Inhaled treprostinil: a therapeutic review

Pulmonary arterial hypertension (PAH) is a life-threatening disease which, if untreated, leads to right ventricular failure and often death. Several effective therapies are now available for PAH, including endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and prostacyclin analogs. The prostacyclin analog treprostinil has proven efficacious when delivered by subcutaneous or intravenous infusion, and most recently by inhalation. Inhaled treprostinil has been shown to be 64%–72% bioavailable in healthy volunteers. Pilot clinical studies have elucidated the acute hemodynamic effects and relative pulmonary selectivity of this agent, as well as established target dosing in PAH and nonoperable chronic thromboembolic PAH. Likewise, chronically administered inhaled treprostinil resulted in clinical and hemodynamic improvement. Both pilot studies confirmed a satisfactory safety profile in patients with PAH. The pivotal Phase III trial, TRIUMPH-I, demonstrated the efficacy and safety of inhaled treprostinil (target dose of 54 μg four times daily) in PAH patients added to background therapies of bosentan or sildenafil, as assessed by improvements in the primary endpoint, peak six-minute walk distance (median placebo-corrected treatment effect of 20 m), as well as select secondary endpoints. Inhaled treprostinil is approved by the US Food and Drug Administration for patients with World Health Organization Group I PAH to improve exercise ability. Studies establishing effectiveness included predominately patients with New York Heart Association functional class III symptoms and etiologies of idiopathic or heritable PAH (56%) or PAH associated with connective tissue diseases (33%)

Relationship Between Time From Diagnosis and Morbidity/Mortality in Pulmonary Arterial Hypertension: Results From the Phase III GRIPHON Study

BACKGROUND: Early initiation of pulmonary arterial hypertension (PAH) therapies is associated with improved long-term outcomes, yet data on the early use of prostacyclin pathway agents are limited. In these post hoc analyses of the Prostacyclin (PGI(2)) Receptor Agonist In Pulmonary Arterial Hypertension (GRIPHON) study, the largest randomized controlled trial for PAH to date, the prognostic value of time from diagnosis and its impact on treatment response were examined. RESEARCH QUESTION: How does time from diagnosis impact morbidity/mortality events and response to selexipag treatment in patients with PAH? STUDY DESIGN AND METHODS: The GRIPHON study randomly assigned 1,156 patients with PAH to selexipag or placebo treatment. Patients were categorized post hoc into a time from diagnosis of ≤ 6 months and > 6 months at randomization. Hazard ratios (selexipag vs placebo) were calculated for the primary end point of morbidity/mortality by time from diagnosis using Cox proportional hazard models. RESULTS: Time from diagnosis was ≤ 6 months in 34.9% and > 6 months in 65.1% of patients. Time from diagnosis was prognostic of morbidity/mortality, with newly diagnosed patients having a poorer long-term outcome than patients diagnosed for longer. Compared with placebo, selexipag reduced the risk of morbidity/mortality in patients with a time from diagnosis of ≤ 6 months and > 6 months, with a more pronounced effect in newly diagnosed patients (hazard ratio, 0.45 [95% CI, 0.33-0.63] and 0.74 [95% CI, 0.57-0.96], respectively; P = .0219 for interaction). INTERPRETATION: In the GRIPHON study, newly diagnosed PAH patients had a worse prognosis than patients with a longer time from diagnosis. The benefit of selexipag treatment on disease progression was more pronounced in patients treated earlier than in patients treated later. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01106014; URL: www.clinicaltrials.gov

risk assessment in pulmonary arterial hypertension insights from the griphon study

BACKGROUND Approaches to risk assessment in pulmonary arterial hypertension (PAH) include the noninvasive French risk assessment approach (number of low-risk criteria based on the European Society of Cardiology and European Respiratory Society guidelines) and Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL) 2.0 risk calculator. The prognostic and predictive value of these methods for morbidity/mortality was evaluated in the predominantly prevalent population of GRIPHON, the largest randomized controlled trial in PAH. METHODS GRIPHON randomized 1,156 patients with PAH to selexipag or placebo. Post-hoc analyses were performed on the primary composite end-point of morbidity/mortality by the number of low-risk criteria (World Health Organization functional class I-II; 6-minute walk distance >440 m; N-terminal pro-brain natriuretic peptide RESULTS Both the number of low-risk criteria and the REVEAL 2.0 risk category were prognostic for morbidity/mortality at baseline and any time-point during the study. Patients with 3 low-risk criteria at baseline had a 94% reduced risk of morbidity/mortality compared to patients with 0 low-risk criteria and were all categorized as low-risk by REVEAL 2.0. The treatment effect of selexipag on morbidity/mortality was consistent irrespective of the number of low-risk criteria or the REVEAL 2.0 risk category at any time-point during the study. Selexipag-treated patients were more likely to increase their number of low-risk criteria from baseline to week 26 than placebo-treated patients (odds ratio 1.69, p = 0.0002); similar results were observed for REVEAL 2.0 risk score. CONCLUSIONS These results support the association between risk profile and long-term outcome and suggest that selexipag treatment may improve risk profile

