Medications for the treatment of pulmonary arterial hypertension: a systematic review and network meta-analysis

Sotatercept: A novel therapeutic approach for pulmonary arterial hypertension through transforming growth factor-β signaling modulation

Pulmonary arterial hypertension (PAH) is a progressive disease marked by degeneration of the lung’s blood vessels. As the disease progresses, the resistance to blood flow in the pulmonary arteries increases, putting a strain on the right side of the heart as it pumps blood through the lungs. PAH is characterized by changes in the structure of blood vessels and excessive cell growth. Untreated PAH leads to irreversible right-sided heart failure, often despite medical intervention. Patients experience a gradual decline in function until they are unable to perform daily activities. Advances in treatment have improved the prognosis for many PAH patients. Currently approved therapies target the prostacyclin, endothelin, nitric oxide, or phosphodiesterase pathways to slow the progression of the disease. To address the unmet need for effective PAH therapies, research efforts are focused on identifying new targets and developing therapies that specifically address the underlying disease mechanisms and restore vascular wall homeostasis. Among these, sotatercept, a fusion protein that targets the transforming growth factor-β superfamily signaling pathway, has emerged as a promising therapeutic option. In this review, we examine the available evidence from clinical trials to assess the potential of sotatercept as a treatment for PAH.

PI3K p85α/HIF-1α accelerates the development of pulmonary arterial hypertension by regulating fatty acid uptake and mitophagy

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by lipid accumulation and mitochondrial dysfunction. This study was designed to investigate the effects of hypoxia-inducible factor-1α (HIF-1α) on fatty acid uptake and mitophagy in PAH.

METHODS

Peripheral blood samples were obtained from PAH patients. Human pulmonary arterial smooth muscle cells and rat cardiac myoblasts H9c2 were subjected to hypoxia treatment. Male Sprague-Dawley rats were treated with monocrotaline (MCT). Right ventricular systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), pulmonary artery remodeling, and lipid accumulation were measured. Cell proliferation and ROS accumulation were assessed. Mitochondrial damage and autophagosome formation were observed. Co-immunoprecipitation was performed to verify the interaction between HIF-1α and CD36/PI3K p85α.

RESULTS

HIF-1α, CD36, Parkin, and PINK1 were upregulated in PAH samples. HIF-1α knockdown or PI3K p85α knockdown restricted the expression of HIF-1α, PI3K p85α, Parkin, PINK1, and CD36, inhibited hPASMC proliferation, promoted H9c2 cell proliferation, reduced ROS accumulation, and suppressed mitophagy. CD36 knockdown showed opposite effects to HIF-1α knockdown, which were reversed by palmitic acid. The HIF-1α activator dimethyloxalylglycine reversed the inhibitory effect of Parkin knockdown on mitophagy. In MCT-induced rats, the HIF-1α antagonist 2-methoxyestradiol (2ME) reduced RVSP, RVHI, pulmonary artery remodeling, lipid accumulation, and mitophagy. Recombinant CD36 abolished the therapeutic effect of 2ME but inhibited mitophagy. Activation of Parkin/PINK1 by salidroside (Sal) promoted mitophagy to ameliorate the pathological features of PAH-like rats, and 2ME further enhanced the therapeutic outcome of Sal.

CONCLUSION

PI3K p85α/HIF-1α induced CD36-mediated fatty acid uptake and Parkin/PINK1-dependent mitophagy to accelerate the progression of experimental PAH.

Dihydromyricetin treats pulmonary hypertension by modulating CKLF1/CCR5 axis-induced pulmonary vascular cell pyroptosis

Pulmonary hypertension (PH) is a progressive cardiopulmonary disease characterized by elevated pulmonary artery pressure and vascular remodeling, resulting in poor prognosis and increased mortality rates. Chemokine-like factor 1 (CKLF1) plays a significant role in inducing inflammation and cell proliferation, both of which are critical processes in the pathogenesis of various diseases. Dihydromyricetin (DMY) has garnered attention for its potent anti-inflammatory properties. This study evaluated the protective effects of DMY against PH, demonstrating that DMY treatment can mitigate pyroptosis in pulmonary artery endothelial cells (PAECs) and pulmonary artery smooth muscle cells (PASMCs) in vivo via the CKLF1/CCR5 axis. Results indicated significant improvements in hemodynamics, inflammatory responses, fibrosis, vascular remodeling, and right ventricular hypertrophy in PH rats following DMY treatment. Furthermore, the interaction between CKLF1 and CCR5 was investigated in CKLF1-/- rats after PH induction. DMY was found to downregulate CKLF1 expression and the inflammatory response in the lungs, with its therapeutic efficacy diminished following CKLF1 knockdown. This study underscores the therapeutic potential of DMY in the management of PH and lays a foundation for future research and clinical applications.

