Improvement in proteinuria with sodium-glucose cotransporter 2 inhibitors and esaxerenone treatment in patients with chronic allograft kidney disease: A case report

Proteinuria is a predictor of end-stage renal disease. The effectiveness of an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker for the reduction in urinary protein excretion and renoprotection in proteinuric chronic kidney disease patients is well known, and coadministration of and sodium-glucose cotransporter inhibitor and the mineralocorticoid receptor blocker eplerenone has recently demonstrated an additive albuminuria-lowering effect in chronic kidney disease patients. Proteinuria is also an independent predictor of end-stage renal disease in kidney transplant recipients. Sodium-glucose cotransporter 2 inhibitors were administered to a 60-year-old man with chronic allograft kidney disease who had increasing urinary protein excretion with valsartan treatment. Although urinary protein excretion decreased drastically, it later increased to the same levels. A nonsteroidal mineralocorticoid receptor blocker, esaxerenone, was added to these medications, again resulting in a decrease in urinary protein excretion. Although the long-term renoprotective effect is not known, these medicines are promising and safe agents to reduce urinary protein excretion in patients with chronic allograft kidney disease.

Mineralocorticoid receptor signaling inhibits bladder cancer progression

The biological or clinical significance of mineralocorticoid receptor (MR) in urothelial cancer remains largely unknown. The present study aimed to determine the functional role of MR in bladder cancer progression. In two of the human bladder cancer lines expressing MR, treatment with a natural MR ligand, aldosterone, significantly reduced cell proliferation and migration, which was restored by three MR antagonists clinically used, spironolactone (except colony formation of androgen receptor-positive cells cultured in the presence of androgens), eplerenone, and esaxerenone. Similarly, MR knockdown via shRNA virus infection resulted in significant increases in cell viability/migration, as well as colony formation, compared with control sublines. In addition, MR knockdown augmented the expression of β-catenin, c-fos, and N-cadherin, and lowered that of E-cadherin and p53, indicating the induction of the cadherin switching. Immunohistochemistry in surgical specimens detected MR signals in 58 (92.1%; 36.5% weakly-positive/1+, 44.4% moderately-positive/2+, and 11.1% strongly-positive/3+) of 63 muscle-invasive bladder cancers, which was significantly lower than in adjacent non-neoplastic urothelial tissues (100%; 15.7% 1+, 37.3% 2+, and 47.1% 3+). Moreover, patients with MR-high (3+) tumor had a significantly lower risk of cancer-specific mortality (P=0.039). Multivariable analysis further showed that strong MR expression was an independent predictor of cancer-specific survival in patients with muscle-invasive bladder cancer (hazard ratio 0.117, P=0.039). These findings suggest that MR signaling functions as a tumor suppressor in urothelial carcinoma and prevents tumor growth. Accordingly, there is a possibility that the concurrent use of anti-mineralocorticoids, particularly eplerenone and esaxerenone, in patients with bladder cancer rather contributes to the promotion of disease progression.

Non-steroidal mineralocorticoid receptor antagonists in patients with chronic kidney disease and type 2 diabetes

Chronic kidney disease (CKD) in patients with type 2 diabetes (T2D) is a major health challenge associated with a disproportionately high burden of end-stage renal disease, cardiovascular disease and death. This review summarizes the rationale, clinical evidence and practical implementation for non-steroidal mineralocorticoid receptor antagonists (nsMRAs), a drug class now approved and recommended for patients with T2D and CKD at risk of cardiorenal disease progression. Three nsMRAs (finerenone, esaxerenone and apararenone) have been evaluated but finerenone is currently the only approved nsMRA for this indication. Two large-scale, placebo-controlled, Phase 3 studies evaluated finerenone added to a maximally tolerated dose of an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker. Over >2 years of treatment, finerenone was associated with a significant reduction in composite endpoints of renal and cardiovascular outcomes versus placebo. Esaxerenone or apararenone have both shown significant improvements in albuminuria versus placebo. In general, nsMRAs were well tolerated. Hyperkalaemia was the most notable treatment-related adverse event and could generally be managed through serum potassium monitoring and dose adjustments. The nsMRAs are now an important component of recommended treatment for CKD associated with T2D, providing a significant reduction in the risk of cardiorenal progression beyond what can be achieved with glucose and blood pressure control.

