal effect in males. Spironolactone increases urinary sodium excretion and urinary sodium-to-potassium ratio in AngII-infused female, but not male, rats. The expression of renal MR and HSD11β2 (11β-hydroxysteroid dehydrogenase type 2) that determines the availability of MR to aldosterone is significantly higher in AngII-infused female rats than in males. ENaC activity is ≈2× lower in spironolactone-treated AngII-infused female rats than in males. Reduced ENaC activity in AngII-infused female rats on spironolactone correlates with increased interaction with ubiquitin ligase Nedd4-2 (neural precursor cell expressed developmentally down-regulated protein 4-2), targeting ENaC for degradation.

CONCLUSIONS

MR-ENaC axis is the primary determinant of excessive renal sodium reabsorption and an attractive antihypertensive target in female rats with AngII-hypertension, but not in males.

Efficacy and safety assessment of mineralocorticoid receptor antagonists in patients with chronic kidney disease

BACKGROUND

The objective of our study is to evaluate the efficacy and safety of mineralocorticoid receptor antagonists (MRAs) and determine the optimal MRA treatment regimen in patients with chronic kidney disease (CKD).

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library from their inception to June 20, 2022. The composite kidney outcome, cardiovascular events, urinary albumin to creatinine ratio (UACR), estimated glomerular filtration rate (EGFR), serum potassium, systolic blood pressure (SBP), diastolic blood pressure (DBP), creatine and creatine clearance were included for analysis. We conducted pairwise meta-analyses and Bayesian network meta-analyses (NMA) and calculated the surface under the cumulative ranking curve (SUCRA).

RESULTS

We included 26 studies with 15,531 participants. By pairwise meta-analyses, we found that MRA treatment could significantly reduce UACR in CKD patients with or without diabetes. Notably, compared to placebo, Finerenone was associated with a lower risk of composite kidney outcome and cardiovascular events. Data from NMA demonstrated an overt UACR reduction without increasing serum potassium by Apararenone, Esaxerenone, and Finerenone in CKD patients. Spironolactone decreased SBP and DBP but elevated CKD patients' serum potassium.

CONCLUSIONS

Compared to placebo, Apararenone, Esaxerenone, and Finerenone might ameliorate albuminuria in CKD patients without causing elevated serum potassium levels. Remarkably, Finerenone conferred a cardiovascular benefit, and Spironolactone lowered blood pressure in CKD patients.

The non-steroidal mineralocorticoid receptor antagonist finerenone and heart failure with preserved ejection fraction

Finerenone is a novel non-steroidal mineralocorticoid receptor (MR) antagonist (MRA) with high binding affinity, high MR selectivity and a short plasma half-life. In two major endpoint-driven clinical trials in patients with chronic kidney disease and type 2 diabetes mellitus (FIDELIO-DKD and FIGARO-DKD), finerenone induced significant cardiorenal protective actions, and has been recently approved for treatment of these patients. Heart failure with preserved ejection fraction (HFpEF) is a devastating clinical syndrome with increasing prevalence and poor prognosis. Pharmacological therapy of HFpEF is very limited and new therapeutic options are urgently needed. Finerenone has been shown to improve multiple pathophysiological parameters of HFpEF in preclinical models. In consonance, pre-specified subgroup analyses of FIDELIO-DKD and FIGARO-DKD suggested a potential beneficial effect of finerenone in HFpEF. This review will discuss the pharmacodynamic and -kinetic profile of finerenone. We will provide a general overview over the complex pathophysiology of HFpEF and data from pre-clinical studies, focusing on how finerenone improves multiple components of this pathophysiology. Finally, we will discuss current and future clinical trials with finerenone in heart failure patients focusing on HFpEF.

Effectiveness of nonsteroidal mineralocorticoid receptor antagonists in patients with diabetic kidney disease

Nonsteroidal mineralocorticoid receptor antagonists (MRAs) are a new class of drugs developed to address the medical need for effective and safer treatment to protect the kidney and the heart in patients with diabetic kidney disease (DKD). There are several drugs within this class at varying stages of clinical development. Finerenone is the first nonsteroidal MRA approved in the US for treating patients with chronic kidney disease (CKD) associated with type 2 diabetes (T2D). In clinical studies, finerenone slowed CKD progression without inducing marked antihypertensive effects. Esaxerenone is a nonsteroidal MRA with proven blood pressure-lowering efficacy that is currently licensed in Japan for treating hypertension. There are also three other nonsteroidal MRAs in mid-to-late stages of clinical development. Here we overview evidence addressing pharmacological and clinical differences between the nonsteroidal MRAs and the steroidal MRAs spironolactone and eplerenone. First, we describe a framework that highlights the role of aldosterone-mediated pathological overactivation of the mineralocorticoid receptor and inflammation as important drivers of CKD progression. Second, we discuss the benefits and adverse events profile of steroidal MRAs, the latter of which are often a limiting factor to their use in routine clinical practice. Finally, we show that nonsteroidal MRAs differ from steroidal MRAs based on pharmacology and clinical effects, giving the potential to expand the therapeutic options for patients with DKD. In the recently completed DKD outcome program comprising two randomized clinical trials - FIDELIO-DKD and FIGARO-DKD - and the FIDELITY analysis of both trials evaluating more than 13,000 patients, the nonsteroidal MRA finerenone demonstrated beneficial effects on the kidney and the heart across a broad spectrum of patients with CKD and T2D. The long-term efficacy of finerenone on cardiac and renal morbidity and mortality endpoints, along with the anti-hypertensive efficacy of esaxerenone, widens the scope of available therapies for patients with DKD.

Novel 1,4-Dihydropyridine Derivatives as Mineralocorticoid Receptor Antagonists

The mineralocorticoid receptor (MR) belongs to the steroid receptor subfamily of nuclear receptors. MR is a transcription factor key in regulating blood pressure and mineral homeostasis. In addition, it plays an important role in a broad range of biological and pathological conditions, greatly expanding its interest as a pharmacological target. Non-steroidal MR antagonists (MRAs) are of particular interest to avoid side effects and achieve tissue-specific modulation of the receptor. The 1,4-dihydropyridine (1,4-DHP) ring has been identified as an appropriate scaffold to develop non-steroidal MRAs. We report the identification of a novel series of 1,4-DHP that has been guided by structure-based drug design, focusing on the less explored DHP position 2. Interestingly, substituents at this position might interfere with MR helix H12 disposition, which is essential for the recruitment of co-regulators. Several of the newly synthesized 1,4-DHPs show interesting properties as MRAs and have a good selectivity profile. These 1,4-DHPs promote MR nuclear translocation with less efficiency than the natural agonist aldosterone, which explains, at least in part, its antagonist character. Molecular dynamic studies are suggestive of several derivatives interfering with the disposition of H12 in the agonist-associated conformation, and thus, they might stabilize an MR conformation unable to recruit co-activators.