Transforming respiratory diseases management: a CMO-based hospital pharmaceutical care model

Introduction

Respiratory diseases encompass a diverse range of conditions that significantly impact global morbidity and mortality. While common diseases like asthma and COPD exhibit moderate symptoms, less prevalent conditions such as pulmonary hypertension and cystic fibrosis profoundly affect quality of life and mortality. The prevalence of these diseases has surged by approximately 40% over the past 3 decades. Despite advancements in pharmacotherapy, challenges in drug administration, adherence, and adverse effects persist. This study aimed to develop and perform an interim validation of a Capacity-Motivation-Opportunity (CMO) model tailored for respiratory outpatients to enhance pharmaceutical care, which is the direct, responsible provision of medication-related care for the purpose of achieving definite outcomes that improve a patient's quality of life, and overall wellbeing.

Methodology

This cross-sectional, multicenter study was conducted from March 2022 to March 2023. It comprised four phases: 1) forming an expert panel of 15 hospital pharmacists, 2) selecting respiratory pathologies based on prevalence and severity, 3) developing the CMO model's pillars, and 4) integrating and conducting an interim validation of the model. The Capacity pillar focused on patient stratification and personalized care; the Motivation pillar aligned therapeutic goals through motivational interviewing; and the Opportunity pillar promoted the use of information and communication technologies (ICTs) for telemedicine.

Results

The model included eight respiratory diseases based on expert assessment. For the Capacity pillar, 22 variables were defined for patient stratification, leading to three priority levels for personalized pharmaceutical care. In a preliminary test involving 201 patients across six hospitals, the stratification tool effectively classified patients according to their needs. The Motivation pillar adapted motivational interviewing techniques to support patient adherence and behavior change. The Opportunity pillar established teleconsultation protocols and ICT tools to enhance patient monitoring and care coordination.

Conclusion

The CMO model, tailored for respiratory patients, provides a comprehensive framework for improving pharmaceutical care. By focusing on patient-centered care, aligning therapeutic goals, and leveraging technology, this model addresses the multifaceted needs of individuals with respiratory conditions. Future studies are necessary to validate this model in other healthcare systems and ensure its broad applicability.

Comparative Effectiveness of Sotatercept and Approved Add-On Pulmonary Arterial Hypertension Therapies: A Systematic Review and Network Meta-Analysis

Background: There are no direct comparisons of sotatercept to add-on therapies approved for pulmonary arterial hypertension (PAH). Objective: This study aimed to compare the efficacy and safety of add-on sotatercept versus other add-on therapies using a network meta-analysis. Data Sources: We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and clinicaltrials.gov until April 15, 2023, for randomized trials involving patients with PAH who were treated with add-on sotatercept or other add-on PAH therapies. Data Extraction: Data extraction and risk-of-bias assessments were performed independently and in duplicate using the Cochrane RoB 2.0 tool. We performed a frequentist random-effects network meta-analysis using the restricted maximum-likelihood estimator and assessed the certainty of evidence using the GRADE (grading of recommendations assessment development, and evaluation) approach. Synthesis: Our search found 18 trials (5,777 patients) eligible for analysis. Sotatercept reduces clinical worsening as compared with placebo (relative risk [RR], 0.21; 95% confidence interval [CI] = 0.11-0.41; with high certainty). Sotatercept probably reduces clinical worsening more, compared with add-on endothelin receptor antagonists (RR, 0.28; 95% CI = 0.14-0.55), inhaled prostanoid (RR, 40.21; 95% CI = 0.07-0.67), and prostanoid taken orally (RR, 0.32; 95% CI = 0.16-0.67; all with moderate certainty). Sotatercept probably improves 6-minute-walk distance compared with placebo (mean difference [MD], 36.89 m; 95% CI = 25.26-48.51). Although sotatercept probably improves 6-minute-walk distance more than add-on endothelin receptor antagonists (MD, 18.38 m; 95% CI = 5.92-30.84) and prostanoid taken orally (MD, 25.66 m; 95% CI = 13.71-37.61), it did not exceed the minimal clinically important difference of 33 m (both with moderate certainty). Conclusions: Sotatercept is an effective add-on therapy for PAH, likely superior to many approved add-on PAH therapies in reducing clinical worsening.

