The evolution of survival of pulmonary arterial hypertension over 15 years

Safety and efficacy of rodatristat ethyl for the treatment of pulmonary arterial hypertension (ELEVATE-2): a dose-ranging, randomised, multicentre, phase 2b trial

BACKGROUND

The role of serotonin in pulmonary arterial hypertension has been extensively studied in recent decades, with preclinical data strongly indicating involvement in disease pathogenesis; however, clinical studies have yielded mixed results.

METHODS

ELEVATE-2 was a phase 2b dose-ranging, randomised, double-blind, placebo-controlled, multicentre trial investigating rodatristat ethyl as a treatment for patients with pulmonary arterial hypertension. The study was conducted at 64 sites across 16 countries in Europe and North America. Eligible participants were aged 18 years or older, had pulmonary arterial hypertension with WHO functional class II or III symptom severity, and had received a stable dose and regimen of one or more pulmonary arterial hypertension treatments for at least 12 weeks. Participants were randomly assigned 1:1:1 to receive two placebo tablets, one placebo and one rodatristat ethyl 300 mg tablet, or two rodatristat ethyl 300 mg tablets twice daily using an interactive response system. Participants, investigators, site personnel, and sponsors were masked to treatment allocation. Participants who completed the 24 week treatment period were invited to continue in an open-label extension. The primary endpoint was percent change in pulmonary vascular resistance (PVR) from baseline to week 24. Primary efficacy analyses were conducted on the intention-to-treat population and analyses of harms were conducted in the safety population, which included all patients who received any amount of the study drug. This trial is registered with ClinicalTrials.gov, NCT04712669, and is now complete.

FINDINGS

Between March 18, 2021 and Dec 13, 2022, 108 participants were enrolled and randomly assigned. 36 participants received placebo, 36 received rodatristat ethyl 300 mg, and 36 received rodatristat ethyl 600 mg twice daily. Overall, 85 (79%) of participants were female and 23 (21%) were male. The mean age was 52·8 years (SD 14·7) in the full analysis set. In the open-label extension phase, 62 (82%) of participants were female and 14 (18%) were male, and the mean age was 52·8 years (SD 14·7); this phase was terminated following sponsor review of unmasked main study results. Least-squares mean percent change in PVR from baseline to week 24 favoured placebo and was 5·8% (SE 18·1) for the placebo group, 63·1% (18·5) for the rodatristat ethyl 300 mg group, and 64·2% (18·0) for the rodatristat ethyl 600 mg group. Treatment-emergent adverse events (TEAE) were reported for 29 (81%) patients in the placebo group, 33 (92%) patients in the rodatristat ethyl 300 mg group, and all 36 (100%) patients in the rodatristat ethyl 600 mg group. TEAE leading to study discontinuation were reported for three (8%) patients in the placebo group, four (11%) patients in the rodatristat ethyl 300 mg group, and four (11%) in the rodatristat ethyl 600 mg group. There was one (3%) TEAE leading to death in the rodatristat ethyl 300 mg group.

INTERPRETATION

Our results indicate that reducing peripheral serotonin concentrations via rodatristat ethyl has a negative effect on pulmonary haemodynamics and cardiac function in patients with pulmonary arterial hypertension. This finding suggests that manipulating this pathway might not be a suitable option for pulmonary arterial hypertension therapy.

FUNDING

Enzyvant Therapeutics (now Sumitomo Pharma America).

Survival, morbidity, and quality of life in pulmonary arterial hypertension patients: a systematic review of outcomes reported by population-based observational studies

BACKGROUND

Comprehensive summaries on real-world outcomes in pulmonary arterial hypertension (PAH)-a rare, incurable condition, are lacking. We conducted a systematic literature review to describe current survival, morbidity, and quality of life (QoL) outcomes in adult and pediatric PAH patients. We searched Medline and Embase electronic databases, clinicaltrials.gov, and encepp.eu entries, and grey literature to identify outcome estimates for right-heart catheterization-confirmed PAH patients from population-based observational studies (search date: 25 Nov 2021). Data were synthesized using a narrative approach and post-hoc subgroup meta-analyses were conducted to explore adult survival by region, disease severity, representativeness, and study period. The search yielded 7473 records. Following screening and full text review, 22 unique studies with 31 individual reports of outcomes were included. Studies were mostly national registries (n = 21), European (n = 13) and covering adults (n = 17); only six had systematic countrywide coverage of centers. Survival was the most frequently reported outcome (n = 22). Global adult 1-, 3-, and 5-year survival ranged from 85 to 99% (n = 15), 65 to 95% (n = 14), and 50 to 86% (n = 9), respectively. Subgroup meta-analysis showed that 1-, 3-, and 5-year survival in Europe was 90% (95% CI 86-94%; n = 8), 78% (95% CI 68-86%; n = 8), and 61% (95% CI 49-72%; n = 6), respectively; 1-year survival in North America was 88% (95% CI 83-93%; n = 3) and 3-year survival in Asia was 85% (95% CI 82-88%; n = 3). No difference in survival between regions was observed. Subgroup analysis suggested higher survival in patients with better baseline functional class; however, interpretation should be cautioned due to large subgroup heterogeneity and potential missingness of data.

