Does the temporary decrease in the estimated glomerular filtration rate (eGFR) after initiation of mineralocorticoid receptor (MR) antagonist treatment lead to a long-term renal protective effect?

A Shared Nephroprotective Mechanism for Renin-Angiotensin-System Inhibitors, Sodium-Glucose Co-Transporter 2 Inhibitors, and Vasopressin Receptor Antagonists: Immunology Meets Hemodynamics

A major paradigm in nephrology states that the loss of filtration function over a long time is driven by a persistent hyperfiltration state of surviving nephrons. This hyperfiltration may derive from circulating immunological factors. However, some clue about the hemodynamic effects of these factors derives from the effects of so-called nephroprotective drugs. Thirty years after the introduction of Renin-Angiotensin-system inhibitors (RASi) into clinical practice, two new families of nephroprotective drugs have been identified: the sodium-glucose cotransporter 2 inhibitors (SGLT2i) and the vasopressin receptor antagonists (VRA). Even though the molecular targets of the three-drug classes are very different, they share the reduction in the glomerular filtration rate (GFR) at the beginning of the therapy, which is usually considered an adverse effect. Therefore, we hypothesize that acute GFR decline is a prerequisite to obtaining nephroprotection with all these drugs. In this study, we reanalyze evidence that RASi, SGLT2i, and VRA reduce the eGFR at the onset of therapy. Afterward, we evaluate whether the extent of eGFR reduction correlates with their long-term efficacy. The results suggest that the extent of initial eGFR decline predicts the nephroprotective efficacy in the long run. Therefore, we propose that RASi, SGLT2i, and VRA delay kidney disease progression by controlling maladaptive glomerular hyperfiltration resulting from circulating immunological factors. Further studies are needed to verify their combined effects.

Improving the residual risk of renal and cardiovascular outcomes in diabetic kidney disease: A review of pathophysiology, mechanisms, and evidence from recent trials

Based on global estimates, almost 10% of adults have diabetes, of whom 40% are estimated to also have chronic kidney disease (CKD). Almost 2 decades ago, treatments targeting the renin-angiotensin system (RAS) were shown to slow the progression of kidney disease. More recently, studies have reported the additive benefits of antihyperglycaemic sodium-glucose co-transporter-2 inhibitors in combination with RAS inhibitors on both CKD progression and cardiovascular outcomes. However, these recent data also showed that patients continue to progress to kidney failure or die from kidney- or cardiovascular-related causes. Therefore, new agents are needed to address this continuing risk. Overactivation of the mineralocorticoid (MR) receptor contributes to kidney inflammation and fibrosis, suggesting that it is an appropriate treatment target in patients with diabetes and CKD. Novel, selective non-steroidal MR antagonists are being studied in these patients, and the results of two large recently completed clinical trials have shown that one such treatment, finerenone, significantly reduces CKD progression and cardiovascular events compared with standard of care. This review summarizes the pathogenic mechanisms of CKD in type 2 diabetes and examines the potential benefit of novel disease-modifying agents that target inflammatory and fibrotic factors in these patients.

Safety and efficacy of esaxerenone in Japanese hypertensive patients with heart failure with reduced ejection fraction: A retrospective study

Esaxerenone, a mineralocorticoid receptor blocker (MRB), is a new antihypertensive agent. However, esaxerenone-related data with respect to hypertension with heart failure are limited. We investigated the safety and efficacy of esaxerenone in hypertensive patients with heart failure with reduced ejection fraction (HFrEF). Hypertensive patients with HFrEF treated with esaxerenone were retrospectively analyzed at two timepoints (short-term: 35±15 days; mid-term: 167±45 days). Adverse events including hyperkalemia (K⁺ >5.5 mEq/L), worsening renal function (WRF; estimated glomerular filtration rate (eGFR) reduction by ≥20%), and hypotension (systolic blood pressure <90 mmHg) were evaluated. eGFR and K⁺, serum creatinine, and brain natriuretic peptide (BNP) levels at baseline, short-term, and mid-term assessments were compared. Patients administered esaxerenone as their first MRB (first-MRB cohort) and those who converted from another MRB (conversion cohort) were separately analyzed. There were 50 (56±10 years old, 26% female) patients. At the short-term assessment, hyperkalemia or hypotension was not observed at a dose of 2.0±0.9 mg/day. Seven patients (14%) showed WRF. K⁺ was slightly elevated (4.12±0.41 to 4.25±0.39 mmol/L, p = 0.07) and eGFR was significantly reduced (66.9±19.6 mL/min/1.73 m² to 62.4±19.7 mL/min/1.73 m², p = 0.006). In the conversion cohort, significant changes in K⁺ and eGFR from baseline were not observed at the short-term assessment. BNP levels were consistently improved regardless of the cohorts (first-MRB cohort, 310 [110–370] pg/mL to 137 [47–152] pg/mL, p = 0.001; conversion cohort, 181 [30–203] pg/mL to 108 [26–146] pg/mL, p = 0.028). At the mid-term assessment, there were no significant changes in K⁺ and eGFR compared with the short-term assessment. In conclusion, esaxerenone was safe for hypertensive patients with HFrEF. Hyperkalemia and hypotension were rarely noted, while eGFR was marginally reduced. Moreover, esaxerenone might be beneficial for HFrEF in terms of BNP level reduction.

