Clinical efficacy of pirfenidone in patients with severe fibrosing interstitial pneumonia

Abstract

Background: Several studies have confirmed that pirfenidone ameliorates disease progression, as reflected by the reduction of pulmonary-function decline and prolonged progression-free survival, in patients with mild-to-moderate idiopathic pulmonary fibrosis (IPF). Aims: We conducted the current study to confirm the clinical efficacy of pirfenidone in patients with severe fibrosing interstitial pneumonia. Methods: We evaluated the clinical data of patients who received pirfenidone between 2009 and 2014 for the treatment of severe fibrosing interstitial pneumonia, diagnosed by published guidelines, with either stage III or IV disease according to the Japanese disease severity score. Changes in respective forced vital capacity (ΔFVC) during the 3-, 6-, 9-, and 12-months periods before (pre-ΔFVC) and after (post-ΔFVC) the commencement of pirfenidone treatment were compared using a paired t -test. Results: This study included 48 patients (35 male, 13 female). Of these, 25 had IPF, 19 had nonspecific interstitial pneumonia, and 4 had other forms of the disease. The mean dose of pirfenidone and duration of therapy were 1343 mg/day and 21 months, respectively. Using the Japanese disease severity score, 15 patients had stage III disease and 33 had stage IV. The mean FVC and %FVC before pirfenidone treatment were 1.89 L and 63.1%, respectively. Compared with the pre-ΔFVC, post-ΔFVC taken after treatment at months 3, 6, 9, and 12 showed considerable improvement; notably, there was significant improvement after 3 months of pirfenidone treatment (p = 0.0155). Conclusions: Pirfenidone may be effective in improving pulmonary function even in patients with severe fibrosing interstitial pneumonia.