Endothelin Receptor Antagonist Research Articles

Exploring the Endothelin-1 pathway in chronic thromboembolic pulmonary hypertension microvasculopathy.

Targeted vasopeptide therapies have significantly advanced the management of pulmonary arterial hypertension (PAH). However, due to insufficient preclinical evidence regarding the involvement of the endothelin-1 (ET-1) pathway in chronic thromboembolic pulmonary hypertension (CTEPH) pathophysiology, the potential of ET-1 receptor antagonism in treating CTEPH remains uncertain. In this study, we investigated the role of the ET-1 pathway in CTEPH microvasculopathy using a multifaceted approach. Plasma ET-1 levels were measured in a cohort of 59 CTEPH patients and 41 healthy controls. Additionally, we evaluated the expression of key ET-1 pathway members in pulmonary explants from CTEPH, idiopathic PAH, and control patients. We used an in vitro system to test the hypothesis that the turbulent flow, observed near the vascular obstructions pathognomonic of CTEPH, enhances ET-1 expression. Our findings were further validated in vivo using a CTEPH piglet model that contains distinct regions representing pre- and post-thrombus lung territories. We found a twofold increase in circulating ET-1 levels in CTEPH patients compared to healthy subjects. Pulmonary explants from CTEPH patients exhibited pronounced overexpression of ET-1, endothelin receptor A (ETA), and phosphorylated myosin light chain (p-MLC) in muscularized pulmonary microvessels, suggesting heightened vascular contraction. In vitro experiments showed that turbulent flow facilitates ET-1 secretion compared to laminar flow regions. Additionally, in the CTEPH piglet model, elevated plasma ET-1 levels were observed compared to controls. Immunofluorescence and confocal microscopy analyses confirmed increased ETA and p-MLC in remodeled arteries from both pulmonary territories. However, ET-1 protein elevation was exclusively observed in the obstructed territory. These findings collectively indicate impaired vascular tone in microvessels of CTEPH patients and the CTEPH piglet model. Furthermore, our data implicates the ET-1 pathway in microvasculopathy, with turbulent flow playing a pathological role. These insights underscore the potential utility of ET-1 receptor antagonists as a promising therapeutic approach for CTEPH treatment.

Endothelin-1 receptor blockade impairs invasion patterns in engineered 3D high-grade serous ovarian cancer tumouroids.

High-grade serous ovarian cancer (HG-SOC), accounting for 70-80% of ovarian cancer deaths, is characterized by a widespread and rapid metastatic nature, influenced by diverse cell types, cell-cell interactions, and acellular components of the tumour microenvironment (TME). Within this tumour type, autocrine and paracrine activation of the endothelin-1 receptors (ET-1R), expressed in tumour cells and stromal elements, drives metastatic progression. The lack of three-dimensional models that faithfully recapitulate the unique HG-SOC TME has been the bottleneck in performing drug screening for personalized medicine. Herein, we developed HG-SOC tumouroids by engineering a dense central artificial cancer mass (ACM) containing HG-SOC cells, nested within a compressed hydrogel recapitulating the stromal compartment comprising type I collagen, laminin, fibronectin, and stromal cells (fibroblasts and endothelial cells). ET-1-stimulated HG-SOC cells in the tumouroids showed an altered migration pattern and formed cellular aggregates, mimicking micrometastases that invaded the stroma. Compared with control cells, ET-1-stimulated tumouroids showed a higher number of invasive bodies, which were reduced by treatment with the dual ET-1 receptor (ET-1R) antagonist macitentan. In addition, ET-1 increased the size of the invading aggregates compared with control cells. This study establishes an experimental 3D multicellular model eligible for mechanical research, investigating the impact of matrix stiffness and TME interactions, which will aid drug screening to guide therapeutic decisions in HG-SOC patients.

Abstract 4119891: Risk Factors of Anemia in Pulmonary Arterial Hypertension Patients with Endothelin Receptor Antagonists Administration and Related Treatment