Renoprotective Effect of the Mineralocorticoid Receptor Antagonist Esaxerenone

Background: The effects of mineralocorticoid receptor antagonists, including the newly introduced esaxerenone, on renal function remain uncertain.

Methods and Results: This retrospective study was performed on patients who received esaxerenone for resistant hypertension between November 2019 and June 2020. Trends in the estimated glomerular filtration rate (eGFR) were compared between the 6-month period before esaxerenone treatment (pre-treatment period) and the 6-month treatment period on esaxerenone. Twenty-six patients (15 men), with a median age of 70 years (interquartile range [IQR] 51–73 years) and a median systolic blood pressure of 146 mmHg (IQR 139–156 mmHg), were included in the study and completed 6 months of esaxerenone therapy without any adverse events. eGFR decreased significantly during the pre-treatment period (from 66.6 to 59.5 mL/min/1.73 m²; P=0.003), whereas eGFR was unchanged during the treatment period (from 59.5 to 61.8 mL/min/1.73 m²; P=0.15). The median change in eGFR differed significantly between the treatment and pre-treatment periods (3.8 [IQR −4.2, 6.8] vs. −6.1 [IQR −11.1, 1.8] mL/min/1.73 m², respectively; P=0.008).

Conclusions: Esaxerenone may have renoprotective effects when administered to treat hypertension. Further studies are needed to understand which patient populations may see greater renoprotective benefits with esaxerenone.

Antihypertensive effects and safety of esaxerenone in patients with moderate kidney dysfunction

Renin–angiotensin system inhibitors are recommended for treating hypertension with chronic kidney disease. The addition of a mineralocorticoid receptor blocker may be one option to achieve target blood pressure. We investigated the efficacy and safety of esaxerenone, a mineralocorticoid receptor blocker, in Japanese hypertensive patients with moderate kidney dysfunction. Two multicenter, open-label, nonrandomized dose escalation studies were conducted to investigate esaxerenone monotherapy and add-on therapy to renin–angiotensin system inhibitor treatment. Esaxerenone therapy was initiated at 1.25 mg/day and titrated to 2.5 and then 5 mg/day for a treatment duration of 12 weeks. Primary endpoints were changes from baseline in sitting systolic and diastolic blood pressure. Safety, pharmacokinetics, and urinary albumin-to-creatinine ratios were also assessed. Thirty-three patients received monotherapy, and 58 received add-on therapy; the mean baseline estimated glomerular filtration rates were 51.9 and 50.9 mL/min/1.73 m², respectively. The esaxerenone dosage was increased to ≥2.5 mg/day in 100% (n = 33) and 93.1% (n = 54) of patients receiving monotherapy and add-on therapy, respectively. Reductions in sitting blood pressure from baseline to the end of treatment were similar (monotherapy: −18.5/−8.8 mmHg; add-on therapy: −17.8/−8.1 mmHg; both P < 0.001). The antihypertensive effects of esaxerenone were consistent across patient subgroups. A serum K⁺ level ≥5.5 mEq/L was observed in seven patients (12.1%) receiving add-on therapy but in none receiving monotherapy. All increases in serum K⁺ levels were transient, and no patient met predefined serum K⁺ level criteria for dose reduction or therapy discontinuation. No patient discontinued treatment owing to kidney function decline. Esaxerenone was effective and well tolerated in hypertensive patients with moderate kidney dysfunction.