A prespecified exploratory analysis from FIDELITY examined finerenone use and kidney outcomes in patients with chronic kidney disease and type 2 diabetes

In FIDELITY, a prespecified pooled analysis of the FIDELIO-DKD and FIGARO-DKD studies, finerenone was found to improve cardiorenal outcomes in patients with type 2 diabetes, a urine albumin-to-creatinine ratio of 30-5000 mg/g, an estimated glomerular filtration rate (eGFR) of 25 ml/min per 1.73 m² or more and also receiving optimized renin-angiotensin system blockade treatment. This present analysis focused on the efficacy and safety of finerenone on kidney outcomes. Among 13,026 patients with a median follow-up of three years, finerenone significantly reduced the hazard of a kidney composite outcome (time to kidney failure, sustained 57% or more decrease in eGFR from baseline, or kidney death) by 23% versus placebo (hazard ratio, 0.77; 95% confidence interval, 0.67-0.88), with a three-year absolute between-group difference of 1.7% (95% confidence interval, 0.7-2.6). Hazard ratios were directionally consistent for a prespecified baseline eGFR and urine albumin-to-creatinine ratio categories (P_interaction = 0.62 and P_interaction = 0.67, respectively), although there was a high degree of uncertainty in the 30-300 mg/g subgroup. Finerenone significantly reduced the hazard of end-stage kidney disease (ESKD) by 20% versus placebo (0.80; 0.64-0.99). Adverse events were similar between treatment arms, although hyperkalemia leading to treatment discontinuation occurred significantly more frequently with finerenone versus placebo (2.4% vs 0.8% and 0.6% vs 0.3% in patients with eGFR less than 60 vs. greater than or equal to 60 ml/min per 1.73 m², respectively). Thus, finerenone improved kidney outcomes, reduced the hazard of ESKD, and is well tolerated in patients with chronic kidney disease and type 2 diabetes.

Efficacy and Safety of Finerenone for Prevention of Cardiovascular Events in Type 2 Diabetes Mellitus With Chronic Kidney Disease: A Meta-analysis of Randomized Controlled Trials

ABSTRACT

Only a few meta-analyses evaluated the effect of finerenone on cardiovascular events in type 2 diabetes mellitus with chronic kidney disease. The main aim of this meta-analysis was to gain more reliable assessments of the efficacy and safety of finerenone for prevention of cardiovascular events in diabetic kidney disease. We searched for finerenone in the treatment of diabetic kidney disease from database (PubMed, Embase, and ClinicalTrials.gov ) until December 30, 2021. Relative risks (RRs) with 95% confidence intervals (CIs) calculated by the Mantel-Haenszel random-effects model were used as summary statistics for the categorical data. We included 4 studies that met the inclusion criteria with 13,943 participants. The finerenone group demonstrated a great benefit in reducing the incidence of major adverse cardiac events (RR: 0.88; 95% CI 0.80-0.96; P = 0.003), all-cause mortality (RR: 0.89; 95% CI 0.80-0.99; P = 0.04), myocardial infarction (RR: 0.79; 95% CI 0.67-0.92; P = 0.003), and new-onset hypertension (RR: 0.71; 95% CI 0.62-0.81; P < 0.00001). No difference was found in adverse events between the finerenone and placebo groups (RR: 1.00; 95% CI [0.98-1.01], P = 0.59), whereas a higher risk of hyperkalemia was observed in the finerenone group than in the placebo group (RR = 2.04, 95% CI 1.80-2.32; P < 0.00001). Besides, cerebrovascular events and new-onset atrial fibrillation did not increase in patients taking finerenone. Overall, finerenone treatment showed a great benefit of reducing the risk of major adverse cardiac events, all-cause mortality, myocardial infarction, and new-onset hypertension events in patients with type 2 diabetes mellitus and chronic kidney disease.

Evolution of Mineralocorticoid Receptor Antagonists in the Treatment of Chronic Kidney Disease Associated with Type 2 Diabetes Mellitus

Chronic kidney disease (CKD) is one of the most frequent complications associated with type 2 diabetes mellitus (T2DM) and is also an independent risk factor for cardiovascular disease. The mineralocorticoid receptor (MR) is a nuclear receptor expressed in many tissue types, including kidney and heart. Aberrant and long-term activation of MR by aldosterone in patients with T2DM triggers detrimental effects (eg, inflammation and fibrosis) in these tissues. The suppression of aldosterone at the early stage of T2DM has been a therapeutic strategy for patients with T2DM-associated CKD. Although patients have been treated with renin-angiotensin system (RAS) blockers for decades, RAS blockers alone are not sufficient to prevent CKD progression. Steroidal MR antagonists (MRAs) have been used in combination with RAS blockers; however, undesired adverse effects have restricted their usage, prompting the development of nonsteroidal MRAs with better target specificity and safety profiles. Recently conducted studies, Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease (FIDELIO-DKD) and Finerenone in Reducing Cardiovascular Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD), have reported that finerenone, a nonsteroidal MRA, improves both renal and cardiovascular outcomes compared with placebo. In this article, we review the history of MRA development and discuss the possibility of its combination with other treatment options, such as sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and potassium binders for patients with T2DM-associated CKD.

Finerenone in diabetic kidney disease: A systematic review and critical appraisal

BACKGROUND & AIMS

Finerenone is a novel non-steroidal mineralocorticoid antagonist (MRA) recently approved for the treatment of chronic kidney disease (CKD) in people with type 2 diabetes (T2D). We aim to conduct a systematic review of finerenone to know the efficacy and safety of finerenone in CKD with or without T2D.

METHODS

A systematic search in the electronic database of PubMed and Google Scholar was made from inception until September 09, 2022, using several MeSH keywords related to finerenone. Ongoing trials were additionally searched from ClinicalTrials.Gov.

RESULTS

Five phase 2 and three phase 3, randomized, double-blind, placebo- or active-controlled studies of finerenone have been published to date and several other randomized and real-world studies of finerenone are currently undergoing.

CONCLUSIONS

In short-term studies in patients with CKD and reduced ejection heart failure, with or without T2D, finerenone 20 mg appears to have a better renal outcome compared with spironolactone and a better mortality outcome compared with eplerenone, with significantly lesser hyperkalemia compared to both spironolactone and finerenone. In long-term studies in patients with CKD and T2D, finerenone 10/20 mg significantly reduces the progression of renal disease and reduced CV endpoints (especially heart failure hospitalization) compared to placebo. Finerenone has no effect on HbA1c, body weight, and sexual side effects including gynecomastia, and has only a modest effect on blood pressure. However, hyperkalemia leading to drug withdrawal was significantly higher with finerenone compared to placebo. Safety data in real-world settings is a pressing priority.