SHORT CONCLUSION

This review describes current disease outcomes based on well-defined and representative PAH populations. There is an overall lack of follow-up data for morbidity and QoL outcomes; survival estimates for pediatric patients are scarce and may not be generalizable to the current treatment era, although publications from large pediatric registries became available after our search date. This study demonstrated a remaining unmet need world-wide to improve long-term prognosis in PAH in the current era.

A Single Center Experience of Pulmonary Arterial Hypertension Management in Korea: A 25-Year Comparative Analysis Following the Introduction of Targeted Therapy

BACKGROUND AND OBJECTIVES

The transformation of pulmonary arterial hypertension (PAH) treatment in Korea, ushered by targeted therapy's advent, prompted our analysis of baseline attributes, treatment trends, and survival shifts within our single-center registry.

METHODS

We examined 230 patients (72.6% female, mean age 40.6±17.4 years) diagnosed and/or treated between 1980 and 2021 in our PAH clinic. Given targeted therapy's introduction and active use since 2007, we compared diagnostic classification, demographics, and treatment patterns at that juncture. Survival analysis encompassed PAH types and the overall population. For historical survival comparison, 50 non-registry patients were retrospectively added, and age-sex matching enabled pooled analysis.

RESULTS

Congenital heart disease-associated pulmonary arterial hypertension (CHD-PAH) constituted the largest subset (43.0%), trailed by connective tissue disease-associated PAH (CTD-PAH, 29.6%) and idiopathic PAH (IPAH, 19.1%). Post-2007, CTD-PAH proportions surged, notably with an elevated initiation rate of targeted therapy (95.4%). Overall survival rates at 1, 5, and 10 years stood at 91.3%, 77.4%, and 65.8%, respectively, with CHD-PAH exhibiting superior survival to idiopathic or CTD-PAH. Age-sex matching analysis indicated survival disparities between those starting immediate targeted therapy vs. conservative treatment upon diagnosis, especially driven by IPAH.

CONCLUSIONS

In the post-introduction of the targeted therapy era, patients with PAH promptly started treatment right away, and higher survival rates of patients who started initial PAH-targeted therapy were demonstrated. The transition towards early treatment initiation might have likely contributed to the elevated survival rates observed in Korea's PAH patient cohort.

Sleep-related disorders in patients with precapillary pulmonary hypertension

Precapillary pulmonary hypertension (PcPH) is associated with the development of sleep-related disorders and impairment of sleep quality. With growing recognition of the clinical relevance of sleep-related conditions in PcPH, this narrative review seeks to discuss the spectrum of disorders encountered in clinical practice, pathophysiological mechanisms linking PcPH with sleep-related disorders, and potential therapeutic considerations. Current evidence demonstrates a higher prevalence of impaired sleep quality, sleep-disordered breathing, sleep-related hypoxia, and restless leg syndrome in patients with PcPH. These sleep-related disorders could further lead to impairment of quality of life in a patient population with already a high symptom burden. Recent data suggest that sleep-related hypoxia is strongly linked to worse right ventricular function and higher risk of transplantation or death. However, limited studies have investigated the role of oxygen therapy or positive airway pressure therapy improving symptoms or outcomes. Abnormal iron homeostasis is highly prevalent in PcPH and may contribute to the development of restless legs syndrome/periodic limb movement of sleep. To improve sleep management in PcPH, we highlight future research agenda and advocate close collaboration between pulmonary hypertension specialists and sleep physicians.

