Management of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a rare pulmonary vascular disease characterized by progressive pulmonary arterial remodeling, increased pulmonary vascular resistance, right ventricular dysfunction, and reduced survival. Effective therapies have been developed that target three pathobiologic pathways in PAH: nitric oxide, endothelin-1, and prostacyclin. Approved therapies for PAH include phosphodiesterase type-5 inhibitors, soluble guanylate cyclase stimulators, endothelin receptor antagonists, prostacyclin analogs, and prostacyclin receptor agonists. Management of PAH in the modern era incorporates multidimensional risk assessment to guide the use of these medications. For patients with PAH and without significant comorbidities, current guidelines recommend two oral medications (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) for low- and intermediate-risk patients, with triple therapy including a parenteral prostacyclin to be considered in those at high or intermediate-high risk. Combination therapy may be poorly tolerated and less effective in patients with PAH and cardiopulmonary comorbidities. Thus, a single-agent approach with individualized decisions to add-on other PAH therapies is recommended in older patients and those with significant comorbid conditions. Management of PAH is best performed in multidisciplinary teams located in experienced centers. Other core pillars of PAH management include supportive and adjunctive treatments including oxygen, diuretics, rehabilitation, and anticoagulation in certain patients. Patients with PAH who progress despite optimal treatment or who are refractory to best medical care should be referred for lung transplantation, if eligible. Despite considerable progress, PAH is often fatal and new therapies that reverse the disease and improve outcomes are desperately needed.

[Targeted therapy for pulmonary arterial hypertension in patients without comorbidities]

The 2022 guidelines on pulmonary hypertension from the European Society of Cardiology (ESC) and the European Respiratory Society (ERS) provide therapeutic strategies that account for the variability in the clinical presentation of newly diagnosed patients. We summarize treatment recommendations for pulmonary arterial hypertension (PAH) in patients without significant comorbidities, particularly for idiopathic, hereditary, drug/toxin-induced, or connective tissue disease-associated PAH. In this group of patients, multidimensional assessments for short-term mortality risk guide initial treatment decisions and treatment decisions during follow-up. Upfront dual combination therapy (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) is recommended for low- and intermediate-risk patients, and triple therapy including a parenteral prostacyclin should be considered in high- or intermediate-high-risk patients. If a low or intermediate-low-risk profile cannot be achieved during therapy, sequential add-on therapy escalation with parenteral prostacyclin or a prostacyclin receptor agonist should be considered, and switching from a phosphodiesterase type-5 inhibitor to a guanylate cyclase stimulator may also be considered.

Effect of vinpocetine alone and in combination with enalapril in experimental model of diabetic cardiomyopathy in rats: possible involvement of PDE-1/TGF-β/ Smad 2/3 signalling pathways

OBJECTIVE

Diabetic cardiomyopathy (DC) is one of the severe secondary complications of diabetes mellitus in humans. Vinpocetine is an alkaloid having pleiotropic pharmacological effects. The present study is designed to investigate the effect of vinpocetine in DC in rats.

METHODS

Rats were fed a high-fat diet for nine weeks along with single dose of streptozotocin after the second week to induce DC. The haemodynamic evaluation was performed to assess the functional status of rats using the Biopac system. Cardiac echocardiography, biochemical, oxidative stress parameters and inflammatory cytokine level were analysed in addition to haematoxylin-eosin and Masson's trichome staining to study histological changes, cardiomyocyte diameter and fibrosis, respectively. Phosphodiesterase-1 (PDE-1), transforming growth factor-β (TGF-β) and p-Smad 2/3 expression in cardiac tissues were quantified using western blot/RT-PCR.

KEY FINDING

Vinpocetine treatment and its combination with enalapril decreased the glucose levels compared to diabetic rats. Vinpocetine improved the echocardiographic parameters and cardiac functional status of rats. Vinpocetine decreased the cardiac biochemical parameters, oxidative stress, inflammatory cytokine levels, cardiomyocyte diameter and fibrosis in rats. Interestingly, expressions of PDE-1, TGF-β and p-Smad 2/3 were ameliorated by vinpocetine alone and in combination with enalapril.

CONCLUSIONS

Vinpocetine is a well-known inhibitor of PDE-1 and the protective effect of vinpocetine in DC is exerted by inhibition of PDE-1 and subsequent inhibition of the expression of TGF-β/Smad 2/3.

