BUILD-3: A Randomized, Controlled Trial of Bosentan in Idiopathic Pulmonary Fibrosis

To demonstrate that bosentan delays IPF worsening or death.

Prospective, randomized (2:1), double-blind, placebo-controlled, event-driven, parallel-group, morbidity-mortality trial of bosentan in adults with IPF of less than 3 years' duration, confirmed by surgical lung biopsy, and without extensive honeycombing on high-resolution computed tomography. The primary endpoint was time to IPF worsening (a confirmed decrease from baseline in FVC ≥ 10% and diffusing capacity of the lung for carbon monoxide ≥ 15%, or acute exacerbation of IPF) or death up to End of Study. Effects of bosentan on health-related quality of life, dyspnea, and the safety and tolerability of bosentan were investigated. MEASUREMENTS AND MAIN RESULTS: Six hundred sixteen patients were randomized to bosentan (n=407) or placebo (=209). No significant difference between treatment groups was observed in the primary endpoint analysis (hazard ratio, 0.85; 95% confidence interval, 0.66-1.10; P=0.2110). No treatment effects were observed on health-related quality of life or dyspnea. Some effects of bosentan treatment were observed in changes from baseline to 1 year in FVC and diffusing capacity of the lung for carbon monoxide. The safety profile for bosentan was similar to that observed in other trials.