Single- and multiple-dose tolerability, safety, pharmacokinetics, and pharmacodynamics of the dual endothelin receptor antagonist aprocitentan in healthy adult and elderly subjects

Aprocitentan: First Approval

Aprocitentan (TRYVIO™) is a once-daily oral dual endothelin A (ETA) and B (ETB) receptor antagonist developed by Idorsia Pharmaceuticals for the treatment of hypertension. The endothelin pathway has been implicated in hypertension. Aprocitentan inhibits the binding of endothelin-1 to ETA and ETB receptors, thereby preventing its deleterious effects and lowering blood pressure. In March 2024, aprocitentan received its first approval in the USA for the treatment of hypertension in combination with other antihypertensive drugs, to lower blood pressure in adults who are not adequately controlled on other drugs. This article summarizes the milestones in the development of aprocitentan leading to this first approval for hypertension not adequately controlled on other drugs.

Population pharmacokinetics of the dual endothelin receptor antagonist aprocitentan in subjects with or without essential or resistant hypertension

Aprocitentan is a novel, potent, dual endothelin receptor antagonist that recently demonstrated efficacy in the treatment of difficult-to-treat (resistant) hypertension. The aim of this study was to develop a population pharmacokinetic (PK) model describing aprocitentan plasma concentration over time, to investigate relationships between subject-specific factors (covariates) and model parameters, and to quantify the influence of the identified covariates on the exposure to aprocitentan via model-based simulations, enabling judgment about the clinical relevance of the covariates.PK data from 902 subjects in ten Phase 1, one Phase 2, and one Phase 3 study were pooled to develop a joint population PK model. The concentration-time course of aprocitentan was described by a two-compartment model with absorption lag time, first-order absorption and elimination, and reduced relative bioavailability following very high doses of 300 and 600 mg.The population PK model described the observed data well. Volume and clearance parameters were associated with body weight. Renal function as reflected by estimated glomerular filtration rate (eGFR), hepatic impairment, and sex were identified as relevant covariates on clearance.The subject-specific characteristics of body weight, eGFR, hepatic impairment, and sex were shown to influence exposure parameters area under the concentration-time curve and maximum concentration in steady state to a limited extent, i.e., not more than 25% different from a reference subject, and therefore do not warrant dose adjustments.

Taming resistant hypertension: The promise of novel pharmacologic approaches and renal denervation

Resistant hypertension is associated with an exceedingly high cardiovascular risk and there remains an unmet therapeutic need driven by pathophysiologic pathways unaddressed by guideline-recommended therapy. While spironolactone is widely considered as the preferable fourth-line drug, its broad application is limited by its side effect profile, especially off-target steroid receptor-mediated effects and hyperkalaemia in at-risk subpopulations. Recent landmark trials have reported promising safety and efficacy results for a number of novel compounds targeting relevant pathophysiologic pathways that remain unopposed by contemporary drugs. These include the dual endothelin receptor antagonist, aprocitentan, the aldosterone synthase inhibitor, baxdrostat and the nonsteroidal mineralocorticoid receptor antagonist finerenone. Furthermore, the evidence base for consideration of catheter-based renal denervation as a safe and effective adjunct therapeutic approach across the clinical spectrum of hypertension has been further substantiated. This review will summarise the recently published evidence on novel antihypertensive drugs and renal denervation in the context of resistant hypertension.

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.

Future treatments in hypertension: Can we meet the unmet needs of patients?

The prevalence of arterial hypertension is approximately 47% in the United States and 55% in Europe. Multiple different medical therapies are used to treat hypertension including diuretics, beta blockers, calcium channel blockers, angiotensin receptor blockers, angiotensin converting enzyme inhibitors, alpha blockers, central acting alpha receptor agonists, neprilysin inhibitors and vasodilators. However, despite the numerous number of medications, the prevalence of hypertension is on the rise, a considerable proportion of the hypertensive population is resistant to these therapeutic modalities and a definitive cure is not possible with the current treatment approaches. Therefore, there is a need for novel therapeutic strategies to provide better treatment and control of hypertension. In this review, our aim is to describe the latest developments in the treatment of hypertension including novel medication classes, gene therapies and RNA-based modalities.

