Esaxerenone and eGFR Changes in Patients with Diabetic Kidney Disease: A Comprehensive Review

Abstract

Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD) worldwide, presenting a major clinical challenge in diabetes management. Esaxerenone, a selective non-steroidal mineralocorticoid receptor antagonist (MRA), has emerged as a promising therapeutic agent for patients with DKD. This review evaluates the impact of esaxerenone on estimated glomerular filtration rate (eGFR) changes in DKD patients, synthesizing recent clinical evidence, mechanistic insights, and practical considerations for nephrologists and endocrinologists. We discuss epidemiology, pathophysiology, risk factors, clinical features, diagnostic approaches, treatment paradigms, recent advances, current guideline recommendations, and the clinical significance of eGFR trajectories in DKD patients treated with esaxerenone.

Introduction

Diabetic kidney disease (DKD) affects up to 40% of patients with diabetes mellitus and is a principal driver of morbidity and mortality due to progressive loss of renal function. Given the limitations of current therapies, novel agents targeting the mineralocorticoid receptor (MR) pathway, such as esaxerenone, are gaining attention. Understanding the effects of esaxerenone on eGFR—a key marker of kidney function—is essential for optimizing DKD management. This review aims to present an evidence-based synthesis of esaxerenone's role in influencing eGFR changes in DKD, integrating recent clinical trials, mechanistic research, and guideline perspectives.

Epidemiology / Disease Burden

DKD is a global health concern, responsible for approximately 50% of ESRD cases in developed nations. The prevalence of DKD is rising in parallel with the increasing incidence of type 2 diabetes. In Japan, for example, DKD is the most common etiology of new dialysis patients. The socioeconomic burden is substantial, encompassing increased hospitalization rates, cardiovascular complications, and reduced quality of life. Early detection and effective intervention are critical to curb CKD progression and associated healthcare costs.

Pathophysiology

DKD is characterized by glomerular hyperfiltration, mesangial expansion, thickening of the glomerular basement membrane, and podocyte injury, culminating in albuminuria and declining eGFR. Hyperactivation of the renin-angiotensin-aldosterone system (RAAS), particularly through the mineralocorticoid receptor, drives inflammation, fibrosis, and oxidative stress in renal tissues. Esaxerenone, by selectively antagonizing MR, counters these deleterious processes, offering renoprotective effects beyond conventional RAAS blockade.

Risk Factors

Key risk factors for the development and progression of DKD include chronic hyperglycemia, hypertension, dyslipidemia, genetic predisposition, obesity, smoking, and longer diabetes duration. Poor glycemic and blood pressure control accelerate nephron loss, while non-adherence to established therapies further compounds risk. Identifying high-risk individuals is critical for early intervention and optimized therapeutic outcomes.

Clinical Features

DKD typically presents as persistent albuminuria (≥30 mg/g creatinine), progressive decline in eGFR, and, in advanced stages, overt proteinuria, hypertension, and edema. Subclinical microalbuminuria often precedes overt nephropathy, highlighting the importance of regular screening in diabetic patients. Clinical course varies, with some patients experiencing rapid eGFR decline, while others progress more slowly.

Diagnosis

Diagnosis of DKD is predicated on elevated urinary albumin excretion and/or reduced eGFR (<60 mL/min/1.73 m²) in the context of diabetes, after excluding other primary renal diseases. Serial measurements of eGFR and albuminuria, alongside assessment of blood pressure and metabolic parameters, are vital for monitoring DKD progression and therapeutic response. Advanced diagnostics, including biomarkers of tubular injury and renal imaging, are under investigation.

Treatment & Management

The management of DKD focuses on stringent glycemic and blood pressure control, RAAS blockade using ACE inhibitors or ARBs, lipid management, and lifestyle modification. Sodium-glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have demonstrated cardiovascular and renal benefits. However, despite optimized therapy, many patients continue to experience progressive eGFR decline, necessitating adjunctive strategies such as MRAs.

Recent Advances / Emerging Therapies

Esaxerenone is a next-generation, highly selective, non-steroidal MRA that has demonstrated efficacy in reducing albuminuria and slowing eGFR decline in DKD patients. Phase III trials (e.g., ESAX-DN) have shown that esaxerenone, when added to standard RAAS inhibition, significantly attenuates urinary albumin excretion and stabilizes eGFR trajectories compared to placebo, with a favorable safety profile regarding hyperkalemia. Mechanistically, esaxerenone blocks MR-mediated pro-fibrotic and pro-inflammatory pathways, thereby mitigating renal structural injury. Ongoing studies are evaluating its long-term effects on hard renal outcomes and cardiovascular events.

Guideline Recommendations

Recent guidelines from the Japan Diabetes Society and the Japanese Society of Nephrology endorse the use of MRAs, including esaxerenone, in DKD patients with persistent albuminuria despite maximal RAAS blockade, provided that serum potassium and renal function are closely monitored. International guidelines (KDIGO 2022) also recognize non-steroidal MRAs as valuable adjuncts in selected patients at high risk of progression, particularly where SGLT2 inhibitors and RAAS inhibitors are insufficient. Clinical judgment, careful titration, and monitoring are essential to minimize adverse effects such as hyperkalemia and acute eGFR dips.

Conclusion

Esaxerenone represents a significant advance in the management of DKD, offering additional renoprotection by attenuating albuminuria and stabilizing eGFR in patients inadequately controlled on traditional therapies. Its favorable safety and efficacy profile, supported by robust clinical evidence, underscores its role as an emerging therapeutic option in high-risk DKD populations. Ongoing research will further elucidate its long-term impact on renal and cardiovascular outcomes, informing best practices for DKD care and improving patient prognosis.