Esaxerenone Protects against Diabetic Cardiomyopathy via Inhibition of the Chemokine and PI3K-Akt Signaling Pathway

(1) Background: Diabetic cardiomyopathy (DCM) is a unique form of cardiomyopathy that develops as a consequence of diabetes and significantly contributes to heart failure in patients. Esaxerenone, a selective non-steroidal mineralocorticoid receptor antagonist, has demonstrated potential in reducing the incidence of cardiovascular and renal events in individuals with chronic kidney and diabetes disease. However, the exact protective effects of esaxerenone in the context of DCM are still unclear. (2) Methods: The DCM model was successfully induced in mice by administering streptozotocin (55 mg/kg per day) for five consecutive days. After being fed a normal diet for 16 weeks, echocardiography was performed to confirm the successful establishment of the DCM model. Subsequent sequencing and gene expression analysis revealed significant differences in gene expression in the DCM group. These differentially expressed genes were identified as potential targets for DCM. By utilizing the Swiss Target Prediction platform, we employed predictive analysis to identify the potential targets of esaxerenone. A protein-protein-interaction (PPI) network was constructed using the common targets of esaxerenone and DCM. Enrichment analysis was conducted using Metascape. (3) Results: Compared to the control, the diabetic group exhibited impaired cardiac function and myocardial fibrosis. There was a total of 36 common targets, with 5 key targets. Enrichment analysis revealed that the chemokine and PI3K-Akt signaling pathway was considered a crucial pathway. A target-pathway network was established, from which seven key targets were identified. All key targets exhibited good binding characteristics when interacting with esaxerenone. (4) Conclusion: The findings of this study suggest that esaxerenone exhibits a favorable therapeutic effect on DCM, primarily by modulating the chemokine and PI3K-Akt signaling pathway.

Rationale and design of a multicenter randomized study comparing the efficacy and safety of esaxerenone versus trichlormethiazide in patients with uncontrolled essential hypertension: EXCITE-HT study

The next-generation mineralocorticoid receptor blocker (MRB) esaxerenone has favorable antihypertensive effects in patients who do not respond to treatment with first-line antihypertensive agents and may be beneficial as a second-line treatment. However, MRBs are currently considered a fourth-line treatment as there is no clinical evidence comparing the efficacy of esaxerenone with other classes of antihypertensive agents. The multicenter, randomized, open-label, parallel-group EXCITE-HT study will evaluate the efficacy and safety of esaxerenone as a second-line agent in the treatment of Japanese patients with uncontrolled essential hypertension. After a 4-week run-in period, patients will receive either esaxerenone or trichlormethiazide for 12 weeks per the package insert and the Japanese Society of Hypertension Guidelines for the Management of Hypertension. At Weeks 4 and 8, the dose of esaxerenone or trichlormethiazide may be increased. Blood pressure (home [morning and bedtime] and office), serum biomarkers, and urinary biomarkers will be measured. The primary efficacy endpoint is the change from baseline in morning home systolic blood pressure/diastolic blood pressure to the end of treatment. The EXCITE-HT study is expected to validate the non-inferiority of esaxerenone to trichlormethiazide and provide the first evidence for the early use of esaxerenone as a second-line agent in the treatment of Japanese patients with uncontrolled essential hypertension instead of its current use as a fourth-line agent.

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.

Protective role of mineralocorticoid receptor signaling in urothelial tumorigenesis

