u-62840 and Lung-Diseases

Persistent pulmonary hypertension (PH) causes significant mortality and morbidity in infants with congenital diaphragmatic hernia (CDH). Since pulmonary vascular abnormalities in CDH develop early during foetal development, we hypothesized that prenatal maternal administration of treprostinil, through its anti-remodelling effect, would improve the PH-phenotype in the nitrofen rat model of CDH.. In a dose-finding study in normal, healthy pregnant rats, we demonstrated target-range foetal plasma treprostinil concentrations without signs of toxicity. Next, an efficacy study was performed assessing the effects of treprostinil administration at 900 and 1500ng/kg/min from gestational day (GD) 16 until term (GD 21) in CDH and control pups. Pulmonary vascular and airway morphometry, lung mechanics, and expression patterns of genes implicated in the prostaglandin vasoactive pathway were studied.. In rats maternal administration of 1500ng/kg/min treprostinil reached target foetal concentrations, with no detrimental maternal or foetal side-effects. Prenatal exposure to 900 and 1500 ng/kg/min treprostinil reduced the medial wall thickness (%MWT) (CDH·900, 38.5± 8·4%; CDH.1500, 40·2±9·7%; CDH, 46·6±8·2%; both p < 0·0001) in rat pups with CDH, however increased the %MWT in normal foetuses (C.T.900, 36·6±11·1%; C.T.1500, 36·9±9·3%; C.P., 26·9±6·2%; both p < 0·001). Pulmonary airway development, lung hypoplasia and pulmonary function were unaffected by drug exposure.. In pregnant rats maternally administered treprostinil crosses the placenta, attains foetal target concentrations, and is well tolerated by both mother and foetuses. This report shows a significant reduction of pulmonary arteriole muscularization with prenatal treprostinil in a nitrofen rat model, supporting the promise of this treatment approach for PH of CDH.. United Therapeutics Corporation provided treprostinil and financial support (ISS-2020-10879).

Topics: Animals; Disease Models, Animal; Epoprostenol; Female; Hernias, Diaphragmatic, Congenital; Hypertension, Pulmonary; Lung; Lung Diseases; Phenotype; Pregnancy; Rats

Pulmonary hypertension (PH) in the setting of parenchymal lung disease adversely affects quality of life and survival. However, PH-specific drugs may result in ventilation/perfusion imbalance and currently, there are no approved PH treatments for this patient population. In the present retrospective study, data from 22 patients with PH associated with lung disease treated with inhaled treprostinil (iTre) and followed up clinically for at least 3 months are presented.. PH was defined by resting right heart catheterization as a mean pulmonary artery pressure (mPAP) ≥ 35 mmHg, or mPAP ≥ 25 mmHg associated with pulmonary vascular resistance ≥ 4 Woods Units. Follow-up evaluation was performed at the discretion of the attending physician.. From baseline to follow-up, we observed significant improvement in functional class (n = 22, functional class III-IV 82 vs. 59%, p = 0.041) and 6-min walk distance (n = 11, 243 ± 106 vs. 308 ± 109; p = 0.022), without a deleterious effect on resting peripheral oxygen saturation (n = 22, 92 ± 6 vs. 94 ± 4; p = 0.014). Most of the patients (86%, n = 19/22) were using long-term nasal supplemental oxygen at baseline. During follow-up, only one patient had increased supplemental oxygen requirement. The most common adverse events were cough, headache, and diarrhea. No severe adverse event was reported.. The results suggest that iTre is safe in patients with Group 3 PH and evidence of pulmonary vascular remodeling in terms of functional class, gas exchange, and exercise capacity. Additionally, iTre was well tolerated. The potential role of PH-specific drugs in Group 3 PH should be further assessed in larger prospective studies.

Topics: Administration, Inhalation; Aged; Antihypertensive Agents; Arterial Pressure; Epoprostenol; Exercise Tolerance; Female; Humans; Hypertension, Pulmonary; Lung Diseases; Male; Middle Aged; Pulmonary Artery; Recovery of Function; Retrospective Studies; Time Factors; Treatment Outcome; Vascular Remodeling; Vascular Resistance

Pulmonary arterial hypertension (PAH) associated with chronic lung disease of infancy can be a life-threatening disease affecting an increasing number of former premature infants. There is a need for improved delivery of targeted PAH therapies for this subgroup of patients who have severe and persistent PAH despite standard respiratory care for chronic lung disease. Currently infants who have severe PAH despite oral or inhaled therapy receive continuous intravenous prostanoid therapy (mostly epoprostenol), which is complicated because of the need for central venous access and associated catheter-related complications. We present a series of 5 infants who were successfully treated with a continuous infusion of subcutaneous treprostinil, which is a longer-acting prostanoid with similar hemodynamic effects. There were improvements in echocardiographic assessment of right ventricular function and estimated pulmonary hypertension, and in respiratory support required within weeks of therapy. Unlike commonly in adults, these 5 infants had no instances of severe site erythema, bleeding, bruising, or infection. In our experience with 5 former extremely preterm infants who had PAH associated with chronic lung disease, subcutaneous treprostinil was safe, efficacious, and well tolerated. We believe that subcutaneous treprostinil can be beneficial in a select group of former premature infants who have chronic lung disease and severe pulmonary arterial hypertension who have not responded adequately to conservative therapies.

Topics: Antihypertensive Agents; Chronic Disease; Epoprostenol; Familial Primary Pulmonary Hypertension; Female; Humans; Hypertension, Pulmonary; Infant; Infusions, Subcutaneous; Lung Diseases; Male