Background: Endothelin receptor antagonists (ERAs) demonstrated significant efficiency in delaying clinical deterioration and improving survival of patients with pulmonary arterial hypertension (PAH). However, the frequent occurrence of anemia after ERAs administration has gained clinical attention currently, whereas the etiology of anemia is unclear. The risk factors of ERAs associated anemia remained undefined. Therefore, we aim to investigate risk factors of developing anemia after ERAs treatment and whether iron supplement could correct anemia. Method: A retrospective cohort study was performed among patients with PAH who received ERAs between January, 2017 and December, 2019 in Fuwai hospital. The primary outcome was development of anemia after ERAs therapy and secondary outcome was correction of anemia after iron supplement. Results: A total of 120 patients with PAH were included in the study and 28 patients developed anemia during follow up . Distinctively, all the patients who developed anemia were female. After ERAs administration, iron metabolism (Ferritin 95.29±144.79 μg/L versus 69.9±118.25 μg/L, P <0.001) and hemoglobin (154.21±23.80 g/L versus 136.12±28.61 g/L, P <0.001) reduced significantly in the total cohort with patients who developed anemia more significant. Baseline iron metabolism (Ferritin: HR 0.98, 95%CI 0.96-0.99, P =0.02) was independently associated with development of anemia after ERAs administration. Compared with patients with iron replete, patients with iron deficiency had over 9-fold risk of developing anemia after receiving ERAs (HR = 9.59, 95%CI 3.62-25.41, P < 0.01). Iron supplement could effectively correct anemia. Conclusion: It is advised that patients receiving ERAs monitor iron metabolism and hemoglobin regularly, especially females and those with low hemoglobin level and compromised iron homeostasis before ERAs administration, which facilitates prevention and early detection of anemia. ERAs-related anemia is mostly mild, oral iron supplement could effectively reverse anemia and aberrant iron metabolism.

Abstract 4134327: Efficacy and safety of aprocitentan in patients with resistant hypertension receiving at least 4 antihypertensive medications including beta (β) blockers

Background: Aprocitentan, a dual ET A /ET B endothelin receptor antagonist, was recently FDA-approved for use in combination with other drugs for the treatment of hypertension not adequately controlled on other antihypertensive drugs. β-blockers are used for the prevention of cardiovascular events and have antihypertensive effects. All subjects in the PRECISION study were hypertensive at screening despite receiving ≥3 antihypertensives, with 63.5% on ≥4 and 16.8% on ≥5 antihypertensives. All were switched to a standardized fixed dose triple combination of amlodipine/valsartan/hydrochlorothiazide; and the 456 patients (62.5% of the 730 total) who were on β-blockers at screening continued throughout the study as well. Of these, 173 (37.9%) had a history of ischemic heart disease and 106 (23.2%) a history of congestive heart failure, vs 52 (19%) and 37 (13.5%) not receiving β-blockers. This preplanned subgroup analysis assessed the efficacy and safety of aprocitentan in patients with resistant hypertension on the triple combination with or without β-blockers. Methods: Changes from baseline (BL) in office systolic blood pressure (SBP) and diastolic BP (DBP) were assessed at Week 4, the end of the double-blind treatment phase with aprocitentan 12.5 mg or 25 mg per day or placebo, and at Week 36, at the end of the single-blind aprocitentan 25 mg treatment phase. Results: There was no difference in the efficacy of aprocitentan when patients were on a β-blocker or not. In patients on β-blockers, 12.5 mg and 25 mg aprocitentan decreased SBP from BL to Week 4 by mean -14.9 mmHg and -14.9 mmHg, respectively, vs -11.2 mmHg in the placebo group; and in patients without β-blockers by -16.5 mmHg and -14.9 mmHg vs -11.8 mmHg. Similar results were seen at Week 36, as compared with BL for both subgroups, and at Week 4 for DBP (Table 1). In patients on β-blockers, the incidence of edema/fluid retention at Week 4 was 9.9%, 19.3% and 2.8% in the aprocitentan 12.5 mg, 25 mg and placebo groups, respectively, as compared with 7.6%, 16.7%, and 1.0% in patients without β-blockers. In both subgroups, most events occurred during the first 8 weeks of treatment. The incidence of edema/fluid retention with aprocitentan was comparable with that of the placebo group in both subgroups thereafter. Conclusions: Aprocitentan is effective in lowering BP and has a good safety and tolerability profile in patients with resistant hypertension who are taking 4 or more antihypertensive drugs including β-blockers.

Abstract 4144559: Sex Differences in Vascular Remodeling in Pulmonary Hypertension are mediated by Endothelin-2

Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial vascular remodelingleading to increased pulmonary artery pressure causing right ventricular hypertrophy, failure anddeath. The incidence of PAH is much higher in female patients, indicating that males may have aprotective factor that could help elucidate the pathogenesis of PAH. We have recently demonstratedthat the Y chromosome gene UTY protects against PH development in mice, however the fulldownstream mechanisms remains unknown. By integrating RNA-Seq on whole lung tissues fromUty-KO and WT male mice with a publically available male and female PAH lung microarraydataset, we found increased expression of Endothelin 2 (ET-2) in the lungs of Uty-KO compared toWT mice with PH as well as in the lungs of female patients compared to males with PAH. The roleof ET-1 is known in PAH, and Endothelin receptor antagonists are a common PAH therapy to whichfemale patients are more responsive. However, ET-2 has yet to be investigated in this context. Wevalidated that ET-2 expression is significantly increased in lung tissue from PAH female patientscompared to males. Plasma ET-2 concentration is also significantly higher in PAH patients versuscontrols. Interestingly, plasma ET-2 negatively correlates with pulmonary vascular resistance (PVR)and mean pulmonary arterial pressure (mPAP) in male PAH patients, whereas plasma ET-2significantly positively correlates with PVR and mPAP in female PAH patients. Functionally, wefound that recombinant ET-2 significantly inhibits proliferation of male pulmonary artery endothelialcells (PAECs), but significantly promotes proliferation in female PAECs. Similarly, ET-2 significantlyincreased proliferation of female pulmonary artery smooth muscle cells (PASMC), but not malePASMC. Together, we show that increased ET-2 expression may contribute to worsening PH bypromoting vascular remodeling in the lung and that elevated ET2 in females may at least partiallyexplain the higher incidence of female PAH patients

Long-Term Safety and Efficacy of Macitentan in Inoperable Chronic Thromboembolic Pulmonary Hypertension: Results from MERIT and its Open-Label Extension.

Evidence for use of pulmonary arterial hypertension targeted-therapies in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is limited. In MERIT-1, the endothelin receptor antagonist macitentan improved hemodynamic and functional parameters versus placebo in patients with inoperable CTEPH over a 24-week double-blind (DB) period. Its open-label (OL) extension study (MERIT-2) provides long-term safety/efficacy data. MERIT-2 (NCT02060721) was a multicenter, single-arm, OL, phase 2 extension study of MERIT-1. Patients completing MERIT-1 were eligible to receive 10 mg macitentan once-daily in MERIT-2. Safety and efficacy (6-min walk distance [6MWD] and change in World Health Organization functional class [WHO FC]) were assessed in all patients in MERIT-2 regardless of treatment received in DB (All patients MERIT-2 OL macitentan 10mg group) and the subgroup of patients receiving DB macitentan in MERIT-1 (Long-term [DB/OL] macitentan 10mg subgroup). Of the 80 patients randomized in MERIT-1, 76 entered MERIT-2 (All patients MERIT-2 OL macitentan 10mg group): 40 who received DB macitentan (DB-macitentan patients) and 36 DB placebo (DB-placebo patients). Median (interquartile range) macitentan exposure in the All patients MERIT-2 OL macitentan 10mg group was 45.5 (26.0, 66.1) months. During the OL period, treatment-emergent adverse events (AE) were reported in 72 (94.7%) patients; most frequent were worsening of pulmonary hypertension (19.7%), decreased hemoglobin (18.4%) and upper respiratory tract infection (15.8%). Fourteen (18.4%) patients died; none were assessed as macitentan-related. At Month 6 post-OL baseline, mean (standard deviation) change in 6MWD was - 0.4m (43.62) for DB-macitentan patients and 10.7m (45.63) for DB-placebo patients; the majority had unchanged (83.3%) or improved (12.5%) WHO FC. Safety/efficacy analyses were consistent in the Long-term (DB/OL) macitentan 10 mg subgroup. These analyses provide long-term safety/efficacy data in patients with inoperable CTEPH treated with macitentan. No unexpected safety findings occurred; reported AEs were consistent with the known safety profile of macitentan. At 6 months post-OL baseline, DB-placebo patients modestly improved 6MWD; DB-macitentan patients maintained improvements observed in MERIT-1. WHO FC was largely unchanged. ClinicalTrials.gov Identifiers: NCT02021292; NCT02060721.

The effect of the endothelin receptor antagonist atrasentan on insulin resistance in phenotypic clusters of patients with type 2 diabetes and chronic kidney disease.