Congruency between clinician-assessed risk and calculated risk of 1-year mortality in patients with pulmonary arterial hypertension: A retrospective chart review

The objective of this analysis was to compare clinician-based and formally calculated risk assessments by REVEAL Lite 2 and COMPERA 2.0 and to characterize parenteral prostacyclin utilization within 90 days of baseline in high-risk patients. A multisite, double-blind, retrospective chart review of patients with pulmonary arterial hypertension (PAH) was conducted with an index period of January 2014-March 2017. Patients were categorized into the "any PAH medication" or "prostacyclin-enriched" cohort based on latest PAH medication initiated within the index period. Clinicians classified the patient's 1-year mortality risk as "low," "intermediate," or "high" based on their clinical assessment. REVEAL Lite 2 and COMPERA 2.0 scores were independently calculated. Risk assessment congruency was evaluated. Parenteral prostacyclin use was evaluated within 90 days of baseline. Thirty-two clinicians participated and abstracted data for 299 patients with PAH. At baseline, mean patient age was 52 years, 6-min walk distance was 226 m, and most patients were WHO functional class II or III. Half of the patients (53%) were classified by clinician assessment as intermediate risk, while most were classified as high risk by REVEAL Lite 2 (59%) and intermediate-high risk by COMPERA 2.0 (52%). Parenteral prostascyclins were underutilized in high-risk patients, and not initiated in a timely fashion. Clinician-assessed risk category was incongruent with tool-based risk assessments in 40%-54% of patients with PAH, suggesting an underestimation of the patient's risk category by clinician gestalt. Additionally, there was a lack of timely prostacyclin initiation for patients with PAH stratified as high-risk by either tool.

Pharmacological Gq inhibition induces strong pulmonary vasorelaxation and reverses pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease with limited survival. Herein, we propose the pharmacological inhibition of Gq proteins as a novel concept to counteract pulmonary vasoconstriction and proliferation/migration of pulmonary artery smooth muscle cells (PASMCs) in PAH. We demonstrate that the specific pan-Gq inhibitor FR900359 (FR) induced a strong vasorelaxation in large and small pulmonary arteries in mouse, pig, and human subjects ex vivo. Vasorelaxation by FR proved at least as potent as the currently used triple therapy. We also provide in vivo evidence that local pulmonary application of FR prevented right ventricular systolic pressure increase in healthy mice as well as in mice suffering from hypoxia (Hx)-induced pulmonary hypertension (PH). In addition, we demonstrate that chronic application of FR prevented and also reversed Sugen (Su)Hx-induced PH in mice. We also demonstrate that Gq inhibition reduces proliferation and migration of PASMCs in vitro. Thus, our work illustrates a dominant role of Gq proteins for pulmonary vasoconstriction as well as remodeling and proposes direct Gq inhibition as a powerful pharmacological strategy in PH.

Orai1/STIMs modulators in pulmonary vascular diseases

Calcium (Ca2+) is a secondary messenger that regulates various cellular processes. However, Ca2+ mishandling could lead to pathological conditions. Orai1 is a Ca2+channel contributing to the store-operated calcium entry (SOCE) and plays a critical role in Ca2+ homeostasis in several cell types. Dysregulation of Orai1 contributed to severe combined immune deficiency syndrome, some cancers, pulmonary arterial hypertension (PAH), and other cardiorespiratory diseases. During its activation process, Orai1 is mainly regulated by stromal interacting molecule (STIM) proteins, especially STIM1; however, many other regulatory partners have also been recently described. Increasing knowledge about these regulatory partners provides a better view of the downstream signalling pathways of SOCE and offers an excellent opportunity to decipher Orai1 dysregulation in these diseases. These proteins participate in other cellular functions, making them attractive therapeutic targets. This review mainly focuses on Orai1 regulatory partners in the physiological and pathological conditions of the pulmonary circulation and inflammation.

Ralinepag Phase II Open-Label Extension Study in Patients with Pulmonary Arterial Hypertension

INTRODUCTION

Ralinepag is a potent, titratable, orally administered prostacyclin (IP) receptor agonist to treat pulmonary arterial hypertension. A phase II randomized, double-blind, parallel-group, placebo-controlled, 22-week study of immediate-release (IR) ralinepag safety and efficacy met its primary endpoint, significantly reducing pulmonary vascular resistance (PVR) compared with placebo. This phase II open-label extension (OLE) study assessed long-term safety and tolerability of ralinepag.

METHODS

Participants were eligible for the OLE if they completed the parent study or experienced a clinical worsening event while receiving placebo. Those previously receiving IR ralinepag remained on their current dose, and participants formerly administered placebo were titrated to the highest tolerated dose. Participants were transitioned to an extended-release ralinepag formulation toward the end of the OLE. The primary objective evaluated long-term safety and tolerability; secondary endpoints included changes in 6-min walk distance (6MWD), World Health Organization/New York Heart Association functional class, clinical worsening, and hemodynamic measures.

