Sildenafil added to pirfenidone in patients with advanced idiopathic pulmonary fibrosis and risk of pulmonary hypertension: A Phase IIb, randomised, double-blind, placebo-controlled study – Rationale and study design

Recent advances in the management of pulmonary hypertension with interstitial lung disease

Pulmonary hypertension (PH) is known to complicate various forms of interstitial lung disease (ILD), including idiopathic pulmonary fibrosis, the interstitial pneumonias and chronic hypersensitivity pneumonitis. Pathogenesis of PH-ILD remains incompletely understood, and probably has overlap with other forms of pre-capillary pulmonary hypertension. PH-ILD carries a poor prognosis, and is associated with increased oxygen requirements, and a decline in functional capacity and exercise tolerance. Despite most patients having mild-moderate pulmonary hypertension, more severe pulmonary hypertension and signs of right heart failure are observed in a subset of cases. Clinical suspicion and findings on pulmonary function, computed tomography and echocardiography are often the initial steps towards diagnosis. Definitive diagnosis is obtained by right heart catheterisation demonstrating pre-capillary pulmonary hypertension. Drugs approved for pulmonary arterial hypertension have been investigated in several randomised controlled trials in PH-ILD patients, leading to discouraging results until the recent INCREASE study. This review provides an overview of the current understanding, approach to diagnosis and recent advances in treatment.

The 6-min walk test as a primary end-point in interstitial lung disease

There is a need for clinical trial end-points to better assess how patients feel and function, so that interventions can be developed which alleviate symptoms and improve quality of life. Use of 6-min walk test (6MWT) outcomes as a primary end-point in interstitial lung disease (ILD) trials is growing, particularly for drugs targeting concurrent pulmonary hypertension. However, 6MWT outcomes may be influenced differentially by interstitial lung and pulmonary vascular components of ILD, making interpretation complicated. We propose that using 6MWT outcomes, including 6-min walk distance or oxygen desaturation, as primary end-points should depend upon the study population (how advanced the ILD is; whether vasculopathy is significant), the degree of disease progression, and, importantly, the effect of study treatment expected. We argue that the 6MWT as a single outcome measure is suitable as a primary end-point if the treatment goal is to improve functional performance or prevent disease progression within a study population of patients with advanced ILD or those with ILD and co-existent vasculopathy. In addition, we discuss the potential of composite primary end-points incorporating 6MWT outcomes, outlining important considerations to ensure that they are appropriate for the study population and treatment goals.

Survey on Sildenafil, Tadalafil, and Vardenafil Concentrations in Food Supplements for Erectile Dysfunction

The aim of the study was to analyze the presence of undeclared sildenafil, tadalafil, and vardenafil in food supplements (FSs) for erectile dysfunction. The presence of sildenafil, tadalafil, and vardenafil was determined using the generated ultraviolet (UV)-spectra and mass-spectrometry (MS)-spectra as well as chromatograms produced by the photodiode array (PDA)-detector and ion trap MS-detector. The results were processed by Xcalibur ver. 2.0.7. Fourteen of the 20 analyzed FSs contained undeclared ingredients. Sildenafil was present in 12 of them. Many violations and discrepancies between the label information and the real composition of the FS were identified. 70% of the samples contained undeclared ingredients of an erectile dysfunction medicinal product. The quantities varied within broad limits from 2 mg per tablet to 116.55 mg per tablet. Sildenafil was present in amounts exceeding 16.55 mg that is the maximum recommended dose, thus creating risk of overdose. Besides that, food supplements adulterated with sildenafil analogues are a health risk for consumer's health as there is no evidence of modified sildenafil toxicity. All analyzed FSs were claimed to be 100% natural, not provoking side effects. No information for any FS contained indications of age limits or risk for interaction with other FSs or medical products.

Combined Pulmonary Fibrosis Emphysema: Role of Cigarette Smoking and Pulmonary Hypertension in a Rural Cohort

Background

Disease heterogeneity in idiopathic pulmonary fibrosis (IPF) often complicates the systematic study of disease, management of patients and clinical investigations.

Objective

To describe combined pulmonary fibrosis emphysema (CPFE) phenotype in a rural Appalachian IPF cohort with the highest smoking rates in the United States.

