Transition from intravenous treprostinil to enteral selexipag in an infant with pulmonary arterial hypertension

Targeted Therapies for Neonatal Pulmonary Hypertension: Beyond Nitric Oxide

Pulmonary hypertension in the neonatal population can be acute or chronic and carries significant risk for morbidity and mortality. It can be idiopathic but more often is associated with comorbid pulmonary and heart disease. There are several pharmacotherapeutics aimed at pulmonary vasodilation. This review highlights the most common agents as well as those on the horizon for the treatment of pulmonary hypertension in the neonate.

Selexipag for the Treatment of Pediatric Pulmonary Hypertension: A Systematic Review

PURPOSE

To systematically evaluate the safety, dosing regimen, and efficacy of selexipag for pediatric patients with pulmonary hypertension (PH).

METHODS

A literature search of the electronic databases of PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar was performed from inception through February 28, 2023. Two reviewers independently searched and evaluated the quality of the studies and pooled data when appropriate. Full-text articles of studies of children diagnosed with PH and treated with selexipag were eligible. Pediatric patients with PH were classified into 2 groups: the add-on therapy group, in which selexipag was used as a third therapy in addition to the baseline treatment, and the transition therapy group, in which patients were switched from parenteral prostacyclin analogs to selexipag.

FINDINGS

Fourteen studies involving 58 pediatric patients with PH were included. All studies were either case reports or case series. Overall, 30 and 28 patients were in the add-on and transition therapy groups, respectively. In both groups, selexipag was initially administered as 50-200 µg twice daily and titrated to a tolerated dosage of 200-1,600 µg twice daily. Prostacyclin analogs were simultaneously weaned for patients in the transition group. In the add-on therapy group, 16 patients (80.0%) were at low risk of the World Health Organization functional class (WHO FC I/II), 12 (76.9%) were at low risk of the 6-minute walk distance (6MWD; >350 m), and 21 (95.5%) were at low risk of the pulmonary vascular resistance index (PVRi; <20 WU/m2). Furthermore, N-terminal pro-brain natriuretic peptide and mean pulmonary arterial pressure were significantly improved. More than 70% of patients experienced common tolerable side effects, such as headache, nausea, and diarrhea. In the transition therapy group, 5 patients (55.6%) were at low risk according to WHO FC I/II, 6 (66.7%) were at low risk according to 6MWD, and 14 (87.5) were at low risk according to PVRi; however, selexipag had no significant effect on their hemodynamic parameters. Additionally, more than 80% of patients experienced no side effects.

IMPLICATIONS

Selexipag as add-on therapy or for transition from prostacyclin analogs may have a favorable safety profile and potential efficacy for pediatric patients with PH. Further high-quality evidence of the efficacy and safety of selexipag for the treatment of pediatric PH is warranted.

Current and emerging pharmacotherapies for the treatment of pulmonary arterial hypertension in infants

INTRODUCTION

Pulmonary hypertension (PH) is a complex condition that encompasses an array of underlying disease processes and affects a diverse population of infants, including those with congenital heart disease, congenital diaphragmatic hernia, persistent PH of the newborn, and those with lung disease such as bronchopulmonary dysplasia. While there are treatments available to adults with PH, limited data exists for infants, especially for the newer medications. Therapies that target the three main pathophysiologic pathways of pulmonary hypertension appear to benefit infants, but which are best for each individual disease process is unclear.

AREAS COVERED

A review of the therapies to treat pulmonary hypertension is covered in this article including the prostacyclin pathway, endothelin pathway, and the nitric oxide pathway. Other adjunctive treatments are also discussed. Findings are based on a PubMed literature search of research papers spanning 1990-2023 and a search of ongoing trials registered with clinicaltrials.gov.

EXPERT OPINION

Overall therapies seem to improve outcomes with most infants with PH. However, given the diverse population of infants with PH, it is imperative to understand the basis for the PH in individual patients and understand which therapies can be applicable. Further research into tailored therapy for the specific populations is warranted.

Case Report: Selexipag in pediatric pulmonary hypertension: Initiation, transition, and titration

Selexipag, a selective prostacyclin receptor agonist, is approved for treating pulmonary arterial hypertension in WHO Group 1 adult patients. Compared to parenteral prostacyclin formulations, selexipag offers a significant improvement in patient's and caregiver's quality of life because of its oral formulation, frequency of administration, and mechanism of action. Although experience in the pediatric population is limited to case reports in older adolescent patients and selexipag is not approved for use in the pediatric pulmonary hypertension population, many pediatric centers are expanding the use of this therapy to this population. We report our institution's experience in the use of selexipag to treat pulmonary hypertension in children under 10 years of age, between 10 and 30 kg. Seven patients were initiated on selexipag therapy including de novo initiation and transition from intravenous treprostinil to oral selexipag. All patients were on stable background therapy with phosphodiesterase-5 inhibitor and endothelin receptor antagonist therapies at baseline. All patients reached their planned goal selexipag dose during admission without the need for changes to the titration schedule and without hemodynamic deterioration. In our experience, oral selexipag is safe and well-tolerated in young pediatric patients with pulmonary hypertension. Based on our favorable experience, we developed an institution-specific selexipag process algorithm for continued successful use in the pediatric population.

A Canadian, retrospective, multicenter experience with selexipag for a heterogeneous group of pediatric pulmonary hypertension patients

Introduction

Selexipag, an oral nonprostanoid prostaglandin receptor agonist, has led to reduced morbidity and mortality in adults with pulmonary arterial hypertension (PAH). While the adult literature has been extrapolated to suggest selexipag as an oral treatment for severe pediatric pulmonary hypertension (PH), longitudinal, multicenter data on the benefits of selexipag in this population are lacking. The purpose of this study is to present a longitudinal, multicentre experience with selexipag in a relatively large cohort of pediatric PH patients and add to the existing selexipag literature.