Efficacy and safety of finerenone for treatment of diabetic kidney disease: current knowledge and future perspective

INTRODUCTION

Diabetic kidney disease (DKD) represents a leading cause of morbidity and mortality in subjects with diabetes and develops in more than one third of diabetic patients. Steroidal mineralocorticoid receptor antagonists (MRAs - eplerenone and spironolactone) reduce mortality in patients with heart failure with reduced ejection fraction (HFrEF). However, in clinical practice the use of steroidal MRAs is limited by the significant risk of hyperkalaemia, especially in patients with impaired renal function. Finerenone, a novel nonsteroidal MRA, shows a higher selectivity and binding affinity for mineralocorticoid receptor (MR) compared to steroidal MRAs and has been shown to reduce chronic kidney disease (CKD) progression and cardiovascular mortality in patients with CKD and T2DM.

AREAS COVERED

This review summarizes the current evidence on efficacy and safety of finerenone in the treatment of patients with CKD and T2DM, and discusses its mechanisms of action investigated in preclinical studies.

EXPERT OPINION

Pharmacological properties of finerenone and its unique tissue distribution are responsible for a lower risk of hyperkalaemia. Therefore, finerenone represents a valuable therapeutic tool in patients with CKD/diabetic kidney disease (DKD). Recent studies have shown that finerenone delays the progression of CKD and reduce cardiovascular events in patients with DKD, highlighting its safety and efficacy in this high-risk population.

Network meta-analysis of mineralocorticoid receptor antagonists for diabetic kidney disease

Diabetic kidney disease (DKD) is one of the major causes of end-stage renal disease (ESRD). To evaluate the efficacy and safety of different types of mineralocorticoid receptor antagonists (MRAs) in diabetic kidney disease patients, we conducted this network meta-analysis by performing a systematic search in PubMed, MEDLINE, EMBASE, Web of Science, the Cochrane Library, and Clinicaltrials.gov. A total of 12 randomized clinical trials with 15,492 patients applying various types of MRAs covering spironolactone, eplerenone, finerenone, esaxerenone, and apararenone were included. The efficacy outcomes were the ratio of urine albumin creatine ratio (UACR) at posttreatment vs. at baseline, change in posttreatment estimated glomerular filtration (eGFR) vs. at baseline, and change in posttreatment systolic blood pressure (SBP) vs. at baseline. The safety outcome was the number of patients suffering from hyperkalemia. High-dose finerenone (MD −0.31, 95% CI: −0.52, −0.11), esaxerenone (MD −0.54, 95% CI: −0.72, −0.30), and apararenone (MD −0.63, 95% CI: −0.90, −0.35) were associated with a superior reduction in proteinuria in patients with DKD. Regarding the change in eGFR, the results of all drugs were similar, and finerenone may have potential superiority in protecting the kidney. Compared with placebo, none of the treatments was associated with a higher probability of controlling systolic blood pressure during treatment. Moreover, spironolactone, esaxerenone, and 20 mg of finerenone presented a higher risk of hyperkalemia. This Bayesian network meta-analysis was the first to explore the optimal alternative among MRAs in the treatment of DKD and revealed the superiority of 20 mg of finerenone among MRAs in treating DKD.

Systematic Review Registration: PROSPERO, identifier (CRD42022313826)

Cardiorenal benefits of mineralocorticoid antagonists in CKD and type 2 diabetes : Lessons from the FIGARO-DKD trial

Diabetic kidney disease (DKD) develops in almost half of all patients with diabetes and is the most common cause of chronic kidney disease (CKD) worldwide. Despite the high risk of chronic renal failure in these patients, only few therapeutic strategies are available. The use of renin-angiotensin system blockers to reduce the incidence of kidney failure in patients with DKD was established years ago and remains the hallmark of therapy. The past 2 years have seen a dramatic change in our therapeutic arsenal for CKD. Sodium-glucose co-transporter‑2 inhibitors (SGLT2s) have been successfully introduced for the treatment of CKD. A further addition is a novel compound antagonizing the activation of the mineralocorticoid receptor: finerenone. Finerenone reduces albuminuria and surrogate markers of cardiovascular disease in patients who are already on optimal therapy. In the past, treatment with other mineralocorticoid receptor antagonists was hampered by a significantly increased risk of hyperkalemia. Finerenone had a much smaller effect on hyperkalemia. Together with a reduced effect on blood pressure and no signs of gynecomastia, this therapeutic strategy had a more specific anti-inflammatory effect and a smaller effect on the volume/electrolyte axis. In the FIDELIO-DKD study comparing the actions of the non-steroidal mineralocorticoid receptor antagonist finerenone with placebo, finerenone reduced the progression of DKD and the incidence of cardiovascular events, with a relatively safe adverse event profile. In this article, we summarize the available evidence on the cardioprotective and nephroprotective effects of finerenone and analyze the molecular mechanisms involved. In addition, we discuss the potential future role of mineralocorticoid receptor inhibition in the treatment of patients with diabetic CKD.

Non-steroidal mineralocorticoid receptor antagonists in cardiorenal disease

Despite existing treatments, patients with heart failure and chronic kidney disease (CKD) remain at high risk for adverse outcomes and progression to end-stage disease. Steroidal mineralocorticoid receptor antagonists (MRAs) such as spironolactone and eplerenone reduce mortality but remain under-prescribed due to the perceived risk of hyperkalaemia and hormonal side effects. The discovery of non-steroidal MRAs represents a major new dimension in cardiorenal disease therapy. Non-steroidal MRAs have high affinity and specificity for the mineralocorticoid receptor (MR) and differ from both steroidal agents and each other with respect to important physiochemical, pharmacodynamic, and pharmacokinetic parameters. Similar to their steroidal counterparts, they have beneficial anti-inflammatory, anti-remodelling, and anti-fibrotic properties in the kidneys, heart, and vasculature. There are several non-steroidal MRAs under development and clinical assessment; of these, only esaxerenone and finerenone are approved for treatment globally. In Japan, esaxerenone is approved for essential hypertension and has been studied in diabetic nephropathy. Compared with steroidal MRAs, finerenone more potently inhibits MR co-regulator recruitment and fibrosis and distributes more evenly between the heart and kidneys. The landmark Phase III trials FIGARO-DKD and FIDELIO-DKD demonstrated that finerenone-reduced major kidney and cardiovascular events on top of maximally tolerated renin-angiotensin-aldosterone system inhibition in patients with CKD associated with Type 2 diabetes. Non-steroidal MRAs are currently under evaluation in heart failure and for synergistic treatment with sodium-glucose contransporter 2 inhibitors. These ground-breaking agents could become an important therapy across the spectrum of cardiorenal disease.