Long-term efficacies of selective vasodilators in pulmonary arterial hypertension: a comprehensive comparison using a spontaneous reporting database

There is no clinical evidence of differences in drugs associated with long-term survival in patients with pulmonary arterial hypertension (PAH) due to the small population and lack of information on death in Japanese medical database systems. This study evaluated whether patient data from a spontaneous reporting database could be used for comparing the effects of pulmonary vasodilators on long-term survival in PAH patients. PAH patient data reported in the Japanese Adverse Drug Event Report (JADER) database from April 2004 to July 2022 were extracted. Kaplan-Meier curves were used to compare survival times. Adjusted hazard ratios (aHRs) for all-cause mortality were determined using Cox proportional hazards models. Of 1969 PAH patients reported in the JADER database, 1208 were included in the survival analyses. The patient demographics were similar to those of the PAH population reported in the Japan Pulmonary Hypertension Registry. Among drugs targeting the prostacyclin pathway, epoprostenol was most associated with long-term survival (aHR, 0.38; 95% confidence interval (CI), 0.23-0.64). The PAH patients treated with endothelin receptor antagonists had improved survival, especially among the macitentan users (aHR, 0.30; 95% CI, 0.22-0.42). Sildenafil was associated with a poor prognosis in the PAH patients (aHR, 1.56; 95% CI, 1.19-2.04). Although our results must be interpreted with caution due to several limitations inherent to spontaneous reporting databases, our approach using the JADER database for survival analysis may provide useful information in limited situations such as the treatment of rare diseases including PAH.

Comprehensive analysis of gastrointestinal side effects in COVID-19 patients undergoing combined pharmacological treatment with azithromycin and hydroxychloroquine: a systematic review and network meta-analysis

During the COVID-19 pandemic, several drugs were repositioned and combined to quickly find a way to mitigate the effects of the infection. However, the adverse effects of these combinations on the gastrointestinal tract are unknown. We aimed investigate whether Hydroxychloroquine (HD), Azithromycin (AZ), and Ivermectin (IV) used in combination for the treatment of COVID-19, can lead to the development of gastrointestinal disorders. This is a systematic review and network meta-analysis conducted using Stata and Revman software, respectively. The protocol was registered with PROSPERO (CRD42023372802). A search of clinical trials in Cochrane Library databases, Embase, Web of Science, Lilacs, PubMed, Scopus and Clinicaltrials.gov conducted on November 26, 2023. The eligibility of the studies was assessed based on PICO criteria, including trials that compared different treatments and control group. The analysis of the quality of the evidence was carried out according to the GRADE. Six trials involving 1,686 COVID-19 patients were included. No trials on the association of HD or AZ with IV met the inclusion criteria, only studies on the association between HD and AZ were included. Nausea, vomiting, diarrhea, abdominal pain and increased transaminases were related. The symptoms of vomiting and nausea were evaluated through a network meta-analysis, while the symptom of abdominal pain was evaluated through a meta-analysis. No significant associations with these symptoms were observed for HD, AZ, or their combination, compared to control. Low heterogeneity and absence of inconsistency in indirect and direct comparisons were noted. Limitations included small sample sizes, varied drug dosages, and potential publication bias during the pandemic peak. This review unveils that there are no associations between gastrointestinal adverse effects and the combined treatment of HD with AZ in the management of COVID-19, as compared to either the use of a control group or the administration of the drugs individually, on the other hand, highlighting the very low or low certainty of evidence for the evaluated outcomes. To accurately conclude the absence of side effects, further high-quality randomized studies are needed.

Pulmonary arterial hypertension treatment: an individual participant data network meta-analysis

BACKGROUND AND AIMS

Effective therapies that target three main signalling pathways are approved to treat pulmonary arterial hypertension (PAH). However, there are few large patient-level studies that compare the effectiveness of these pathways. The aim of this analysis was to compare the effectiveness of the treatment pathways in PAH and to assess treatment heterogeneity.