Type 2 diabetes (T2D) patients with a clinical phenotype characterized by a high degree of insulin resistance are at increased risk of chronic kidney disease (CKD). We previously demonstrated that the endothelin receptor antagonist (ERA) atrasentan reduced insulin resistance in T2D. In this study, we compared the effect of atrasentan on insulin resistance across different phenotypic clusters of patients with T2D. We performed a post hoc analysis of the SONAR trial, a randomized, placebo-controlled trial of the ERA atrasentan in patients with T2D and CKD. Patients were stratified into four previously identified phenotypic clusters: severe insulin-deficient diabetes (SIDD), severe insulin-resistant diabetes (SIRD), mild obesity-related diabetes (MOD) and mild age-related diabetes (MARD). Changes in insulin resistance, assessed by HOMA-IR, were compared between the phenotypic clusters using a mixed effects model. In total, 931 patients were included in the analysis. In the overall population, atrasentan compared to placebo reduced HOMA-IR by 12.9% [95%CI 3.5,21.4]. This effect of atrasentan was more pronounced in clusters characterized by insulin resistance or deficiency: (SIRD cluster 26.2% [95% CI 3.8,43.3] and SIDD cluster 18.5% [95%CI -3.8,35.9]), although the latter did not reach statistical significance. The effect of atrasentan compared to placebo was less pronounced in the other two clusters (MARD 12.2% [95% CI -1.7,24.12] and MOD -5.3% [95% CI -28.9,13.9]). Atrasentan significantly improved insulin sensitivity in patients with T2D and CKD, especially in those characterized by high insulin resistance (SIRD cluster). Further studies are warranted to investigate the long-term clinical outcomes of atrasentan treatment in these distinct phenotypic clusters.

IgA Vasculitis (Henoch-Schönlein Purpura): An Update on Treatment.

Objective: IgA vasculitis (IgAV), previously named as Henoch-Schönlein purpura, is the most frequent systemic vasculitis in children. In adults, IgAV is less common although it is associated with more severe disease. In fact, the frequency of glomerulonephritis (referred to as IgAV nephritis) in adults is higher than in children and tends to present more severely, with around 10-30% of those affected eventually progressing to end-stage renal disease. In this review, we describe the pathophysiology, main clinical features, diagnosis of the disease, and latest clinical data regarding IgAV therapy. Methods: A narrative literature review, primarily based on articles published in PubMed, was conducted. In addition to discussing the main aspects of glucocorticoids and conventional disease-modifying drugs used in the management of IgAV, this review focuses on the latest information reported regarding biologics and potential future therapies. Results: Glucocorticoids are the first-line therapy for IgAV, especially in adults with severe manifestations. Colchicine, dapsone, and methotrexate can be useful for controlling minor manifestations. Several immunomodulatory agents, such as cyclosporine A, tacrolimus, and mycophenolate mofetil, have shown favorable results as glucocorticoid-sparing agents. Leflunomide has shown promising results but requires further study. The use of rituximab has demonstrated efficacy in reducing relapse frequency, lowering the cumulative glucocorticoid burden, and achieving long-term remission of the disease in children and adults with IgAV. Immunoglobulins and plasma exchange therapy can also be useful in difficult and life-threatening situations. Other potential therapies with encouraging results include TRF-budesonide, B-cell-directed therapy, B-cell-depleting agents, sodium-glucose cotransporter-2 inhibitors, endothelin receptor antagonists, and complement pathway inhibitors. Conclusions: Glucocorticoids are the first-line therapy for IgAV, especially in adults with severe manifestations. The role of various immunomodulatory therapies, such as calcineurin inhibitors and mycophenolate mofetil, remains promising, while rituximab reduces the long-term side effects of glucocorticoids and can help achieve disease remission. Other potential therapies with encouraging results require further research.

Efficacy of specific drug class therapy in pulmonary arterial hypertension associated with HIV, portal hypertension or both: a single Center experience

Abstract Background Pulmonary arterial hypertension (PAH) is a rare complication of both HIV infection (HIV-PAH) and portal hypertension (Po-PAH); it can occur in patients with both diseases (HIV/Po-PAH). The use of the PAH-specific drug classes (prostanoids, endothelin-1 receptor antagonists [ERA] and phosphodiesterase-5 inhibitors [PDE5-i]) is largely justified by retrospective and observational case reports since, to date, there are no randomized clinical trials except for the PORTICO trial which demonstrated the efficacy of macitentan in Po-PAH. Purpose the aim of the study was to evaluate the efficacy of PAH-specific drugs, both monotherapy and dual oral upfront therapy (ERA + PDE5i started within 1 month apart), in patients with Po-PAH, HIV/Po-PAH and HIV-PAH. Methods Between 1998 and 2023 we enrolled patients with Po-PAH, HIV-PAH and HIV/Po-PAH referred to our Center and undergoing monotherapy with prostanoid, ERA and PDE5-I or dual upfront oral therapy. The efficacy of the drugs was assessed by comparing clinical parameters (NYHA functional class), exercise capacity (six-minute walking test) and hemodynamic parameters at baseline and after a treatment period of 3-6 months. The data are expressed as mean and standard deviation and were compared with Student's t-test for paired data. Results 128 patients were enrolled (83 Po-PAH, 23 HIV/Po-PAH and 22 HIV-PAH). 20 were treated with ERA monotherapy, 90 with PDE5-I, 13 with prostanoids and 5 treated with dual oral upfront therapy. Conclusions Prostanoids, ERAs and PDE5-Is, both in monotherapy and as dual upfront oral therapy, are associated with a significant improvement in functional class, exercise capacity and hemodynamic parameters. The effect of such drugs is similar to patients suffering from other forms of PAH.