Roles of Mineralocorticoid Receptors in Cardiovascular and Cardiorenal Diseases

Mineralocorticoid receptor (MR) activation in the heart and vessels leads to pathological effects, such as excessive extracellular matrix accumulation, oxidative stress, and sustained inflammation. In these organs, the MR is expressed in cardiomyocytes, fibroblasts, endothelial cells, smooth muscle cells, and inflammatory cells. We review the accumulating experimental and clinical evidence that pharmacological MR antagonism has a positive impact on a battery of cardiac and vascular pathological states, including heart failure, myocardial infarction, arrhythmic diseases, atherosclerosis, vascular stiffness, and cardiac and vascular injury linked to metabolic comorbidities and chronic kidney disease. Moreover, we present perspectives on optimization of the use of MR antagonists in patients more likely to respond to such therapy and review the evidence suggesting that novel nonsteroidal MR antagonists offer an improved safety profile while retaining their cardiovascular protective effects. Finally, we highlight future therapeutic applications of MR antagonists in cardiovascular injury.

Differentiation between emerging non-steroidal and established steroidal mineralocorticoid receptor antagonists: head-to-head comparisons of pharmacological and clinical characteristics

INTRODUCTION

Mineralocorticoid receptor (MR) antagonists (MRAs) provide cardiorenal protection. However steroidal MRAs might induce hyperkalemia and sex hormone-related adverse effects. Several novel non-steroidal MRAs are being developed that are highly selective for the MR and may have an improved safety profile.

AREAS COVERED

This narrative review summarizes data from head-to-head comparisons of emerging non-steroidal MRAs with older steroidal MRAs, including pharmacological characteristics, pharmacokinetic properties, clinical outcomes, and safety, and highlights similarities and differences between emerging agents and established steroidal MRAs.

EXPERT OPINION

Head-to-head comparisons in phase 2 trials suggest that the new non-steroidal MRAs exhibit at least equivalent efficacy to steroidal MRAs but may have a better safety profile in patients with heart failure and/or kidney disease. When also taking into account data from recent phase 3 placebo-controlled trials, these novel non-steroidal MRAs have the potential to provide a cardiorenal benefit above that of current optimized standard-of-care treatment in a high-risk population with reduced renal function, and with a lower risk of hyperkalemia. To optimize therapy, further research is needed to clarify the molecular differences in the mode of action of non-steroidal MRAs versus steroidal MRAs, and biomarkers that are predictive of MRA response need to be identified and validated.

The Role of the Mineralocorticoid Receptor and Mineralocorticoid Receptor-Directed Therapies in Heart Failure

Mineralocorticoid receptor (MR) antagonists (MRA), also referred to as aldosterone blockers, are now well-recognized for their clinical benefit in patients who have heart failure (HF) with reduced ejection fraction (HFrEF). Recent studies have also shown MRA can improve outcomes in patients with HFpEF, where the ejection fraction is preserved but left ventricular filling is reduced. While the MR is a steroid hormone receptor best known for antinatriuretic actions on electrolyte homeostasis in the distal nephron, it is now established that the MR has many physiological and pathophysiological roles in the heart, vasculature, and other nonepithelial tissue types. It is the impact of MR activation on these tissues that underpins the use of MRA in cardiovascular disease, in particular HF. This mini-review will discuss the origins and the development of MRA and highlight how their use has evolved from the "potassium-sparing diuretics" spironolactone and canrenone over 60 years ago, to the more receptor-selective eplerenone and most recently the emergence of new nonsteroidal receptor antagonists esaxerenone and finerenone.

Mineralocorticoid Receptor Antagonism in Chronic Kidney Disease

The overactivation of the mineralocorticoid receptor (MR) in animal models of chronic kidney disease (CKD) increases sodium retention and hypertension and provokes inflammation and fibrosis in the kidneys, blood vessels, and the heart; these processes play an important role in the progression of cardiorenal disease. Accordingly, blockade of the MR is an attractive therapeutic intervention to retard the progression of CKD and improve cardiovascular morbidity and mortality. Finerenone is a novel, nonsteroidal MR antagonist (MRA) with a unique mode of action that is distinct from currently available steroidal MRAs. In animal models of CKD, finerenone has a more favorable benefit/risk ratio as compared with the steroidal MRAs such as spironolactone and eplerenone. In patients with type 2 diabetes and heart and/or kidney disease, phase II trials have revealed that compared with spironolactone, eplerenone, or placebo, finerenone displays benefits that exceed the risks of MR antagonism. In patients with CKD and type 2 diabetes, a large phase III trial has shown that, compared with placebo, finerenone improved kidney failure and cardiovascular outcomes. In the first part of this article, we explore the safety and efficacy of spironolactone and eplerenone in early- and late-stage CKD. In the second part, we describe the mechanism of action of finerenone and discuss the promising role of this nonsteroidal MRA as a novel therapeutic opportunity to improve clinical outcomes in patients with CKD.

Nonsteroidal mineralocorticoid receptor antagonism for cardiovascular and renal disorders - New perspectives for combination therapy

During the recent 30 years, there has been a dramatic increase in knowledge about the role of aldosterone and the mineralocorticoid receptor (MR) in the pathophysiology of cardiovascular (CV) and kidney diseases. The scientific perspective on the aldosterone/MR ensemble extended from a previously renal epithelial-centered focus on sodium-potassium exchange to a broader view as systemic modulators of extracellular matrix, inflammation and fibrosis. Spironolactone was launched as the first antagonist of aldosterone 27 years before the MR was cloned. It was classified as a potassium-sparing diuretic, based on its initial clinical characterization as a diuretic and its preferred activity to compensate for the potassium loss induced by loop diuretics when used in combination. The second steroidal MR antagonist was eplerenone which was discovered at a time when the role of aldosterone and MR in cardiac fibrosis was rediscovered. The constraint of developing potentially life-threatening hyperkalaemia when used in combination with other inhibitors of the renin-angiotensin-system (RAS) in patients with reduced kidney function initiated extensive research and development activities with the goal to identify novel nonsteroidal MR antagonists with an improved benefit-risk ratio. Here we summarize major current clinical trials with MRAs in different CV and renal diseases. Addition of the nonsteroidal MRA finerenone to optimal RAS blockade recently reduced CV and kidney outcomes in two large phase III trials in patients with chronic kidney disease (CKD) and type 2 diabetes (T2D). We provide an outlook on further opportunities for combination therapy of nonsteroidal MRA finerenone with RAS inhibitors and sodium-glucose cotransporter-2 inhibitors (SGLT2i).