METHODS

A network meta-analysis was performed using individual participant data of 6811 PAH patients from 20 Phase III randomized clinical trials of therapy for PAH that were submitted to the US Food and Drug Administration. Individual drugs were grouped by the following treatment pathways: endothelin, nitric oxide, and prostacyclin pathways.

RESULTS

The mean (±standard deviation) age of the sample was 49.2 (±15.4) years; 78.4% were female, 59.7% had idiopathic PAH, and 36.5% were on background PAH therapy. After covariate adjustment, targeting the endothelin + nitric oxide pathway {β: 43.7 m [95% confidence interval (CI): 32.9, 54.4]}, nitric oxide pathway [β: 29.4 m (95% CI: 22.6, 36.3)], endothelin pathway [β: 25.3 m (95% CI: 19.8, 30.8)], and prostacyclin pathway [oral/inhaled β: 19.1 m (95% CI: 14.2, 24.0), intravenous/subcutaneous β: 24.4 m (95% CI: 15.1, 33.7)] significantly increased 6 min walk distance at 12 or 16 weeks compared with placebo. Treatments also significantly reduced the likelihood of having clinical worsening events. There was significant heterogeneity of treatment effects by age, body mass index, hypertension, diabetes, and coronary artery disease.

CONCLUSIONS

Drugs targeting the three traditional treatment pathways significantly improve outcomes in PAH, with significant treatment heterogeneity in patients with some comorbidities. Randomized clinical trials are warranted to identify the most effective treatment strategies in a personalized approach.

How do network meta-analyses address intransitivity when assessing certainty of evidence: a systematic survey

OBJECTIVES

To describe how systematic reviews with network meta-analyses (NMAs) that used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) NMA approach addressed intransitivity when assessing certainty of evidence.

DESIGN

Systematic survey.

DATA SOURCES

Medline, Embase and Cochrane Database of Systematic Reviews from September 2014 to October 2022.

ELIGIBILITY CRITERIA

Systematic reviews of randomised controlled trials with aggregate data NMAs that used the GRADE NMA approach for assessing certainty of evidence.

DATA EXTRACTION AND SYNTHESIS

We documented how reviewers described methods for addressing intransitivity when assessing certainty of evidence, how often they rated down for intransitivity and their explanations for rating down.

RESULTS

Of the 268 eligible systematic reviews, 44.8% (120/268) mentioned intransitivity when describing methods for assessing the certainty of evidence. Of these, 28.3% (34/120) considered effect modifiers and from this subset, 67.6% (23/34) specified the effect modifiers; however, no systematic review noted how they chose the effect modifiers. 15.0% (18/120) mentioned looking for differences between the direct comparisons that inform the indirect estimate. No review specified a threshold for difference in effect modifiers between the direct comparisons that would lead to rating down for intransitivity. Reviewers noted rating down indirect evidence for intransitivity in 33.1% of systematic reviews, and noted intransitivity for network estimates in 23.0% of reviews. Authors provided an explanation for rating down for intransitivity in 59.6% (31/52) of the cases in which they rated down. Of the 31 in which they provided an explanation, 74.2% (23/31) noted they detected differences in effect modifiers and 67.7% (21/31) specified in what effect modifiers they detected differences.

CONCLUSIONS

A third of systematic reviews with NMAs using the GRADE approach rated down for intransitivity. Limitations in reporting of methods to address intransitivity proved considerable. Whether the problem is that reviewers neglected to address rating down for transitivity at all, or whether they did consider but not report, is not clear. At minimum systematic reviews with NMAs need to improve their reporting practices regarding intransitivity; it may well be that they need to improve their practice in transitivity assessment. How to best address intransitivity may remain unclear for many reviewers thus additional GRADE guidance providing practical instructions for addressing intransitivity may be desirable.