Ambrisentan reverses the prosenescent and anti-autophagic effect of high glucose on human pulmonary artery endothelial cells exposed to hypoxia

Abstract Background Cardiovascular (CV) comorbidities (systemic hypertension, hyperlipidemia, obesity, diabetes mellitus, peripheral arterial disease, coronary artery disease) are associated with reduced treatment response to specific drugs for group 1 pulmonary arterial hypertension (PAH). Often this epidemiological evidence is the result of misdiagnosis of group 2 PH associated with left heart disease, but it can also be explained as the intrinsic loss of the ability of pulmonary endothelial cells to respond to specific antiremodeling drugs. Aims To evaluate the impact of high glucose and hyperosmolar stress on the responsiveness of human pulmonary artery endothelial cells (hPAECs) to the endothelin receptor antagonist ambrisentan in terms of senescence, autophagic activity, viability and expression of some microRNAs involved in pulmonary arterial remodeling. Methods We incubated hPAECs with high glucose (HG, 30.5 mM) or high mannitol (HM, 25 mM), with/without ambrisentan (0.02 nM) in normoxia (N) or hypoxia (H) for 24 h and tested them for cell viability (MTT assay), protein and miRNA levels, autophagy and senescence (β-Gal assay) in vitro. Results H induced cell death as compared to N (752 ± 44 vs 701 ± 45 Abs units, p = 0.03). H reduced autophagy (Figure 1A-C) and induced senescence (Figure 1D), an effect further potentiated by HG and HM. Treatment with A in N and H significantly reversed the effect of HG but not HM on autophagy (Figure 1A-C) and senescence (Figure 1D). H increased the abundance of antiapoptotic miR124-3, compared to N in vehicle (V)-treated hPAEC (p=0.008) (Figure 2A), and induced a similar effect on antiapoptotic and proliferative miR191-3p, although not statistically significant (Figure 2B). In N, A potentiated the expression of both miR124-3p (p=0.007) and miR191-3p (p=0.02) in HG-treated hPAEC, and only miR191-3p in HM-treated hPAEC (p=0.01). A induced a similar effect on miR191-3p in hPAEC exposed to H+HG (p=0.02), with a non-statistically significant trend on miR124-3p. Conclusions In hPAEC exposed to H, A retains its pro-autophagic and antisenescent effects in an in vitro model mimicking diabetes. miR124-3p and miR191-3p may act as biomarkers of disease and treatment response to specific drugs in patients with PAH.Figure 1:autophagy and senescenceFigure 2:miRNA expression

Treatment of Systemic Sclerosis Complicated By Cardiac Arrhythmia: A Case Report

Cardiac manifestations are occasionally observed in Systemic Sclerosis patients. Primary cardiac involvement may occur as a direct consequence of the disease. Arrhythmias are also thought to be a direct result from conduction system fibrosis. Early diagnosis and treatment of arrhythmia can be rewarding for this patient as if intreated may lead to a fatal outcome. Beta blockers used to treat arrythmia may worsen Raynaud’s symptom in systemic sclerosis. So there has been a controversy regarding the treatment of arrhythmia in Systemic Sclerosis. Here we are reporting a case of Systemic Sclerosis who presented with palpitation and digital gangrene. Her resting ECG showed multiple premature ventricular complexes whereas echocardiogram did not show any significant abnormality. Then She was treated with non-selective beta blocker without any progression of her Raynaud’s. For her digital gangrene, along with other conventional treatment (like nifedipine & tadalafil) she was treated with endothelin receptor antagonist (bosentan) and showed good response. J Dhaka Med Coll. 2023; 32(1) : 92-95

The Selective Endothelin Receptor Antagonist SC0062 in IgA Nephropathy: A Randomized Double-Blind Placebo-Controlled Clinical Trial.

