Tracleer (bosentan) may be of significant benefit to people with borderline or less severe pulmonary hypertension (PH) due to idiopathic pulmonary fibrosis (IPF), results from an ongoing clinical trial suggest.
According to interim data collected from the Japanese study, Tracleer — an approved therapy for pulmonary arterial hypertension (PAH) — significantly improved the prognosis of treated IPF-PH patients and and their capacity to perform daily life activities, without a worsening in pulmonary function.
Preliminary data from the long-term trial (UMIN000004749), still recruiting in Japan and expected to run through 2022, were recently released.
The study, “Potential benefit of bosentan therapy in borderline or less severe pulmonary hypertension secondary to idiopathic pulmonary fibrosis — an interim analysis of results from a prospective, single-center, randomized, parallel-group study,” was published in the journal BMC Pulmonary Medicine.
IPF is a chronic, progressive disease characterized by the scarring of lung tissue. Patients with IPF are at risk of developing PH as the disease progresses. But, as the study noted, there are no approved therapies to treat “patients with pulmonary hypertension (PH) secondary to idiopathic pulmonary fibrosis (IPF), particularly those with idiopathic honeycomb lung.”
Previous studies have suggested that PAH treatments, such as Tracleer, can be beneficial for patients with respiratory diseases and PH as a secondary condition. But while other clinical trials failed to show efficacy, the researchers noted their failure might be due to the wide range of patients tested or because of more advanced disease.
“The benefit of early intervention with bosentan may not have been sufficiently explored in those with mildly elevated PAP [pulmonary arterial pressure] in these trials,” they wrote in the study.
To better understand Tracleer’s potential, a research team evaluated its effectiveness and safety in a selected group of 26 IPF patients with borderline or mild PH — defined as no evidence of hypoxia, or oxygen deprivation, at rest or during the six-minute walk test — but progressive respiratory failure and completely organized honeycomb lung.
Patients were randomly assigned to receive either Tracleer or no PH treatment for two years. Every six months, they were tested for signs of respiratory failure, capacity to perform daily life activities, and their lung and heart health.
Preliminary analysis showed treated patients were at a reduced risk of worsening dyspnea (difficulty breathing) compared to the untreated control group. In addition, untreated patients required increased doses of oxygen and were hospitalized more often than treated ones.
In terms of clinical outcomes, the researchers also found that Tracleer significantly slowed loss of lung function, and treated patients responded better in physical tests, such as the six-minute walk test and treadmill exercise test, suggesting a significantly improved capacity to perform daily life activities.
Still, they cautioned that these results are not conclusive due to the small number of patients involved.
“Thus, while the study appears to provide potentially valuable findings at this stage, their relevance and/or validity require [close examination] when the final data of this trial become available,” the researchers wrote.
Still, “the study appears to suggest that the bosentan-treated group fared remarkably better than the untreated group,” the study states, and the researchers plan to report further on the impact of Tracleer in these patients as more two-year data becomes available.