The expression status of mineralocorticoid receptor (MR) and its biological significance in human urothelial carcinoma remain unknown. The present study aimed to determine the functional role of MR in the development of urothelial cancer. In human normal urothelial SVHUC cells with exposure to a chemical carcinogen 3-methylcholanthrene (MCA), we assessed the effects of a natural MR ligand, aldosterone, and 3 MR antagonists, including spironolactone, eplerenone, and esaxerenone, as well as knockdown of MR via shRNA virus infection, on their neoplastic/malignant transformation. The in vitro system with carcinogen challenge showed that aldosterone and anti-mineralocorticoids significantly prevented and promoted, respectively, the neoplastic transformation of SVHUC cells. Similarly, MR knockdown in SVHUC cells considerably induced MCA-mediated neoplastic transformation, compared with a control subline. In addition, MR knockdown or antagonist treatment resulted in increases in the expression of β-catenin, c-Fos, and N-cadherin, and a decrease in that of E-cadherin. Meanwhile, spironolactone, which is known to possess anti-androgenic activity, rather suppressed the neoplastic transformation of a SVHUC subline stably expressing wild-type androgen receptor, indicating its dominant effect via the androgen receptor pathway. Immunohistochemistry in surgical specimens detected MR signals in 77 (98.7%; 23.1% weak/1+, 42.3% moderate/2+, and 33.3% strong/3+) of 78 non-invasive bladder tumors, which was significantly (P<0.001) lower than in adjacent non-neoplastic urothelial tissues (100%; 20.5% 2+ and 79.5% 3+). Moreover, the risks for disease recurrence after transurethral surgery were marginally lower in female patients with MR-high (2+/3+) tumor (P=0.068) and significantly lower in all patients with MR-high/glucocorticoid receptor-high tumor (P=0.025), compared with respective controls. These findings suggest that MR signaling functions as a suppressor for urothelial tumorigenesis.

Aldosterone, Mineralocorticoid Receptor Activation, and CKD: A Review of Evolving Treatment Paradigms

Mineralocorticoid receptor (MR) activation is involved in propagating kidney injury, inflammation, and fibrosis and in the progression of chronic kidney disease (CKD). Multiple clinical studies have defined the efficacy of MR antagonism in attenuating progressive kidney disease, and the US Food and Drug Administration recently approved the nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone for this indication. In this review, we consider the basic science and clinical applicability of MR antagonism. Because hyperkalemia constitutes a constraint to implementing evidence-based MR blockade, we review MRA-associated hyperkalemia in the context of finerenone and discuss evolving mitigation strategies to enhance the safety and efficacy of this treatment. Although the FIDELIO-DKD and FIGARO-DKD clinical trials focused solely on patients with type 2 diabetes mellitus, we propose that MR activation and the resulting inflammation and fibrosis act as a substantive pathogenetic mediator not only in people with diabetic CKD but also in those with CKD without diabetes. We close by briefly discussing both recently initiated and future clinical trials that focus on extending the attributes of MR antagonism to a wider array of nondiabetic kidney disorders, such as patients with nonalbuminuric CKD.

Reduction in the magnitude of serum potassium elevation in combination therapy with esaxerenone (CS-3150) and sodium-glucose co-transporter-2 inhibitor in patients with diabetic kidney disease: Subanalysis of two phase 3 studies

AIMS/INTRODUCTION

We evaluated the effect of co-administration of esaxerenone and a sodium-glucose cotransporter 2 (SGLT2) inhibitor on the magnitude of serum potassium elevation in Japanese patients with diabetic kidney disease.

MATERIALS AND METHODS

We conducted a prespecified subanalysis of data from two phase 3 studies: a multicenter, randomized, double-blind, placebo-controlled trial in patients with type 2 diabetes and microalbuminuria (J308); and a multicenter, single-arm, open-label trial in patients with type 2 diabetes and macroalbuminuria (J309). Changes in serum potassium levels during the studies and other measures were evaluated according to SGLT2 inhibitor use.

RESULTS

In both studies, time course changes in serum potassium levels, and incidence rates of serum potassium elevation were lower in patients with co-administration of SGLT2 inhibitor in both the placebo and esaxerenone groups than those without the inhibitor. In contrast, time course changes and mean percent changes from baseline in urinary albumin-to-creatinine ratio (UACR), the proportion of patients with albuminuria remission, and time course changes in blood pressure did not change with or without SGLT2 inhibitor, while UACR and blood pressure were reduced with esaxerenone. The blood glucose-lowering effect of SGLT2 inhibitor was not affected by esaxerenone.

CONCLUSIONS

In Japanese patients with type 2 diabetes and albuminuria treated with esaxerenone, concomitant use of SGLT2 inhibitor reduced the magnitude of serum potassium elevation without any change of its antihypertensive and albuminuria-suppressing effects. Co-administration of esaxerenone and SGLT2 inhibitor may be a beneficial treatment option for patients with diabetic kidney disease.

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 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.