Materials and methods

We performed a retrospective, multicenter review describing the clinical outcomes of pediatric PH patients receiving selexipag in addition to standard oral pulmonary vasodilator therapy across three Canadian centers between January 2005 and June 2021.

Results

Twenty-four pediatric patients (fifteen female) with a mean age of 9.7 (range 2.0-15.5) years were included. Of this cohort, eighteen (75.0%) were in group 1, one (4.2%) was in group 2, four (16.7%) were in group 3, and one (4.2%) was in group 4. Twenty-two (91.7%) patients were on dual PH therapy after six months. Dosing was targeted to achieve 20-30 mcg/kg/dose orally every twelve hours. Median dose after twelve months was 30 mcg/kg/dose. Twelve months following selexipag initiation, median decreases of 0.2 cm in tricuspid annular plane systolic excursion, 3.5 mmHg in right-ventricular systolic pressure, and 6.1 mmHg in mean pulmonary arterial pressure were observed; none of these changes were statistically significant. Three patients died, one clinically deteriorated and required admission to a pediatric intensive care unit, ten had gastrointestinal symptoms, and three had flushing.

Conclusion

Selexipag appears to be a safe and effective adjunctive therapy for pediatric PH patients and has a tolerable adverse effect profile aside from gastrointestinal disturbances. Additional prospective studies of changes in hemodynamics and functional classification over a longer period and with a larger sample are needed. Future research should aim to identify subgroups that stand to benefit from the addition of selexipag as well as optimal timing and dosing for the pediatric population.

Early diagnosis and targeted approaches to pulmonary vascular disease in bronchopulmonary dysplasia

Pulmonary hypertension has emerged as a life-threatening disease in preterm infants suffering from bronchopulmonary dysplasia (BPD). Its development is closely linked to respiratory disease, as vasculogenesis and alveologenesis are closely interconnected. Once clinically significant, BPD-associated pulmonary hypertension (BPD-PH) can be challenging to manage, due to poor reversibility and multiple comorbidities frequently associated. The pulmonary vascular disease process underlying BPD-PH is the result of multiple innate and acquired factors, and emerging evidence suggests that it progressively develops since birth and, in certain instances, may begin as early as fetal life. Therefore, early recognition and intervention are of great importance in order to improve long-term outcomes. Based on the most recent knowledge of BPD-PH pathophysiology, we review state-of-the-art screening and diagnostic imaging techniques currently available, their utility for clinicians, and their applicability and limitations in this specific population. We also discuss some biochemical markers studied in humans as a possible complement to imaging for the detection of pulmonary vascular disease at its early stages and the monitoring of its progression. In the second part, we review pharmacological agents currently available for BPD-PH treatment or under preclinical investigation, and discuss their applicability, as well as possible approaches for early-stage interventions in fetuses and neonates. IMPACT: BPD-associated PH is a complex disease involving genetic and epigenetic factors, as well as environmental exposures starting from fetal life. The value of combining multiple imaging and biochemical biomarkers is emerging, but requires larger, multicenter studies for validation and diffusion. Since "single-bullet" approaches have proven elusive so far, combined pharmacological regimen and cell-based therapies may represent important avenues for research leading to future cure and prevention.

Safety and Tolerability of a Rapid Transition From Intravenous Treprostinil to Oral Selexipag in Three Adolescent Patients With Pulmonary Arterial Hypertension

There is limited published experience with transitioning pediatric patients from parenteral treprostinil to oral selexipag therapy. In addition, published transitions have typically been protracted, taking several weeks to complete. We present a case series of 3 adolescent patients who were transitioned from parenteral treprostinil to oral selexipag over a 5- to 7-day period. Their clinical courses leading up to the transitions are summarized and their outcomes are described. The 3 patients were successfully rapidly transitioned during an inpatient hospitalization without any observed adverse events or prostacyclin-related side effects. We conclude that when indicated rapid transition of parenteral to oral prostacyclin therapy may be performed safely in adolescents in an inpatient setting.

Update on pediatric pulmonary arterial hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) causes high morbidity and mortality in children. In this review, we discuss advances in diagnosis and treatment of this disorder.

RECENT FINDINGS

Proceedings published from the 2018 World Symposium updated the definition of pulmonary hypertension to include all adults and children with mean pulmonary artery pressure more than 20 mmHg. Targeted PAH therapy is increasingly used off-label, but in 2017, bosentan became the first Food and Drug Administration-targeted PAH therapy approved for use in children.

SUMMARY

In recent years, advanced imaging and clinical monitoring have allowed improved risk stratification of pulmonary hypertension patients. New therapies, approved in adults and used off-label in pediatric patients, have led to improved outcomes for affected children.

Opportunities and challenges of pharmacotherapy for pulmonary arterial hypertension in children

Pediatric pulmonary hypertension (PAH) is a rare disease that carries a poor prognosis if left untreated. Although there are published guidelines for the treatment of children with pulmonary hypertension, due to the limited number of robust pediatric clinical trials, recommendations are often based on limited data or clinical experience. Furthermore, many practical aspects of care, particularly for the pediatric patient, are learned through experience and best navigated with a multidisciplinary team. While newer PAH therapies have been approved for adults, there is still limited but expanding experience in pediatrics. This new information will help improve the targets of goal-oriented therapy. Lastly, this review highlights practical aspects in the use of the different therapies available for the treatment of pediatric pulmonary hypertension.