Methods

CPFE patients (n = 60) in a developed IPF cohort (n = 153) were characterized. Groups (CPFE vs IPF without emphysema) were categorized based on the predominant HRCT patterns of UIP (n = 109). Demographics, clinical variables, and treatment details were recorded. Kaplan–Meier survival and multivariate logistic regression analysis were performed.

Results

The prevalence of CPFE in our IPF cohort was 45% (n = 49). The CPFE group was younger (73.9 vs 78.2), had a more extensive smoking history (93.9% vs 53.3%) with greater mean smoking pack years (49.09 vs 15.39) and had lower percentage predicted DL_CO on presentation (38.35 vs 51.09) compared to IPF without emphysema group. Both groups shared equivalent higher burden of comorbidities, including pulmonary hypertension (PH) (46.9% vs 33.3%). One-fifth of patients were prescribed antifibrotics and only a subset (5%) of patients underwent lung transplantation. There was a non-significant trend towards reduced survival in CPFE (p = 0.076). Smoking status and DL_CO predicted CPFE in our cohort. Body mass index (BMI), PH, and pirfenidone use were significant predictors of mortality.

Conclusion

CPFE was highly prevalent in our rural IPF cohort. In contrast to previous studies, CPFE group was older and had higher female (approx. 30%) occurrence. A greater exposure to cigarette smoke and reduced DL_CO at diagnosis predicted CPFE. Lower BMI and PH predicted higher mortality whereas use of pirfenidone improved survival in our cohort. This study highlights a complex interaction of cigarette smoking, advanced fibrosis of UIP, PH and potential utility of antifibrotic agents in CPFE phenotype. Substantial burden of comorbidities, older age, and the limited utilization of advanced therapeutics in the cohort emphasize the challenges faced by rural Appalachian patients.

Clinical trials in group 3 pulmonary hypertension

PURPOSE OF REVIEW

Despite worse outcomes associated with the development of pulmonary hypertension in chronic lung disease, there are no approved treatments for this population. The present review summarizes the recent clinical trials in World Symposium on Pulmonary Hypertension (WSPH) Group 3 pulmonary hypertension, with a particular focus on the study of pulmonary arterial hypertension (PAH)-targeted therapy.

RECENT FINDINGS

Multiple recent randomized controlled trials have studied a host of PAH-specific medications in the treatment of WSPH Group 3 pulmonary hypertension, including endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and prostacyclins. In pulmonary hypertension associated with chronic obstructive lung disease (PH-COPD) and with interstitial lung disease (PH-ILD), most trials have shown conflicting or negative results, although they have been limited by variable patient populations and small sample sizes. Recent large-scale trial data demonstrate that inhaled treprostinil is associated with improved outcomes in the PH-ILD population.

SUMMARY

Although most PAH medications have not shown consistent benefit in the WSPH Group 3 population, recent work suggests that inhaled treprostinil has an important role in the treatment of PH-ILD. Efforts are ongoing to evaluate the efficacy of other medications, identify optimal treatment candidates, and define clinically meaningful endpoints in WSPH Group 3 pulmonary hypertension.

Idiopathic pulmonary fibrosis and pulmonary hypertension: Heracles meets the Hydra

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease where the additional presence of pulmonary hypertension (PH) reduces survival. In particular, the presence of coexistent pulmonary vascular disease in patients with advanced lung parenchymal disease results in worse outcomes than either diagnosis alone. This is true with respect to the natural histories of these diseases, outcomes with medical therapies, and even outcomes following lung transplantation. Consequently, there is a striking need for improved treatments for PH in the setting of IPF. In this review, we summarize existing therapies from the perspective of molecular mechanisms underlying lung fibrosis and vasoconstriction/vascular remodelling and discuss potential future targets for pharmacotherapy. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

MiR-200a inversely correlates with Hedgehog and TGF-β canonical/non-canonical trajectories to orchestrate the anti-fibrotic effect of Tadalafil in a bleomycin-induced pulmonary fibrosis model

