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

Aprocitentan, a dual endothelin-1 (ET-1) antagonist for treating resistant hypertension: Mechanism of action and therapeutic potential

Hypertension is reaching epidemic proportions worldwide and is a significant public health concern. However, ∼15% of patients with hypertension continue to experience elevated blood pressure, even after taking antihypertensive medications [such as angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs), dihydropyridine calcium channel blockers (CCBs) and thiazide diuretics], a condition referred to as resistant hypertension (RH). Within the complex realm of blood pressure regulation and vascular function, endothelin-1 (ET-1), a potent vasoconstrictor, plays a pivotal role. Recent research, particularly a Phase III clinical trial (NCT03541174), has shed light on the potential of aprocitentan, a dual ET-1 receptor antagonist, in significantly lowering blood pressure in individuals with RH. In this review, we summarize the mechanism of action and therapeutic potential of aprocitentan as an innovative approach for treating RH.

Cost-utility of ambrisentan and bosentan for pediatric pulmonary arterial hypertension

INTRODUCTION

Despite the increasing evidence supporting the efficacy of ambrisentan and bosentan in improving functional classes among pediatric patients with pulmonary arterial hypertension (PAH), there is a lack of information regarding their cost implications. Therefore, the objective of this study is to assess the cost-utility of bosentan compared to ambrisentan for the treatment of pediatric patients with PAH in Colombia.

METHODS

We employed a Markov model to estimate the costs and quality-adjusted life-years (QALYs) associated with the use of ambrisentan or bosentan in pediatric patients diagnosed with pulmonary arterial hypertension (PAH). To ensure the reliability of our findings, we conducted sensitivity analyses to assess the robustness of the model. In our cost-effectiveness analysis, we evaluated the outcomes at a willingness-to-pay (WTP) threshold of US$5,180.

RESULTS

The expected annual cost per patient receiving ambrisentan was estimated to be $16,055 (95% CI 15,937 -16,172), while for bosentan it was $14,503 (95% CI 14,489 -14,615). The QALYs per person estimated for ambrisentan were 0.39 (95% CI 0.381-0.382), whereas for bosentan it was 0.40 (95% CI 0.401-0.403).

CONCLUSION

Our economic evaluation shows that ambrisentan is not cost-effective regarding bosentan to in treating pulmonary arterial hypertension in C.

Insights into Endothelin Receptors in Pulmonary Hypertension

Pulmonary hypertension (PH) is a disease which affects the cardiopulmonary system; it is defined as a mean pulmonary artery pressure (mPAP) > 20 mmHg as measured by right heart catheterization at rest, and is caused by complex and diverse mechanisms. In response to stimuli such as hypoxia and ischemia, the expression and synthesis of endothelin (ET) increase, leading to the activation of various signaling pathways downstream of it and producing effects such as the induction of abnormal vascular proliferation during the development of the disease. This paper reviews the regulation of endothelin receptors and their pathways in normal physiological processes and disease processes, and describes the mechanistic roles of ET receptor antagonists that are currently approved and used in clinical studies. Current clinical researches on ET are focused on the development of multi-target combinations and novel delivery methods to improve efficacy and patient compliance while reducing side effects. In this review, future research directions and trends of ET targets are described, including monotherapy and precision medicine.

Endothelin Receptor Antagonists in Kidney Disease

Endothelin (ET) is found to be increased in kidney disease secondary to hyperglycaemia, hypertension, acidosis, and the presence of insulin or proinflammatory cytokines. In this context, ET, via the endothelin receptor type A (ET_A) activation, causes sustained vasoconstriction of the afferent arterioles that produces deleterious effects such as hyperfiltration, podocyte damage, proteinuria and, eventually, GFR decline. Therefore, endothelin receptor antagonists (ERAs) have been proposed as a therapeutic strategy to reduce proteinuria and slow the progression of kidney disease. Preclinical and clinical evidence has revealed that the administration of ERAs reduces kidney fibrosis, inflammation and proteinuria. Currently, the efficacy of many ERAs to treat kidney disease is being tested in randomized controlled trials; however, some of these, such as avosentan and atrasentan, were not commercialized due to the adverse events related to their use. Therefore, to take advantage of the protective properties of the ERAs, the use of ET_A receptor-specific antagonists and/or combining them with sodium-glucose cotransporter 2 inhibitors (SGLT2i) has been proposed to prevent oedemas, the main ERAs-related deleterious effect. The use of a dual angiotensin-II type 1/endothelin receptor blocker (sparsentan) is also being evaluated to treat kidney disease. Here, we reviewed the main ERAs developed and the preclinical and clinical evidence of their kidney-protective effects. Additionally, we provided an overview of new strategies that have been proposed to integrate ERAs in kidney disease treatment.

The potential benefit of endothelin receptor antagonists' therapy in idiopathic pulmonary fibrosis: A meta-analysis of results from randomized controlled trials

BACKGROUND

Fibrotic diseases take a very heavy toll in terms of morbidity and mortality equal to or even greater than that caused by metastatic cancer. This meta-analysis aimed to evaluate the effect of endothelin receptor antagonists on idiopathic pulmonary fibrosis.

METHOD

A systematic search of the clinical trials from the Medline, Google Scholar, Cochrane Library, and PubMed electronic databases was performed. Stata version 12.0 statistical software (Stata Crop LP, College Station, TX) was adopted as statistical software.

RESULT

A total of 5 studies, which included 1500 participants. Our analysis found there is no significant difference between using the endothelin receptor antagonists' group and placebo groups regarding the lung function via estimating both the change of forced vital capacity from baseline and DLco index. Exercise capacity and serious adverse effects are taken into consideration as well; however, there is still no significant change between the 2 groups.

CONCLUSION

This meta-analysis provides insufficient evidence to support that endothelin receptor antagonists' administration provides a benefit among included participants who encounter idiopathic pulmonary fibrosis.

The use of pulmonary arterial hypertension therapies in Eisenmenger syndrome

INTRODUCTION

For many years, treatment options for patients with Eisenmenger physiology had been restricted to conservative measures to alleviate multi-system complications. The use of pulmonary arterial hypertension (PAH)-targeted therapies in patients with Eisenmenger syndrome (ES) changed the course of the disease, since they substantially improved clinical outcomes and increased survival.

AREAS COVERED

In this review, we primarily focus on the use of PAH pharmacotherapies in ES. A literature search was carried out in PubMed, Scopus and Cochrane Database up to May 2021. We thoroughly discuss current evidence about mechanisms of action, safety, and efficacy of these agents and present challenges and gaps in literature regarding the recommended treatment approach.

EXPERT OPINION

Unlike other forms of PAH, we usually treat patients with ES more conservatively as we lack evidence that aggressive management is safe and effective in this complex population. Several issues on the time of initiation of PAH-targeted therapies, choice between monotherapy vs. upfront combination therapy, and time of escalation still remain challenging and require further investigation. Therapeutic management should be guided by patients' individual evaluation based on available prognostic markers. More well-designed trials are warranted to assess the benefits of new PAH-targeted agents and combination therapies.