Hepatotoxicidad en pacientes tratados con antagonistas del receptor de la endotelina: revisión sistemática y metaanálisis de ensayos clínicos aleatorizados

Safety, pharmacokinetics, and pharmacodynamics in healthy Chinese volunteers treated with SC0062, a highly selective endothelin-A receptor antagonist

This study evaluated the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and food effects (FE) of SC0062, a highly active endothelin-A (ETA ) receptor antagonist, in healthy subjects. The primary objectives of this first-in-human phase I study, comprised of single-ascending-dose, multiple-ascending-dose, and FE parts, were to characterize the safety and tolerability of SC0062, and FE. The secondary objectives were to determine the PK behavior of SC0062 and its major active metabolite M18, whereas exploratory objectives focused on PD effects, principally effects on endothelin-1 (ET-1) and total bile acids (TBA). Single doses of 10 to 100 mg and multiple daily doses of 20 and 50 mg for 6 days were well tolerated. SC0062 was rapidly absorbed and plasma exposure of SC0062 and M18 increased disproportionately with dose, achieving steady state by day 3, with accumulation ratios of 1.22 and 1.89 on day 6 for SC0062 and M18, respectively. The geometric mean (geometric standard deviation) terminal elimination half-life (t1/2 ) values of SC0062 and M18 were 7.25 (1.70) h and 13.73 (1.32) h, respectively. Plasma ET-1 concentrations were dose-proportional, whereas plasma TBA concentrations behaved erratically. Following a single 50 mg dose of SC0062 after a high-fat meal, Cmax values for SC0062 and M18 increased by 41% and 32%, respectively, and median Tmax values for SC0062 were 3 h longer than fasting values; exposure was unaffected. These favorable safety, PK, and PD results provide a foundation for further studies of SC0062 in pulmonary arterial hypertension, chronic kidney disease, and other relevant indications.

Comparative assessment of efficacy and safety of ambrisentan and bosentan in patients with pulmonary arterial hypertension: A meta-analysis

WHAT IS KNOWN AND OBJECTIVE

Two endothelin receptor antagonists, ambrisentan and bosentan, have been demonstrated to be effective individually compared with placebo in the treatment of patients with pulmonary arterial hypertension (PAH). This network meta-analysis compared the efficacy and safety of ambrisentan and bosentan in patients with PAH.

METHODS

Clinical trials were identified from the Cochrane Central Register of Controlled Trials (CENTRAL/CCTR), EMBASE and PubMed databases. Weighted mean differences (MD) with 95% confidence intervals (CI) were calculated for continuous outcomes (6-min walk distance [6MWD] and Borg dyspnoea index [BDI]). Hazard ratio (HR) was calculated for binary outcomes, including clinical worsening, discontinuation due to adverse events (AEs) and liver dysfunction. Surface under cumulative ranking curve (SUCRA) was used to rank the treatments in each index.

RESULTS

Five clinical trials from four published studies (total patients: n = 920) were included. Ambrisentan and bosentan showed no significant difference in 6MWD (MD: -1.32; 95% CI: -27.87, 25.31, SUCRA score: ambrisentan 0.73, bosentan 0.77), BDI (MD: -0.16; 95% CI: -0.98, 0.65, SUCRA score: ambrisentan 0.83, bosentan 0.66), clinical worsening (HR: 0.99; 95% CI: 0.33, 2.94, SUCRA score: ambrisentan 0.75, bosentan 0.74) and discontinuation due to AEs (HR: 0.84; 95% CI: 0.11, 5.86, SUCRA score: ambrisentan 0.47, bosentan 0.57). However, ambrisentan was significantly better than bosentan with respect to abnormal liver function (HR: 23.18; 95% CI: 2.24, 377.20, SUCRA score: ambrisentan 0.99, bosentan 0.02).

WHAT IS NEW AND CONCLUSION

The results of this network meta-analysis suggest that ambrisentan was similar to bosentan in efficacy, while it exhibited better tolerability with respect to abnormal liver function in comparison with bosentan, in patients with PAH.

Update on Endothelin Receptor Antagonists in Hypertension

PURPOSE OF REVIEW

To review the most recent data on the development of endothelin receptor antagonists (ERAs) for the treatment of hypertension and the management of diabetic nephropathy RECENT FINDINGS: Recent reviews and meta-analyses of experimental and clinical data obtained with ERAs confirmed that endothelin receptor blockade is associated with significant decreases in blood pressure in essential hypertension but also in resistant hypertension. In addition, in patients with diabetic nephropathy, ERAs induce significant 30-40% decreases in albuminuria when administered on top of blockers of the renin-angiotensin system. Yet, the benefits of ERAs have often been limited by their tolerability profile, essentially fluid retention and the development of edema and liver toxicity. Hence, several programs have been interrupted. Today, only one ERA, aprocitentan, is still under development for the treatment of resistant hypertension. Regarding the place of ERAs in the management of diabetic nephropathy, the results of the SONAR trial with atrasentan are eagerly awaited but the recent interruption of this trial because of insufficient events is worrisome, as one might not obtain all the expected information for this major trial. Blockade of endothelin receptor have a high potential in the treatment of hypertension and the prevention of the progression of renal diseases such as diabetic nephropathy. Today, the number of clinical programs investigating the potential benefits of ERAs is limited and more data must be obtained to define the real place of ERAs in these indications.

Atrasentan for the treatment of diabetic nephropathy

INTRODUCTION

Endothelin-1 (ET-1) is the most potent vasoconstrictor, and is involved in the renal regulation of salt and water homeostasis. When produced in excess in the kidney, ET-1 promotes proteinuria and tubulointerstitial injury. There is great interest in the clinical use of endothelin receptor antagonists (ERAs) in chronic kidney disease (CKD), mainly in diabetic nephropathy (DN). Areas covered: Physiopathological actions of ET-1 on the kidney. Both dual ETAR/ET_BR (bosentan) or ET_AR specific endothelin antagonists (avosentan and atrasentan, among others), which have progressed to early clinical development, with particular emphasis on atrasentan. Expert opinion: Different phase I and II clinical trials with ERAs in DN, mostly with atrasentan, have shown that these drugs have a marked anti-proteinuric effect on residual proteinuria when administered as add-on therapy in addition to ACEi or ARAII treatment. In the past few years, a series of randomized controlled trials investigating new approaches to DN have provided negative or inconclusive data, or even were terminated due to safety concerns or lack of efficacy. Therefore, we eagerly but cautiously await the results of the ongoing SONAR trial with atrasentan in more than 4,000 patients including assessment of renal and cardiovascular hard-end points (estimated primary completion date, July 2018).