Exploring efficacy and safety of oral Pirfenidone for progressive, non-IPF lung fibrosis (RELIEF) - a randomized, double-blind, placebo-controlled, parallel group, multi-center, phase II trial

Background: Pirfenidone is currently approved in the EU for the treatment of mild to moderate idiopathic pulmonary fibrosis (IPF) and offers a beneficial risk-benefit profile. However, there are several other, progressive fibrotic lung diseases, in which conventional anti-inflammatory therapy is not sufficiently effective and antifibrotic therapies may offer a novel treatment option. Methods/Design: We designed a study protocol for inclusion of patients with progressive fibrotic lung disease despite conventional anti-inflammatory therapy (EudraCT 2014-000861-32). The study population comprises patients with collagen-vascular disease-associated lung fibrosis (CVD-LF), fibrotic non-specific interstitial pneumonia (fNSIP), chronic hypersensitivity pneumonitis (cHP), and asbestos-related lung fibrosis (ALF). Disease progression needs to be proven by slope calculation of at least three Forced Vital Capacity (FVC) values obtained within 624 months prior to inclusion, documenting an annualized decline in percent predicted FVC of 5% (absolute) or more despite appropriate conventional therapy. Absolute change in percent predicted FVC from baseline - analyzed using a rank analysis of covariance (ANCOVA) model - will serve as efficacy-related primary study endpoint. Discussion: There is an urgent unmet clinical need for effective therapies for patients with a progressive fibrotic lung disease other than IPF. The current study protocol is unique with respect to selecting patients with different disease entities of lung fibrosis which have, however, essential pathophysiological characteristics in common. Moreover, by selecting patients with evidence of disease progression despite conventional therapy, the protocol ensures that a cohort of interstitial lung disease (ILD) patients with a high unmet medical need is targeted and it may allow a sufficiently high event rate for evaluation of treatment responses.