Aprocitentan: A new development of resistant hypertension

As the blood pressure threshold for commencing antihypertensive treatment diminishes, the cohort suffering from resistant hypertension (RH) correspondingly expands. Notwithstanding the availability of known antihypertensive medications, there exists a conspicuous lacuna in therapeutic options specifically intended for the management of RH. Currently, aprocitentan is the sole endothelin receptor antagonist (ERA) under development for addressing this pressing clinical challenge. Aprocitentan (ACT-132577), deriving its active form as a metabolite of macitentan, demonstrates oral potency as a dual endothelin (ET) receptor antagonist. This compound effectively obstructs the binding of endothelin-1 (ET-1) to both ETA and ETB receptors, exhibiting an inhibitory potency ratio of 1:16. Clinical investigation of aprocitentan has advanced to phase 3 trials, yielding promising preliminary outcomes.

Novel Dual Endothelin Inhibitors in the Management of Resistant Hypertension

Resistant hypertension (RH) is defined as the failure to achieve blood pressure control despite using triple combination therapy with a renin-angiotensin system inhibitor (RAS-i), a calcium antagonist, and a diuretic. The endothelin (ET) system is implicated in the regulation of vascular tone, primarily through vasoconstriction, intervenes in cardiac contractility with inotropic effects, and contributes to water and sodium renal reabsorption. ET inhibitors, currently approved for the treatment of pulmonary hypertension, seem to be also useful for essential hypertension and RH as well. Studies into the development of new dual ET inhibitors, which inhibit both type A and B ET (ETA and ETB) receptors, present initial results of managing RH. Aprocitentan (ACT-132577) is a novel, orally active and well tolerated dual ET receptor antagonist, which has been examined in several experimental studies and clinical trials with promising results for RH control. The recent publication of the large PRECISION study in The Lancet journal provides further reassurance regarding the efficacy and safety of aprocitentan for RH, with the aim of overcoming unmet needs in the management of this difficult group of patients.

New Dual Endothelin Receptor Antagonist Aprocitentan in Hypertension: A Systematic Review and Meta-Analysis

Hypertension is one of the most common disorders encountered, yet pharmacotherapy for resistant hypertension has limited effective options. Aprocitentan is postulated to be a novel anti-hypertensive. The main goal was to determine the effect of aprocitentan on blood pressure among patients with hypertension. A thorough search of five electronic databases, including PubMed Central, PubMed, EMBASE, Springer, and Google Scholar, was carried out. The study included nine articles with a total of 2024 participants. With doses exceeding 25 mg, plasma ET-1(endothelin-1) concentrations, which show ETB (Endothelin receptor type B) receptor antagonism, significantly rose. Aprocitentan significantly reduced systolic and diastolic blood pressure with both doses of 10mg and 25mg in patients with hypertension. Further research is warranted to evaluate the efficacy, safety, and long-term outcomes of aprocitentan and its synergistic effect with other anti-hypertensives.

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.

Endothelin receptor antagonists in kidney protection for diabetic kidney disease and beyond?

The burden of chronic kidney disease is increasing worldwide, largely due to the increasing global prevalence of diabetes mellitus and hypertension. While renin angiotensin system inhibitors and sodium-glucose cotransporter two inhibitors are the management cornerstone for reducing kidney and cardiovascular complications in patients with diabetic and non-diabetic kidney disease (DKD), they are partially effective and further treatments are needed to prevent the progression to kidney failure. Endothelin receptor antagonism represent a potential additional therapeutic option due to its beneficial effect on pathophysiological processes involved in progressive kidney disease including proteinuria, which are independently associated with progression of kidney disease. This review discusses the biological mechanisms of endothelin receptor antagonists (ERA) in kidney protection, the efficacy and safety of ERA in randomised controlled trials reporting on kidney outcomes, and its potential future use in both diabetic and non-DKDs.

