Dual Endothelin Antagonism with Aprocitentan as a Novel Therapeutic Approach for Resistant Hypertension

Highlights on U.S. FDA-approved halogen-containing drugs in 2024

This comprehensive review offers an update on the FDA-approved halogen-containing drugs in 2024. The agency approved a total of 50 drugs, including small molecules and macromolecules. Excitingly, 16 out of 50 are halogen-containing drugs, indicated to diagnose, mitigate and treat the various human diseases. Among halogens, fluorine and chlorine are highly prevalent in drug discovery and development. Therefore, the properties of fluorine and chlorine and their impact on the drug profile are briefly discussed. In addition, the specific role of halogens in these drugs has been discussed with the help of structure-activity relationships (SARs), co-crystal structures, and closely related literature precedents. This review also provides the additional information for each drug, such as trade name, active ingredients, route of administration, approval date, sponsors, indication, mode of action, major drug metabolizing enzyme(s), and route of elimination. We expect that the present review may garner the attention of drug discovery researchers and inspire them toward the potential applications of halogens to discover novel therapeutics in the future.

Resistant Hypertension: A Brief Review of Pathophysiology

A 52-year-old male comes to the internal medicine clinic for a follow-up for the management of hypertension. He was initially diagnosed with hypertension 5 years ago. His other past medical history includes obesity and hyperlipidemia. His current medications currently include losartan 100 mg daily, hydrochlorothiazide 25 mg, and amlodipine 10 mg. His physical exam is significant for an elevated in-office blood pressure of 160/105 mmHg, BMI 38, and neck circumference > 40 cm. He also reports snoring at night and having significant daytime sleepiness despite getting over 8 hours of sleep each night. This patient meets the most recent diagnostic criteria per the American Heart Association for resistant hypertension. Resistant hypertension is an increasingly prevalent phenotype encountered in both primary care and subspecialty clinics. Multiple comorbidities, including obesity, sleep apnea, chronic kidney disease, heart failure, and diabetes mellitus, are associated with resistant hypertension. Our understanding of the potential etiologies for this condition continues to evolve rapidly. We used a narrative review to explore four research areas in the pathophysiology of resistant hypertension (the sympathetic nervous system, aldosterone excess, endothelial dysfunction, and inflammation) and explore the novel therapies currently in development.

Efficacy and Safety of Aprocitentan in the Treatment of Hypertension: A Meta-Analysis of Evidence from Randomized Controlled Trials

Background

Hypertension is one of the most prevalent disorders encountered in medical practice, yet effective pharmacotherapy options for resistant hypertension are limited. In this meta-analysis, we aimed to evaluate the efficacy and safety of aprocitentan in treating hypertension.

Methods

We searched PubMed, Embase, ClinicalTrials.gov, and the Cochrane Library databases from inception to June 3, 2024, for randomized controlled trials (RCTs) that compared the efficacy and safety between aprocitentan and placebo in treating hypertension. According to the dosage of aprocitentan, the study was divided into a low-dose group (10-12.5 mg), medium-dose group (25 mg), and high-dose group (50 mg).

Results

This meta-analysis included five RCTs, which incorporated 1224 patients, and displayed that aprocitentan can reduce the mean sitting systolic blood pressure (msSBP) [(low dose subgroup: mean difference (MD): -3.85 mmHg; 95% confidence interval (CI): -7.47 to -0.23; p = 0.040; medium dose group: MD: -5.56 mmHg; 95% CI: -10.69 to -0.44; p = 0.030)], mean sitting diastolic blood pressure (msDBP) (low dose subgroup: MD: -3.95 mmHg; 95% CI: -4.06 to -3.85; p < 0.001; medium dose group: MD: -4.75 mmHg; 95% CI: -5.91 to -3.60; p < 0.001), 24-hour ambulatory systolic blood pressure (maSBP) (low dose group: MD: -4.18 mmHg; 95% CI: -4.32 to -4.04; p < 0.001; medium dose group: MD: -5.89 mmHg; 95% CI: -6.03 to -5.75; p < 0.001), and 24-hour ambulatory diastolic blood pressure (maDBP) (low dose group: MD: -4.33 mmHg; 95% CI: -4.42 to -4.24; p < 0.001; medium dose group: MD: -5.82 mmHg; 95% CI: -5.91 to -5.73; p < 0.001). In the high-dose group, there was no difference between the aprocitentan and placebo groups in the msSBP (MD: -4.83 mmHg; 95% CI: -11.44 to 1.79; p = 0.150). Meanwhile, the safety profile of aprocitentan was good, and no significant differences in the frequency of adverse events (AEs) and serious adverse events (SAEs) were observed compared to the placebo.