Few reports have documented the ability of phosphodiesterase-5 inhibitors (PDE-5-Is) to ameliorate idiopathic pulmonary fibrosis (IPF) mainly by their anti-inflammatory/antioxidant capacities, without unveiling the possible molecular mechanisms involved. Because of the recent role of miR-200 family and Sonic Hedgehog (SHH) trajectory in IPF, we have studied their impact on the anti-fibrotic potential of tadalafil against bleomycin-induced pulmonary fibrosis. Animals were allocated into normal-control, bleomycin-fibrotic control, and bleomycin post-treated with tadalafil or dexamethasone, as the reference drug. On the molecular level, tadalafil has reverted the bleomycin effect on all the assessed parameters. Tadalafil upregulated the gene expression of miR-200a, but decreased the smoothened (SMO) and the transcription factors glioma-associated oncogene homolog (Gli-1, Gli-2), members of SHH pathway. Additionally, tadalafil ebbed transforming growth factor (TGF)-β, its canonical (SMAD-3/alpha smooth muscle actin [α-SMA] and Snail), and non-canonical (p-Akt/p-Forkhead box O3 (FOXO3) a) pathways. Besides, a strong negative correlation between miR-200a and the analyzed pathways was proved. The effect of tadalafil was further confirmed by the improved lung structure and the reduced Ashcroft score/collagen deposition. The results were comparable to that of dexamethasone. In conclusion, our study has highlighted the involvement of miR-200a in the anti-fibrotic effect of tadalafil with the inhibition of SHH hub and the pro-fibrotic pathways (TGF-β/ SMAD-3/α-SMA, Snail and p-AKT/p-FOXO3a). Potential anti-fibrotic effect of tadalafil. Modulation of miR200a/SHH/canonical and non-canonical TGF-β trajectories. → : stimulatory effect; ┴: inhibitory effect.

The adoption of nintedanib in systemic sclerosis: the SENSCIS study

We live in an era of respiratory medicine in which there is increasing awareness of interstitial lung diseases (ILDs). This is probably due to the publication of evidence-based guidelines [1, 2] and the discovery of newer drugs [3, 4]. These advances are particularly evident for idiopathic pulmonary fibrosis (IPF), which is to date the only fibrotic disease with specific pharmacologic-approved treatments. The burgeoning interest in pulmonary fibrosis has recently shifted its focus to the possibility of using therapeutic interventions available for IPF on other non-IPF ILDs, including pulmonary fibrosis secondary to systemic sclerosis (SSc). ILD represents one of the most relevant complications of SSc [5], but a standard treatment has yet to be achieved. Currently, the therapeutic management of SSc-ILD includes a “wait and see” approach in patients with a slow functional decay, and an immunosuppressive strategy (cyclophosphamide or mycophenolate) in patients with progressive ILD [6]. The Safety and Efficacy of Nintedanib in Systemic Sclerosis (SENSCIS) trial[7] explored the use of nintedanib, an intracellular inhibitor of tyrosine kinases currently approved for IPF, in scleroderma patients.

Nintedanib shows a statistically significant effect on lung function decay in patients with ILD secondary to systemic sclerosis, but no effect on skin fibrosis and on health-related quality of lifehttp://bit.ly/2vfJRj7

Targeting the NO-cGMP-PDE5 pathway in COVID-19 infection. The DEDALO project

Background

A pandemic outbreak of COVID‐19 has been sweeping the world since December. It begins as a respiratory infection that, mainly in men with diabetes or renal impairment, evolves into a systemic disease, with SARDS, progressive endothelial cell damage, abnormal clotting and impaired cardiovascular and liver function. Some clinical trials are testing biological drugs to limit the immune system dysregulation, “cytokines storm,” that causes the systemic complications of COVID‐19. The contraindications of these drugs and their cost raise concerns over the implications of their widespread availability.

Objectives

Numerous clinical and experimental studies have revealed a role for the nitric oxide (NO)‐cyclic GMP‐phosphodiesterase type 5 (PDE5) pathway in modulating low‐grade inflammation in patients with metabolic diseases, offering cardiovascular protection. PDE5 inhibition favors an anti‐inflammatory response by modulating activated T cells, reducing cytokine release, lowering fibrosis, increasing oxygen diffusion, stimulating vascular repair. PDE5 is highly expressed in the lungs, where its inhibition improves pulmonary fibrosis, a complication of severe COVID‐19 disease.