Key Points Patients with IgA nephropathy and significant proteinuria are at high risk of progressive kidney function loss and kidney failure.We report the results of a clinical trial assessing the selective endothelin receptor antagonist SC0062 for the treatment of IgA nephropathy.SC0062 led to clinically meaningful improvements in proteinuria and did not increase risk of peripheral edema at higher doses. Background Endothelin receptor type A activation contributes to kidney injury in patients with IgA nephropathy. SC0062 is a novel selective endothelin receptor type A antagonist. We report the results of a phase 2 dose-finding trial to characterize the efficacy and safety of SC0062 in patients with IgA nephropathy. Methods We conducted a randomized, placebo-controlled, double-blind, clinical trial in adults with biopsy-proven IgA nephropathy and eGFR ≥30 ml/min per 1.73 m2 with urinary protein-creatinine ratio (UPCR) ≥0.75 g/g or proteinuria ≥1 g/24 hour despite using maximum tolerated doses of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Patients were randomized 1:1:1:1 to 24-week treatment with SC0062 5, 10, and 20 mg or matching placebo once daily. The primary efficacy outcome was percent change from baseline in UPCR in 24-hour urine samples after 12 weeks of treatment. Secondary end points included changes in eGFR. Safety outcomes including treatment emerging adverse events and serious adverse events were recorded. Results Overall, 131 patients (mean age 42 years [SD, 11]; mean eGFR 72 ml/min per 1.73 m2 [SD 24] and median 24-hour UPCR 1.2 g/g [25th–75th percentile, 0.9–1.5 g/g]) were randomized to placebo (n=34) or SC0062 5 mg (n=33), 10 mg (n=32), or 20 mg (n=32). All SC0062 doses reduced UPCR versus placebo throughout treatment. At week 12, placebo-corrected geometric mean changes (95% confidence interval) from baseline in UPCR with SC0062 5, 10, and 20 mg were−27.6% (−43.0 to −8.2), −20.5% (−37.4 to 1.0), and −38.1% (−51.4 to −21.0), respectively, and at week 24 they were−22.4% (−42.2 to 4.3), −30.9% (−48.6 to −7.0), and −51.6% (−64.2 to −34.6), respectively. No differences in eGFR were observed among treatment groups. The proportion of participants with treatment emerging adverse events or serious adverse events was balanced among treatment groups. Peripheral edema was reported by 2 (6%), 1 (3%), 1 (3%) participants in the 5, 10, and 20 mg SC0062-treated groups, respectively, compared with 5 (15%) in the placebo group. Conclusions In patients with IgA nephropathy, SC0062 reduced proteinuria and did not increase risk of peripheral edema. Clinical Trial registry name and registration number: A Study to Evaluate the Efficacy and Safety of SC0062 in the Treatment of CKD, NCT05687890.

Clinical adverse events to letairis: a real-world drug safety study based on FDA Adverse Event Reporting System (FAERS)

ABSTRACT Background Letairis (ambrisentan), an endothelin receptor antagonist (ERA), is a critical medication for pulmonary arterial hypertension (PAH). Despite its efficacy, its safety profile is under scrutiny, warranting a detailed analysis. Research design and methods This study leveraged the FDA Adverse Event Reporting System (FAERS) from Q1 2007 to Q4 2023, focusing on Letairis as the primary suspect in adverse events. Employing advanced data mining techniques, such as Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-item Gamma Poisson Shrinker (MGPS), the study aimed to uncover safety signals. Results A total of 43,774 cases were identified, with Letairis implicated in 16,038,963 adverse event reports. There was a notable predominance of female patients (75.30%), with a median age around 64 years. Severe outcomes, including hospitalization (51.63%) and fatalities (20.44%), were prevalent. Signal strength analysis highlighted concerns in infections and infestations, as well as cardiac disorders. Conclusion The analysis underscores the need for vigilant pharmacovigilance and highlights Letairis’s potential to induce serious AEs, particularly in female and elderly populations. These findings are instrumental in guiding clinical practice and future drug safety assessments.

Urinary Clusterin as a Pharmacodynamic Response Biomarker for the Endothelin Receptor Antagonist Atrasentan

Urinary Clusterin as a Pharmacodynamic Response Biomarker for the Endothelin Receptor Antagonist Atrasentan

Formulation Optimization and Evaluation of Patented Solid Lipid Nanoparticles of Ambrisentan for Pulmonary Arterial Hypertension.