Bioinformatics analysis to identify potential biomarkers for the pulmonary artery hypertension associated with the basement membrane

Pulmonary arterial hypertension (PAH) is a rapidly progressing cardiopulmonary disease. It is characterized by increased pulmonary artery pressure and vascular resistance. The most notable histopathological characteristic is vascular remodeling. The changes in the basement membrane (BM) are believed to be related to vascular remodeling. It is crucial to identify potential biomarkers associated with the BM in PAH, to guide its treatment. The microarray datasets GSE117261 and GSE113439 were downloaded from the Gene Expression Omnibus. Two data sets were examined to identify genes associated with the BM by analyzing gene expression changes. Next, we analyzed the relevant genes in the Kyoto Encyclopedia of Genes and Genomes using Gene Ontology and Disease Ontology annotationand conducted pathway enrichment analysis. We conducted a protein-protein interaction network analysis on the genes related to BMs and used the cell cytoHubba plug-in to identify the hub genes. Furthermore, we conducted an immune infiltration analysis and implemented a histogram model. Finally, we predicted and analyzed potential therapeutic drugs for PAH and set up a miRNA network of genetic markers. Six candidate genes related to BMs, namely Integrin Subunit Alpha V, Integrin Subunit Alpha 4, ITGA2, ITGA9, Thrombospondin 1, and Collagen Type IV Alpha 3 Chain, were identified as potential modulators of the immune process in PAH. Furthermore, ginsenoside Rh1 was found to significantly impact drug targeting based on its interactions with the six BM-related genes identified earlier. A novel biomarker related to the BM, which plays a crucial role in the development of PAH, has been identified.

Refined risk stratification, current treatment, and new therapeutic approaches in pulmonary arterial hypertension

The 2022 European Society of Cardiology/European Respiratory Society (ESC/ERS) guidelines for pulmonary hypertension have introduced a refined risk stratification to guide both initial and subsequent treatment of pulmonary arterial hypertension (PAH). The risk stratification at PAH diagnosis still comprises three risk categories (low, intermediate, high) and lists some new parameters. As the estimated 1‑year mortality is more than 20% in high-risk patients after diagnosis, an initial triple-combination therapy including parenteral prostacyclin analogues is recommended for this group. All other patients should receive a dual-combination therapy with an endothelin receptor antagonist and a phosphodiesterase‑5 inhibitor. However, this approach of initial combination therapy is only recommended for classic PAH, while monotherapy followed by regular follow-up and individualized therapy should be used for patients with cardiopulmonary comorbidities. For PAH patients without cardiopulmonary comorbidities, it is recommended to assess their risk at follow-up with a new 4‑strata classification, where the intermediate-risk group is split on the basis of three noninvasive parameters. Importantly, changes from intermediate-high to intermediate-low risk have been shown to be associated with a better prognosis. In addition, the recommendations on treatment escalation became more precise with the addition of a prostacyclin receptor agonist or switching a phosphodiesterase‑5 inhibitor to a soluble guanylate cyclase stimulator for intermediate-low risk and proceeding to triple-combination therapy with parenteral prostacyclin analogues already for intermediate-high risk. With sotatercept, the first non-vasodilator PAH treatment will become available in the near future to further enrich our treatment options for this chronic and still severe disease.

Emerging biologics for the treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare pulmonary vascular disorder, wherein mean systemic arterial pressure (mPAP) becomes abnormally high because of aberrant changes in various proliferative and inflammatory signalling pathways of pulmonary arterial cells. Currently used anti-PAH drugs chiefly target the vasodilatory and vasoconstrictive pathways. However, an imbalance between bone morphogenetic protein receptor type II (BMPRII) and transforming growth factor beta (TGF-β) pathways is also implicated in PAH predisposition and pathogenesis. Compared to currently used PAH drugs, various biologics have shown promise as PAH therapeutics that elicit their therapeutic actions akin to endogenous proteins. Biologics that have thus far been explored as PAH therapeutics include monoclonal antibodies, recombinant proteins, engineered cells, and nucleic acids. Because of their similarity with naturally occurring proteins and high binding affinity, biologics are more potent and effective and produce fewer side effects when compared with small molecule drugs. However, biologics also suffer from the limitations of producing immunogenic adverse effects. This review describes various emerging and promising biologics targeting the proliferative/apoptotic and vasodilatory pathways involved in PAH pathogenesis. Here, we have discussed sotatercept, a TGF-β ligand trap, which is reported to reverse vascular remodelling and reduce PVR with an improved 6-minute walk distance (6-MWDT). We also elaborated on other biologics including BMP9 ligand and anti-gremlin1 antibody, anti-OPG antibody, and getagozumab monoclonal antibody and cell-based therapies. Overall, recent literature suggests that biologics hold excellent promise as a safe and effective alternative to currently used PAH therapeutics.