Design and rationale of randomized, double-blind trial of the efficacy and safety of pirfenidone in patients with fibrotic hypersensitivity pneumonitis

Abstract

Hypersensitivity pneumonitis (HP) is an immunologically mediated form of lung disease resulting from inhalational exposure to any of a large variety of antigens. A subgroup of patients with HP develops pulmonary fibrosis (fibrotic HP, FHP), a significant cause of morbidity and mortality. This study will evaluate the safety and efficacy of the antifibrotic pirfenidone in treating FHP.This single-center, randomized, double-blind, placebo-controlled trial is enrolling adults with FHP (ClinicalTrials.gov: NCT02958917). Study participants must have fibrotic abnormalities involving ≥5% of the lung parenchyma on high-resolution CT scan, forced vital capacity ≥40% and diffusing capacity of the lung for carbon monoxide ≥30% of predicted values. Study participants will be randomized in a 2:1 ratio to receive pirfenidone 2403 mg·d−1 or placebo. The primary efficacy endpoint is the mean change in %FVC from baseline to week 52. A number of secondary endpoints have been chosen to evaluate the safety and efficacy in different domains.