Ambrisentan for the treatment of adults with pulmonary arterial hypertension: a review

Endothelin-1 axes in the framework of predictive, preventive and personalised (3P) medicine

Endothelin-1 (ET-1) is involved in the regulation of a myriad of processes highly relevant for physical and mental well-being; female and male health; in the modulation of senses, pain, stress reactions and drug sensitivity as well as healing processes, amongst others. Shifted ET-1 homeostasis may influence and predict the development and progression of suboptimal health conditions, metabolic impairments with cascading complications, ageing and related pathologies, cardiovascular diseases, neurodegenerative pathologies, aggressive malignancies, modulating, therefore, individual outcomes of both non-communicable and infectious diseases such as COVID-19. This article provides an in-depth analysis of the involvement of ET-1 and related regulatory pathways in physiological and pathophysiological processes and estimates its capacity as a predictor of ageing and related pathologies,a sensor of lifestyle quality and progression of suboptimal health conditions to diseases for their targeted preventionand as a potent target for cost-effective treatments tailored to the person.

Pulmonary hypertension in majority countries: opportunities amidst challenges

PURPOSE OF REVIEW

Pulmonary hypertension is a deadly disease, the causes of which vary between geographical regions. Eighty four percentage of the world's population lives in majority countries (also called low-income and middle-income countries), yet data on pulmonary hypertension in these settings are proportionally scarce. This article provides a review of pulmonary hypertension in majority countries, focusing in detail on the most common causes in these regions, and highlights contextual challenges faced.

RECENT FINDINGS

Epidemiological data confirms a complex and overlapping array of causes, with pulmonary hypertension because of conditions such as rheumatic heart disease, HIV, schistosomiasis, chronic lung disease and sickle cell disease. Delayed pulmonary hypertension diagnosis remains a concern and is ascribed to a lack of resources and lack of pulmonary hypertension awareness by health professionals. Pulmonary hypertension diagnosis is frequently considered once signs of right heart failure emerge, while echocardiography and right heart catheterization are unavailable in many settings. Accurate data on the prevalence of pulmonary hypertension in many of these regions are needed and could be achieved by establishing and frequent review of national databases where the incident and prevalent pulmonary hypertension cases are captured.

SUMMARY

There is urgent need for pulmonary hypertension advocacy among clinicians in the primary, secondary and tertiary healthcare sectors of majority countries, and validated noninvasive diagnostic algorithms are needed. Increased awareness and early diagnosis are likely to improve outcomes of pulmonary hypertension patients in these regions, and potentially stimulate locally relevant research.

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.

The potential of antioxidant activity of methanolic extract of Coscinium fenestratum (Goetgh.) Colebr (Menispermaceae)

To explore the possible bioactive compounds and to study the antioxidant capacity of Coscinium fenestratum (Goetgh.) Colebr (Menispermaceae), the qualitative and quantitative phytochemical screening for various secondary metabolites were evaluated. Using the GC-MS analysis, a total number of 30 phytochemical compounds were predicted with their retention time, molecular weight, molecular formula, peak area, structure and activities. The most prevailing heterocyclic compound was Bis(2,4,6- triisopropylphenyl) phosphinicazide (6.70%). The antioxidant activity was evaluated by spectrophotometric methods using the reducing power assay and the DPPH• and ABTS•+ scavenging assays. The activity was determined to be increased in all the test samples with the increase in the volume of the extract. C. fenestratum possess a good source of many bioactive compounds that are used to prevent diseases linked with oxidative stress.

Systemic Sclerosis Pathogenesis and Emerging Therapies, beyond the Fibroblast

Systemic sclerosis (SSc) is a complex rheumatologic autoimmune disease in which inflammation, fibrosis, and vasculopathy share several pathogenic pathways that lead to skin and internal organ damage. Recent findings regarding the participation and interaction of the innate and acquired immune system have led to a better understanding of the pathogenesis of the disease and to the identification of new therapeutic targets, many of which have been tested in preclinical and clinical trials with varying results. In this manuscript, we review the state of the art of the pathogenesis of this disease and discuss the main therapeutic targets related to each pathogenic mechanism that have been discovered so far.

Surveillance on The Safety and Efficacy of Ambrisentan (Volibris Tablet 2.5 mg) in Patients with Pulmonary Arterial Hypertension in Real Clinical Practice: Post-marketing Surveillance (Interim Analysis Report)

BACKGROUND AND OBJECTIVE

Pulmonary arterial hypertension (PAH) is an intractable and rare disease and the accumulation of clinical evidence under real-world setting is needed. A post-marketing surveillance for the endothelin receptor antagonist ambrisentan (Volibris tablet) has been conducted by all-case investigation since September 2010. This paper is an interim report on the safety and efficacy of ambrisentan in 702 patients with PAH.

METHODS

PAH patients aged 15 years or older were subjected to the analysis. The safety analysis by overall cases or stratification of patient backgrounds and the efficacy analysis were investigated.

RESULTS

Regarding patient characteristics, the 702 patients subjected to safety analysis included 543 (77.4%) women and 546 (77.8%) patients at WHO functional class II/III. The mean observational time was 392.7 days. A total of 324 adverse drug reaction (ADR) occurred in 204 (29.1%) patients. Common ADRs (≥ 2%) included anemia (4.6%), peripheral edema (4.1%), headache (3.6%), edema and face edema (2.6% each), abnormal hepatic function (2.3%), and epistaxis (2.1%). There were 82 serious ADRs occurring in 44 (6.3%) patients (385 serious adverse events in 184 (26.2%) patients). Although 11 (1.6%) interstitial lung disease (ILD) cases were reported, all were observed in patients with disease that may contribute to ILD and therefore it is difficult to assess if ambrisentan was associated with these events. There was no difference in safety in relation to the presence/absence of connective tissue disease-related PAH (CTD-PAH) or combination therapy. Among 677 patients subjected to efficacy analysis, those in whom hemodynamic status was determined before and after treatment showed improvement in the mean pulmonary arterial pressure and pulmonary vascular resistance after treatment.