Materials and methods

We performed a systematic review of all evidence documenting any involvement of the NO‐cGMP‐PDE5 axis in the pathophysiology of COVID‐19, presenting the ongoing clinical trials aimed at modulating this axis, including our own “silDEnafil administration in DiAbetic and dysmetaboLic patients with COVID‐19 (DEDALO trial).”

Results

The reviewed evidence suggests that PDE5 inhibitors could offer a new strategy in managing COVID‐19 by (i) counteracting the Ang‐II‐mediated downregulation of AT‐1 receptor; (ii) acting on monocyte switching, thus reducing pro‐inflammatory cytokines, interstitial infiltration and the vessel damage responsible for alveolar hemorrhage‐necrosis; (iii) inhibiting the transition of endothelial and smooth muscle cells to mesenchymal cells in the pulmonary artery, preventing clotting and thrombotic complications.

Discussion and Conclusion

If the ongoing trials presented herein should provide positive findings, the low cost, wide availability and temperature stability of PDE5 inhibitors could make them a major resource to combat COVID‐19 in developing countries.

Comorbidities in idiopathic pulmonary fibrosis: an underestimated issue

Idiopathic pulmonary fibrosis (IPF) is a progressive and fibrosing lung disease with a poor prognosis. Between 60% and 70% of IPF patients die of IPF; the remaining causes of death may be due to comorbidities occurring in this ageing population. Interest in the role played by comorbidities in IPF has increased in the past few years. The optimal clinical management of IPF is multifaceted and not only involves antifibrotic treatment, but also vaccinations, oxygen supplementation, evaluation of nutritional status as well as psychological support and patient education. Symptom management, pulmonary rehabilitation, palliative care and treatment of comorbidities represent further areas of clinical intervention. This review analyses the major comorbidities observed in IPF, focusing on those that have the greatest impact on mortality and quality of life (QoL). The identification and treatment of comorbidities may help to improve patients' health-related QoL (i.e. sleep apnoea and depression), while some comorbidities (i.e. lung cancer, cardiovascular diseases and pulmonary hypertension) influence survival. It has been outlined that gathering comorbidities data improves the prediction of survival beyond the clinical and physiological parameters of IPF.

The therapy of idiopathic pulmonary fibrosis: what is next?

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease, characterised by progressive scarring of the lung and associated with a high burden of disease and early death. The pathophysiological understanding, clinical diagnostics and therapy of IPF have significantly evolved in recent years. While the recent introduction of the two antifibrotic drugs pirfenidone and nintedanib led to a significant reduction in lung function decline, there is still no cure for IPF; thus, new therapeutic approaches are needed. Currently, several clinical phase I-III trials are focusing on novel therapeutic targets. Furthermore, new approaches in nonpharmacological treatments in palliative care, pulmonary rehabilitation, lung transplantation, management of comorbidities and acute exacerbations aim to improve symptom control and quality of life. Here we summarise new therapeutic attempts and potential future approaches to treat this devastating disease.

Pharmacotherapy and adjunctive treatment for idiopathic pulmonary fibrosis (IPF)

Idiopathic pulmonary fibrosis (IPF) is an advancing and fatal lung disease with increasing incidence and prevalence. Nintedanib and pirfenidone were approved by the FDA for the treatment of IPF in 2014 based on positive phase 3 trials, and both of these antifibrotic drugs are conditionally recommended in the 2015 ATS/ERS/JRS/ALAT Clinical Practice Guideline. Although an improvement over previously suggested therapies, their capacity to reduce, but not completely arrest or improve, lung function over time presents an opportunity for novel or add-on pharmacologic agents. The purpose of this review is to deliver a brief overview of the results of phase 3/4 IPF trials with pirfenidone and nintedanib, as well as highlight encouraging results of phase 1/2 trials with novel therapies. Long-term studies indicate that pirfenidone and nintedanib are effective IPF treatments, with acceptable safety and tolerability. The combination of pirfenidone and nintedanib appear safe. Promising results have recently been made public for several phase 2 trials with novel targets, including the autotaxin-lysophosphatidic acid (ATX/LPA) pathway, connective tissue growth factor (CTGF), pentraxin-2, G protein-coupled receptor agonists/antagonists, αvβ6 integrin, and galectin-3. Results of treatments directed at gastro-esophageal reflux in patients with IPF have also been published. Currently, monotherapy with pirfenidone or nintedanib is the mainstay of pharmacological treatment for IPF. Innovative therapies along with combinations of pharmacological agents hold great promise for the future.

