Pirfenidone as a treatment for asbestos-related lung fibrosis? A retrospective case series

Abstract

Pirfenidone is an established treatment for idiopathic pulmonary fibrosis (IPF). The efficacy in other fibrotic lung diseases has not been tested so far. Asbestos-related lung disease can manifest with inflammation and progressive lung fibrosis with currently no approved treatment option. Pirfenidone with its anti-inflammatory and antifibrotic effects might represent a possible drug treatment. As differentiating between IPF and asbestos-related disease is difficult, patients with a UIP-pattern and signs of asbestos-related disease were retrospectively analyzed within the idiopathic interstitial pneumonia-cohort study. Signs for asbestos-related disease included significant exposure in all patients, pleural plaques in 3/4 patients, presence of asbestos fibres in bronchoalveolar lavage or tissue in 2/4 patients. All 4 patients showed progressive fibrosis within 6 months prior to treatment with a mean decline in forced vital capacity (FVC) of 325 +/- 200 ml. They were subsequently treated with Pirfenidone (3x801mg/day). All patients showed stabilization or even improvement of FVC after 3-6 months of Pirfenidone treatment. Increase of FVC after 6 months was in average +173 +/- 220ml. Side effects were comparable to observed side effects in IPF (nausea, weight loss, phototoxicity) and led to dose reduction in 2 patients (3x534mg/day). In conclusion, this retrospective case series suggest that treatment with Pirfenidone in patients with possible asbestos-related progressive lung fibrosis is well tolerated and resulted in stabilization or even improvement of FVC. Nevertheless, these retrospective findings require confirmation in randomized, placebo-controlled prospective trials.