Effect of the Nonsteroidal Mineralocorticoid Receptor Blocker, Esaxerenone, on Nocturnal Hypertension: A Post Hoc Analysis of the ESAX-HTN Study

BACKGROUND

Nocturnal hypertension is an important phenotype of abnormal diurnal blood pressure (BP) variability and a known risk marker for target organ damage and cardiovascular events. This study aimed to assess the differential BP-lowering effects of esaxerenone vs. eplerenone on nocturnal BP in hypertensive patients with different nocturnal dipping patterns.

METHODS

This was a post hoc analysis of the "Esaxerenone (CS-3150) Compared to Eplerenone in Patients with Essential Hypertension" study (NCT02890173), which was a phase 3, multicenter, randomized, controlled, double-blind, parallel-group clinical study conducted in Japan. Ambulatory BP monitoring data were collected.

RESULTS

Patients (n = 1,001) were randomized to esaxerenone 2.5 mg/day (n = 331) or 5 mg/day (n = 338), or eplerenone 50 mg/day (n = 332). Reductions in nighttime systolic BP (95% confidence interval) were significantly greater with 2.5 and 5 mg/day esaxerenone vs. eplerenone (-2.6 [-5.0, -0.2] and -6.4 mm Hg [-8.8, -4.0], respectively). Esaxerenone significantly reduced nighttime BP from baseline compared with eplerenone in non-dippers with previously uncontrolled BP. In addition, esaxerenone did not markedly alter nighttime BP in extreme dipper patients. In the esaxerenone 5 mg/day group, esaxerenone-induced decreases in nighttime BP were greater than eplerenone-induced decreases in older patients.

CONCLUSIONS

Esaxerenone may be an effective treatment option for nocturnal hypertension, especially in older patients and those with a non-dipper pattern of nocturnal BP.

Characterization of Direct Perturbations on Voltage-Gated Sodium Current by Esaxerenone, a Nonsteroidal Mineralocorticoid Receptor Blocker

Esaxerenone (ESAX; CS-3150, Minnebro^®) is known to be a newly non-steroidal mineralocorticoid receptor (MR) antagonist. However, its modulatory actions on different types of ionic currents in electrically excitable cells remain largely unanswered. The present investigations were undertaken to explore the possible perturbations of ESAX on the transient, late and persistent components of voltage-gated Na⁺ current (I_Na) identified from pituitary GH₃ or MMQ cells. GH₃-cell exposure to ESAX depressed the transient and late components of I_Na with varying potencies. The IC₅₀ value of ESAX required for its differential reduction in peak or late I_Na in GH₃ cells was estimated to be 13.2 or 3.2 μM, respectively. The steady-state activation curve of peak I_Na remained unchanged during exposure to ESAX; however, recovery of peak I_Na block was prolonged in the presence 3 μM ESAX. In continued presence of aldosterone (10 μM), further addition of 3 μM ESAX remained effective at inhibiting I_Na. ESAX (3 μM) potently reversed Tef-induced augmentation of I_Na. By using isosceles-triangular ramp pulse with varying durations, the amplitude of persistent I_Na measured at high or low threshold was enhanced by the presence of tefluthrin (Tef), in combination with the appearance of the figure-of-eight hysteretic loop; moreover, hysteretic strength of the current was attenuated by subsequent addition of ESAX. Likewise, in MMQ lactotrophs, the addition of ESAX also effectively decreased the peak amplitude of I_Na along with the increased current inactivation rate. Taken together, the present results provide a noticeable yet unidentified finding disclosing that, apart from its antagonistic effect on MR receptor, ESAX may directly and concertedly modify the amplitude, gating properties and hysteresis of I_Na in electrically excitable cells.

Cardioprotective Effects of a Nonsteroidal Mineralocorticoid Receptor Blocker, Esaxerenone, in Dahl Salt-Sensitive Hypertensive Rats

