CHICAGO, IL -- October 24, 2007 -- Inhaled iloprost failed to show significant clinical benefit in patients with idiopathic pulmonary fibrosis (IPF) in a randomised, placebo-controlled study presented here at CHEST 2007, the annual meeting of the American College of Chest Physicians.
An earlier pilot study had found significant pulmonary vasodilation with inhaled iloprost, suggesting that it could be of value in patients with IPF and pulmonary hypertension, which frequently accompanies late-stage IPF.
In a poster session October 24, Chad McQueen, PharmD, Associate Clinical Director, Actelion Pharmaceuticals US Inc., Short Hills, New Jersey, United States, presented results from the multicentre Aerosolised Iloprost: A Clinical Trial in IPF to Improve Ventilation and Exercise (ACTIVE) study of iloprost in 51 patients with IPF, pulmonary hypertension and exercise limitation.
Patients received six to nine inhalation sessions daily for 6 weeks with either placebo or iloprost at 2.5 or 5 mcg per session. Primary efficacy measures were the 6-minute walking distance (6MWD) test, change in New York Heart Association functional class and several standard dyspnoea rating scales.
No significant differences in efficacy were found between iloprost and placebo, either overall or at any time point in the study. Patients receiving placebo improved slightly from baseline in the 6MWD test at the 12-week evaluation (gain of 10 meters from baseline) while those taking iloprost worsened (reduction of 31 meters), although the difference was not significant.
Dyspnoea measures were similar between placebo and iloprost at baseline and at the end of therapy.
The data also showed a trend in favour of placebo for mean oxygen saturation. As a result, according to the poster, \"Caution should be exercised when using pulmonary vasodilators such as iloprost in patients with fixed lung disease.\"
Otherwise no unexpected adverse effects were seen in the trial beyond those reported previously for iloprost.
The researchers attributed the unexpected lack of clinical benefit in the trial to several factors: small patient numbers, relatively short duration of therapy, and potential confounding effects from concomitant medications.
The authors said there is no known effective therapy for IPF.
A relatively high proportion of patients with NYHA functional class II disease were randomised to the iloprost arm compared with the placebo arm (46.2% vs 28.0%). \"There was consequently less room for improvement\" in the iloprost group, it said. |