From ABCD to E for endothelin in resistant hypertension

The potent vasoconstrictor peptide endothelin-1 has long been recognized as a physiological regulator of vascular tone. However, pharmacological blockade of the endothelin-1 pathway has few proven indications thus far. A recent clinical trial for resistant hypertension published in The Lancet may yet herald a new era for endothelin receptor antagonists into the clinical mainstream.

Dual endothelin antagonist aprocitentan for resistant hypertension (PRECISION): a multicentre, blinded, randomised, parallel-group, phase 3 trial

BACKGROUND

Resistant hypertension is associated with increased cardiovascular risk. The endothelin pathway has been implicated in the pathogenesis of hypertension, but it is currently not targeted therapeutically, thereby leaving this relevant pathophysiological pathway unopposed with currently available drugs. The aim of the study was to assess the blood pressure lowering efficacy of the dual endothelin antagonist aprocitentan in patients with resistant hypertension.

METHODS

PRECISION was a multicentre, blinded, randomised, parallel-group, phase 3 study, which was done in hospitals or research centres in Europe, North America, Asia, and Australia. Patients were eligible for randomisation if their sitting systolic blood pressure was 140 mm Hg or higher despite taking standardised background therapy consisting of three antihypertensive drugs, including a diuretic. The study consisted of three sequential parts: part 1 was the 4-week double-blind, randomised, and placebo-controlled part, in which patients received aprocitentan 12·5 mg, aprocitentan 25 mg, or placebo in a 1:1:1 ratio; part 2 was a 32-week single (patient)-blind part, in which all patients received aprocitentan 25 mg; and part 3 was a 12-week double-blind, randomised, and placebo-controlled withdrawal part, in which patients were re-randomised to aprocitentan 25 mg or placebo in a 1:1 ratio. The primary and key secondary endpoints were changes in unattended office systolic blood pressure from baseline to week 4 and from withdrawal baseline to week 40, respectively. Secondary endpoints included 24-h ambulatory blood pressure changes. The study is registered on ClinicalTrials.gov, NCT03541174.

FINDINGS

The PRECISION study was done from June 18, 2018, to April 25, 2022. 1965 individuals were screened and 730 were randomly assigned. Of these 730 patients, 704 (96%) completed part 1 of the study; of these, 613 (87%) completed part 2 and, of these, 577 (94%) completed part 3 of the study. The least square mean (SE) change in office systolic blood pressure at 4 weeks was -15·3 (SE 0·9) mm Hg for aprocitentan 12·5 mg, -15·2 (0·9) mm Hg for aprocitentan 25 mg, and -11·5 (0·9) mm Hg for placebo, for a difference versus placebo of -3·8 (1·3) mm Hg (97·5% CI -6·8 to -0·8, p=0·0042) and -3·7 (1·3) mm Hg (-6·7 to -0·8; p=0·0046), respectively. The respective difference for 24 h ambulatory systolic blood pressure was -4·2 mm Hg (95% CI -6·2 to -2·1) and -5·9 mm Hg (-7·9 to -3·8). After 4 weeks of withdrawal, office systolic blood pressure significantly increased with placebo versus aprocitentan (5·8 mm Hg, 95% CI 3·7 to 7·9, p<0·0001). The most frequent adverse event was mild-to-moderate oedema or fluid retention, occurring in 9%, 18%, and 2% for patients receiving aprocitentan 12·5 mg, 25 mg, and placebo, during the 4-week double-blind part, respectively. This event led to discontinuation in seven patients treated with aprocitentan. During the trial, a total of 11 treatment-emergent deaths occurred, none of which were regarded by the investigators to be related to study treatment.

INTERPRETATION

In patients with resistant hypertension, aprocitentan was well tolerated and superior to placebo in lowering blood pressure at week 4 with a sustained effect at week 40.

FUNDING

Idorsia Pharmaceuticals and Janssen Biotech.

