Challenges in idiopathic pulmonary fibrosis trials: the point on end-points.

Idiopathic pulmonary fibrosis (IPF) is the most common of the idiopathic interstitial pneumonias and is associated with both a variable clinical course and a poor prognosis. Investigators involved in clinical trials and clinicians reviewing the IPF literature are confronted with daunting challenges in selecting reliable outcome measures, interpreting the clinical and statistical importance of these findings, and applying this knowledge to the clinical care of their patients. In order to evaluate the efficacy of new treatment regimens, a number of studies have been performed, employing a range of clinical and surrogate end-points. In most studies, the primary end-point consists of a single outcome measure. A desirable single clinical end-point for IPF should be reliable, valid, responsive to changes in disease status, clinically meaningful, predictive of clinical outcome and responsive to treatment effect of a given intervention. Proper consideration and effective choice of outcome measures used in IPF studies will help establish effective and achievable drug development programmes and will enable clinicians and investigators to make informed critical decisions in recommending a treatment regimen to their IPF patients.