The Antifibrotic Effects of Inhaled Treprostinil: An Emerging Option for ILD

Influence of metabolic factors on systemic sclerosis complicated with severe interstitial lung disease based on high-resolution computed tomography grading

OBJECTIVES

Systemic sclerosis complicated with interstitial lung disease (SSc-ILD) is a rare autoimmune disease with a dismal prognosis. To analyze the common clinical indicators of systemic sclerosis (SSc) complicated with severe interstitial lung disease (ILD) patients based on the grading of lung high-resolution computed tomography (HRCT) and to explore the risk factors of severe (ILD).

METHODS

A retrospective analysis was performed on 72 newly diagnosed and treated SSc-ILD patients in the Affiliated Hospital of Xuzhou Medical University from June 2013 to August 2023. The interstitial lung disease was divided into grades 1, 2, and 3 according to the HRCT images. Grades 1 and 2 were classified as a non-severe group (42 cases), and grade 3 was a severe group (30 cases). The general data and laboratory examination results of the two groups were analyzed. A logistic regression model was established, and the receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of risk factors for severe SSc-ILD patients.

RESULTS

Patients in the severe group had lower height (1.610 ± 0.059 vs 1.574 ± 0.078, P = 0.031), triglyceride (TG) (1.796 ± 0.743 vs 1.265 (1.04, 1.63), P = 0.026) and total protein (TP) (77.96 ± 8.784 vs 72.709 ± 8.042, P = 0.011)than those in the non-severe group. The area under the curve of height, TG, and TP combined with the diagnosis of systemic sclerosis complicated with severe interstitial lung disease was 0.839, and the sensitivity and specificity were 0.750 and 0.781, respectively.

CONCLUSION

Low TG and TP may be the risk factors for SSc patients with severe interstitial lung disease. Therefore, it is promising as a potential therapeutic target for SSc-ILD and warrants appropriate follow-up in further studies of patients. Key Points • We hoped to pay attention to the influence of metabolic factors on connective tissue disease complicated with interstitial lung disease due to the relationship between metabolism and immunity is complicated.

Fibrosis: cross-organ biology and pathways to development of innovative drugs

Fibrosis is a pathophysiological mechanism involved in chronic and progressive diseases that results in excessive tissue scarring. Diseases associated with fibrosis include metabolic dysfunction-associated steatohepatitis (MASH), inflammatory bowel diseases (IBDs), chronic kidney disease (CKD), idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc), which are collectively responsible for substantial morbidity and mortality. Although a few drugs with direct antifibrotic activity are approved for pulmonary fibrosis and considerable progress has been made in the understanding of mechanisms of fibrosis, translation of this knowledge into effective therapies continues to be limited and challenging. With the aim of assisting developers of novel antifibrotic drugs, this Review integrates viewpoints of biologists and physician-scientists on core pathways involved in fibrosis across organs, as well as on specific characteristics and approaches to assess therapeutic interventions for fibrotic diseases of the lung, gut, kidney, skin and liver. This discussion is used as a basis to propose strategies to improve the translation of potential antifibrotic therapies.

Inhaled treprostinil in group 3 pulmonary hypertension associated with lung disease: results of the INCREASE and PERFECT studies

Group 3 pulmonary hypertension (PH) associated with lung disease is a common cause of PH and is associated with substantial morbidity and mortality. Multiple studies of pulmonary arterial hypertension (PAH) therapies in this population have demonstrated conflicting results regarding their safety and efficacy, and therefore the optimum treatment for this group is unknown. The INCREASE and PERFECT randomised, double-blind, placebo-controlled trials attempted to address this unmet need by exploring the role of inhaled treprostinil (iTRE) in PH associated with interstitial lung disease (PH-ILD) and PH associated with COPD (PH-COPD), respectively. In the INCREASE and PERFECT studies individuals were randomised to placebo or iTRE, which was administered via an ultrasonic, pulsed-delivery nebuliser to a maximum dose of 72 μg, four times a day. The INCREASE study randomised 326 subjects with PH-ILD over a 16-week period and met its primary endpoint of change in 6-min walk distance, with a treatment effect of +31.12 m (p<0.001). Reduced disease progression events and increased forced vital capacity were also reported in the treatment arm in a post hoc analysis. By contrast, the PERFECT study was stopped prematurely by the data and safety monitoring committee due to evidence that iTRE increased serious adverse events in subjects with PH-COPD. This journal club provides an overview of these important trials and highlights pertinent unanswered questions in this field.

