RT Journal Article SR Electronic T1 MUSIC: Efficacy and safety of macitentan in idiopathic pulmonary fibrosis (IPF) JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P1778 VO 40 IS Suppl 56 A1 Juergen Behr A1 Rachel Million-Rousseau A1 Adele Morganti A1 Loïc Perchenet A1 Ganesh Raghu YR 2012 UL http://erj.ersjournals.com/content/40/Suppl_56/P1778.abstract AB Endothelin-1 may contribute to IPF pathophysiology. The prospective double-blind Macitentan USe in an IPF Clinical (MUSIC) trial (NCT00903331) investigated the endothelin receptor antagonist macitentan in adults with IPF of <3 years duration and a histological pattern of usual interstitial pneumonia on surgical lung biopsy. Patients were randomised 2:1 to macitentan (10 mg once daily) or placebo. The primary objective was to show that from baseline up to Month 12 macitentan positively affects forced vital capacity (FVC) versus placebo. Baseline demographics and characteristics were comparable between treatment arms.View this table:Mean (range) exposure to macitentan was 14.3 (0.0–24.6) months and to placebo was 15.4 (6.3–24.3) months. Median (95% confidence limit) change in FVC was −0.20 L (−0.29 to −0.16) for macitentan and −0.20 L (−0.28 to −0.13) for placebo; ie. no treatment effect on FVC was observed. No difference in time to IPF worsening or death was observed. Adverse events in ≥10% of macitentan-treated patients with a ≥5% difference versus placebo comprised peripheral oedema, anaemia (both favoured placebo), cough (favoured macitentan). Hepatic aminotransferase elevations >3× upper limit of normal occurred in 3.4% of macitentan recipients and 5.1% of placebo recipients. In summary, the primary objective was not met. Long-term macitentan exposure was well tolerated with rates of elevated hepatic aminotransferases comparable to placebo.