Peter Kolkhof

Effect of Finerenone on Albuminuria in Patients With Diabetic Nephropathy: A Randomized Clinical Trial

IMPORTANCEnSteroidal mineralocorticoid receptor antagonists, when added to a renin-angiotensin system blocker, further reduce proteinuria in patients with chronic kidney disease but may be underused because of a high risk of adverse events.nnnOBJECTIVEnTo evaluate the safety and efficacy of different oral doses of the nonsteroidal mineralocorticoid receptor antagonist finerenone, given for 90 days to patients with diabetes and high or very high albuminuria who are receiving an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker.nnnDESIGN, SETTING, AND PARTICIPANTSnRandomized, double-blind, placebo-controlled, parallel-group study conducted at 148 sites in 23 countries. Patients were recruited from June 2013 to February 2014 and the study was completed in August 2014. Of 1501 screened patients, 823 were randomized and 821 received study drug.nnnINTERVENTIONSnParticipants were randomly assigned to receive oral, once-daily finerenone (1.25 mg/d, nu2009=u200996; 2.5 mg/d, nu2009=u200992; 5 mg/d, nu2009=u2009100; 7.5 mg/d, nu2009=u200997; 10 mg/d, nu2009=u200998; 15 mg/d, nu2009=u2009125; and 25 mg/d, nu2009=u2009119) or matching placebo (nu2009=u200994) for 90 days.nnnMAIN OUTCOMES AND MEASURESnThe primary outcome was the ratio of the urinary albumin-creatinine ratio (UACR) at day 90 vs at baseline. Safety end points were changes from baseline in serum potassium and estimated glomerular filtration rate.nnnRESULTSnThe mean age of the participants was 64.2 years; 78% were male. At baseline, 36.7% of patients treated had very high albuminuria (UACR ≥300 mg/g) and 40.0% had an estimated glomerular filtration rate of 60 mL/min/1.73 m2 or lower. Finerenone demonstrated a dose-dependent reduction in UACR. The primary outcome, the placebo-corrected mean ratio of the UACR at day 90 relative to baseline, was reduced in the finerenone 7.5-, 10-, 15-, and 20-mg/d groups (for 7.5 mg/d, 0.79 [90% CI, 0.68-0.91; Pu2009=u2009.004]; for 10 mg/d, 0.76 [90% CI, 0.65-0.88; Pu2009=u2009.001]; for 15 mg/d, 0.67 [90% CI, 0.58-0.77; P<.001]; for 20 mg/d, 0.62 [90% CI, 0.54-0.72; Pu2009<u2009.001]). The prespecified secondary outcome of hyperkalemia leading to discontinuation was not observed in the placebo and finerenone 10-mg/d groups; incidences in the finerenone 7.5-, 15-, and 20-mg/d groups were 2.1%, 3.2%, and 1.7%, respectively. There were no differences in the incidence of the prespecified secondary outcome of an estimated glomerular filtration rate decrease of 30% or more or in incidences of adverse events and serious adverse events between the placebo and finerenone groups.nnnCONCLUSIONS AND RELEVANCEnAmong patients with diabetic nephropathy, most receiving an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker, the addition of finerenone compared with placebo resulted in improvement in the urinary albumin-creatinine ratio. Further trials are needed to compare finerenone with other active medications.nnnTRIAL REGISTRATIONnclinicaltrials.gov Identifier: NCT1874431.

Sulfenic Acid Modification of Endothelin B Receptor is Responsible for the Benefit of a Nonsteroidal Mineralocorticoid Receptor Antagonist in Renal Ischemia

AKI is associated with high mortality rates and the development of CKD. Ischemia/reperfusion (IR) is an important cause of AKI. Unfortunately, there is no available pharmacologic approach to prevent or limit renal IR injury in common clinical practice. Renal IR is characterized by diminished nitric oxide bioavailability and reduced renal blood flow; however, the mechanisms leading to these alterations are poorly understood. In a rat model of renal IR, we investigated whether the administration of the novel nonsteroidal mineralocorticoid receptor (MR) antagonist BR-4628 can prevent or treat the renal dysfunction and tubular injury induced by IR. Renal injury induced by ischemia was associated with increased oxidant damage, which led to a cysteine sulfenic acid modification in endothelin B receptor and consequently decreased endothelial nitric oxide synthase activation. These modifications were efficiently prevented by nonsteroidal MR antagonism. Furthermore, we demonstrated that the protective effect of BR-4628 against IR was lost when a selective endothelin B receptor antagonist was coadministered. These data describe a new mechanism for reduced endothelial nitric oxide synthase activation during renal IR that can be blocked by MR antagonism with BR-4628.