Pathology of idiopathic pulmonary fibrosis with particular focus on vascular endothelium and epithelial injury and their therapeutic potential

Idiopathic pulmonary fibrosis (IPF) remains a challenging disease with no drugs available to change the trajectory. It is a condition associated with excessive and highly progressive scarring of the lungs with remodelling and extracellular matrix deposition. It is a highly "destructive" disease of the lungs. The diagnosis of IPF is challenging due to continuous evolution of the disease, which also makes early interventions very difficult. The role of vascular endothelial cells has not been explored in IPF in great detail. We do not know much about their contribution to arterial or vascular remodelling, extracellular matrix changes and contribution to pulmonary hypertension and lung fibrosis in general. Endothelial to mesenchymal transition appears to be central to such changes in IPF. Similarly, for epithelial changes, the process of epithelial to mesenchymal transition seem to be the key both for airway epithelial cells and type-2 pneumocytes. We focus here on endothelial and epithelial cell changes and its contributions to IPF. In this review we revisit the pathology of IPF, mechanistic signalling pathways, clinical definition, update on diagnosis and new advances made in treatment of this disease. We discuss ongoing clinical trials with mode of action. A multidisciplinary collaborative approach is needed to understand this treacherous disease for new therapeutic targets.

Vascular involvement in idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrosing and progressive interstitial lung disease of unknown aetiology with a pathogenesis still partly unknown. Several microvascular and macrovascular abnormalities have been demonstrated in the pathogenesis of IPF and related pulmonary hypertension (PH), a complication of the disease.

Methods

We carried out a non-systematic, narrative literature review aimed at describing the role of the vasculature in the natural history of IPF.

Results

The main molecular pathogenetic mechanisms involving vasculature (i.e. endothelial-to-mesenchymal transition, vascular remodelling, endothelial permeability, occult alveolar haemorrhage, vasoconstriction and hypoxia) and the genetic basis of vascular remodelling are described. The prevalence and clinical relevance of associated PH are highlighted with focus on the vasculature as a prognostic marker. The vascular effects of current antifibrotic therapies, the role of pulmonary vasodilators in the treatment of disease, and new pharmacological options with vascular-targeted activity are described.

Conclusions

The vasculature plays a key role in the natural history of IPF from the early phases of disease until development of PH in a subgroup of patients, a complication related to a worse prognosis. Pulmonary vascular volume has emerged as a novel computed tomography finding and a predictor of mortality, independent of PH. New pharmacological options with concomitant vascular-directed activity might be promising in the treatment of IPF.

Pharmacological Treatment of Interstitial Lung Diseases: A Novel Landscape for Inhaled Agents

Interstitial lung diseases (ILDs) encompass a heterogeneous group of over 200 disorders that require individualized treatment. Antifibrotic agents, such as nintedanib and pirfenidone, have remarkably revolutionized the treatment landscape of patients with idiopathic pulmonary fibrosis (IPF). Moreover, the approval of nintedanib has also expanded the therapeutic options for patients with progressive pulmonary fibrosis other than IPF. However, despite recent advances, current therapeutic strategies based on antifibrotic agents and/or immunomodulation are associated with non-negligible side effects. Therefore, several studies have explored the inhalation route aiming to spread higher local concentrations while limiting systemic toxicity. In this review, we examined the currently available literature about preclinical and clinical studies testing the efficacy and safety of inhalation-based antifibrotics, immunomodulatory agents, antioxidants, mucolytics, bronchodilators, and vasodilator agents in ILDs.

New Therapies in Outpatient Pulmonary Medicine

Newer medications and devices, as well as greater understanding of the benefits and limitations of existing treatments, have led to expanded treatment options for patients with lung disease. Treatment advances have led to improved outcomes for patients with asthma, chronic obstructive pulmonary disease, interstitial lung disease, pulmonary hypertension, and cystic fibrosis. The risks and benefits of available treatments are substantially variable within these heterogeneous disease groups. Defining the role of newer therapies mandates both an understanding of these disorders and overall treatment approaches. This section will review general treatment approaches in addition to focusing on newer therapies for these conditions..