RESULTS

In total, 45/61 participants enrolled in the OLE study, 30 from the IR ralinepag group and 15 from the placebo group. The most common adverse events (AEs) were known prostacyclin-related effects (e.g., headache, 64.4%; diarrhea, 37.8%; jaw pain, 33.3%). There was a notable decline in AEs after reaching and maintaining a stable dose. At month 24 after entering the OLE, 6MWD significantly increased by a mean of 36.3 m (P = 0.004) from OLE baseline, and most participants remained stable in their functional class (84.8%). Post-baseline PVR in 1 or 2 years decreased by a median of 52.2 dyn.s/cm5 and mean pulmonary arterial pressure decreased by a median of 2.0 mmHg (P = 0.05).

CONCLUSION

Ralinepag produced sustained, durable improvements in 6MWD along with durable reductions in PVR and a manageable AE profile. Most participants continuing treatment with ralinepag maintained functional measures throughout the OLE and those switching from placebo to ralinepag often experienced functional improvements.

The ALPHA phase 1 study: pulmonary ArteriaL hypertension treated with CardiosPHere-Derived allogeneic stem cells

BACKGROUND

Pulmonary Arterial Hypertension (PAH) is a progressive condition with no cure. Even with pharmacologic advances, survival remains poor. Lung pathology on PAH therapies still shows impressive occlusive arteriolar remodelling and plexiform lesions. Cardiosphere-derived cells (CDCs) are heart-derived progenitor cells exhibiting anti-inflammatory and immunomodulatory effects, are anti -fibrotic, anti-oxidative and anti-apoptotic to potentially impact several aspects of PAH pathobiology. In preclinical trials CDCs reduced right ventricular (RV) systolic pressure, RV hypertrophy, pulmonary arteriolar wall thickness and inflammation.

METHODS

The ALPHA study was a Phase 1a/b study in which CDCs were infused into patients with Idiopathic (I)PAH, Heritable (H) HPAH, PAH-connective tissue disease (CTD) and PAH-human immunodeficiency virus (HIV). The study was IRB approved and DSMB monitored. Phase 1a, was an open label study (n = 6). Phase 1b was a double-blind placebo-controlled study (n = 20) in which half received 100 million CDCs (the maximum feasible dose from manufacturing perspective) and half placebo (PLAC) infusions. Right heart catheterization (RHC) and cardiac MR imaging (cMR) were performed at baseline and at 4 months post infusion. Patients were followed over a year.

FINDINGS

No short-term clinical safety adverse events (AE) were related to the IP, the primary outcome measure. There were no adverse hemodynamic, gas exchange, rhythm or other clinical events following infusion and in the 1st 23 h monitored in hospital. There were no long-term AEs over 12 months noted, including unrelated limited hospitalizations. No immunologic short or long-term AEs were noted. We examined exploratory outcomes across multiple domains to determine encouraging signals to motivate future advanced phase testing. Phase 1a data showed encouraging observations for both 50 and 100 million CDC doses. Several encouraging findings favouring CDCs (n = 16) compared to placebo (n = 10) were noted. On cMR, the RV end diastolic volume (RVEDV) and index (RVEDVI) decreased with CDCs with a rise in the PLAC group. The 6-min walk distance was increased 2 months post infusion in the CDC group compared with PLAC. With PLAC, diffusing capacity (DLCO) decreased at 4 months but was unchanged with CDCs. Serum creatinine decreased with CDCs at 4 months. Encouraging observations favouring CDCs were also noted for RV fractional area change on echo and RV ejection fraction (RVEF) on cMR at 4 months. No differences were observed for mean pulmonary artery pressures or pulmonary vascular resistance. Review of long-term data to 12 months showed continued decline in DLCO for the PLAC cohort at 6 months with no change through 12 months. By contrast, CDC subjects showed an unchanged DLCO over 12-months. For parameters exhibiting early encouraging exploratory findings in CDC subjects, no further improvement was noted in long-term follow up through 12 months.

INTERPRETATION

Intravenous CDCs were safe in both the short and long term in PAH subjects and thus may be safe in larger cohorts, in line with our extensive track record of safety in clinical trials for other conditions. Further, CDCs exhibited encouraging exploratory findings across several domains. Repeat dosing (quarterly, over one year) of intravenous CDCs has been reported to yield highly significant sustained disease-modifying bioactivity in subjects with advanced Duchenne muscular dystrophy. Because only single CDC doses were used here, the findings represent a lower limit estimate of CDC's potential in PAH. Upcoming phase 2 studies would logically use a repeat dosing paradigm.

FUNDING

California Institute for Regenerative Medicine (CIRM). Project Number: CLIN2-09444.

