Endothelin receptor antagonists in clinical research--lessons learned from preclinical and clinical kidney studies.

Abstract

Endothelin receptor antagonists (ETRAs) are approved for the treatment of pulmonary hypertension and scleroderma-related digital ulcers. The efforts to approve this class of drugs for renal indications, however, failed so far. Preclinical studies were promising. Transgenic overexpression of ET-1 or ET-2 in rodents causes chronic renal failure. Blocking the ET system was effective in the treatment of renal failure in rodent models. However, various animal studies indicate that blocking the renal tubular ETAR and ETBR causes water and salt retention partially mediated via the epithelial sodium transporter in tubular cells. ETRAs were successfully tested clinically in renal indications in phase 2 trials for the treatment of diabetic nephropathy. They showed efficacy in terms of reducing albumin excretion on top of guideline based background therapy (RAS blockade). However, these promising results could not be translated to successful phase III trials so far. The spectrum of serious adverse events was similar to other phase III trials using ETRAs. Potential underlying reasons for these failures and options to solve these issues are discussed. In addition preclinical and clinical studies suggest caution when addressing renal patient populations such as patients with hepatorenal syndrome, patients with any type of cystic kidney disease and patients at risk of contrast media induced nephropathy. The lessons learned in renal indications are also important for other potential promising indications of ETRAs like cancer and heart failure.

• Authors: Christoph Reichetzeder, Oleg Tsuprykov, Berthold Hocher
• Journal: Life sciences (Life Sci) Vol. 118 Issue 2 Pg. 141-8 (Nov 24 2014) ISSN: 1879-0631 [Electronic] Netherlands
• PMID: 24607774 (Publication Type: Journal Article, Review)
• Copyright: Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Chemical References

• Endothelin Receptor Antagonists
• Endothelins

Topics

• Animals
• Biomedical Research
• Diabetic Nephropathies (drug therapy, metabolism)
• Disease Models, Animal
• Endothelin Receptor Antagonists (adverse effects, pharmacology, therapeutic use)
• Endothelins (metabolism)
• Humans
• Kidney (drug effects, pathology)