Assessing the Effectiveness of Pirfenidone in Idiopathic Pulmonary Fibrosis: Long-Term, Real-World Data from European IPF Registry (eurIPFreg)

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic pulmonary disease with rising incidence. In this study the effectiveness of pirfenidone, as measured by longitudinal change in individual slope of forced vital capacity (FVC) prior to and after initiating pirfenidone treatment, was evaluated in IPF patients recruited into the European registry for idiopathic pulmonary fibrosis (eurIPFreg). Secondary variables were the evaluation of the change in individual slope of diffusion capacity of the lungs for carbon monoxide (DLco), the Borg dyspnea scale, and six-minute walking distance (6MWD), as well as survival analyses. Results: Data of 122 eurIPFreg patients, who had at least two pulmonary function tests (PFTs) prior to or under treatment with pirfenidone, were analyzed by calculating slope-changes. The global analysis revealed an average slope change of +1.48 +/- 0.28 (% per annum (p.a)) after start of treatment (p < 0.001), reflecting a reduction in annual FVC decline of approx. 50% under pirfenidone; it also showed a reduction in DLco, and increase in 6MWD (both p < 0.0001), as well as a flattening of the Borg dyspnea scale (p = 0.02). The median survival under treatment was 4.82 years. Patients with a more restrictive disease (FVC < 80% pred.), with a rapid progression (FVC decline >10% pred. p.a.), previous smokers and patients > 60 years of age seemed to profit more from pirfenidone treatment. Conclusions: We report the effectiveness of pirfenidone in a European "real world" IPF cohort with outcome data extending up to 9 years. Global analyses demonstrated a positive effect of pirfenidone on the decline of the lung function over time. Survival was dependent on Gender-Age-Physiology (GAP) score and age prior to therapy.