Outcomes of listing for lung and heart-lung transplantation in pulmonary hypertension: comparative experience in France and the UK

Background

Lung or heart-lung transplantation (LT/HLT) for severe pulmonary hypertension (PH) as the primary disease indication carries a high risk of waiting list mortality and post-transplant complications. France and the UK both have coordinated PH patient services but with different referral pathways for accessing LT services.

Methods

We conducted a comparative analysis of adult PH patients listed for LT/HLT in the UK and France.

Results

We included 211 PH patients in France (2006-2018) and 170 in the UK (2010-2019). Cumulative incidence of transplant, delisting and waiting list death within 3 years were 81%, 4% and 11% in France versus 58%, 10% and 15% in the UK (p<0.001 for transplant and delisting; p=0.1 for death). Median non-priority waiting time was 45 days in France versus 165 days in the UK (p<0.001). High-priority listing occurred in 54% and 51% of transplanted patients respectively in France and the UK (p=0.8). Factors associated with achieving transplantation related to recipients' height, male sex, clinical severity and priority listing status. 1-year post-transplant survival was 78% in France and 72% in the UK (p= 0.04).

Conclusion

Access to transplantation for PH patients is better in France than in the UK where more patients were delisted due to clinical deterioration because of longer waiting time. High rates of priority listing occurred in both countries. Survival for those achieving transplantation was slightly better in France. Ensuring optimal outcomes after transplant listing for PH patients is challenging and may involve early listing of higher risk patients, increasing donor lung utilisation and improving allocation rules for these specific patients.

A Bioinformatic Algorithm based on Pulmonary Endoarterial Biopsy for Targeted Pulmonary Arterial Hypertension Therapy

Background

Optimal pharmacological therapy for pulmonary arterial hypertension (PAH) remains unclear, as pathophysiological heterogeneity may affect therapeutic outcomes. A ranking methodology based on pulmonary vascular genetic expression analysis could assist in medication selection and potentially lead to improved prognosis.

Objective

To describe a bioinformatics approach for ranking currently approved pulmonary arterial antihypertensive agents based on gene expression data derived from percutaneous endoarterial biopsies in an animal model of pulmonary hypertension.

Methods

We created a chronic PAH model in Micro Yucatan female swine by surgical anastomosis of the left pulmonary artery to the descending aorta. A baseline catheterization, angiography and pulmonary endoarterial biopsy were performed. We obtained pulmonary vascular biopsy samples by passing a biopsy catheter through a long 8 French sheath, introduced via the carotid artery, into 2- to 3-mm peripheral pulmonary arteries. Serial procedures were performed on days 7, 21, 60, and 180 after surgical anastomosis. RNA microarray studies were performed on the biopsy samples.

Results

Utilizing the medical literature, we developed a list of PAH therapeutic agents, along with a tabulation of genes affected by these agents. The effect on gene expression from pharmacogenomic interactions was used to rank PAH medications at each time point. The ranking process allowed the identification of a theoretical optimum three-medication regimen.

Conclusion

We describe a new potential paradigm in the therapy for PAH, which would include endoarterial biopsy, molecular analysis and tailored pharmacological therapy for patients with PAH.

The evolution of survival of pulmonary arterial hypertension over 15 years

The prognosis of pulmonary arterial hypertension (PAH) remains dismal. Over the years, multiple therapeutic advances have been introduced. This study evaluates the evolution of PAH survival over the past 15 years. We included 293 consecutive adult patients diagnosed with PAH between 2005 and 2019 (median age: 61.8 years, 70.3% female). Patients were divided into three cohorts based on the time of diagnosis: 2005-2009, 2010-2014, and 2015-2019 (2005-2009: n = 56; 2010-2014: n = 111; 2015-2019: n = 126). Transplant-free survival was measured from the date of right heart catheterization until patients reached the composite endpoint of lung transplant or death. Multivariable cox-pulmonary hypertension regression was used to study the effect of the time of diagnosis. The final cox model was fitted in both younger and older patients to evaluate the difference between these groups. During a median follow-up time of 4.1 (interquartile range: 2.2-7.3) years, 9 patients underwent lung transplantation and 151 patients died. The median overall transplant-free survival was 6.2 (5.5-8.0) years. Patients older than 56 years at baseline who were diagnosed in 2005-2009 showed better survival compared to patients diagnosed in 2010-2014 and 2015-2019 with an adjusted hazard ratio of, respectively, 2.12 (1.11-4.03) and 2.83 (1.41-5.69). Patients younger than 56 years showed neither an improved nor deteriorated survival over time. In conclusion, survival in patients with PAH did not improve over time, despite more available therapeutic options. This might be partly due to the changed demographic characteristics of the PAH patients and a still important diagnostic delay.