Ensifentrine, a Novel Phosphodiesterase 3 and 4 Inhibitor for the Treatment of Chronic Obstructive Pulmonary Disease: Randomized, Double-Blind, Placebo-controlled, Multicenter Phase III Trials (the ENHANCE Trials)

Rationale: Ensifentrine is a novel, selective, dual phosphodiesterase (PDE)3 and PDE4 inhibitor with bronchodilator and antiinflammatory effects. Replicate phase III trials of nebulized ensifentrine were conducted (ENHANCE-1 and ENHANCE-2) to assess these effects in patients with chronic obstructive pulmonary disease (COPD). Objectives: To evaluate the efficacy of ensifentrine compared with placebo for lung function, symptoms, quality of life, and exacerbations in patients with COPD. Methods: These phase III, multicenter, randomized, double-blind, parallel-group, placebo-controlled trials were conducted between September 2020 and December 2022 at 250 research centers and pulmonology practices in 17 countries. Patients aged 40-80 years with moderate to severe symptomatic COPD were enrolled. Measurements and Main Results: Totals of 760 (ENHANCE-1) and 789 (ENHANCE-2) patients were randomized and treated, with 69% and 55% receiving concomitant long-acting muscarinic antagonists or long-acting β2-agonists, respectively. Post-bronchodilator FEV1 percentage predicted values were 52% and 51% of predicted normal. Ensifentrine treatment significantly improved average FEV1 area under the curve at 0-12 hours versus placebo (ENHANCE-1, 87 ml [95% confidence interval, 55, 119]; ENHANCE-2, 94 ml [65, 124]; both P < 0.001). Ensifentrine treatment significantly improved symptoms (Evaluating Respiratory Symptoms) and quality of life (St. George's Respiratory Questionnaire) versus placebo at Week 24 in ENHANCE-1 but not in ENHANCE-2. Ensifentrine treatment reduced the rate of moderate or severe exacerbations versus placebo over 24 weeks (ENHANCE-1, rate ratio, 0.64 [0.40, 1.00]; P = 0.050; ENHANCE-2, rate ratio, 0.57 [0.38, 0.87]; P = 0.009) and increased time to first exacerbation (ENHANCE-1, hazard ratio, 0.62 [0.39, 0.97]; P = 0.038; ENHANCE-2, hazard ratio, 0.58 [0.38, 0.87]; P = 0.009). Adverse event rates were similar to those for placebo. Conclusions: Ensifentrine significantly improved lung function in both trials, with results supporting exacerbation rate and risk reduction in a broad COPD population and in addition to other classes of maintenance therapies. Clinical trial registered with www.

CLINICALTRIALS

gov and EudraCT (ENHANCE-1, www.

CLINICALTRIALS

gov identifier NCT04535986, EudraCT identifier 2020-002086-34; ENHANCE-2, www.

CLINICALTRIALS

gov identifier NCT04542057, EudraCT identifier 2020-002069-32).

Longitudinal assessment of vascular calcification in generalized arterial calcification of infancy

BACKGROUND

Generalized arterial calcification of infancy (GACI), also known as idiopathic infantile arterial calcification, is a very uncommon genetic disorder characterized by calcifications and stenoses of large- and medium-size arteries that can lead to end-organ damage.

OBJECTIVE

To describe changes in imaging findings in 10 children with GACI at a single institution from 2010 to 2021.

MATERIALS AND METHODS

In this retrospective study we reviewed initial and follow-up body imaging in children with genetic confirmation of GACI at our hospital. All initial images were analyzed for the presence and distribution of arterial calcifications, stenoses and wall thickening/irregularity within the chest, abdomen and pelvis. We compared available follow-up studies to the initial imaging findings. We extracted clinical information including prenatal and postnatal treatment from the children's medical records.

RESULTS

We evaluated 10 children (five boys) with a diagnosis of GACI. Median age at first body imaging was 8 days (range: 1 day to 5 years). Six children were identified prenatally and four postnatally. Postnatal presentation included cardiac failure, seizures and hypertension. Images in newborns (n = 8) most commonly showed diffuse arterial calcifications (6/8; 75%), while stenoses were less common (2/8; 25%) during this period. Two children were diagnosed after the neonatal period - one in infancy and one during childhood. In total, half the children (5/10; 50%) had arterial stenoses - three cases visualized at first imaging and two identified on follow-up images during infancy. Stenoses had completely resolved in one child (1/5; 20%) at last follow-up. Eight children received prenatal or postnatal treatment or both. All children who received both prenatal and postnatal treatment (n = 4) had completely resolved calcifications at last follow-up.