A Randomized Controlled Study of Finerenone vs. Eplerenone in Japanese Patients With Worsening Chronic Heart Failure and Diabetes and/or Chronic Kidney Disease

BACKGROUNDnFinerenone, a nonsteroidal mineralocorticoid receptor antagonist, was evaluated in Japanese patients with heart failure (HF) with reduced ejection fraction and chronic kidney disease and/or diabetes mellitus.nnnMETHODSANDRESULTSnARTS-HF Japan was a randomized, double-blind, phase 2b study. Patients (n=72) received oral, once-daily (o.d.) finerenone (2.5, 5, 7.5, 10 or 15 mg, up-titrated to 5, 10, 15, 20, or 20 mg, respectively, on day 30) or eplerenone (25 mg every other day, increased to 25 mg o.d. on day 30, and 50 mg on day 60) for 90 days. The primary endpoint was the proportion of individuals with a decrease of >30% in plasma NT-proBNP at day 90. Safety endpoints included the incidence of hyperkalemia. Decreases in NT-proBNP occurred in 23.1% of patients in the eplerenone group and 15.4%, 23.1%, 45.5%, 27.3% and 45.5% in the 2.5→5 mg, 5→10 mg, 7.5→15 mg, 10→20 mg and 15→20 mg finerenone groups, respectively (all P=NS). Mean changes in serum potassium levels were similar between groups.nnnCONCLUSIONSnBecause of the small sample size, limited conclusions can be drawn. Considering the results of ARTS-HF and that finerenone was well tolerated in Japanese patients in ARTS-HF Japan, the safety and efficacy of finerenone should be further explored in a large outcomes trial including Japanese patients. (Circ J 2016; 80: 1113-1122).

Differentiation of arginine vasopressin antagonistic effects by selective V2 versus dual V2/V1a receptor blockade in a preclinical heart failure model.

Arginine vasopressin (AVP) is increased in patients with heart failure (HF). Its actions are linked to free water reabsorption (V2-) and arteriolar vasoconstriction (V1a receptor). AVP can exacerbate the cardiorenal syndrome with excess fluid retention and afterload increase. Tolvaptan (TOL; selective V2 antagonist) and Conivaptan (CON; dual V1a/V2 antagonist) are two AVP antagonists that counteract the action of AVP with distinct profiles. We investigated the therapeutic effects of CON and TOL in an acute HF model. Mongrel dogs were paced continuously at 220 beats/min. After 14 days, the animals underwent acute testing. Dogs were instrumented to measure cardiac output, blood pressure, pulmonary artery pressure, and left ventricular dP/dtmax. Additionally, during the acute experiments, vasopressin was infused intravenously (4 mU/kg/min) to achieve constant and controlled pathophysiological levels of AVP. Subsequently, animals received either CON or TOL (n = 6; 0.1-mg/kg bolus). There were no significant differences in effect on mean arterial pressure, dP/dtmax, central venous pressure, and urine output between CON and TOL. In contrast, cardiac output increased by 0.15 l/min after CON and decreased by 0.6 l/min after TOL (P < 0.01). Accordingly, the total peripheral resistance increased after TOL by 250 dyn*s/cm5 and decreased after CON by 125 dyn*s/cm5 (P < 0.01). In conclusion, it was demonstrated that in an acute HF model, CON lowered, whereas TOL increased afterload. The results suggest that dual V1a/V2 blockade in the acute HF setting could be beneficial compared with selective V2 blockade. Chronic experiments are needed to determine whether this finding can translate into a sustained clinical advantage.

Cardiac glycosides potently inhibit C-reactive protein synthesis in human hepatocytes.

Elevated plasma levels of C-reactive protein (CRP), the prototype acute-phase protein (APP), are predictive for future cardiovascular events. Controversial evidence suggests that CRP may play a causal role in cardiovascular disease. CRP synthesis inhibition is a potential approach for reducing cardiovascular mortality. We show here that endogenous and plant-derived inhibitors of the Na(+)/K(+)-ATPase, i.e. the cardiac glycosides ouabain and digitoxin, inhibit IL-1beta- and IL-6-induced APP expression in human hepatoma cells and primary human hepatocytes (PHH) at nanomolar concentrations. Inhibition is demonstrated on transcriptional and on protein level. The molecular target of cardiac glycosides, i.e. the alpha1 subunit of the Na(+)/K(+)-ATPase, is strongly expressed in human hepatocytes. Inhibition of APP synthesis correlates with the potency of cardiac glycosides at the Na(+)/K(+)-ATPase. The trigger for APP expression inhibition is an increase in intracellular calcium since the calcium ionophore calcimycin is also active. Qualified specificity of oubain for hepatocellular APP synthesis inhibition is demonstrated by lack of effectivity on IL-1beta-induced IL-6 release from primary human coronary artery smooth muscle cells. The inhibitory activity of cardiac glycosides on CRP expression may have important implications for the treatment of cardiovascular disease. Cardiac glycosides may be used for CRP synthesis inhibition in the future.