We investigated the effects of esaxerenone, a novel, nonsteroidal, and selective mineralocorticoid receptor blocker, on cardiac function in Dahl salt-sensitive (DSS) rats. We provided 6-week-old DSS rats a high-salt diet (HSD, 8% NaCl). Following six weeks of HSD feeding (establishment of cardiac hypertrophy), we divided the animals into the following two groups: HSD or HSD + esaxerenone (0.001%, w/w). In survival study, all HSD-fed animals died by 24 weeks of age, whereas the esaxerenone-treated HSD-fed animals showed significantly improved survival. We used the same protocol with a separate set of animals to evaluate the cardiac function by echocardiography after four weeks of treatment. The results showed that HSD-fed animals developed cardiac dysfunction as evidenced by reduced stroke volume, ejection fraction, and cardiac output. Importantly, esaxerenone treatment decreased the worsening of cardiac dysfunction concomitant with a significantly reduced level of systolic blood pressure. In addition, treatment with esaxerenone in HSD-fed DSS rats caused a reduced level of cardiac remodeling as well as fibrosis. Furthermore, inflammation and oxidative stress were significantly reduced. These data indicate that esaxerenone has the potential to mitigate cardiac dysfunction in salt-induced myocardial injury in rats.

Esaxerenone (CS-3150) in Patients with Type 2 Diabetes and Microalbuminuria (ESAX-DN): Phase 3 Randomized Controlled Clinical Trial

BACKGROUND AND OBJECTIVES

Diabetic kidney disease is an important complication of type 2 diabetes. In a phase 2b study, adding esaxerenone to renin-angiotensin system inhibitors dose dependently reduced the urinary albumin-to-creatinine ratio in patients with type 2 diabetes and microalbuminuria. This 52-week phase 3 study further investigated the effects of esaxerenone on the urinary albumin-to-creatinine ratio in this patient group.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this multicenter, randomized, double-blind study, patients with type 2 diabetes and a urinary albumin-to-creatinine ratio of 45 to <300 mg/g creatinine treated with renin-angiotensin system inhibitors were randomized to esaxerenone or placebo for 52 weeks (n=455). Esaxerenone was initiated at 1.25 mg/d and titrated to 2.5 mg/d on the basis of serum potassium monitoring. The primary endpoint was the proportion of patients achieving urinary albumin-to-creatinine ratio remission (<30 mg/g creatinine and ≥30% reduction from baseline on two consecutive occasions).

RESULTS

Overall, 49 (22%) and nine (4%) patients in the esaxerenone and placebo groups, respectively, achieved urinary albumin-to-creatinine ratio remission (absolute difference 18%; 95% confidence interval, 12% to 25%; P<0.001). The percent change in urinary albumin-to-creatinine ratio from baseline to end of treatment was significantly higher with esaxerenone versus placebo (-58% versus 8%; geometric least-squares mean ratio to placebo 0.38, 95% confidence interval, 0.33 to 0.44). There was a significant improvement with esaxerenone versus placebo in time to first remission (hazard ratio, 5.13; 95% confidence interval, 3.27 to 8.04) and time to first transition to urinary albumin-to-creatinine ratio ≥300 mg/g creatinine (hazard ratio, 0.23; 95% confidence interval, 0.11 to 0.48). More patients had a serum potassium level ≥6.0 or ≥5.5 mEq/L on two consecutive measurements in the esaxerenone group (20 [9%]) versus placebo (5 [2%]); these events were asymptomatic and resolved after dosage reduction or treatment discontinuation.

CONCLUSIONS

Adding esaxerenone to existing renin-angiotensin system inhibitor therapy in patients with type 2 diabetes and microalbuminuria increased the likelihood of albuminuria returning to normal levels, and reduced progression of albuminuria to higher levels.

Randomized, Double-Blind, Single-Dose, Placebo-Controlled Crossover Study to Evaluate the Effects of Esaxerenone on QTc Interval in Healthy Subjects

This phase 1 single-center, single-dose, double-dummy, placebo-controlled, 4-period and 4-sequence crossover study assessed the potential of esaxerenone, a novel nonsteroidal mineralocorticoid receptor blocker used to treat hypertension, to affect cardiac repolarization. In this double-blind study, 55 subjects were randomized to single doses of 10 mg esaxerenone (therapeutic dose), 40 mg esaxerenone (supratherapeutic dose), 400 mg moxifloxacin, or placebo. Serial electrocardiograms and pharmacokinetics (PK) were obtained over 24 and 168 hours, respectively. The primary end point was Fridericia-corrected QT interval (QTcF). Secondary end points included safety and PK. Assay sensitivity was confirmed as the lower limit of 90% confidence interval (90%CIs) for placebo-corrected change from baseline QTcF (∆∆QTcF) for moxifloxacin was >5 milliseconds at the prespecified times; mean ∆∆QTcF was 12.5 milliseconds at 3 and 4 hours postdose. The upper 90%CI limits of ∆∆QTcF were ≤0 milliseconds at all times for both doses of esaxerenone. No concentration-QTc relationship was identified. Therefore, esaxerenone had no potential to inhibit cardiac repolarization. No deaths or serious adverse events (AEs) occurred; 1 subject discontinued the study because of a treatment-emergent AE unrelated to esaxerenone. This clinical evaluation showed that esaxerenone has no QTc prolongation potential.