Practical management of oral treprostinil in patients with pulmonary arterial hypertension: Lessons from ADAPT, EXPEDITE, and expert consensus

BACKGROUND

Oral treprostinil is a prostacyclin analogue approved to treat pulmonary arterial hypertension (PAH) by delaying disease progression and improving exercise capacity. Higher doses of oral treprostinil correlate with increased treatment benefit. Titrations may be challenging due to common side effects of prostacyclin-class therapies.

STUDY DESIGN AND METHODS

The multicenter, prospective, real-world, observational ADAPT Registry study followed adult patients with PAH for up to 78 weeks after initiating oral treprostinil (NCT03045029). Dosing, titration, and transitions of oral treprostinil were at the discretion of the prescriber. Patient-reported incidence and treatment of common side effects were collected to understand side effect management and tolerability. Insights from literature and expert recommendations were added to provide a consolidated resource for oral treprostinil use.

RESULTS

In total, 139 participants in ADAPT completed ≥1 weekly survey; (median age 60.0 years, 76 % female). Median treatment duration of oral treprostinil was 13.1 months. During early therapy (Months 1-5), 62 % (78/126) of patients reported headache and diarrhea, and 40 % (50/126) reported nausea. At Month 6, many patients who reported side effects during early therapy reported an improvement (61 % headache, 44 % diarrhea, 70 % nausea). Common side effect treatments, including acetaminophen, loperamide, and ondansetron, were effective. Approximately one-quarter of patients reporting the most common side effects were untreated at Month 6.

CONCLUSION

Patient selection for, and initiation and titration of, oral treprostinil should be individualized and may include parenteral treprostinil induction-transition for faster titration. Assertive side effect management may help patients reach higher and more efficacious doses of oral treprostinil.

Highlights on Future Treatments of IPF: Clues and Pitfalls

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by irreversible scarring of lung tissue, leading to death. Despite recent advancements in understanding its pathophysiology, IPF remains elusive, and therapeutic options are limited and non-curative. This review aims to synthesize the latest research developments, focusing on the molecular mechanisms driving the disease and on the related emerging treatments. Unfortunately, several phase 2 studies showing promising preliminary results did not meet the primary endpoints in the subsequent phase 3, underlying the complexity of the disease and the need for new integrated endpoints. IPF remains a challenging condition with a complex interplay of genetic, epigenetic, and pathophysiological factors. Ongoing research into the molecular keystones of IPF is critical for the development of targeted therapies that could potentially stop the progression of the disease. Future directions include personalized medicine approaches, artificial intelligence integration, growth in genetic insights, and novel drug targets.

Pathological mechanisms and novel drug targets in fibrotic interstitial lung disease

BACKGROUND

Interstitial lung diseases (ILDs) are a diverse group of conditions characterized by inflammation and fibrosis in the lung. In some patients with ILD, a progressive fibrotic phenotype develops, which is associated with an irreversible decline in lung function and a poor prognosis.

MAIN BODY

The pathological mechanisms that underlie this process culminate in fibroblast activation, proliferation, and differentiation into myofibroblasts, which deposit extracellular matrix proteins and result in fibrosis. Upstream of fibroblast activation, epithelial cell injury and immune activation are known initiators of fibrosis progression, with multiple diverse cell types involved. Recent years have seen an increase in our understanding of the complex and interrelated processes that drive fibrosis progression in ILD, in part due to the advent of single-cell RNA sequencing technology and integrative multiomics analyses. Novel pathological mechanisms have been identified, which represent new targets for drugs currently in clinical development. These include phosphodiesterase 4 inhibitors and other molecules that act on intracellular cyclic adenosine monophosphate signaling, as well as inhibitors of the autotaxin-lysophosphatidic acid axis and  α v  integrins. Here, we review current knowledge and recent developments regarding the pathological mechanisms that underlie progressive fibrotic ILD, including potential therapeutic targets.

CONCLUSION

Knowledge of the pathological mechanisms that drive progressive fibrosis in patients with ILD has expanded, with the role of alveolar endothelial cells, the immune system, and fibroblasts better elucidated. Drugs that target novel mechanisms hold promise for expanding the future therapeutic armamentarium for progressive fibrotic ILD.

