Bosentan for patients with steroid-resistant pulmonary sarcoidosis: a randomised controlled trial.

Background: Sarcoidosis is a disorder of unknown aetiology. Most patients have steroid-responsive disease, but side effects and steroid resistance may necessitate alternative treatments. Endothelin has in-vitro fibrogenic activity and the endothelin system is activated in sarcoidosis.
Objectives: We studied the efficacy and safety of the endothelin receptor antagonist bosentan in sarcoidosis patients.
Methods: In a prospective 12-month, double-blind, 1:1-randomised, placebo-controlled phase II trial, we assessed the effect of bosentan in patients with steroid-resistant sarcoidosis and with impaired exercise capacity and/or resting lung function. Primary endpoints were safety and overall response rate of total lung capacity, diffusion capacity, peak oxygen uptake, 6-minute walking distance and chest computed tomography score. Secondary endpoints included adverse events and quality of life.
Main Results: Twenty patients were randomised. Three patients discontinued the study medication prematurely. No serious drug-related adverse events occurred. At 12 months no statistically significant differences were observed in the primary endpoints including total lung capacity, diffusion capacity, 6-minute walking distance, peak oxygen uptake, and computed tomography-score. Sixty-three percent of the patients treated with bosentan showed an increase of 10% in at least one of the primary endpoints, compared with 67% in the placebo group (p = 1).
Conclusions: There is no evidence to support efficacy of bosentan as an antifibrotic treatment for patients with steroid-resistant pulmonary sarcoidosis. Bosentan was well tolerated and no drug-related adverse effects were observed within the study population.
Trial Registration: ISRCTN registry, ISRCTN73579020.