Mineralocorticoid Receptor Antagonists in Diabetic Kidney Disease

Diabetes mellitus is a global health issue and main cause of chronic kidney disease. Both diseases are also linked through high cardiovascular morbidity and mortality. Diabetic kidney disease (DKD) is present in up to 40% of diabetic patients; therefore, prevention and treatment of DKD are of utmost importance. Much research has been dedicated to the optimization of DKD treatment. In the last few years, mineralocorticoid receptor antagonists (MRA) have experienced a renaissance in this field with the development of non-steroidal MRA. Steroidal MRA have known cardiorenal benefits, but their use is limited by side effects, especially hyperkalemia. Non-steroidal MRA still block the damaging effects of mineralocorticoid receptor overactivation (extracellular fluid volume expansion, inflammation, fibrosis), but with fewer side effects (hormonal, hyperkalemia) than steroidal MRA. This review article summarizes the current knowledge and newer research conducted on MRA in DKD.

Nonsteroidal Mineralocorticoid Receptor Antagonists: Exploring Role in Cardiovascular Disease

ABSTRACT

Aldosterone, a mineralocorticoid hormone, plays a role in the pathophysiology of many cardiovascular disease states. Mineralocorticoid receptor antagonists (MRAs) have been shown to improve clinical outcomes in select patient populations. However, use of available steroidal receptor antagonists, eplerenone and spironolactone, is often limited by the risk or development of hyperkalemia. Nonsteroidal MRAs have been designed to overcome this limitation. The nonsteroidal MRAs have been studied in patients with heart failure with reduced ejection fraction, hypertension, and to lower the risk of cardiac and renal outcomes in those with type 2 diabetes and renal disease. In this review, the pharmacology of the MRAs is compared, the data evaluating the use of nonsteroidal MRAs are examined, and the place of this new generation of therapy is discussed. At this time, it seems that there could be a future role for nonsteroidal MRAs to reduce the risk of renal outcomes in high-risk individuals.

Steroidal and non-steroidal mineralocorticoid receptor antagonists in cardiorenal medicine

This review covers the last 80 years of remarkable progress in the development of mineralocorticoid receptor (MR) antagonists (MRAs) from synthesis of the first mineralocorticoid to trials of nonsteroidal MRAs. The MR is a nuclear receptor expressed in many tissues/cell types including the kidney, heart, immune cells, and fibroblasts. The MR directly affects target gene expression—primarily fluid, electrolyte and haemodynamic homeostasis, and also, but less appreciated, tissue remodelling. Pathophysiological overactivation of the MR leads to inflammation and fibrosis in cardiorenal disease. We discuss the mechanisms of action of nonsteroidal MRAs and how they differ from steroidal MRAs. Nonsteroidal MRAs have demonstrated important differences in their distribution, binding mode to the MR and subsequent gene expression. For example, the novel nonsteroidal MRA finerenone has a balanced distribution between the heart and kidney compared with spironolactone, which is preferentially concentrated in the kidneys. Compared with eplerenone, equinatriuretic doses of finerenone show more potent anti-inflammatory and anti-fibrotic effects on the kidney in rodent models. Overall, nonsteroidal MRAs appear to demonstrate a better benefit–risk ratio than steroidal MRAs, where risk is measured as the propensity for hyperkalaemia. Among patients with Type 2 diabetes, several Phase II studies of finerenone show promising results, supporting benefits on the heart and kidneys. Furthermore, finerenone significantly reduced the combined primary endpoint (chronic kidney disease progression, kidney failure, or kidney death) vs. placebo when added to the standard of care in a large Phase III trial.

Enantioselective Total Synthesis of (-)-Finerenone Using Asymmetric Transfer Hydrogenation

(−)‐Finerenone is a nonsteroidal mineralocorticoid receptor antagonist currently in phase III clinical trials for the treatment of chronic kidney disease in type 2 diabetes. It contains an unusual dihydronaphthyridine core. We report a 6‐step synthesis of (−)‐finerenone, which features an enantioselective partial transfer hydrogenation of a naphthyridine using a chiral phosphoric acid catalyst with a Hantzsch ester. The process is complicated by the fact that the naphthyridine exists as a mixture of two atropisomers that react at different rates and with different selectivities. The intrinsic kinetic resolution was converted into a kinetic dynamic resolution at elevated temperature, which enabled us to obtain (−)‐finerenone in both high yield and high enantioselectivity. DFT calculations have revealed the origin of selectivity.

Mineralocorticoid Receptor Antagonists Decrease the Rates of Positive Screening for Primary Aldosteronism

OBJECTIVE

Mineralocorticoid receptor antagonists (MRAs) are effective in patients with resistant hypertension and/or primary aldosteronism (PA). Screening for PA should ideally be conducted after stopping medications that might interfere with the renin-angiotensin-aldosterone system, but this is challenging in patients with recalcitrant hypertension or hypokalemia. Herein, we aimed to evaluate the impact of MRAs on PA screening in clinical practice.

METHODS

We conducted a retrospective cohort study of patients with hypertension who had plasma aldosterone and renin measurements before and after MRA use in a tertiary referral center, over 19 years.

RESULTS

A total of 146 patients, 91 with PA, were included and followed for up to 18 months. Overall, both plasma renin and aldosterone increased after MRA initiation (from median, interquartile range: 0.5 [0.1, 0.8] to 1.2 [0.6, 4.8] ng/mL/hour and from 19.1 [12.9, 27.7] to 26.4 [17.1, 42.3] ng/dL, respectively; P<.0001 for both), while the aldosterone/renin ratio (ARR) decreased from 40.3 (18.5, 102.7) to 23.1 (8.6, 58.7) ng/dL per ng/mL/hour (P<.0001). Similar changes occurred irrespective of the MRA treatment duration and other antihypertensives used. Positive PA screening abrogation after MRA initiation was found in 45/94 (48%) patients. Conversely, 17% of patients had positive PA screening only after MRA treatment, mostly due to correction of hypokalemia. An initially positive screening test was more likely altered by high MRA doses and more likely persistent in patients with confirmed PA or taking beta-blockers.

CONCLUSION

MRAs commonly reduce ARR and the proportion of positive PA screening results. When PA is suspected, screening should be repeated off MRAs.

ABBREVIATIONS

ACEI = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; ARR = aldosterone/renin ratio; DRC = direct renin concentration; MRA = mineralocorticoid receptor antagonist; PA = primary aldosteronism; PAC = plasma aldosterone concentration; PRA = plasma renin activity; RAAS = renin-angiotensin-aldosterone system.

Mineralocorticoid receptor antagonists in patients with chronic kidney disease

Mineralocorticoid receptor antagonists (MRA) can reduce cardiovascular morbidity and mortality in patients with heart failure and ischemic heart disease. In addition, these agents have been used in patients with diabetic nephropathy to control proteinuria and slow down chronic kidney disease (CKD) progression. Current guidelines recommend against the use of MRAs in patients with advanced CKD. However, there is growing interest on their use in this population that has unmet needs (high cardiovascular morbidity and mortality) and unique challenges (risk of acute kidney injury or hyperkalemia). This narrative review discusses the emerging role of MRAs for the management of cardiovascular disease and/or the prevention of CKD progression, highlighting results from randomized controlled trials and presenting real-world data from available registries. Results from recent trials in patients on maintenance dialysis are also discussed.