Ambrisentan is a new endothelin receptor antagonist extensively used to manage pulmonary or pulmonary arterial hypertension. The therapeutic efficacy of Ambrisentan is limited due to its reduced solubility, higher log P (3.4), and thus less bioavailability. The recent investigation was concentrated on the improvement of solubility, and bioavailability of Ambrisentan for the therapy of hypertension via solid lipid nanoparticles (SLN) administered orally. XRD evaluated the compatibility of Ambrisentan with lipids with FTIR, DSC, and crystalline nature. The SLN was developed by High-pressure homogenization method. The Glyceryl monostearate and Tween 80 indicated the highest solubility, hence selected. The optimization was performed with Box-Behnken Design considering the concentration of GMS (X1), Tween 80 (X2), stirring speed (X3) as independent factors and particle size (Y1), entrapment efficiency (Y2) as dependent factors. The Patents on the SLN are Indian 202321053691, U.S. Patent, 10,973,798B2, U.S. Patent 10,251,960B2, U.S. Patent 2021/0069121A1 and U.S. Patent 2022/0151945A1. The optimized batch F1 showed particle size (130 nm), ZP (-18.9 mV), and entrapment efficiency (85.73 %). The dual release pattern (prompt and sustained) was achieved with the SLNloaded Ambrisentan for about 24 hours. The lyophilized sample was subjected to SEM, which also revealed a spherical shape of a colloidal dispersion with a particle size of 126 nm. Hence, the F1 batch is highly recommended for solid oral delivery and also for the pilot-plant scale-up. A marked improvement in the solubility and dissolution of Ambrisentan was attained with the SLN. Moreover, the sustained delivery via the oral route enabled the patient's comfort, compliance, and therapeutic efficacy.

Macitentan and Tadalafil Combination Therapy in Incident and Prevalent Pulmonary Arterial Hypertension: Real-World Evidence from the OPUS/OrPHeUS Studies.

Historically, patients recently (≤6months) diagnosed with pulmonary arterial hypertension (PAH; incident) have had poorer survival than those with a longer (>6months) time from PAH diagnosis (prevalent). Despite guideline recommendations for initial combination therapy for most patients with PAH, many are initiated and maintained on monotherapy. Real-world evidence to evaluate the benefit of early combination treatment in newly-diagnosed patients is lacking. Patients with PAH initiating combination therapy with the endothelin receptor antagonist macitentan and the phosphodiesterase-5 inhibitor tadalafil (M+T) were identified from the combined dataset of the US, multicenter OPUS (prospective, observational drug registry; NCT02126943) and OrPHeUS (retrospective, medical chart review; NCT03197688) studies (2013-2020). Descriptive analyses were performed for the incident and prevalent cohorts, as well as the subcohort of incident patients who received M+T as first-line combination therapy (incident initial combination). In OPUS/OrPHeUS, 1336 patients with PAH received M+T during the observation period. For the incident [n=453 (33.9%)], incident initial combination [n=272 (20.4%)], and prevalent [n=837 (62.6%)] cohorts: median (Q1, Q3) M+T exposure was 14.2 (4.2, 27.5), 12.2 (3.2, 25.5), and 14.7 (4.5, 28.0) months. 12-month Kaplan-Meier estimates (95% confidence limits) for survival were 91.2% (87.7, 93.7), 88.5% (83.2, 92.2), and 92.9% (90.6, 94.6), for patients free from hospitalization were 59.4% (54.1, 64.4), 56.3% (49.1, 62.9), and 62.3% (58.5, 65.9), and for patients persisting on combination therapy were 68.6% (63.9, 72.8), 65.0% (58.8, 70.6) and 66.9% (63.5, 70.0). Adverse events (OPUS only) were reported in 77.8%, 80.2%, and 80.3% of patients, respectively, with no unexpected adverse events observed. Despite a historically worse prognosis, incident patients receiving M+T, including as initial combination therapy, had similar survival and hospitalization as prevalent patients. Safety profiles were similar across cohorts. Together, these data support the use of early combination therapy with macitentan and tadalafil.

Early Addition of Selexipag to Double Therapy for Pulmonary Arterial Hypertension

A subgroup analysis of a randomized clinical trial established the efficacy of selexipag plus background therapy (monotherapy or double oral therapy [DOT]) vs placebo plus background therapy and found that the addition of selexipag within 6 months had an added benefit. However, the timing of selexipag addition to DOT and the incremental benefit in clinical practice is not well studied. To compare triple oral therapy (TOT) consisting of selexipag, endothelin receptor antagonist (ERA), and phosphodiesterase type 5 inhibitor (PDE5i) vs DOT consisting of ERA and PDE5i. This comparative effectiveness study was conducted using data from the US Komodo claims database to emulate a randomized trial. Patients aged 18 years or older with pulmonary arterial hypertension (PAH) treated with ERA plus PDE5i with records from July 2015 through June 2022 were duplicated to TOT and DOT and artificially censored when observed treatment deviated from assigned treatment. Hypothetical randomization was emulated using inverse probability of treatment weighting, and the study accounted for censoring-induced selection bias using inverse probability of censoring weighting. A pooled logistic model estimated the per-protocol difference between treatment groups. Data were analyzed from November 2022 through July 2023. TOT (addition of selexipag within 3, 6, and 12 months of initiating DOT) vs DOT. Adjusted risk of all-cause hospitalization, PAH-related hospitalization, and PAH-related disease progression over a 2-year follow-up. A total of 2966 patients with PAH (mean [SD] age, 54.3 [14.0] years; 2125 female [71.6%]) met eligibility criteria. Adding selexipag within 6 months of ongoing DOT was associated with a reduction in risk for all-cause hospitalization (adjusted hazard ratio [aHR], 0.82; 95% CI, 0.72-0.94), PAH-related hospitalization (aHR, 0.81; 95% CI, 0.70-0.95), and PAH-related progression (aHR, 0.82; 95% CI, 0.70-0.95) vs DOT alone. There were no associations if selexipag was initiated within 12 months for all-cause hospitalization, PAH-related hospitalization, or PAH-related disease progression. The association remained with a greater decrease in risk for disease progression vs DOT for selexipag initiation within 3 months (aHR, 0.74; 95% CI, 0.61-0.90). This study found that early selexipag addition to ERA plus PDE5i was associated with a reduction in risk of hospitalization and disease progression. These findings suggest that delays in selexipag initiation likely contribute to suboptimal patient and health system outcomes.

