act-058362 and Albuminuria

The urotensin system has been hypothesized to play an important role in the pathophysiology of diabetic nephropathy. In this multicenter, randomized, double-blind, placebo-controlled, 2-period crossover study, the effects of the urotensin receptor antagonist palosuran on urinary albumin excretion and blood pressure in hypertensive patients with type 2 diabetic nephropathy treated with a single blocker of the renin-angiotensin-aldosterone system were assessed. Patients with 24-hour albuminuria >0.5 and <3.0 g, systolic blood pressure >135 and <170 mm Hg, and/or diastolic blood pressure >85 and <110 mm Hg received both palosuran 125 mg BID and placebo for 4 weeks each. Fifty-four patients (20% women; mean age: 61.6 years, blood pressure: 155/84 mm Hg, and albuminuria: 1016 mg per 24 hours) were included in the per-protocol analysis. Palosuran did not affect albuminuria, blood pressure, glomerular filtration rate, or renal plasma flow significantly. These results question whether urotensin receptor antagonism represents a new treatment strategy in this high-risk patient population.

Topics: Adult; Aged; Albuminuria; Antihypertensive Agents; Blood Pressure; Creatinine; Cross-Over Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Humans; Hypertension; Male; Middle Aged; Placebos; Quinolines; Receptors, G-Protein-Coupled; Renin-Angiotensin System; Urea; Urotensins

In patients with renal disease increased urotensin II plasma levels have been observed. We have investigated whether palosuran, a potent, selective, and competitive antagonist of the urotensin II receptor, has effects in patients who are prone to the development of renal disease.. Macroalbuminuric, diabetic patients, categorized by renal function, were treated with oral doses of 125 mg palosuran twice daily for 13.5 days in addition to treatment with either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. The 24-hour urinary albumin excretion rate was determined twice at baseline and after 13.5 days of treatment. Plasma concentrations of palosuran were determined for 12 hours after the first and last drug intake. Renal hemodynamics was measured before and after 12.5 days of treatment. Tolerability and safety parameters were monitored.. An overall clinically significant reduction of 24.3% (geometric mean) (95% confidence interval, 4.1 to 45.0) in the 24-hour urinary albumin excretion rate was observed (P = .014). No effect was observed on renal hemodynamic parameters. Palosuran was rapidly absorbed with maximum plasma concentrations at 1 hour after drug administration. The accumulation factor was 1.7 (geometric mean) (95% confidence interval, 1.3 to 2.1). Palosuran was well tolerated.. The good tolerability profile and the decrease in the 24-hour urinary albumin excretion rate may benefit diabetic patients with renal failure with regard to their disease progression. Larger placebo-controlled trials in this patient population are needed to investigate whether urotensin II receptor antagonists, given as monotherapy or combination therapy, may improve the current treatment of diabetic nephropathy.

Topics: Aged; Albuminuria; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Area Under Curve; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Fatigue; Female; Glomerular Filtration Rate; Headache; Humans; Hypertension; Male; Middle Aged; Nasopharyngitis; Quinolines; Receptors, G-Protein-Coupled; Renal Circulation; Treatment Outcome; Urea

Urotensin-II (U-II) is a cyclic peptide that acts through a specific G-protein-coupled receptor, UT receptor. Urotensin-II and UT receptors have been described in pancreas and kidney, but their function is not well understood. We studied the effects of chronic treatment of diabetic rats with the orally active selective U-II receptor antagonist palosuran. Streptozotocin treatment causes pancreatic beta-cell destruction and leads to the development of hyperglycemia, dyslipidemia, and renal dysfunction. Long-term treatment of streptozotocin-induced diabetic rats with palosuran improved survival, increased insulin, and slowed the increase in glycemia, glycosylated hemoglobin, and serum lipids. Furthermore, palosuran increased renal blood flow and delayed the development of proteinuria and renal damage. The U-II system is unique in that it plays a role both in insulin secretion and in the renal complications of diabetes. Urotensin receptor antagonism might be a new therapeutic approach for the treatment of diabetes.

Topics: Albuminuria; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Kidney; Male; Pancreas; Quinolines; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Streptozocin; Urea