Therapeutic Potential of Treprostinil Inhalation Powder for Patients with Pulmonary Arterial Hypertension: Evidence to Date

Pulmonary arterial hypertension (PAH) is a complex and incurable disease for which pulmonary vasodilators remain the core therapy. Of the three primary pathways that vasodilators target, the prostacyclin pathway was the earliest to be used and currently has the largest number of modalities for drug delivery. Inhaled treprostinil has been introduced as a treatment option in PAH and, more recently, pulmonary hypertension (PH) due to interstitial lung disease (PH-ILD), and the earlier nebulized form has been joined by a dry powder form allowing for more convenient use. In this review, we discuss inhaled treprostinil, focusing on the dry powder inhalation (DPI) formulation, and explore its dosing, applications, and evidence to support patient tolerance and acceptance. Recent trials underpinning the evidence for use of inhaled treprostinil and the most recent developments concerning the drug are discussed. Finally, the review looks briefly into premarket formulations of inhaled treprostinil and relevant early studies suggesting efficacy in PAH treatment.

Treatment of idiopathic pulmonary fibrosis: an update on emerging drugs in phase II & III clinical trials

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a progressive, debilitating lung disease with poor prognosis. Although two antifibrotics have been approved in the past decade there are no curative therapies.

AREAS COVERED

This review highlights the current landscape of IPF research in the development of novel compounds for the treatment of IPF while also evaluating repurposed medications and their role in the management of IPF. The literature search includes studies found on PubMed, conference abstracts, and press releases until March 2024.

EXPERT OPINION

Disease progression in IPF is driven by a dysregulated cycle of microinjury, aberrant wound healing, and propagating fibrosis. Current drug development focuses on attenuating fibrotic responses via multiple pathways. Phosphodiesterase 4 inhibitors (PDE4i), lysophosphatidic acid (LPA) antagonists, dual-selective inhibitor of αvβ6 and αvβ1 integrins, and the prostacyclin agonist Treprostinil have had supportive phase II clinical trial results in slowing decline in forced vital capacity (FVC) in IPF. Barriers to drug development specific to IPF include the lack of a rodent model that mimics IPF pathology, the nascent understanding of the role of genetics affecting development of IPF and response to treatment, and the lack of a validated biomarker to monitor therapeutic response in patients with IPF. Successful treatment of IPF will likely include a multi-targeted approach anchored in precision medicine.

Comprehensive review of potential drugs with anti-pulmonary fibrosis properties

Pulmonary fibrosis is a chronic and progressive lung disease characterized by the accumulation of scar tissue in the lungs, which leads to impaired lung function and reduced quality of life. The prognosis for idiopathic pulmonary fibrosis (IPF), which is the most common form of pulmonary fibrosis, is generally poor. The median survival for patients with IPF is estimated to be around 3-5 years from the time of diagnosis. Currently, there are two approved drugs (Pirfenidone and Nintedanib) for the treatment of IPF. However, Pirfenidone and Nintedanib are not able to reverse or cure pulmonary fibrosis. There is a need for new pharmacological interventions that can slow or halt disease progression and cure pulmonary fibrosis. This review aims to provide an updated overview of current and future drug interventions for idiopathic pulmonary fibrosis, and to summarize possible targets of potential anti-pulmonary fibrosis drugs, providing theoretical support for further clinical combination therapy or the development of new drugs.

Vasoactive drugs for the treatment of pulmonary hypertension associated with interstitial lung diseases: a systematic review

OBJECTIVES

Vasoactive drugs have exhibited clinical efficacy in addressing pulmonary arterial hypertension, manifesting a significant reduction in morbidity and mortality. Pulmonary hypertension may complicate advanced interstitial lung disease (PH-ILD) and is associated with high rates of disability, hospitalisation due to cardiac and respiratory illnesses, and mortality. Prior management hinged on treating the underlying lung disease and comorbidities. However, the INCREASE trial of inhaled treprostinil in PH-ILD has demonstrated that PH-ILD can be effectively treated with vasoactive drugs.

METHODS

This comprehensive systematic review examines the evidence for vasoactive drugs in the management of PH-ILD.

RESULTS

A total of 1442 pubblications were screened, 11 RCTs were considered for quantitative synthesis. Unfortunately, the salient studies are limited by population heterogeneity, short-term follow-up and the selection of outcomes with uncertain clinical significance.