CONCLUSION

The interim results showed safety consistent with the known profile of ambrisentan in terms of the types and frequencies of ADRs in patients with PAH in real clinical practice, in comparison with previous clinical trials in Japan and the rest of the world. Thus, these results provided another corroboration of the tolerability of ambrisentan and we continue to monitor proper use information via the post-marketing surveillance to ensure any new safety signals are identified in a timely manner (ClinTrial.gov: NCT01406327).

HIV-associated pulmonary hypertension

PURPOSE OF REVIEW

HIV-associated pulmonary arterial hypertension (HIV-PAH) is a well-recognized severe cardiovascular complication of HIV infection that confers an adverse prognosis irrespective of the stage of disease. This review will summarize the available data on HIV-PAH epidemiology and provide insights into the pathophysiology and therapeutic strategies currently available.

RECENT FINDINGS

Patients with HIV are several thousand times more likely to develop HIV-PAH compared to the incidence of idiopathic PAH. Several HIV viral proteins are implicated in the pathogenesis although the exact mechanism remains unknown. In the past two decades, there have been several new treatment strategies that appear effective in treating HIV-PAH. Novel pathophysiologic mechanisms implicating the transforming growth factor β receptor family may offer novel therapeutic targets in the future.

SUMMARY

As antiretroviral therapy continues to improve health outcomes for patients with HIV, there needs to be a shift in focus of care toward chronic noncommunicable diseases. Among cardiovascular disease-complicating chronic HIV infection, HIV-PAH is a severe progressive disease that leads to right heart failure and death. Currently available treatment strategies are effective, however, furthering our understanding of HIV-PAH will be critical as it is likely to become the commonest cause of PAH worldwide.

Impaired systemic oxygen extraction in treated exercise pulmonary hypertension: a new engine in an old car?

Ambrisentan in 22 patients with pulmonary hypertension diagnosed during exercise (ePH) improved pulmonary hemodynamics; however, there was only a trend toward increased maximum oxygen uptake (VO₂max) secondary to decreased maximum exercise systemic oxygen extraction (Ca-vO₂). We speculate that improved pulmonary hemodynamics at maximum exercise “unmasked” a pre-existing skeletal muscle abnormality.

Ambrisentan: a review of its use in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease defined by an elevation in pulmonary arterial pressure that can lead to right heart failure and death. Ambrisentan is a selective endothelin receptor antagonist approved for the treatment of idiopathic, heritable PAH and connective tissue disease-associated PAH. Ambrisentan has been shown to improve exercise capacity and hemodynamics with an acceptable side-effect profile. It has also proven to be safely used in combination with other PAH-specific medications, especially with phosphodiesterase-5 inhibitors. In the recent randomized trial, AMBITION, it was shown that upfront combination therapy of ambrisentan and tadalafil significantly decreased the risk of clinical failure compared with monotherapy. This review describes the drug profile of ambrisentan and its safety and efficacy in the treatment of PAH.

Comparative efficacy and acceptability of endothelin receptor antagonists for pulmonary arterial hypertension: A network meta-analysis

BACKGROUND

Endothelin receptor antagonists (ERAs) such as ambrisentan, sitaxsentan, bosentan and macitentan are primary drug therapies for pulmonary arterial hypertension (PAH) patients. However, the optimal drugs for PAH remained controversial due to heterogeneous nature of randomized control trials (RCTs).

METHODS

Apart from traditional meta-analysis, network meta-analysis (NMA) was performed in this study for multiple comparisons among PAH therapies. The 6 minute walking distance (6MWD) and clinical worsening were efficacy outcomes whereas serious adverse effects (SAE) and all-cause discontinuation were acceptability outcomes. The weighted mean difference (WMD) and odds ratio (OR) along with their 95% confidence interval (95% CI) or 95% credible interval (95% CrI) were used to evaluate the positive and negative effects of these therapies on PAH patients.

RESULTS

By synthesizing direct evidence from 10 studies with a total number of 2172 patients, we discovered that all of the four PAH therapies significantly increased the average 6MWD in comparison to the placebo (P-value<0.05). Moreover, bosentan and ambrisentan both showed significant association with a decrease in the risk of clinical worsening compared to placebo. Regarding of all-cause discontinuation, ambrisentan is the only therapy which was significantly associated with a risk decrease compared to placebo. However, there was no sufficient evidence suggesting significant difference in any efficacy or acceptability outcomes between any two of the PAH therapies (P-value>0.05).

CONCLUSION

Ambrisentan could be considered as the most appropriate therapy among the four ERAs for PAH patients. Bosentan also behaved well, but it is not as safe as ambrisentan.

Managing adult Fontan patients: where do we stand?

The Fontan operation is performed as a palliative procedure to improve survival in infants born with a functionally univentricular circulation. The success of the operation is demonstrated by a growing adult Fontan population that exists with this unique physiology. Late follow-up has demonstrated expected and unexpected sequelae, and has shown multisystem effects of this circulation. This review discusses the challenges of managing the late complications in terms of understanding this unique physiology and the innovative therapeutic interventions that are being investigated. The challenge remains to maintain quality of life for adult survivors, as well as extending life expectancy.

Innovative solutions are required to meet the challenges of the Fontan circulation faced in adult lifehttp://ow.ly/XTSm305oH8b