CONCLUSION

Children with GACI might have characteristic vascular calcifications at birth that raise the suspicion of this disease. Arterial calcifications decrease or disappear spontaneously or after treatment, but arterial stenoses usually persist. Calcifications and arterial stenoses can be easily identified and followed with non-contrast CT and CT angiography.

The clinical relevance of Raynaud's phenomenon symptom characteristics in systemic sclerosis

Raynaud's phenomenon (RP) is a cardinal feature of systemic sclerosis (SSc) and manifests with pain, digital colour change, sensory symptoms, and impaired function. SSc-RP is exacerbated by cold exposure (RP 'attacks') but many patients report persistent symptoms of background digital ischaemia. The aim of our study was to examine the significance of RP with digital colour change with or without symptoms, and persistent colour change in between attacks. Patients with SSc responses were obtained from the Patient Survey of experiences of Raynaud's Phenomenon (PASRAP). We enquired about symptoms associated with Raynaud's attacks, and persistent symptoms in between attacks. Data were analysed as descriptive statistics with appropriate parametric/non-parametric testing. Relevant PASRAP survey question data from 747 evaluable SSc patients from across three continents were analysed. Isolated colour change was rare (29/484, 6%). Digital ulcers were more common in SSc-RP associated with other sensory symptoms (42.1% vs. 24.1%, P=0.057) and more readily treated with phosphodiesterase-type 5 inhibitors (22.5% vs. 10.3%%, P=0.124). Over one-third of patients (n=92/239, 38%) reported persistent colour change in between Raynaud's attacks. Patients with persistent colour change were more likely to have pulmonary arterial hypertension (15.2% vs. 7.5%, P=0.057) and be treated with calcium channel blockers (54.3% vs. 39.0%, P=0.021). SSc-RP with colour change and other symptoms and/or or persistent decolourisation in between attacks were more likely to have vascular complications of SSc and be treated with vascular therapies. Future research should explore the judicious use of vascular therapies as a potential form of disease modification in SSc. Key Points • Isolated colour change without other symptoms is rare in SSc patients. • SSc patients often identify persistent symptoms in between attacks of RP. • SSc-RP with colour change and other symptoms, or persistent decolourisation, may have greater disease severity and be treated with vascular therapies.

A Dose-Ranging Study of the Novel Inhaled Dual PDE 3 and 4 Inhibitor Ensifentrine in Patients with COPD Receiving Maintenance Tiotropium Therapy

PURPOSE

Ensifentrine is an inhaled dual inhibitor of phosphodiesterase (PDE) 3 and 4 that has shown bronchodilatory effects and symptom improvement in clinical studies in patients with chronic obstructive pulmonary disease (COPD), and anti-inflammatory effects in healthy volunteers in a model of COPD-like inflammation. This manuscript reports on the results of the clinical study examining if ensifentrine provides meaningful improvements in lung function when added on to tiotropium over 4 weeks in patients with COPD who have impaired lung function and symptoms despite treatment with tiotropium.

PATIENTS AND METHODS

This randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study recruited patients with moderate-to-severe COPD. Patients were randomized to open-label tiotropium once daily (QD) plus (+) blinded escalating doses of ensifentrine or placebo twice daily (BID). Effects on lung function, symptoms and quality of life (QoL) were assessed over 4 weeks.

RESULTS

A total of 416 COPD patients were randomized and 413 received at least one dose of blinded study medication + tiotropium. All ensifentrine doses produced a significant and dose-dependent increase in peak forced expiratory volume in 1 second (FEV1) from baseline to Week 4, with placebo-corrected differences of 77.5 mL when added to tiotropium (0.375 mg; 95% CI: 4.8, 150.1 mL; p=0.037) to 124.2 mL (3 mg; 95% CI: 51.0, 196.8 mL; p<0.001). A significant increase in average FEV1 (0-12h) was shown at Week 4 with the 3 mg dose (87.3 mL; 95% CI: 20.0, 154.5 mL; p=0.011). Clinically meaningful and statistically significant improvements in the St. George's Respiratory Questionnaire - COPD (SGRQ-C) additive to tiotropium were observed at Week 4, exceeding the minimally clinically important difference of 4 units with the 1.5 and 3 mg doses. Adverse events were similar in frequency between the ensifentrine and placebo arms.

CONCLUSION

This clinical study demonstrated that nebulized ensifentrine added on to tiotropium produced clinically important improvements in lung function and QoL over 4 weeks in COPD patients receiving tiotropium who demonstrated symptoms and lung function impairment, with a safety profile similar to placebo.