CONCLUSIONS

This systematic review underscores the necessity of establishing a precision medicine-oriented strategy, directed at uncovering and addressing the intricate cellular and molecular mechanisms that underlie the pathophysiology of PH-ILD.

PROSPERO REGISTRATION NUMBER

CRD42023457482.

The complement cascade in lung injury and disease

BACKGROUND

The complement system is an important arm of immune defense bringing innate and adaptive immunity. Although originally regarded as a major complementary defense mechanism against pathogens, continuously emerging evidence has uncovered a central role of this complex system in several diseases including lung pathologies.

MAIN BODY

Complement factors such as anaphylatoxins C3a and C5a, their receptors C3aR, C5aR and C5aR2 as well as complement inhibitory proteins CD55, CD46 and CD59 have been implicated in pathologies such as the acute respiratory distress syndrome, pneumonia, chronic obstructive pulmonary disease, asthma, interstitial lung diseases, and lung cancer. However, the exact mechanisms by which complement factors induce these diseases remain unclear. Several complement-targeting monoclonal antibodies are reported to treat lung diseases.

CONCLUSIONS

The complement system contributes to the progression of the acute and chronic lung diseases. Better understanding of the underlying mechanisms will provide groundwork to develop new strategy to target complement factors for treatment of lung diseases.

Tyvaso DPI: Drug-device characteristics and patient clinical considerations

Tyvaso DPI is a drug-device combination therapy comprised of a small, portable, reusable, breath-powered, dry powder inhaler (DPI) for the delivery of treprostinil. It is approved for the treatment of pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease. Tyvaso DPI utilizes single-use prefilled cartridges to ensure proper dosing. Unlike nebulizer devices, administration of Tyvaso DPI is passive and does not require coordination with the device. The low-flow rate design results in targeted delivery to the peripheral lungs due to minimal drug loss from impaction in the oropharynx. The inert fumaryl diketopiperazine (FDKP) excipient forms microparticles that carry treprostinil into the airways, with a high fraction of the particles in the respirable range. In a clinical study in patients with pulmonary arterial hypertension, Tyvaso DPI had similar exposure and pharmacokinetics, low incidence of adverse events, and high patient satisfaction compared with nebulized treprostinil solution. Tyvaso DPI may be considered as a first prostacyclin agent or for those that do not tolerate other prostacyclin formulations, patients with pulmonary comorbidities, patients with mixed Group 1 and Group 3 pulmonary hypertension, or those that prefer an active lifestyle and need a portable, non-invasive treatment. Tyvaso DPI is a patient-preferred, maintenance-free, safe delivery option that may improve patient compliance and adherence.

Emerging role of immune cells as drivers of pulmonary fibrosis

The pathogenesis of pulmonary fibrosis, including idiopathic pulmonary fibrosis (IPF) and other forms of interstitial lung disease, involves a complex interplay of various factors including host genetics, environmental pollutants, infection, aberrant repair and dysregulated immune responses. Highly variable clinical outcomes of some ILDs, in particular IPF, have made it difficult to identify the precise mechanisms involved in disease pathogenesis and thus the development of a specific cure or treatment to halt and reverse the decline in patient health. With the advent of in-depth molecular diagnostics, it is becoming evident that the pathogenesis of IPF is unlikely to be the same for all patients and therefore will likely require different treatment approaches. Chronic inflammation is a cardinal feature of IPF and is driven by both innate and adaptive immune responses. Inflammatory cells and activated fibroblasts secrete various pro-inflammatory cytokines and chemokines that perpetuate the inflammatory response and contribute to the recruitment and activation of more immune cells and fibroblasts. The balance between pro-inflammatory and regulatory immune cell subsets, as well as the interactions between immune cell types and resident cells within the lung microenvironment, ultimately determines the extent of fibrosis and the potential for resolution. This review examines the role of the innate and adaptive immune responses in pulmonary fibrosis, with an emphasis on IPF. The role of different immune cell types is discussed as well as novel anti-inflammatory and immunotherapy approaches currently in clinical trial or in preclinical development.