The role of aldosterone inhibitors in cardiac ischemia-reperfusion injury

Myocardial ischaemia-reperfusion (I/R) injury is a well-known term for exacerbation of cellular destruction and dysfunction after the restoration of blood flow to a previously ischaemic heart. A vast number of studies that have demonstrated that the role of mineralocorticoids in cardiovascular diseases is based on the use of pharmacological mineralocorticoid receptor (MR) antagonists. This review paper aimed to summarize current knowledge on the effects of MR antagonists on myocardial I/R injury as well as postinfarction remodeling. Animal models, predominantly the Langendorff technique and left anterior descending coronary artery occlusion, have confirmed the potency of MR antagonists as preconditioning and postconditioning agents in limiting infarct size and postinfarction remodeling. Several preclinical studies in rodents have established and proved possible mechanisms of cardioprotection by MR antagonists, such as reduction of oxidative stress, reduction of inflammation, and apoptosis, therefore limiting the infarct zone. However, the results of some clinical trials are inconsistent, since they reported no benefit of MR antagonists in acute myocardial infarction. Due to this, further studies and the results of ongoing clinical trials regarding MR antagonist administration in patients with acute myocardial infarction are being awaited with great interest.

Aldosterone and the mineralocorticoid receptor in renal injury: A potential therapeutic target in feline chronic kidney disease

There is a growing body of experimental and clinical evidence supporting mineralocorticoid receptor (MR) activation as a powerful mediator of renal damage in laboratory animals and humans. Multiple pathophysiological mechanisms are proposed, with the strongest evidence supporting aldosterone-induced vasculopathy, exacerbation of oxidative stress and inflammation, and increased growth factor signalling promoting fibroblast proliferation and deranged extracellular matrix homeostasis. Further involvement of the MR is supported by extensive animal model experiments where MR antagonists (such as spironolactone and eplerenone) abrogate renal injury, including ischaemia-induced damage. Additionally, clinical trials have shown MR antagonists to be beneficial in human chronic kidney disease (CKD) in terms of reducing proteinuria and cardiovascular events, though current studies have not evaluated primary end points which allow conclusions to made about whether MR antagonists reduce mortality or slow CKD progression. Although differences between human and feline CKD exist, feline CKD shares many characteristics with human disease including tubulointerstitial fibrosis. This review evaluates the evidence for the role of the MR in renal injury and summarizes the literature concerning aldosterone in feline CKD. MR antagonists may represent a promising therapeutic strategy in feline CKD.

Non-steroidal mineralocorticoid antagonists: Prospects for renoprotection in diabetic kidney disease

Diabetic kidney disease (DKD) is the major cause of kidney failure in the world and the combination of DKD and diabetes mellitus contributes to an additive incidence of worsening cardiovascular mortality rates. Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) remain the mainstay of therapy and have reduced kidney function decline in DKD from 8 to 10 to ~4 mL/min/y. Sodium-glucose co-transporter-2 (SGLT2) inhibitors, in the presence of ACE inhibitors or ARB agents, further slowdown DKD progression by an additional 58% to 1.8 mL/min/y. Moreover, SGLT2 inhibitors reduce heart failure risk. However, the normal rate of kidney function decline in humans is between 0.7 and 0.9 mL/min/y, hence, there is still room for improvement. Mineralocorticoid receptor antagonists (MRAs) already have a track record of benefit in heart failure risk reduction, and efficacy in reducing albuminuria and treating resistant hypertension; however hyperkalaemia and other adverse effects preclude their routine use in DKD. Novel non-steroidal MRAs offer a reduced risk of hyperkalaemia, and yet have many benefits that they share with their steroidal cousins. This paper reviews the data for both steroidal and non-steroidal MRAs in DKD and presents some data from soon-to-be-completed ongoing renal and cardiovascular outcome trials in DKD.

Glucose and Blood Pressure-Dependent Pathways-The Progression of Diabetic Kidney Disease

The major clinical associations with the progression of diabetic kidney disease (DKD) are glycemic control and systemic hypertension. Recent studies have continued to emphasize vasoactive hormone pathways including aldosterone and endothelin which suggest a key role for vasoconstrictor pathways in promoting renal damage in diabetes. The role of glucose per se remains difficult to define in DKD but appears to involve key intermediates including reactive oxygen species (ROS) and dicarbonyls such as methylglyoxal which activate intracellular pathways to promote fibrosis and inflammation in the kidney. Recent studies have identified a novel molecular interaction between hemodynamic and metabolic pathways which could lead to new treatments for DKD. This should lead to a further improvement in the outlook of DKD building on positive results from RAAS blockade and more recently newer classes of glucose-lowering agents such as SGLT2 inhibitors and GLP1 receptor agonists.

Results from Drug-Drug Interaction Studies In Vitro and In Vivo Investigating the Effect of Finerenone on the Pharmacokinetics of Comedications

BACKGROUND AND OBJECTIVES

In vivo studies were performed with the novel, selective, non-steroidal mineralocorticoid receptor antagonist finerenone to assess the relevance of inductive and/or inhibitory effects on cytochrome P450 (CYP) enzymes observed in vitro.

METHODS

CYP isoenzyme-specific substrates were incubated in vitro with finerenone or its metabolites to investigate reversible and irreversible inhibitory as well as inductive potential. Three crossover studies in healthy male volunteers investigated the effects of finerenone (20 mg orally) on the pharmacokinetics of the index substrates midazolam (CYP3A4, n = 30), repaglinide (CYP2C8, n = 28) and warfarin (CYP2C9, n = 24).

RESULTS

Finerenone caused direct inhibitory effects on CYP activities in vitro in the rank order CYP2C8, CYP1A1 > CYP3A4 > CYP2C9 and CYP2C19, but not on other major CYP isoforms. Moreover, irreversible inhibition of CYP3A4 was observed. The major metabolites of finerenone demonstrated minor reversible inhibition of CYP1A1, CYP2C9 and CYP3A4 with no hint of time-dependent inhibition of any CYP isoform. Calculations from in vitro data according to regulatory guidelines suggested likely inhibition of CYP2C8 and CYP3A4 in vivo, whereas this was not the case for CYP1A1, CYP2C9 and CYP2C19. Furthermore, finerenone and three of its metabolites were inducers of CYP3A4 in vitro with predicted weak-to-moderate in vivo relevance. Studies in healthy volunteers, prompted by these results, demonstrated no effect of finerenone on CYP isoenzymes for which in vitro data had indicated potential inhibition or induction.

CONCLUSION

Administration of finerenone 20 mg once daily confers no risk of clinically relevant drug-drug interactions with substrates of cytochrome P450 enzymes.

