Safety and efficacy of pirfenidone in idiopathic pulmonary fibrosis in clinical practice

Background: Previous pirfenidone trials have only involved patients with mild-to-moderate idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate the safety and efficacy of pirfenidone in patients with mild-to-severe IPF in clinical practice.

Methods: The clinical records of 76 patients who were diagnosed with IPF and received pirfenidone were reviewed.

Results: The most frequent adverse event was anorexia, although the grade of anorexia in most patients was mild. Dose reduction of pirfenidone improved anorexia in 84% affected patients, which resulted in a high medication compliance rate. The mean forced vital capacity (FVC) at the initiation of pirfenidone therapy in this study was approximately 10% lower than that in previous clinical trials. The mean change in FVC during the 6-month period prior to the therapy initiation was -188 mL, which improved to -19 mL during the 6-month period after therapy. Significant attenuation in percentage predicted diffusion capacity of the lung for carbon monoxide decline was also achieved after pirfenidone therapy initiation. The efficacy of pirfenidone in attenuating the degree of FVC decline was higher in the group with FVC decline of ≥150 mL during the 6-month period prior to therapy initiation. The levels of serum markers, such as KL-6 and SP-D, were also lowered by the therapy.

Conclusions: These results showed that pirfenidone was well-tolerated and had beneficial effects in patients with mild-to-severe and/or progressive IPF. The degree of disease progression prior to the initiation of pirfenidone therapy had an impact on the response to the therapy.