Endothelin receptor antagonists in chronic kidney disease

Endothelin-1 is a potent vasoconstrictor that has diverse physiological functions in the kidney, including in the regulation of blood flow and glomerular filtration, electrolyte homeostasis and endothelial function. Overexpression of endothelin-1 contributes to the pathophysiology of both diabetic and non-diabetic chronic kidney disease (CKD). Selective endothelin receptor antagonists (ERAs) that target the endothelin A (ET_A) receptor have demonstrated benefits in animal models of kidney disease and in clinical trials. In patients with type 2 diabetes and CKD, the selective ET_A ERA, atrasentan, reduced albuminuria and kidney function decline. Concerns about the increased risks of fluid retention and heart failure with ERA use have led to the design of further trials to optimize dosing and patient selection. More recent studies have shown that the dual ET_A receptor and angiotensin receptor blocker, sparsentan, preserved kidney function with minimal fluid retention in patients with IgA nephropathy. Moreover, combined administration of a low dose of the ET_A-selective ERA, zibotentan, with the sodium-glucose cotransporter 2 (SGLT2) inhibitor, dapagliflozin, enhanced albuminuria reduction and mitigated fluid retention in patients with CKD. Notably, sparsentan and aprocitentan have received FDA approval for the treatment of IgA nephropathy and treatment-resistant hypertension, respectively. This Review describes our current understanding of the use of ERAs in patients with CKD to guide their optimal safe and effective use in clinical practice.