Design and Baseline Characteristics of the Finerenone in Reducing Cardiovascular Mortality and Morbidity in Diabetic Kidney Disease Trial

BACKGROUND

Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials.

PATIENTS AND METHODS

The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate ≥25 mL/min/1.73 m2 and albuminuria (urinary albumin-to-creatinine ratio ≥30 to ≤5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level α = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure.

CONCLUSIONS

FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen.

TRIAL REGISTRATION

EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049.

Design and Baseline Characteristics of the Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease Trial

BACKGROUND

Among diabetics, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality, and progression of their underlying disease. Finerenone is a novel, non-steroidal, selective mineralocorticoid-receptor antagonist which has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD), while revealing only a low risk of hyperkalemia. However, the effect of finerenone on renal and CV outcomes has not been investigated in long-term trials yet.

METHODS

The Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease -(FIDELIO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important renal and CV outcomes in T2D patients with CKD. FIDELIO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 5.5 years. FIDELIO-DKD randomized 5,734 patients with an estimated glomerular filtration rate (eGFR) ≥25-<75 mL/min/1.73 m2 and albuminuria (urinary albumin-to-creatinine ratio ≥30-≤5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of primary outcome (overall two-sided significance level α = 0.05), the composite of time to first occurrence of kidney failure, a sustained decrease of eGFR ≥40% from baseline over at least 4 weeks, or renal death.

CONCLUSION

FIDELIO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of renal and CV events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen.

Mineralocorticoid Receptor Antagonists Stimulate Human Hair Growth ex vivo

Whilst topical steroids represent one of the most frequently administered treatments for skin and hair diseases, predominantly based on their glucocorticoid receptor-mediated anti-inflammatory effects, the mineralocorticoid effects of topical steroids have received surprisingly little attention. However, the role of mineralocorticoid receptor (MR) signaling is now known to extend beyond the kidney, with human skin, including the hair follicle (HF), expressing the MR. Using microdissected female HFs treated ex vivo with MR agonists and antagonists, we sought to determine the effects of MR-mediated signaling in the cutaneous context. Indeed, not only did the skin and HF epithelium express the MR at both the gene and protein level, but its expression was hair cycle dependent. Moreover, the selective MR antagonist eplerenone promoted hair shaft elongation and hair matrix keratinocyte proliferation whilst delaying catagen (HF regression). These novel observations suggest that the female human HF is sensitive to the inhibition of MR signaling and provide the first evidence that sustained MR signaling may even be required to maintain the growth phase (anagen) of human scalp HFs. Indeed, these data encourage the systematic evaluation of MR agonists and antagonists in human hair growth control so as to identify much-needed, novel anti-hirsutism and/or hair growth-promoting agents, respectively.

Diabetic nephropathy: an insight into molecular mechanisms and emerging therapies

Introduction: Diabetic kidney disease (DKD) is a major cause of morbidity and mortality in diabetes and is the most common cause of proteinuric and non-proteinuric forms of end-stage renal disease (ESRD). Control of risk factors such as blood glucose and blood pressure is not always achievable or effective. Significant research efforts have attempted to understand the pathophysiology of DKD and develop new therapies. Areas covered: We review DKD pathophysiology in the context of existing and emerging therapies that affect hemodynamic and metabolic pathways. Renin-angiotensin system (RAS) inhibition has become standard care. Recent evidence for renoprotective activity of SGLT2 inhibitors and GLP-1 agonists is an exciting step forward while endothelin receptor blockade shows promise. Multiple metabolic pathways of DKD have been evaluated with varying success; including mitochondrial function, reactive oxygen species, NADPH oxidase (NOX), transcription factors (NF-B and Nrf2), advanced glycation, protein kinase C (PKC), aldose reductase, JAK-STAT, autophagy, apoptosis-signaling kinase 1 (ASK1), fibrosis and epigenetics. Expert opinion: There have been major advances in the understanding and treatment of DKD. SGLT2i and GLP-1 agonists have demonstrated renoprotection, with novel therapies under evaluation. Addressing the interaction between hemodynamic and metabolic pathways may help achieve prevention, attenuation or even reversal of DKD.

The renin-angiotensin-aldosterone system and its therapeutic targets

The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in the regulation of blood pressure and body fluid homeostasis and is a mainstay for the treatment of cardiovascular and renal diseases. Angiotensin II and aldosterone are the two most powerful biologically active products of the RAAS, inducing all of the classical actions of the RAAS including vasoconstriction, sodium retention, tissue remodeling and pro-inflammatory and pro-fibrotic effects. In recent years, new components of the RAAS have been discovered beyond the classical pathway that have led to the identification of depressor or so-called protective RAAS pathways and the development of novel therapies targeting this system. Moreover, dual inhibitors which block the RAAS and other systems involved in the regulation of blood pressure or targeting upstream of angiotensin II by selectively deleting liver-derived angiotensinogen, the precursor to all angiotensins, may provide superior treatment for cardiovascular and renal diseases and revolutionize RAAS-targeting therapy.

New pharmacological strategies for protecting kidney function in type 2 diabetes

Type 2 diabetes is the leading cause of impaired kidney function, albuminuria, and renal replacement therapy globally, thus placing a large burden on health-care systems. Current treatment strategies rely on intensive glucose lowering as well as strict blood pressure control through blockade of the renin-angiotensin-aldosterone system. Such approaches might slow decline in kidney function, but many patients progress to end-stage kidney failure despite optimal therapy. In recent clinical trials, new-generation glucose-lowering drug classes, the sodium-glucose co-transporter-2 inhibitors and agents that target the incretin pathway, have been shown to improve kidney outcomes in patients with type 2 diabetes. Other new approaches, which have been developed on the basis of an improved understanding of the mechanisms that contribute to kidney damage in the context of diabetes, include use of drugs that block endothelin receptors (eg, atrasentan) and non-steroidal mineralocorticoid receptors (eg, finerenone). In this Review, we provide an overview of recent clinical data relevant to these new therapeutic approaches for management of kidney disease in the context of type 2 diabetes.

The Role of Mineralocorticoid Receptor Antagonists in Heart Failure with Reduced Ejection Fraction

Background:

Heart failure (HF) is a worldwide modern epidemic, associated with significant morbidity and mortality. Several causes have been identified for the syndrome, most of which share common pathophysiologic pathways, including neurohormonal activation. Central to the latter lies activation of the reninangiotensin- aldosterone system, and its effects on cardiovascular disease progression.

Objectives:

The aim of this review is to summarize the pathophysiology of aldosterone and the effects of its blockage in the failing heart, as well as to provide state-of-the-art evidence, and address future perspectives regarding the use of mineralocorticoid receptor antagonists in heart failure with reduced ejection fraction.