Crystal structure of the mineralocorticoid receptor ligand-binding domain in complex with a potent and selective nonsteroidal blocker, esaxerenone (CS-3150)

Activation of the mineralocorticoid receptor (MR) has long been considered a risk factor for cardiovascular diseases. It has been reported that the novel MR blocker esaxerenone shows high potency and selectivity for MR in vitro as well as great antihypertensive and renoprotective effects in salt-sensitive hypertensive rats. Here, we determined the cocrystal structure of the MR ligand-binding domain (MR-LBD) with esaxerenone and found that esaxerenone binds to MR-LBD in a unique manner with large side-chain rearrangements, distinct from those of previously published MR antagonists. This structure also displays an antagonist form that has not been observed for MR previously. Such a unique binding mode of esaxerenone provides great insight into the novelty, potency, and selectivity of this novel antihypertensive drug.

Double-Blind Randomized Phase 3 Study Comparing Esaxerenone (CS-3150) and Eplerenone in Patients With Essential Hypertension (ESAX-HTN Study)

Mineralocorticoid receptors (MRs) are implicated in the pathology of hypertension. MR blockers are recommended for the treatment of salt-sensitive or resistant hypertension. However, use of currently available MR blockers is limited by adverse events. This phase 3 multicenter, randomized, double-blind study compared the efficacy and safety of esaxerenone, a new selective nonsteroidal MR blocker, at 2.5 and 5 mg/day and eplerenone 50 mg/day in Japanese patients with essential hypertension. After a 4-week washout period, 1001 eligible adults with hypertension were randomized evenly to esaxerenone 2.5 or 5 mg/day or eplerenone 50 mg/day treatments, taken orally once daily for 12 weeks. Primary end points were changes in sitting systolic or diastolic blood pressure (BP) from baseline at the end of treatment. Esaxerenone 2.5 mg/day was noninferior to eplerenone for reductions in sitting and 24-hour BP. Reductions in BP with esaxerenone 5 mg/day were significantly greater than those with esaxerenone 2.5 mg/day. Changes in diurnal BP showed persistent 24-hour antihypertensive effects in all treatment groups. The proportions of patients achieving target sitting BP (<140/90 mm Hg) were 31.5%, 41.2%, and 27.5% with esaxerenone 2.5 and 5 mg/day and eplerenone 50 mg/day, respectively. Incidences of adverse events (all mild or moderate) were similar across treatment groups. These results indicate that esaxerenone is an effective and well-tolerated MR blocker in Japanese patients with essential hypertension, with BP-lowering activity at least equivalent to eplerenone. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT02890173.

Effects of the novel nonsteroidal mineralocorticoid receptor blocker, esaxerenone (CS-3150), on blood pressure and urinary angiotensinogen in low-renin Dahl salt-sensitive hypertensive rats

Herein, we studied the effects of the novel nonsteroidal selective mineralocorticoid receptor (MR) blocker, esaxerenone, on blood pressure and renal injury in Dahl salt-sensitive (DSS) rats. We also monitored intact urinary and total angiotensinogen (AGT). DSS rats were given a normal salt diet (NS: 0.4% NaCl, n = 10), a high-salt diet (HS: 8% NaCl, n = 10), HS + esaxerenone (1 mg/kg/day, p.o., n = 10), or HS + losartan (angiotensin II receptor blocker, 10 mg/kg/day, p.o., n = 10) for 6 weeks. Glomerular and tubulointerstitial tissues were obtained via a laser capture method. HS-treated DSS rats developed hypertension, albuminuria, and glomerular injury, which were associated with increased glomerular desmin staining and reduced mRNA levels of glomerular podocin and nephrin. HS-treated DSS rats also showed tubulointerstitial fibrosis with an increase in renal oxidative stress (4-hydroxynonenal staining). The urinary ((total AGT-intact AGT)/intact AGT) ratio, an indicator of intrarenal renin activity, was significantly suppressed in HS-treated DSS rats. Treatment with esaxerenone significantly decreased blood pressure, while losartan did not. Furthermore, esaxerenone attenuated the development of albuminuria, glomerular injury, and tubulointerstitial fibrosis more than losartan did, and this effect was associated with reduced renal oxidative stress. These data indicate that esaxerenone has antihypertensive and renal protective effects in salt-dependent hypertensive mice with suppressed intrarenal renin activity, as indicated by low levels of the urinary (total AGT-intact AGT)/intact AGT ratio.