Novel antihypertensive action of rutin is mediated via inhibition of angiotensin converting enzyme/mineralocorticoid receptor/angiotensin 2 type 1 receptor (ATR1) signaling pathways in uninephrectomized hypertensive rats

Hypertension is the most common cardiovascular disease that affects approximately 26% of adult population, worldwide. Rutin is one of the important flavonoids that is consumed in the daily diet, and found in many food items, vegetables, and beverages. Uninephrectomy (UNX) of the left kidney was performed, followed by induction of hypertension. The rats were randomly divided into four groups of 10 rats: group 1-Sham-operated rats; group 2-UNX rats, group 3-UNX-L-NAME (40 mg/kg) plus rutin (100 mg/kg bwt), and groups 4-UNX-L-NAME plus lisinopril (10 mg/kg bwt), orally for 3 weeks. Results revealed significant heightening of arterial pressure and oxidative stress indices, while hypertensive rats treated with rutin had lower expressions of angiotensin converting enzyme (ACE) and mineralocorticoid receptor in uninephrectomized rats. Together, rutin as a novel antihypertensive flavonoid could provide an unimaginable benefits for the management of hypertension through inhibition of angiotensin converting enzyme and mineralocorticoid receptor. PRACTICAL APPLICATIONS: Hypertension has been reported to be the most common cardiovascular disease, affecting approximately 26% of the adult population worldwide with predicted prevalence to increase by 60% by 2025. Recent advances in phytomedicine have shown flavonoids to be very helpful in the treatment of many diseases. Flavonoids have been used in the treatment and management of cardiovascular diseases, obesity and hypertension. The study revealed that rutin, a known flavonoid inhibited angiotensin converting enzyme (ACE), angiotensin 2 type 1 receptor (ATR1), and mineralocorticoid receptor (MCR), comparable to the classic ACE inhibitor, Lisinopril, indicating the novel antihypertensive property of rutin. Therefore, flavonoids such as rutin found in fruits and vegetables could, therefore, serve as an antihypertensive drug regimen. Combining all, functional foods rich in flavonoids could be used as potential therapeutic candidates for managing uninephrectomized hypertensive patients.

Apararenone in patients with diabetic nephropathy: results of a randomized, double-blind, placebo-controlled phase 2 dose-response study and open-label extension study

Background

We investigated the efficacy and safety of apararenone (MT-3995), a non-steroidal compound with mineralocorticoid receptor agonist activity, in patients with stage 2 diabetic nephropathy (DN).

Methods

The study had two parts: a dose–response, parallel-group, randomized, double-blind, placebo-controlled, multicenter, phase 2, 24-week study and an open-label, uncontrolled, 28-week extension study. Primary and secondary endpoints were the 24-week percent change from baseline in urine albumin to creatine ratio (UACR) and 24- and 52-week UACR remission rates. Safety parameters were changes from baseline in estimated glomerular filtration rate (eGFR) and serum potassium at 24 and 52 weeks, and incidences of adverse events (AEs) and adverse drug reactions (ADRs).

Results

In the dose–response period, 73 patients received placebo and 73, 74, and 73 received apararenone 2.5 mg, 5 mg, and 10 mg, respectively. As a percentage of baseline, mean UACR decreased to 62.9%, 50.8%, and 46.5% in the 2.5 mg, 5 mg, and 10 mg apararenone groups, respectively, at week 24 (placebo: 113.7% at week 24; all P < 0.001 vs placebo). UACR remission rates at week 24 were 0.0%, 7.8%, 29.0%, and 28.1% in the placebo and apararenone 2.5 mg, 5 mg, and 10 mg groups, respectively. eGFR tended to decrease and serum potassium tended to increase, but these events were not clinically significant. AE incidence increased with dose while ADR incidence did not.

Conclusion

The UACR-lowering effect of apararenone administered once daily for 24 weeks in patients with stage 2 DN was confirmed, and the 52-week administration was safe and tolerable.

Clinical trial registration

NCT02517320 (dose–response study) and NCT02676401 (extension study)

Electronic supplementary material

The online version of this article (10.1007/s10157-020-01963-z) contains supplementary material, which is available to authorized users.