Single-dose pharmacokinetics, safety, and tolerability of the dual endothelin receptor antagonist aprocitentan in subjects with moderate hepatic impairment

The effect of moderate hepatic impairment on the pharmacokinetics (PK), safety, and tolerability of the dual endothelin receptor antagonist aprocitentan was clinically investigated as 25% of aprocitentan is cleared through the liver. Aprocitentan is in clinical development for the treatment of resistant hypertension. This was an open-label, Phase 1 study. Subjects were recruited in two groups (i.e., moderate hepatic impairment (Child-Pugh B; n = 8) and matched healthy subjects (n = 9) and received a single oral dose of 25 mg aprocitentan. Thereafter, they were observed for 14 days. Due to personal reasons one healthy subject discontinued the study. The PK of aprocitentan were similar between subjects with moderate hepatic impairment and healthy subjects, with maximum plasma concentrations (C_max) reached at 4.0 h. There was no difference in C_max, indicated by the geometric means ratio (90% confidence interval) of 1.03 (0.86-1.24). There was a lower apparent clearance, a similar apparent volume of distribution, a longer terminal half-life (56.4 h vs 48.3 h in healthy subjects), and an increase in area under the curve from zero to infinity of 23% in moderate hepatically impaired subjects compared to healthy subjects. There were no differences observed in plasma protein binding (range 98.7-99.0%). Aprocitentan was well tolerated, and headache was the only adverse event reported by one subject. In conclusion, there were no clinically relevant differences in PK between subjects with moderate hepatic impairment and healthy subjects. Based on these results, aprocitentan can be administered in subjects with mild and moderate hepatic impairment and dose adjustment is not required.Clinical Trial Registration ClinicalTrials.gov NCT04252495.

Aprocitentan, A Dual Endothelin Receptor Antagonist Under Development for the Treatment of Resistant Hypertension

Aprocitentan (ACT-132577) is an orally active, dual endothelin-1 (ET-1) receptor antagonist that prevents the binding of ET-1 to both ETA/ETB receptors. It is an active metabolite of macitentan (obtained by oxidative depropylation), an orphan drug used for the treatment of pulmonary arterial hypertension. Aprocitentan is highly bound to plasma proteins and is eliminated in both urine and feces. It is well tolerated across all doses (up to 600 mg with single dose and 100 mg once a day at multiple doses). Its pharmacokinetic profile shows a half-life of 44 h, fitting a once-daily dosing regimen with plasma ET-1 concentrations (reflecting ET receptor antagonism), significantly increasing with doses ≥ 25 mg. Only minor differences in exposure between healthy females and males, healthy elderly and adult subjects, fed and fasted conditions, and renal function have been observed. Aprocitentan in patients with resistant hypertension is currently under investigation in the PRECISION phase III trial (ClinicalTrials identifier: NCT03541174). Nonetheless, results of pre-clinical data and studies in humans support the potential role of aprocitentan in this clinical setting. The absolute blood pressure (BP) reductions with aprocitentan are in the ranges established as a surrogate for reduction in cardiovascular morbidity in hypertension. Significant changes in BP with aprocitentan are observed within 14 days, and its BP-lowering effects have also been documented with ambulatory BP monitoring. Finally, aprocitentan enhances the BP-lowering effects of other antihypertensive drugs, including renin-angiotensin-system blockers. In conclusion, aprocitentan ameliorates the effects of ET-1 and could potentially reduce BP and provide broader cardiovascular protection in patients with resistant hypertension. Available data support the hypothesis that this new agent could expand our antihypertensive arsenal in resistant hypertension, making aprocitentan an attractive candidate for further large-scale trials.

A Population Pharmacokinetic Model of Macitentan and Its Active Metabolite Aprocitentan in Healthy Volunteers and Patients with Pulmonary Arterial Hypertension

BACKGROUND

Macitentan and its active metabolite, aprocitentan, are non-peptide, potent, dual endothelin receptor antagonists. Macitentan is approved for the treatment of pulmonary arterial hypertension in adults, at a dose of 10 mg/day.