Blood pressure management strategies and podocyte health.

Hypertension (HTN) is one of the key global cardiovascular risk factors, which is tightly linked to kidney health and disease development. Podocytes, glomerular epithelial cells that play a pivotal role in maintenance of the renal filtration barrier, are significantly affected by increased glomerular capillary pressure in HTN. Damage or loss of these cells causes proteinuria, which marks the initiation of the HTN-driven renal damage. It goes without saying that effective BP management should not only mitigate cardiovascular risks but also preserve renal function by protecting podocyte integrity. This review offers a comprehensive examination of current blood pressure (BP) management strategies and their implications for podocyte structure and function and emphasizes strategies for the reduction of proteinuria in HTN. We explore primary and secondary antihypertensive agents, including ACE inhibitors, ARBs, calcium channel blockers, diuretics, as well as newer therapies (SGLT2 blocking and endothelin receptor antagonism), emphasizing their mechanistic roles in safeguarding podocytes and curtailing proteinuria.

Blockade of endothelin receptors mitigates SARS-CoV-2-induced osteoarthritis.

Joint pain and osteoarthritis can occur as coronavirus disease 2019 (COVID-19) sequelae after infection. However, little is known about the damage to articular cartilage. Here we illustrate knee joint damage after wild-type, Delta and Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in vivo. Rapid joint injury with cystic lesions at the osteochondral junction was observed in two patients with post-COVID osteoarthritis and recapitulated in a golden Syrian hamster model. SARS-CoV-2-activated endothelin-1 signalling increased vascular permeability and caused viral spike proteins leakage into the subchondral bone. Osteoclast activation, chondrocyte dropout and cyst formation were confirmed histologically. The US Food and Drug Administration-approved endothelin receptor antagonist, macitentan, mitigated cystic lesions and preserved chondrocyte number in the acute phase of viral infection in hamsters. Delayed macitentan treatment at post-acute infection phase alleviated chondrocyte senescence and restored subchondral bone loss. It is worth noting that it could also attenuate viral spike-induced joint pain. Our work suggests endothelin receptor blockade as a novel therapeutic strategy for post-COVID arthritis.

Pressing Update: Aprocitentan for the Treatment of Hypertension.

This article reviews the published data including the pharmacology, efficacy, and safety of aprocitentan, a novel endothelin receptor antagonist developed to treat hypertension in conjunction with additional agents. A literature search was conducted from drug discovery until May 2024 through PubMed, MEDLINE, and National Institutes of Health Clinical Trials Registry utilizing the following search terms: Tryvio, aprocitentan, hypertension, resistant hypertension, endothelin receptor antagonist, and ACT-132577. All relevant English-language studies, or studies that could be appropriately translated into English, containing the pharmacology, pharmacokinetics, safety, and efficacy of aprocitentan, were selected for review. In the setting of resistant hypertension, aprocitentan has shown significant reductions in blood pressure in both medical office and 24-hour ambulatory settings at 4 weeks with a sustained effect at 40 weeks. Studies evaluating cardiovascular risk reduction have not been conducted at this time. Fluid retention and edema were the most frequent adverse events reported in clinical studies with aprocitentan. As a class, endothelin receptor antagonists may cause fetal harm; aprocitentan should be used with caution to avoid embryo-fetal toxicity. Owing to the existent barriers for the treatment of resistant hypertension, aprocitentan presents itself as an effective option when added to traditional antihypertensives. This single-strength, once-daily regimen may serve as an appealing option to both patients and prescribers. Aprocitentan is a safe and effective medication for the treatment of hypertension when added to other pharmacological therapies.