Symptom Improvement Following Treatment with the Inhaled Dual Phosphodiesterase 3 and 4 Inhibitor Ensifentrine in Patients with Moderate to Severe COPD - A Detailed Analysis

Introduction

Ensifentrine is an inhaled first-in-class dual inhibitor of phosphodiesterase (PDE) 3 and 4. In a four-week randomized, double-blind, placebo-controlled, parallel-group study in patients with chronic obstructive pulmonary disease (COPD), nebulized ensifentrine 0.75 to 6mg twice daily significantly improved bronchodilation and symptoms, with all doses being well tolerated. Here, we report data for a number of prespecified exploratory and post hoc endpoints from this study that help to further profile the effect of ensifentrine on symptoms.

Methods

Eligible patients were males or females aged 40-75 years with COPD, post-bronchodilator forced expiratory volume in 1 second 40-80% predicted. Other than being clinically stable for at least four weeks prior to entry, there were no symptomatic inclusion or exclusion criteria. The outcome measures reported in this manuscript are the Evaluating Respiratory Symptoms [E-RS™:COPD] questionnaire total score and subscales (breathlessness, cough/sputum and chest symptoms) at Weeks 1-4, Transition Dyspnea Index (TDI) focal score at Weeks 2 and 4, and St George's Respiratory Questionnaire - COPD Specific (SGRQ-C) total score and domain data (symptoms, activity and impacts) at Week 4.

Results

There was a gradual improvement versus placebo with all ensifentrine doses for all three E-RS™:COPD subscales from Week 1 to Week 4, with the greatest ensifentrine effect on the breathlessness subscale, and all four doses superior to placebo from Week 2 onwards (p<0.05). For TDI focal score, all ensifentrine doses were superior to placebo at Weeks 2 and 4 (p<0.05). In the individual SGRQ-C domains at Week 4, ensifentrine had the greatest effect on the symptoms domain, with ensifentrine 6mg superior to placebo (p<0.05).

Conclusion

In these analyses, ensifentrine demonstrated a notable early and meaningful effect on dyspnea, with this effect observed across two different assessment tools.

Congenital diaphragmatic hernia: current status and review of the literature

Treatment of congenital diaphragmatic hernia (CDH) challenges obstetricians, pediatric surgeons, and neonatologists. Persistent pulmonary hypertension (PPHT) associated with lung hypoplasia in CDH leads to a high mortality rate at birth. PPHT is principally due to an increased muscularization of the arterioles. Management of CDH has been greatly improved by the introduction of prenatal surgical intervention with tracheal obstruction (TO) and by more appropriate postnatal care. TO appears to accelerate fetal lung growth and to increase the number of capillary vessels and alveoli. Improvement of postnatal care over the last years is mainly due to the avoidance of lung injury by applying low peak inflation pressure during ventilation. The benefits of other drugs or technical improvements such as the use of inhaled nitric oxide or extracorporeal membrane oxygenation (ECMO) are still being debated and no single strategy is accepted worldwide. Despite intensive clinical and experimental research, the treatment of newborn with CDH remains difficult.

Efficacy and tolerability of vardenafil in men with mild depression and erectile dysfunction: the depression-related improvement with vardenafil for erectile response study

OBJECTIVE

Erectile dysfunction and depression are highly associated. Previous studies have shown benefits of phosphodiesterase-5 inhibitor treatment for erectile dysfunction associated with antidepressant therapy or subsyndromal depression. The present study assessed the safety and efficacy of vardenafil in men with erectile dysfunction and untreated mild depression.

METHOD

In this 12-week, multicenter, randomized, flexible-dose, parallel-group, double-blind study, 280 men with erectile dysfunction for at least 6 months and untreated mild major depression received placebo or vardenafil, 10 mg/day, for 4 weeks, with the option to titrate to 5 mg/day or 20 mg/day after each of two consecutive 4-week intervals. Endpoints included International Index of Erectile Function erectile function domain and 17-item Hamilton Depression Rating Scale (HAM-D) scores.

RESULTS

Vardenafil produced statistically significant and clinically meaningful improvement in all erectile function parameters. The International Index of Erectile Function erectile function domain score was 22.9 with vardenafil compared to 14.9 with placebo. The HAM-D score was lower in the vardenafil group (7.9) than in the placebo group (10.1). Treatment with vardenafil was the most important predictor for return to normal erectile function. Improvement in International Index of Erectile Function erectile function domain score was the most important predictor of remission in depressive symptoms.