Method:

Literature was reviewed for studies that assess the pathophysiology of aldosterone in HF with reduced ejection fraction (HFrEF), and the effects of mineralocorticoid receptor antagonists (MRAs) in this condition.

Results:

Several major society guidelines have synthesized the available evidence on HFrEF management, and drugs that block the renin-angiotensin-aldosterone system at different levels continue to form the key component of standard of care for these patients. Mineralocorticoid receptor antagonists are an important part of HFrEF pharmacologic treatment, and their use is supported by a high level of evidence studies. This class of drugs demonstrated significant benefits for morbidity and mortality, across the spectrum oh HFrEF, including patients after acute myocardial infarction.

Conclusion:

Current evidence supports the central role of aldosterone in HFrEF progression, and the significant benefits on outcomes with the use of MRAs.

Future Anti-aldosterone Agents

Background:

Targeting the renin-angiotensin-aldosterone axis is one of the most important therapeutic pathways for blood pressure control, renal and cardiovascular protection.

Objective:

In this review, the new nonsteroidal mineralcorticoid receptor antagonists will be presented with a special focus on finerenone and its randomized controlled trials along with an introduction to the clinically promising aldosterone synthase inhibitors.

Method:

We conducted an in-detail review of the literature in order to draft a narrative review on the field.

Results:

Development of new anti-aldosterone agents focusing on the diverse components of aldosterone production and action is now taking place. Nonsteroidal mineralοcorticoid receptor antagonists are safe and effective therapeutic solutions with finerenone being the most well-studied agent with promising clinical data extending its efficacy in diabetes mellitus, chronic kidney disease and heart failure. Aldosterone synthase inhibitors impact the hormonal balance but there are still limitations regarding the duration of action and adverse effect of the glycolcorticoid axis.

Conclusion:

Novel third-generation, nonsteroidal mineralocorticoid receptor antagonists seem to offer great advantages, which may lead to a wider use of mineralocorticoid receptor antagonists. Future randomized controlled trials are needed to evaluate significant perspectives.

Mineralocorticoid Receptor Antagonists in Essential and Resistant Hypertension

Background:

Mineralocorticoid receptor antagonists are a second-line class of antihypertensive drugs, which have been accounted for as the optimal add-on therapy in the triple algorithm for the management of resistant hypertension.

Objectives:

To assess the effects of mineralocorticoid receptor antagonists in the treatment of patients with essential hypertension and resistant hypertension.

Method:

We conducted a meticulous review of the literature and comprehensive identification of the clinical trials assessing the efficacy of mineralocorticoid receptor antagonists in individuals with primary and resistant hypertension.

Results:

MRAs have been thoroughly tested in several clinical studies in relevance to blood pressure lowering effects, over the last six decades. Accumulating data observed that MRAs resulted in a significant reduction in blood pressure level in patients with resistant hypertension. In addition, spironolactone was found to beneficially affect the management of resistant hypertension.

Conclusion:

Mineralocorticoid receptor antagonists exert a significant antihypertensive effect. Future welldesigned randomized controlled studies are greatly needed to address crucial clinical aspects in the field.

Pharmacokinetics of the Novel, Selective, Non-steroidal Mineralocorticoid Receptor Antagonist Finerenone in Healthy Volunteers: Results from an Absolute Bioavailability Study and Drug-Drug Interaction Studies In Vitro and In Vivo

BACKGROUND AND OBJECTIVES

Finerenone is a selective, non-steroidal mineralocorticoid receptor antagonist. In vivo and in vitro studies were performed to assess absolute bioavailability of finerenone, the effect of metabolic enzyme inhibitors on the pharmacokinetics of finerenone and its metabolites, the quantitative contribution of the involved enzymes cytochrome P450 (CYP) 3A4 and CYP2C8 and the relevance of gut wall versus liver metabolism.

METHODS

The pharmacokinetics, safety and tolerability of finerenone (1.25-10 mg orally or 0.25-1.0 mg intravenously) were evaluated in healthy male volunteers in four crossover studies. Absolute bioavailability was assessed in volunteers receiving finerenone orally and by intravenous infusion (n = 15) and the effects of erythromycin (n = 15), verapamil (n = 13) and gemfibrozil (n = 16) on finerenone pharmacokinetics were investigated. Finerenone was also incubated with cryopreserved human hepatocytes in vitro in the presence of erythromycin, verapamil or gemfibrozil.

RESULTS

Finerenone absolute bioavailability was 43.5% due to first-pass metabolism in the gut wall and liver. The geometric mean AUC_0-∞ ratios of finerenone (drug + inhibitor/drug alone) were 3.48, 2.70 and 1.10 with erythromycin, verapamil and gemfibrozil, respectively. The contribution ratio of CYP3A4 to the metabolic clearance of finerenone derived from these values was 0.88-0.89 and was consistent with estimations based on in vitro data, with the remaining metabolic clearance due to CYP2C8 involvement.

CONCLUSION

Finerenone is predominantly metabolized by CYP3A4 in the gut wall and liver. Increases in systemic exposure upon concomitant administration of inhibitors of this isoenzyme are predictable and consistent with in vitro data. Inhibition of CYP2C8, the second involved metabolic enzyme, has no relevant effect on finerenone in vivo.

Role of Aldosterone in Renal Fibrosis

Aldosterone is a mineralocorticoid hormone, as its main renal effect has been considered as electrolyte and water homeostasis in the distal tubule, thus maintaining blood pressure and extracellular fluid homeostasis through the activation of mineralocorticoid receptor (MR) in epithelial cells. However, over the past decade, numerous studies have documented the significant role of aldosterone in the progression of chronic kidney disease (CKD) which has become a subject of interest. It is being studied that aldosterone can affect cardiovascular and renal system, thereby contributing to tissue inflammation, injury, glomerulosclerosis, and interstitial fibrosis. Aldosterone acts on renal vessels, renal cells (glomerular mesangial cells, podocytes, vascular smooth muscle cells, tubular epithelial cells, and interstitial fibroblasts), and infiltrating inflammatory cells, inducing reactive oxygen species (ROS) production, upregulated epithelial growth factor receptor (EGFR), and type 1 angiotensin (AT1) receptor expressions, and activating nuclear factor kappa B (NF-κB), activator protein-1 (AP-1), and EGFR to further promote cell proliferation, apoptosis, and proliferation. Phenotypic transformation of epithelial cells stimulates the expression of transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), osteopontin (OPN), and plasminogen activator inhibitor-1 (PAI-1), eventually leading to renal fibrosis. MR antagonisms are related to inhibition of aldosterone-mediated pro-inflammatory and pro-fibrotic effect. In this review, we will summarize the important role of aldosterone in the pathogenesis of renal injury and fibrosis, emphasizing on its multiple underlying mechanisms and advances in aldosterone research along with the potential therapeutics for targeting MR in a renal fibrosis.