Management of Pulmonary Hypertension Associated with Chronic Lung Disease

Pulmonary hypertension (PH) is a common complication of chronic lung diseases, particularly in chronic obstructive pulmonary disease (COPD) and interstitial lung diseases (ILD) and especially in advanced disease. It is associated with greater mortality and worse clinical course. Given the high prevalence of some respiratory disorders and because lung parenchymal abnormalities might be present in other PH groups, the appropriate diagnosis of PH associated with respiratory disease represents a clinical challenge. Patients with chronic lung disease presenting symptoms that exceed those expected by the pulmonary disease should be further evaluated by echocardiography. Confirmatory right heart catheterization is indicated in candidates to surgical treatments, suspected severe PH potentially amenable with targeted therapy, and, in general, in those conditions where the result of the hemodynamic assessment will determine treatment options. The treatment of choice for these patients who are hypoxemic is long-term oxygen therapy and pulmonary rehabilitation to improve symptoms. Lung transplant is the only curative therapy and can be considered in appropriate cases. Conventional vasodilators or drugs approved for pulmonary arterial hypertension (PAH) are not recommended in patients with mild-to-moderate PH because they may impair gas exchange and their lack of efficacy shown in randomized controlled trials. Patients with severe PH (as defined by pulmonary vascular resistance >5 Wood units) should be referred to a center with expertise in PH and lung diseases and ideally included in randomized controlled trials. Targeted PAH therapy might be considered in this subset of patients, with careful monitoring of gas exchange. In patients with ILD, inhaled treprostinil has been shown to improve functional ability and to delay clinical worsening.

The oxylipin analog CS585 prevents platelet activation and thrombosis through activation of the prostacyclin receptor

Cardiovascular disease remains the primary cause of morbidity and mortality globally. Platelet activation is critical for maintaining hemostasis and preventing the leakage of blood cells from the vessel. There has been a paucity in the development of new drugs to target platelet reactivity. Recently, the oxylipin 12(S)-hydroxy-eicosatrienoic acid (12-HETrE), which is produced in platelets, was shown to limit platelet reactivity by activating the prostacyclin receptor. Here, we demonstrated the synthesis of a novel analog of 12-HETrE, known as CS585. Human blood and mouse models of hemostasis and thrombosis were assessed for the ability of CS585 to attenuate platelet activation and thrombosis without increasing the risk of bleeding. Human platelet activation was assessed using aggregometry, flow cytometry, western blot analysis, total thrombus formation analysis system, microfluidic perfusion chamber, and thromboelastography. Hemostasis, thrombosis, and bleeding assays were performed in mice. CS585 was shown to potently target the prostacyclin receptor on the human platelet, resulting in a highly selective and effective mechanism for the prevention of platelet activation. Furthermore, CS585 was shown to inhibit platelet function in human whole blood ex vivo, prevent thrombosis in both small and large vessels in mouse models, and exhibit long-lasting prevention of clot formation. Finally, CS585 was not observed to perturb coagulation or increase the risk of bleeding in the mouse model. Hence, CS585 represents a new validated target for the treatment of thrombotic diseases without the risk of bleeding or off-target activation observed with other prostaglandin receptor agonists.

Phenotypes of Sarcoidosis-Associated Pulmonary Hypertension-A Challenging Mystery

Sarcoidosis has been a well-recognised risk factor for pulmonary hypertension (PH) for a long time, but still, the knowledge about this concatenation is incomplete. Sarcoidosis-associated PH (SAPH) is an uncommon but serious complication associated with increased morbidity and mortality among sarcoidosis patients. The real epidemiology of SAPH remains unknown, and its pathomechanisms are not fully explained. Sarcoidosis is a heterogeneous and dynamic condition, and SAPH pathogenesis is believed to be multifactorial. The main roles in SAPH development play: parenchymal lung disease with the destruction of pulmonary vessels, the extrinsic compression of pulmonary vessels by conglomerate masses, lymphadenopathy or fibrosing mediastinitis, pulmonary vasculopathy, LV dysfunction, and portal hypertension. Recently, it has been recommended to individually tailor SAPH management according to the predominant pathomechanism, i.e., SAPH phenotype. Unfortunately, SAPH phenotyping is not a straightforward process. First, there are gaps in our understanding of undergoing processes. Second, the assessment of such a pivotal element as pulmonary vasculature on a microscopic level is non-feasible in SAPH patients antemortem. Finally, SAPH is a dynamic condition, multiple phenotypes usually coexist, and patients can switch between phenotypes during the course of sarcoidosis. In this article, we summarise the basic knowledge of SAPH, describe SAPH phenotypes, and highlight some practical problems related to SAPH phenotyping.