OBJECTIVE

The objective of this study was to develop a comprehensive population model to describe the pharmacokinetics of macitentan and aprocitentan in healthy adults and adult subjects with pulmonary arterial hypertension.

METHODS

Pharmacokinetic data of 452 subjects in nine studies, after single and repeated doses (dose range 0.2-600 mg), were pooled for a non-linear mixed-effects analysis and the assessment of covariates, i.e., body weight, age, sex, race, renal and hepatic impairment, health status (healthy volunteers vs patients with pulmonary arterial hypertension), and formulation (capsules vs tablets) on pharmacokinetic parameters.

RESULTS

The final model was an open one-compartment disposition model, with linear elimination for macitentan and linear formation and elimination for aprocitentan. A semi-mechanistic absorption model described the dose dependency and multiple peaks observed for macitentan. For a female patient with pulmonary arterial hypertension after oral administration at 10 mg, macitentan reached a maximum concentration after 9 h and, following daily dosing, reached steady state after 3 days with a twofold accumulation factor. The apparent volume of distribution was 34 L and clearance was 1.39 L/h. Aprocitentan reached maximum concentration after 51 h and steady state after 9 days, with a 12.5-fold accumulation factor. Body weight, sex, race, renal impairment, health status, and formulation were statistically significant covariates on pharmacokinetic parameters.

CONCLUSIONS

The comprehensive population pharmacokinetic model adequately described the pharmacokinetics of macitentan and aprocitentan across different dose concentrations, regimens, and formulations. Several covariates significantly influenced the pharmacokinetics of macitentan and aprocitentan, but none was considered clinically relevant.

Aprocitentan (a Dual Endothelin-Receptor Antagonist) for Treatment-Resistant Hypertension

ABSTRACT

Treatment-resistant hypertension (TRH) is associated with increased cardiovascular risks and progression of chronic kidney disease. The pathophysiology of TRH is multifactorial, including overactivity of the renin-angiotensin-aldosterone system and sympathetic nervous system, endothelial dysfunction, and volume overload. Endothelin-1 is a vasoconstrictive peptide that causes neurohormonal and sympathetic activation, increased aldosterone synthesis and secretion, endothelial dysfunction, vascular hypertrophy and remodeling, and fibrosis. Endothelin-1 acts through 2 receptors, ETA and ETB. Activation of ETA receptors in vascular smooth muscle cells results in vasoconstriction, whereas ETB receptor activation results in vasoconstriction in the vascular smooth muscle cells and vasodilation through nitric oxide release in endothelial cells. Aprocitentan is novel, oral, dual endothelin-receptor antagonist that has demonstrated a more favorable tolerability and safety profile in early clinical trials compared with other endothelin-receptor antagonists studied. Phase 2 trial data support a significant reduction in blood pressure compared to placebo and similar blood pressure reduction compared to a moderately dosed angiotensin-converting enzyme inhibitor in patients with essential hypertension. An ongoing phase 3 randomized clinical trial is evaluating aprocitentan's efficacy and safety in patients with TRH receiving multiple antihypertensives. Additional research is needed to determine aprocitentan's role in therapy, but this agent may be a suitable treatment option for TRH.

Endothelin-targeted new treatments for proteinuric and inflammatory glomerular diseases: focus on the added value to anti-renin-angiotensin system inhibition

Chronic kidney disease (CKD) is the main cause of end-stage renal disease worldwide arising as a frequent complication of diabetes, obesity, and hypertension. Current therapeutic options, mainly based of inhibition of the renin-angiotensin system (RAS), provide imperfect renoprotection if started at an advanced phase of the disease, and treatments that show or even reverse the progression of CKD are needed. The endothelin (ET) system contributes to the normal renal physiology; however, robust evidence suggests a key role of ET-1 and its cognate receptors, in the progression of CKD. The effectiveness of ET receptor antagonists in ameliorating renal hemodynamics and fibrosis has been largely demonstrated in different experimental models. A significant antiproteinuric effect of ET receptor antagonists has been found in diabetic and non-diabetic CKD patients even on top of RAS blockade, and emerging evidence from ongoing clinical trials highlights their beneficial effects on a wide range of kidney disorders.