Suppression of rapidly progressive mouse glomerulonephritis with the non-steroidal mineralocorticoid receptor antagonist BR-4628

Background/Aim Steroidal mineralocorticoid receptor antagonists (MRAs) are effective in the treatment of kidney disease; however, the side effect of hyperkalaemia, particularly in the context of renal impairment, is a major limitation to their clinical use. Recently developed non-steroidal MRAs have distinct characteristics suggesting that they may be superior to steroidal MRAs. Therefore, we explored the benefits of a non-steroidal MRA in a model of rapidly progressive glomerulonephritis. Methods Accelerated anti-glomerular basement membrane (GBM) glomerulonephritis was induced in groups of C57BL/6J mice which received no treatment, vehicle or a non-steroidal MRA (BR-4628, 5mg/kg/bid) from day 0 until being killed on day 15 of disease. Mice were examined for renal injury. Results Mice with anti-GBM glomerulonephritis which received no treatment or vehicle developed similar disease with severe albuminuria, impaired renal function, glomerular tuft damage and crescents in 40% of glomeruli. In comparison, mice which received BR-4628 displayed similar albuminuria, but had improved renal function, reduced severity of glomerular tuft lesions and a 50% reduction in crescents. The protection seen in BR-4628 treated mice was associated with a marked reduction in glomerular macrophages and T-cells and reduced kidney gene expression of proinflammatory (CCL2, TNF-α, IFN-γ) and profibrotic molecules (collagen I, fibronectin). In addition, treatment with BR-4626 did not cause hyperkalaemia or increase urine Na+/K+ excretion (a marker of tubular dysfunction). Conclusions The non-steroidal MRA (BR-4628) provided substantial suppression of mouse crescentic glomerulonephritis without causing tubular dysfunction. This finding warrants further investigation of non-steroidal MRAs as a therapy for inflammatory kidney diseases.

Finerenone Attenuates Endothelial Dysfunction and Albuminuria in a Chronic Kidney Disease Model by a Reduction in Oxidative Stress

Albuminuria is an early marker of renovascular damage associated to an increase in oxidative stress. The Munich Wistar Frömter (MWF) rat is a model of chronic kidney disease (CKD), which exhibits endothelial dysfunction associated to low nitric oxide availability. We hypothesize that the new highly selective, non-steroidal mineralocorticoid receptor (MR) antagonist, finerenone, reverses both endothelial dysfunction and microalbuminuria. Twelve-week-old MWF (MWF-C; MWF-FIN) and aged-matched normoalbuminuric Wistar (W-C; W-FIN) rats were treated with finerenone (FIN, 10 mg/kg/day p.o.) or vehicle (C) for 4-week. Systolic blood pressure (SBP) and albuminuria were determined the last day of treatment. Finerenone lowered albuminuria by >40% and significantly reduced SBP in MWF. Aortic rings of MWF-C showed higher contractions to either noradrenaline (NA) or angiotensin II (Ang II), and lower relaxation to acetylcholine (Ach) than W-C rings. These alterations were reversed by finerenone to W-C control levels due to an upregulation in phosphorylated Akt and eNOS, and an increase in NO availability. Apocynin and 3-amino-1,2,4-triazole significantly reduced contractions to NA or Ang II in MWF-C, but not in MWF-FIN rings. Accordingly, a significant increase of Mn-superoxide dismutase (SOD) and Cu/Zn-SOD protein levels were observed in rings of MWF-FIN, without differences in p22phox, p47phox or catalase levels. Total SOD activity was increased in kidneys from MWF-FIN rats. In conclusion, finerenone improves endothelial dysfunction through an enhancement in NO bioavailability and a decrease in superoxide anion levels due to an upregulation in SOD activity. This is associated with an increase in renal SOD activity and a reduction of albuminuria.

0278 : Mineralocorticoid receptor antagonism with BR-4628 protects against renal injury induced by ischemia/reperfusion

Introduction The main cause of acute kidney injury (AKI) is ischemia/ reperfusion (IR). AKI has been associated with chronic kidney disease progression and cardiac alterations. Previous studies showed that in a rat model of kidney IR, mineralocorticoid receptor (MR) antagonism with spironolactone prevents tubular injury and renal dysfunction. Despite their benefits in renal diseases, the current MR antagonists have strong limitations like hyperkalemia, thus motivating the search of novel antagonists with safer profile. Objective Test the efficacy of the non-steroidal MR antagonist BR-4628 against renal injury induced by IR. Methods Twenty male wistar rats were divided in 4 groups: sham-operated (S), bilateral renal ischemia (IR) for 25min, treated with BR-4628 (10mg/kg) either 3 days before IR (B10-pre) or 3 hours after IR (B10-post). All groups were studied 24h after reperfusion. Blood sample was taken for creatinine and urea quantification. The right kidney was processed for molecular studies and the left for histopathological analysis. Results Rats with IR developed renal injury characterized by renal dysfunction, increase in tubular injury markers (Hsp72 and Kim-1), oxidized proteins and pro-inflammatory cytokines. These alterations were absent in the B10-pre and B10-post IR groups. IR induced an increased expression of the M1 macrophage markers iNOS, CCL3, TNF-alpha and MCP-1 (inflammatory phenotype) that was fully prevented with the BR-4628 pre-treatment. Furthermore we observed that in the B10-pre and B10-post groups there was a greater expression of M2 macrophage markers; IL4r, FIZZ1 and Igfr2 (wound healing phenotype), as compared to the non-treated IR group. Conclusion We show for the first time that the non-steroidal BR-4628 MR antagonist is effective to prevent or treat renal injury induced by IR possibly through a mechanism involving macrophage polarization towards the wound healing phenotype.