Hepatic ischemia-reperfusion syndrome and its effect on the cardiovascular system: The role of treprostinil, a synthetic prostacyclin analog

Hepatic ischemia-reperfusion syndrome has been the subject of intensive study and experimentation in recent decades since it is responsible for the outcome of several clinical entities, such as major hepatic resections and liver transplantation. In addition to the organ's post reperfusion injury, this syndrome appears to play a central role in the dysfunction of distant tissues and systems. Thus, continuous research should be directed toward finding effective therapeutic options to improve the outcome and reduce the postoperative morbidity and mortality rates. Treprostinil is a synthetic analog of prostaglandin I2, and its experimental administration has shown encouraging results. It has already been approved by the Food and Drug Administration in the United States for pulmonary arterial hypertension and has been used in liver transplantation, where preliminary encouraging results showed its safety and feasibility by using continuous intravenous administration at a dose of 5 ng/kg/min. Treprostinil improves renal and hepatic function, diminishes hepatic oxidative stress and lipid peroxidation, reduces hepatictoll-like receptor 9 and inflammation, inhibits hepatic apoptosis and restores hepatic adenosine triphosphate (ATP) levels and ATP synthases, which is necessary for functional maintenance of mitochondria. Treprostinil exhibits vasodilatory properties and antiplatelet activity and regulates proinflammatory cytokines; therefore, it can potentially minimize ischemia-reperfusion injury. Additionally, it may have beneficial effects on cardiovascular parameters, and much current research interest is concentrated on this compound.

Lipid metabolism in idiopathic pulmonary fibrosis: From pathogenesis to therapy

Idiopathic pulmonary fibrosis (IPF) is a chronic irreversible interstitial lung disease characterized by a progressive decline in lung function. The etiology of IPF is unknown, which poses a significant challenge to the treatment of IPF. Recent studies have identified a strong association between lipid metabolism and the development of IPF. Qualitative and quantitative analysis of small molecule metabolites using lipidomics reveals that lipid metabolic reprogramming plays a role in the pathogenesis of IPF. Lipids such as fatty acids, cholesterol, arachidonic acid metabolites, and phospholipids are involved in the onset and progression of IPF by inducing endoplasmic reticulum stress, promoting cell apoptosis, and enhancing the expression of pro-fibrotic biomarkers. Therefore, targeting lipid metabolism can provide a promising therapeutic strategy for pulmonary fibrosis. This review focuses on lipid metabolism in the pathogenesis of pulmonary fibrosis.

Pulmonary Hypertension in the Course of Interstitial Lung Diseases-A Personalised Approach Is Needed to Identify a Dominant Cause and Provide an Effective Therapy

The prevalence of pulmonary hypertension (PH) complicating interstitial lung diseases (ILDs) is 3.5-15% at an early stage, and up to 90% in ILD patients listed for lung transplantation. In addition, other types of PH may occur in patients with ILDs due to concomitant conditions. Therefore, any significant PH occurring in the setting of ILD requires a proper differential workup. PH increases morbidity and mortality in ILDs. The pathomechanisms underlying PH due to ILD (PH-ILD) are not fully known, and there is no straightforward correlation between the presence or severity of PH-ILD and the severity of ILD. Severe PH in mild ILD without other explanatory causes constitutes a dilemma of differentiating between PH due to ILD and pulmonary arterial hypertension coexisting with ILDs. The heterogeneity and poor prognosis of patients with ILDs coexisting with PH necessitate an individualised approach to the management of this condition. This review presents recent advances in understanding and treatment options in PH-ILD. It also addresses practical issues, such as when to suspect and how to screen for PH in ILD, what are the indications for right heart catheterisation, and how to approach an individual ILD patient to determine the dominant PH cause and apply adequate management.