Hypertension: Current trends and future perspectives

Hypertension is a significant and increasing global health issue. It is a leading cause of cardiovascular disease and premature death worldwide due to its effects on end organs, and through its associations with chronic kidney disease, diabetes mellitus and obesity. Despite current management strategies, many patients do not achieve adequate blood pressure (BP) control. Hypertension-related cardiovascular mortality rates are rising in tandem with the increasing global prevalence of chronic kidney disease, diabetes mellitus and obesity. Improving BP control must therefore be urgently prioritised. Strategies include utilising existing antihypertensive agents more effectively, and using treatments developed for co-existing conditions (such as sodium-glucose cotransporter 2 inhibitors for diabetes mellitus) that offer additional BP-lowering and cardiovascular benefits. Additionally, novel therapeutic agents that target alternative prohypertensive pathways and that offer broader cardiovascular protection are under development, including dual angiotensin receptor-neprilysin inhibitors. Nonpharmacological strategies such as immunotherapy are also being explored. Finally, advancing knowledge of the human genome and molecular modification technology may usher in an exciting new era of personalised medicine, with the potential to revolutionise the management of hypertension.

Multiple-Dose Pharmacokinetics, Safety, and Tolerability of Aprocitentan, a Dual Endothelin Receptor Antagonist, in Healthy Japanese and Caucasian Subjects

Aprocitentan is an orally active dual endothelin receptor antagonist currently in development for treatment of difficult-to-control (resistant) hypertension. In phase 1 and 2 studies, aprocitentan has been characterized predominantly in Caucasian subjects. In this bridging, double-blind study, 20 healthy Japanese and Caucasian male and female subjects received 25 mg of aprocitentan or placebo once daily for 10 days and were monitored until 216 hours after the last dosing. The pharmacokinetics of aprocitentan were similar between ethnicities. At steady state, maximum plasma concentration was reached at 4 and 3 hours, and elimination half-life was 49.1 and 48.8 hours for Japanese and Caucasian subjects, respectively. The accumulation index was around 3 for both populations. Geometric means ratios for maximum plasma concentration and area under the plasma concentration-time curve during 1 dosing interval were around 1, with 90% confidence interval ranging from 0.87 to 1.30. Aprocitentan was safe and well tolerated in both groups. As no clinically relevant differences were found between Japanese and Caucasian subjects, it is unlikely that the pharmacokinetics of aprocitentan would differ significantly between Caucasian subjects and other ethnicities. Aprocitentan can therefore be administered at a dose level of up to 25 mg in any ethnicity without dose adjustment.

Effects of the Dual Endothelin Receptor Antagonist Aprocitentan on Body Weight and Fluid Homeostasis in Healthy Subjects on a High Sodium Diet

Aprocitentan is a novel, oral, dual endothelin receptor antagonist (ERA) in development in difficult-to-control hypertension. As fluid retention and edema are concerns with ERAs, we investigated whether aprocitentan causes weight gain in healthy subjects on a high sodium diet and explored potential mechanisms if occurring. This double-blind, randomized, placebo-controlled, crossover study enrolled 28 subjects. Three doses of aprocitentan (10, 25, or 50 mg/day for 9 days) were compared with placebo. Increases in body weight were observed with aprocitentan (placebo-corrected mean weight gains [90% confidence interval]) of 0.43 [0.05-0.80], 0.77 [0.03-1.51], and 0.83 [0.33-1.32] kg at 10 mg, 25 mg, and 50 mg, respectively. Decreases in hemoglobin and uric acid were observed. Plasma volume increased at most by 5.5% without dose-response relationship. Urinary sodium excretion decreased at 10 mg and 25 mg but not at 50 mg. Therefore, aprocitentan produced moderate weight increases in healthy subjects on high sodium diet, without obvious sodium retention.