Management of Idiopathic Pulmonary Fibrosis

Objective: Provide information for pharmacists on idiopathic pulmonary fibrosis (IPF) and its treatment. Study Selection and Data Extraction: All articles with data from randomized controlled trials of nintedanib or pirfenidone were reviewed. Data Synthesis: IPF is a progressive and ultimately fatal interstitial lung disease characterized by decline in lung function and worsening dyspnea. It is uncommon and mainly occurs in individuals aged >60 years, particularly men with a history of smoking. Nintedanib and pirfenidone were approved in the United States for the treatment of IPF in 2014 and received conditional recommendations in the 2015 American Thoracic Society/European Respiratory Society/Japanese Respiratory Society/Latin American Thoracic Association treatment guidelines. These drugs slow the progression of IPF by reducing the rate of decline in lung function. Their adverse event profile is characterized mainly by gastrointestinal events, which can be managed through dose adjustment and symptom management. Management of IPF should also include smoking cessation, vaccinations, and supportive care such as patient education, pulmonary rehabilitation, and the use of supplemental oxygen as well as optimizing the management of comorbidities. Relevance to Patient Care and Clinical Practice: This review provides clinical pharmacists with information on the course of IPF, what can be expected of current treatments, and how to help patients manage their drug therapy. Conclusions: IPF is a progressive disease, but treatments are available that can slow the progression of the disease. Clinical pharmacists can play an important role in the care of patients with IPF through patient education, monitoring medication compliance and safety, ensuring drugs for comorbidities are optimized, and preventive strategies such as immunizations.

The Future of Pharmacological Treatment in Idiopathic Pulmonary Fibrosis

The therapeutic approach in idiopathic pulmonary fibrosis has changed substantially over the past 5 years. National and international guidelines for the pharmacological treatment of IPF recommend 2antifibrotic drugs, nintedanib and pirfenidone. The use of both these drugs is supported by high-level evidence, with benefits including not only slower disease progression but also a reduction in the annual risk of death. Currently, the therapeutic management of these patients prioritizes both the use of drugs that act on the pathogenic mechanisms of the disease, and the positive effect of improving quality of life with integrated multidisciplinary support, including nutrition, physical activity, education, emotional support, and palliation of symptoms. The overall aim is to ensure that the patient remains as well as possible for as long as possible after diagnosis. However, the goal of the new antifibrotic combinations that are currently under evaluation in clinical trials is to use the potential antifibrotic synergy to enhance the therapeutic benefit or completely halt disease progression, by acting simultaneously on different pathogenic pathways. Another line of investigation involves markers that might be useful for identifying patients who may benefit more from certain antifibrotics than from others, which would make it possible to optimize resources and take the first steps toward precision medicine in pulmonary fibrosis. Below, we review the main potential areas for improvement in the pharmacological treatment of idiopathic pulmonary fibrosis in the short, medium, and long term.

A comprehensive and practical approach to the management of idiopathic pulmonary fibrosis

Introduction: Idiopathic pulmonary fibrosis (IPF) is a debilitating, progressive, and fatal fibrotic pulmonary disease with a prognosis comparable to that of lung cancer. IPF management is a complex process that involves pharmacological and nonpharmacological interventions, extensive patient education, and addressing patient needs that change through the course of the illness. Areas covered: This review summarizes the key aspects of a multifaceted, multidisciplinary, individualized approach to IPF care that incorporates available treatment options, strategies to improve compliance with antifibrotic therapies, pulmonary rehabilitation, and the integration of palliative care for symptom management. Aspects of care discussed include the use of antifibrotic therapy and nonpharmacological treatments, targeted education and psychosocial support, evaluation and management of comorbidities, and early integration of palliative care. Expert opinion: By incorporating this comprehensive approach to disease management, physicians can address most aspects of care for a patient with IPF to optimize survival and quality of life.

