An interim report of a long-term ongoing prospective single-center study evaluating the effects of bosentan on idiopathic pulmonary fibrosis (IPF)-associated pulmonary hypertension (PH) was published in BMC Pulmonary Medicine. The results of the study to date suggest that a subset of patients with IPF may experience clinical improvements as well as better prognosis with bosentan therapy.
The authors noted that currently no drugs have been approved for the treatment of patients with PH secondary to IPF. In this study, patients with IPF with borderline or less severe PH and completely organized honeycomb lung but no interstitial inflammation were randomly assigned to either bosentan or no treatment for PH for 2 years. Participants were assessed at baseline and every 6 months for respiratory failure, activities of daily living, and lung and heart functions. After they detected a significant survival benefit for active treatment, the investigators performed an interim analysis.
Compared with the 12 patients in the control group, the 12 bosentan-treated patients experienced significant improvement in hospital-free survival (603.44 days vs 358.87 days for controls; hazard ratio [HR], 0.19; P =.017) and overall survival (671 days vs 433.78 days for controls; HR, 0.10; P =.0082). There were also benefits for activities of daily living, pulmonary circulation, and diffusing capacity of the lung for carbon monoxide for participants treated with bosentan from baseline to 6 or 12 months. Furthermore, bosentan was associated with a trend toward a decrease in adverse events and improvement in respiratory status.
The primary limitation of this study is the small number of patients. However, when the detection of benefit triggered the interim analysis, only half the number of patients targeted had completed the study. In such a small study group, it is also possible that the inclusion or exclusion of patients with rapid elevation of pulmonary arterial pressure may have affected the results. Nonetheless, the authors noted that bosentan therapy may be associated with improved prognosis in patients similar to those in this study.
The authors plan to prepare a final report after further accrual of patients required to complete the study.
Tanaka Y, Hino M, Gemma A. 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 [published online December 13, 2017]. BMC Pulm Med. doi 10.1186/s12890-017-0523-2