Conclusions

Aprocitentan significantly reduces blood pressure and has a good safety profile. However, it is worth noting that high doses of aprocitentan (50 mg) did not yield better blood pressure-lowering effects.

Aprocitentan: a new emerging prospect in the pharmacotherapy of hypertension

BACKGROUND

Resistant hypertension (RH) is linked to higher risks of cardiovascular events and there remains an unmet therapeutic need driven by pathophysiologic pathways unaddressed by guideline-recommended therapy. Whilst spironolactone is considered the preferred fourth-line therapy, its broad application is limited by its safety profile. Aprocitentan is a novel dual endothelin (ET) A and B receptors antagonist that has been recently approved by the FDA.

OBJECTIVE

This review aims to summarise the available evidence on the discovery, pharmacokinetic, pharmacodynamic, efficacy, and safety of aprocitentan in the pharmacotherapy of RH.

METHODS

We searched PubMed, Embase, and International Pharmaceutical Abstracts to identify relevant papers on aprocitentan use. Clinical trial registries were also searched.

RESULTS

Aprocitentan targets the ET pathway which remains unopposed by contemporary alternative therapies for RH. It differs from other ET receptor antagonists in its pharmacological profile, as it is eliminated independently of CYP450 or BCRP, making it less likely to cause drug-drug interactions. Current evidence demonstrates that compared to placebo, aprocitentan significantly reduces blood pressure (BP) as measured via unattended automated office BP and 24-hour ambulatory BP. The most frequently reported adverse effects were fluid retention/edema and anaemia.

CONCLUSION

Aprocitentan is a novel therapy for the management of RH that significantly reduces BP when compared to placebo. It delivers exciting prospects for future therapeutic options in the setting of RH and expands insights into its pathophysiology. However there is lack of data in relation to broader cardiovascular and renal protection, as well as its long-term safety profile.

Recent developments in the management of resistant hypertension: focus on endothelin receptor antagonists

Resistant hypertension is characterized by the inability of guideline-recommended triple combination therapy to control blood pressure (BP) to target. It is associated with a significantly increased risk of adverse outcomes. Despite abundant preclinical evidence supporting the critical role of the endothelin pathway in resistant hypertension (RH), clinical implementation of endothelin antagonists for the treatment of hypertension was hindered by various factors. Recently, the novel dual endothelin-receptor antagonist aprocitentan was tested in individuals with resistant hypertension in the PRECISION trial and provided compelling evidence supporting both short and longer-term safety and clinically meaningful and sustained BP lowering efficacy. These findings resulted in the recent regulatory approval of aprocitentan by the FDA. Aprocitentan may be a particularly useful antihypertensive option for individuals with advanced age, chronic kidney disease, and albuminuria.

Medical Measures in Hypertensives Considered Resistant

BACKGROUND

Patients with resistant hypertension are the group of hypertensive patients with the highest cardiovascular risk.

METHODS

All rules and guidelines for treatment of hypertension should be followed strictly to obtain blood pressure (BP) control in resistant hypertension. The mainstay of treatment of hypertension, also for resistant hypertension, is pharmacological treatment, which should be tailored to each patient's specific phenotype. Therefore, it is pivotal to assess nonadherence to pharmacological treatment as this remains the most challenging problem to investigate and manage in the setting of resistant hypertension.

RESULTS

Once adherence has been confirmed, patients must be thoroughly worked-up for secondary causes of hypertension. Until such possible specific causes have been clarified, the diagnosis is apparent treatment-resistant hypertension (TRH). Surprisingly few patients remain with true TRH when the various secondary causes and adherence problems have been detected and resolved. Refractory hypertension is a term used to characterize the treatment resistance in hypertensive patients using ≥5 antihypertensive drugs. All pressor mechanisms may then need blockage before their BPs are reasonably controlled.

CONCLUSIONS

Patients with resistant hypertension need careful and sustained follow-up and review of their medications and dosages at each term since medication adherence is a very dynamic process.