Single- and multiple-dose escalation study to assess pharmacokinetics, pharmacodynamics and safety of oral esaxerenone in healthy Japanese subjects

AIMS

To characterize the pharmacokinetics, pharmacodynamics and safety of esaxerenone, a mineralocorticoid receptor antagonist, in healthy adult Japanese men.

METHODS

Double-blind, placebo-controlled, sequential, dose-escalation studies were conducted in subjects randomized to receive oral once-daily esaxerenone (ranges: 5-200 mg [single-dose]; 10-100 mg over 10 days [multiple-dose]) or placebo under fasting conditions. Plasma concentrations were analysed by liquid chromatograph-tandem mass spectrometry. Pharmacokinetic parameters were determined by noncompartment analysis. Plasma/urine levels of pharmacodynamic biomarkers for mineralocorticoid receptor activity were evaluated.

RESULTS

In total, 48/48 and 39/40 subjects completed the single- and multiple-dose studies, respectively. Exposures were generally dose-proportional. The t_max , t_1/2 and CL/F remained unchanged, independent of dose; the respective ranges were 1.5-4.0 h, 22.3-25.1 h, and 4.0-5.2 l h^-1 (multiple-dose study). V_z /F ranged from 136.5 to 283.7 l in the multiple-dose study, and exposure reached steady state by day 4. The mean observed accumulation ratio, by dose, ranged from 1.36-1.98. The urinary Na⁺ /K⁺ ratio increased after single-dose administration; however, its relationship to the doses tested remains unclear. Plasma renin activity, active renin concentration and aldosterone concentration increased dose-dependently. Although blood potassium levels increased dose-dependently in the multiple-dose study (reaching a maximum mean ± standard deviation of 4.63 ± 0.354 mmol l^-1 in the 100-mg group), no safety/tolerability-related problems were detected in either study.

CONCLUSIONS

Exposure levels in healthy adults receiving esaxerenone were generally dose-proportional. Dose-dependent changes in plasma pharmacodynamic biomarkers for the mineralocorticoid receptor were identified during multiple-dose treatment and support the pharmacological activity of esaxerenone. No important safety concerns were identified.

30 YEARS OF THE MINERALOCORTICOID RECEPTOR: Mineralocorticoid receptor antagonists: 60 years of research and development

The cDNA of the mineralocorticoid receptor (MR) was cloned 30 years ago, in 1987. At that time, spirolactone, the first generation of synthetic steroid-based MR antagonists (MRAs), which was identified in preclinical in vivo models, had already been in clinical use for 30 years. Subsequent decades of research and development by Searle & Co., Ciba-Geigy, Roussel Uclaf and Schering AG toward identifying a second generation of much more specific steroidal MRAs were all based on the initial 17-spirolactone construct. The salient example is eplerenone, first described in 1987, coincidentally with the cloning of MR cDNA. Its launch on the market in 2003 paralleled intensive drug discovery programs for a new generation of non-steroidal MRAs. Now, 30 years after the cDNA cloning of MR and 60 years of clinical use of steroidal MRAs, novel non-steroidal MRAs such as apararenone, esaxerenone and finerenone are in late-stage clinical trials in patients with heart failure, chronic kidney disease (CKD), hypertension and liver disease. Finerenone has already been studied in over 2000 patients with heart failure plus chronic kidney disease and/or diabetes, and in patients with diabetic kidney disease, in five phase II clinical trials. Here, we reflect on the history of the various generations of MRAs and review characteristics of the most important steroidal and non-steroidal MRAs.