Idiopathic Pulmonary Fibrosis for Cardiologists: Differential Diagnosis, Cardiovascular Comorbidities, and Patient Management

The presence of rare comorbidities in patients with cardiovascular disease (CVD) presents a diagnostic challenge to cardiologists. In evaluating these patients, cardiologists are faced with a unique opportunity to shorten diagnosis times and direct patients towards correct treatment pathways. Idiopathic pulmonary fibrosis (IPF), a type of interstitial lung disease (ILD), is an example of a rare disease where patients frequently demonstrate comorbid CVD. Both CVD and IPF most commonly affect a similar patient demographic: men over the age of 60 years with a history of smoking. Moreover, IPF and heart failure (HF) share a number of symptoms. As a result, patients with IPF can be misdiagnosed with HF and vice versa. This article aims to increase awareness of IPF among cardiologists, providing an overview for cardiologists on the differential diagnosis of IPF from HF, and describing the signs and symptoms that would warrant referral to a pulmonologist with expertise in ILD. Once patients with IPF have received a diagnosis, cardiologists can have an important role in managing patients who are candidates for a lung transplant or those who develop pulmonary hypertension (PH). Group 3 PH is one of the most common cardiovascular complications diagnosed in patients with IPF, its prevalence varying between reports but most often cited as between 30% and 50%. This review summarizes the current knowledge on Group 3 PH in IPF, discusses data from clinical trials assessing treatments for Group 1 PH in patients with IPF, and highlights that treatment guidelines recommend against these therapies in IPF. Finally, this article provides the cardiologist with an overview on the use of the two approved treatments for IPF, the antifibrotics pirfenidone and nintedanib, in patients with IPF and CVD comorbidities. Conversely, the impact of treatments for CVD comorbidities on patients with IPF is also discussed.Funding: F. Hoffmann-La Roche, Ltd.Plain Language Summary: Plain language summary available for this article.

Phosphodiesterase 5 inhibitors for pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) comprises a group of complex and heterogenous conditions, characterised by elevated pulmonary artery pressure, and which left untreated leads to right-heart failure and death. PH includes World Health Organisation (WHO) Group 1 pulmonary arterial hypertension (PAH); Group 2 consists of PH due to left-heart disease (PH-LHD); Group 3 comprises PH as a result of lung diseases or hypoxia, or both; Group 4 includes PH due to chronic thromboembolic occlusion of pulmonary vasculature (CTEPH), and Group 5 consists of cases of PH due to unclear and/or multifactorial mechanisms including haematological, systemic, or metabolic disorders. Phosphodiesterase type 5 (PDE5) inhibitors increase vasodilation and inhibit proliferation.

OBJECTIVES

To determine the efficacy of PDE5 inhibitors for pulmonary hypertension in adults and children.

SEARCH METHODS

We performed searches of CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science up to 26 September 2018. We handsearched review articles, clinical trial registries, and reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials that compared any PDE5 inhibitor versus placebo, or any other PAH disease-specific therapies, for at least 12 weeks. We include separate analyses for each PH group.

DATA COLLECTION AND ANALYSIS

We imported studies identified by the search into a reference manager database. We retrieved the full-text versions of relevant studies, and two review authors independently extracted data. Primary outcomes were: change in WHO functional class, six-minute walk distance (6MWD), and mortality. Secondary outcomes were haemodynamic parameters, quality of life/health status, dyspnoea, clinical worsening (hospitalisation/intervention), and adverse events. When appropriate, we performed meta-analyses and subgroup analyses by severity of lung function, connective tissue disease diagnosis, and radiological pattern of fibrosis. We assessed the evidence using the GRADE approach and created 'Summary of findings' tables.