Endothelin Receptor Antagonists: Status Quo and Future Perspectives for Targeted Therapy

The endothelin axis, recognized for its vasoconstrictive action, plays a central role in the pathology of pulmonary arterial hypertension (PAH). Treatment with approved endothelin receptor antagonists (ERAs), such as bosentan, ambrisentan, or macitentan, slow down PAH progression and relieves symptoms. Several findings have indicated that endothelin is further involved in the pathogenesis of certain other diseases, making ERAs potentially beneficial in the treatment of various conditions. In addition to PAH, this review summarizes the use and perspectives of ERAs in cancer, renal disease, fibrotic disorders, systemic scleroderma, vasospasm, and pain management. Bosentan has proven to be effective in systemic sclerosis PAH and in decreasing the development of vasospasm-related digital ulcers. The selective ERA clazosentan has been shown to be effective in preventing cerebral vasospasm and delaying ischemic neurological deficits and new infarcts. Furthermore, in the SONAR (Study Of Diabetic Nephropathy With Atrasentan) trial, the selective ERA atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease. These data suggest atrasentan as a new therapy in the treatment of diabetic nephropathy and possibly other renal diseases. Preclinical studies regarding heart failure, cancer, and fibrotic diseases have demonstrated promising effects, but clinical trials have not yet produced measurable results. Nevertheless, the potential benefits of ERAs may not be fully realized.

Randomized Dose-Response Study of the New Dual Endothelin Receptor Antagonist Aprocitentan in Hypertension

Supplemental Digital Content is available in the text.

This study examined the dose-response characteristics of aprocitentan, a dual endothelin A/endothelin B receptor antagonist, in patients with essential hypertension. In a randomized, double-blind, parallel study design, eligible patients with a sitting diastolic blood pressure (BP) of 90–109 mm Hg received aprocitentan 5, 10, 25, or 50 mg, placebo, or lisinopril 20 mg as a positive control once daily for 8 weeks. Multiple automated office BP readings were obtained with patients resting unattended (unattended automated office BP) at baseline, weeks 2, 4, and 8. Ambulatory BP was monitored for 24 hours at baseline and week 8. After a single-blind placebo run-in period, 490 eligible patients were randomized to the double-blind phase, with 409 patients completing 8 weeks of therapy per protocol. Aprocitentan 10, 25, and 50 mg decreased sitting systolic/diastolic unattended automated office BP from baseline to week 8 (placebo-corrected decreases: 7.05/4.93, 9.90/6.99, and 7.58/4.95 mm Hg, respectively, P≤0.014 versus placebo), compared with an unattended automated office BP reduction of 4.84/3.81 mm Hg with lisinopril 20 mg. For patients with valid ambulatory BP, aprocitentan 10, 25, and 50 mg significantly decreased placebo-corrected 24-hour BP by 3.99/4.04, 4.83/5.89, and 3.67/4.45 mm Hg, respectively. Incidence of adverse events was similar in the aprocitentan groups (22.0%–40.2%) and the placebo group (36.6%). Aprocitentan produced dose-dependent decreases in hemoglobin, hematocrit, albumin, and uric acid, an increase in estimated plasma volume, but no change in weight versus placebo. These findings support further investigation of aprocitentan at doses of 10 to 25 mg in hypertension.

Hypertension and Cardiovascular Mortality in Patients with Cushing Syndrome

Patients with Cushing syndrome have an increased mortality rate, primarily due to increased cardiovascular death, which is driven by hypertension, diabetes, obesity, and dyslipidemia. These should be evaluated before and after active hypercortisolism, and each should be treated specifically. Antihypertensives may be chosen based on probable pathophysiology. Thus, inhibitors of the renin-angiotensinogen system are recommended. Mineralocorticoid antagonists are helpful in hypokalemic patients. Other agents are often needed to normalize blood pressure. If medical treatment of Cushing syndrome is chosen, the goal should be to normalize cortisol (or its clinical action); if this is not achieved, it is more difficult to treat comorbidities.