CONCLUSIONS

Vardenafil was well tolerated and highly efficacious in men with erectile dysfunction and untreated mild major depression. Significant improvements in erectile function and depression were observed in patients treated with vardenafil versus placebo. Erectile dysfunction treatment should be considered a component of therapy for men with depression and erectile dysfunction.

The brown spider Loxosceles laeta: source of the remedy Tarentula cubensis?

The homeopathic remedy Tarentula cubensis (Cuban tarantula), used in homeopathy to treat abscesses with burning pains, gangrene, septicaemia, toxaemia, has been grouped by homeopathic authorities with either the mygalomorph or wolf spiders. The original specimen used for preparation of the mother tincture was decomposed, leaving the spider's exact identity in doubt. Investigation of the toxicological and clinical literature, compared with homeopathic materia medica, reveals the brown spider, Loxosceles laeta, indigenous to South America but present also in Mid- and North America, as a more likely source. Venoms of spiders of the genus Loxosceles cause severe necrotic arachnidism, as well as, in some cases, a life-threatening systemic reaction marked by renal failure, disseminated intravascular coagulation, thrombocytopeania, coma and convulsions.

Pronucleotides: toward the in vivo delivery of antiviral and anticancer nucleotides

To overcome the many hurdles preventing the use of antiviral and anticancer nucleosides as therapeutics, the development of a prodrug methodology (i.e., pronucleotide) for the in vivo delivery of nucleotides has been proposed as a solution. The ideal pronucleotide should be non-toxic, stable in plasma and blood, capable of being i. v. and/or orally dosed, and intracellularly convertible to the corresponding nucleotide. Although this goal has yet to be achieved, many clever and imaginative pronucleotide approaches have been developed, which are likely to be important pharmacological tools. This review will discuss the major advances and future directions of the emerging field of antiviral and anticancer pronucleotide design and development.

Function and protective capacity of Treponema pallidum subsp. pallidum glycerophosphodiester phosphodiesterase

Infectious syphilis, caused by the spirochete bacterium Treponema pallidum subsp. pallidum, remains a public health concern worldwide. The immune-response evasion mechanisms employed by T. pallidum are poorly understood, and prior attempts to identify immunoprotective antigens for subsequent vaccine design have been unsuccessful. Previous investigations conducted in our laboratory identified the T. pallidum glycerophosphodiester phosphodiesterase as a potential immunoprotective antigen by using a differential immunologic expression library screen. In studies reported here, heterologous expression of the T. pallidum glycerophosphodiester phosphodiesterase in Escherichia coli yielded a full-length, enzymatically active protein. Characterization of the recombinant molecule showed it to be bifunctional, in that it exhibited specific binding to human immunoglobulin A (IgA), IgD, and IgG in addition to possessing enzymatic activity. IgG fractionation studies revealed specific binding of the recombinant enzyme to the Fc fragment of human IgG, a characteristic that may play a role in enabling the syphilis spirochete to evade the host immune response. In further investigations, immunization with the recombinant enzyme significantly protected rabbits from subsequent T. pallidum challenge, altering lesion development at the sites of challenge. In all cases, animals immunized with the recombinant molecule developed atypical pale, flat, slightly indurated, and nonulcerative reactions at the challenge sites that resolved before lesions appeared in the control animals. Although protection in the immunized rabbits was incomplete, as demonstrated by the presence of T. pallidum in the rabbit infectivity test, glycerophosphodiester phosphodiesterase nevertheless represents a significantly immunoprotective T. pallidum antigen and thus may be useful for inclusion in an antigen cocktail vaccine for syphilis.

Targeting phosphodiesterases as a strategy for killing tumor cells

Ribonucleases (RNases) are being employed as alternative cytotoxic proteins to the conventionally used ones such as ricin and Pseudomonas exotoxin. Mammalian RNases are attractive enzymes because of their comparable cytotoxicity when suitably directed and the likelihood of lower immunogenicity compared to plant and bacterial toxins. Bovine seminal RNase (BSRNase) is a member of the RNase superfamily, but differs in many interesting ways. Unlike the rest of the family it is dimeric, and possesses antitumor and immunosuppressive properties. These features make it a choice candidate for a single-chain antibody (scFv) based immunotoxin. This work describes preliminary data on the construction, expression in Escherichia coli and characterization of a tumor-specific scFv (directed against human placental alkaline phosphatase)-BSRNase chimeric molecule. It is shown that the created molecule has RNA degrading activity and antigen-binding activity when refolded from bacterial inclusion bodies.