MAIN RESULTS

We included 36 studies with 2999 participants (with pulmonary hypertension from all causes) in the final review. Trials were conducted for 14 weeks on average, with some as long as 12 months. Two trials specifically included children.Nineteen trials included group 1 PAH participants. PAH participants treated with PDE5 inhibitors were more likely to improve their WHO functional class (odds ratio (OR) 8.59, 95% confidence interval (CI) 3.95 to 18.72; 4 trials, 282 participants), to walk 48 metres further in 6MWD (95% CI 40 to 56; 8 trials, 880 participants), and were 22% less likely to die over a mean duration of 14 weeks (95% CI 0.07 to 0.68; 8 trials, 1119 participants) compared to placebo (high-certainty evidence). The number needed to treat to prevent one additional death was 32 participants. There was an increased risk of adverse events with PDE5 inhibitors, especially headache (OR 1.97, 95% CI 1.33 to 2.92; 5 trials, 848 participants), gastrointestinal upset (OR 1.63, 95% CI 1.07 to 2.48; 5 trials, 848 participants), flushing (OR 4.12, 95% CI 1.83 to 9.26; 3 trials, 748 participants), and muscle aches and joint pains (OR 2.52, 95% CI 1.59 to 3.99; 4 trials, 792 participants).Data comparing PDE5 inhibitors to placebo whilst on other PAH-specific therapy were limited by the small number of included trials. Those PAH participants on PDE5 inhibitors plus combination therapy walked 19.66 metres further in six minutes (95% CI 9 to 30; 4 trials, 509 participants) compared to placebo (moderate-certainty evidence). There were limited trials comparing PDE5 inhibitors directly with other PAH-specific therapy (endothelin receptor antagonists (ERAs)). Those on PDE5 inhibitors walked 49 metres further than on ERAs (95% CI 4 to 95; 2 trials, 36 participants) (low-certainty evidence). There was no evidence of a difference in WHO functional class or mortality across both treatments.Five trials compared PDE5 inhibitors to placebo in PH secondary to left-heart disease (PH-LHD). The quality of data were low due to imprecision and inconsistency across trials. In those with PH-LHD there were reduced odds of an improvement in WHO functional class using PDE5 inhibitors compared to placebo (OR 0.53, 95% CI 0.32 to 0.87; 3 trials, 285 participants), and those using PDE5 inhibitors walked 34 metres further compared to placebo (95% CI 23 to 46; 3 trials, 284 participants). There was no evidence of a difference in mortality. Five trials compared PDE5 inhibitors to placebo in PH secondary to lung disease/hypoxia, mostly in COPD. Data were of low quality due to imprecision of effect and inconsistency across trials. There was a small improvement of 27 metres in 6MWD using PDE5 inhibitors compared to placebo in those with PH due to lung disease. There was no evidence of worsening hypoxia using PDE5 inhibitors, although data were limited. Three studies compared PDE5 inhibitors to placebo or other PAH-specific therapy in chronic thromboembolic disease. There was no significant difference in any outcomes. Data quality was low due to imprecision of effect and heterogeneity across trials.

AUTHORS' CONCLUSIONS

PDE5 inhibitors appear to have clear beneficial effects in group 1 PAH. Sildenafil, tadalafil and vardenafil are all efficacious in this clinical setting, and clinicians should consider the side-effect profile for each individual when choosing which PDE5 inhibitor to prescribe.While there appears to be some benefit for the use of PDE5 inhibitors in PH-left-heart disease, it is not clear based on the mostly small, short-term studies, which type of left-heart disease stands to benefit. These data suggest possible harm in valvular heart disease. There is no clear benefit for PDE5 inhibitors in pulmonary hypertension secondary to lung disease or chronic thromboembolic disease. Further research is required into the mechanisms of pulmonary hypertension secondary to left-heart disease, and cautious consideration of which subset of these patients may benefit from PDE5 inhibitors. Future trials in PH-LHD should be sufficiently powered, with long-term follow-up, and should include invasive haemodynamic data, WHO functional class, six-minute walk distance, and clinical worsening.

Novel management strategies for idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) treatment was revolutionized by the advent of two novel antifibrotics, nintedanib and pirfenidone. However, neither is a panacea and other agents are still sorely needed. This review presents on-going efforts to improve outcomes for patients with IPF by targeting novel pharmacologic pathways, improving comorbidity management, and aiming for improved quality of life. Areas covered: We provide an overview of on-going basic and clinical science efforts focused on development of additional drug therapies for patients with IPF. Known and emerging pathogenic pathways such as the microbiome and pulmonary vasculature hold promise as targets for therapy. While the focus remains on pharmacologic intervention, the impact of comorbidities and their management may also impact patient outcomes significantly. Supportive care with pulmonary rehabilitation, oxygen therapy, and palliative care remain integral at various stages of the disease course. Finally, lung transplant is the only lifesaving intervention for patients with end-stage fibrosis. Expert commentary: Future investigation should aim to prevent the initial insult or injury that engages the multiple pathways associated with the development and progression of IPF. Targeted therapies represent just one management aspect with a multidisciplinary approach necessary for the global holistic care of these complex patients.