Pulmonary hypertension inhaled therapies: An updated review

Treatments of pulmonary hypertension (PH) continue to evolve with approval of new therapies. The currently FDA approved inhaled PH therapies include inhaled iloprost for group 1 pulmonary arterial hypertension (PAH), inhaled treprostinil solution and treprostinil dry powder inhaler for both group 1 PAH and group 3 PH associated with interstitial lung disease (PH-ILD). Inhaled treprostinil was recently approved for group 3 PH-ILD based on the results of INCREASE trial and the newer formulation of treprostinil dry powder that comes with a new inhaler was recently approved for both group 1 PAH and group 3 PH-ILD based on BREEZE study. The pipeline for inhaled PH therapies includes several promising molecules that can enrich the current PH therapeutic era and mitigate several systemic side effects by directly delivering the drug to the target organ. In this review article we summarize the evidence for the currently approved inhaled PAH/PH therapies, discuss the available inhalation devices, present a roadmap for successful treatment strategy, and present several inhaled PAH/PH therapies in the pipeline.

[Highlights 56th SEPAR Congress]

The Spanish Society of Pneumology and Thoracic Surgery (SEPAR) has held its 56th congress in Granada from 8 to 10 June 2023. The SEPAR congress has established itself as the leading scientific meeting for specialists in medicine and respiratory care, reaching a record of participation this year with 2600 attendees. Our society thus demonstrates its leadership in the management of respiratory diseases, as well as its growth and progress in order to achieve excellence. In this review, we offer a summary of some notable issues addressed in six selected areas of interest: chronic obstructive pulmonary disease (COPD), asthma, interstitial lung diseases (ILDs), tuberculosis and respiratory infections, pulmonary circulation, and respiratory nursing.

Long-term inhaled treprostinil for pulmonary hypertension due to interstitial lung disease: INCREASE open-label extension study

INTRODUCTION

The 16-week randomised, placebo-controlled INCREASE trial (RCT) met its primary end-point by improving 6-min walk distance (6MWD) in patients receiving inhaled treprostinil for pulmonary hypertension due to interstitial lung disease (PH-ILD). The open-label extension (OLE) evaluated long-term effects of inhaled treprostinil in PH-ILD.

METHODS

Of 258 eligible patients, 242 enrolled in the INCREASE OLE and received inhaled treprostinil. Assessments included 6MWD, pulmonary function testing, N-terminal pro-brain natriuretic peptide (NT-proBNP), quality of life and adverse events. Hospitalisations, exacerbations of underlying lung disease and death were recorded.

RESULTS

At INCREASE OLE baseline, patients had a median age of 70 years and a mean 6MWD of 274.2 m; 52.1% were male. For the overall population, the mean 6MWD at week 52 was 279.1 m and the mean change from INCREASE RCT baseline was 3.5 m (22.1 m for the prior inhaled treprostinil arm and -19.5 m for the prior placebo arm); the median NT-proBNP decreased from 389 pg·mL-1 at RCT baseline to 359 pg·mL-1 at week 64; and the absolute (% predicted) mean forced vital capacity change from RCT baseline to week 64 was 51 mL (2.8%). Patients who received inhaled treprostinil versus placebo in the RCT had a 31% lower relative risk of exacerbation of underlying lung disease in the OLE (hazard ratio 0.69 (95% CI 0.49-0.97); p=0.03). Adverse events leading to drug discontinuation occurred in 54 (22.3%) patients.

CONCLUSIONS

These results support the long-term safety and efficacy of inhaled treprostinil in patients with PH-ILD, and are consistent with the results observed in the INCREASE RCT.

An update on current and emerging drug treatments for idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic Pulmonary Fibrosis (IPF) is a progressive and devastating lung disease, characterized by progressive lung scarring.

AREAS COVERED

Prior to antifibrotic therapy (pirfenidone and nintedanib), there was no validated pharmaceutical therapy for IPF. Both antifibrotics can slow disease progression, however, IPF remains a detrimental disease with poor prognosis and treated survival rates of less than 7 years from diagnosis. Despite their effect the disease remains non-reversible and progressing whilst their side effect profile is often challenging. Treatment of comorbidities is also crucial. In this review, we discuss the current pharmacological management as well as management of comorbidities and symptoms. We also reviewed clinicaltrials.gov and summarised all the mid to late stage clinical trials (phase II and III) registered in IPF over the last 7 years and discuss the most promising drugs in clinical development.

EXPERT OPINION

Future for IPF management will need to focus on current unresolved issues. First a primary pathogenetic pathway has not been clearly identified. Future management may involve a combination of brushstroke approach with antifibrotics with targeted treatments for specific pathways in patient subsets following an 'oncological' approach. Another unmet need is management of exacerbations, which are deathly in most cases as well as either treating or preventing lung cancer.