Results of an Expert Consensus Survey on the Treatment of Pulmonary Arterial Hypertension With Oral Prostacyclin Pathway Agents

Background Treatment of pulmonary arterial hypertension (PAH) has evolved substantially over the past two decades and varies according to etiology, functional class (FC), hemodynamic parameters, and other clinical factors. Current guidelines do not provide definitive recommendations regarding the use of oral prostacyclin pathway agents (PPAs) in PAH. To provide guidance on the use of these agents, an expert panel was convened to develop consensus statements for the initiation of oral PPAs in adults with PAH. Methods A systematic literature search was conducted using MEDLINE. The established RAND/University of California Los Angeles appropriateness method, which incorporates the Delphi method and the nominal group technique, was used to create consensus statements. Idiopathic, heritable, repaired congenital heart defect, and drug- or toxin-induced PAH (IPAH+) was considered as one etiologic grouping. The process was focused on the use of oral treprostinil or selexipag in patients with IPAH+ or connective tissue disease-associated PAH and FC II or III symptoms receiving background dual endothelin receptor antagonist/phosphodiesterase type 5 inhibitor therapy. Results The panel developed 14 consensus statements regarding the appropriate use of oral PPAs in the target population. The panel identified 13 clinical scenarios in which selexipag may be considered as a treatment option. Conclusions The paucity of clinical evidence overall, and particularly from randomized trials in this setting, creates a gap in knowledge. These consensus statements are intended to aid physicians in navigating treatment options and using oral PPAs in the most appropriate manner in patients with PAH

Pulmonary Arterial Hypertension-Related Morbidity Is Prognostic for Mortality

BACKGROUND: Registry data suggest that disease progression in pulmonary arterial hypertension (PAH) is indicative of poor prognosis. However, the prognostic relevance of PAH-related morbidity has not been formally evaluated in randomized controlled trials. OBJECTIVES: The purpose of these analyses was to assess the impact of morbidity events on the risk of subsequent mortality using the landmark method and data from the SERAPHIN and GRIPHON studies. METHODS: For each study, the risk of all-cause death up to the end of the study was assessed from the landmark time point (months 3, 6, and 12) according to whether a patient had experienced a primary endpoint morbidity event before the landmark. Each analysis was conducted using data from all patients who were available for survival follow-up at the landmark. RESULTS: In the SERAPHIN study, on the basis of the 3-month landmark time point, patients who experienced a morbidity event before month 3 had an increased risk of death compared with patients who did not (hazard ratio [HR]: 3.39; 95% confidence interval [CI]: 1.94 to 5.92). In the GRIPHON study, on the basis of the 3-month landmark time point, there was also an increased risk with a HR of 4.48; (95% CI: 2.98 to 6.73). Analyses based on 6-month and 12-month landmarks also showed increased risk in patients who experienced morbidity events, albeit with a reduced HR. CONCLUSIONS: These results demonstrate the prognostic relevance of PAH-related morbidity as defined in the SERAPHIN and GRIPHON studies, highlighting the importance of preventing disease progression in patients with PAH and supporting the clinical relevance of SERAPHIN and GRIPHON morbidity events. (Study of Macitentan [ACT-064992] on Morbidity and Mortality in Patients With Symptomatic Pulmonary Arterial Hypertension [SERAPHIN]; NCT00660179; Selexipag [ACT-293987] in Pulmonary Arterial Hypertension [GRIPHON]; NCT01106014). ispartof: Journal of the American College of Cardiology vol:71 issue:7 pages:752-763 ispartof: location:United States status: publishe

Evaluation of Dyspnea and Exercise Intolerance After Acute Pulmonary Embolism

Long-term dyspnea and exercise intolerance are common clinical problems after acute pulmonary embolism. Unfortunately, no single test can distinguish among the range of potential pathologic outcomes after pulmonary embolism. We illustrate a stepwise approach to post-pulmonary embolism evaluation that uses a hierarchic series of clinically validated diagnostic tests. The algorithm is represented by the acronym SEARCH, which stands for Symptom screening, Exercise testing, Arterial perfusion, Resting echocardiography, Confirmatory chest imaging, and Hemodynamics measured by right heart catheterization. We illustrate the algorithm with a patient whom we saw in our pulmonary embolism follow-up clinic. Patients are asked at least 6 months after pulmonary embolism whether they have returned to their baseline level of respiratory comfort and exercise tolerance. Patients with dyspnea and exercise intolerance undergo noninvasive cardiopulmonary exercise testing to identify elevated ventilatory dead space ratios, decreased stroke volume augmentation with exercise, and other physiologic abnormalities during exertion. Ventilation-perfusion scanning is performed on those patients with exercise-related physiologic findings to confirm the presence of residual pulmonary arterial obstruction or to suggest alternative diagnoses. Resting echocardiography may provide evidence of pulmonary hypertension; confirmatory imaging with pulmonary angiography or CT angiography may disclose findings characteristic of chronic pulmonary artery obstruction. Finally, right heart catheterization is performed to confirm chronic thromboembolic pulmonary hypertension; if resting pulmonary hemodynamics are normal, then invasive cardiopulmonary exercise testing may disclose exercise-induced defects