Effectiveness of combined therapy with pirfenidone and inhaled<scp>N</scp>‐acetylcysteine for advanced idiopathic pulmonary fibrosis: A case–control study

Abstract

Abstract Background and objective Treatment with pirfenidone may slow the decline in vital capacity and increase progression‐free survival ( PFS ) in idiopathic pulmonary fibrosis ( IPF ). The effects of combination therapy with inhaled N ‐acetylcysteine ( NAC ) and pirfenidone are unclear. We assessed the effects of this combination therapy in patients with advanced IPF . Methods Patients with a diagnosis of advanced IPF ( J apanese R espiratory S ociety stage III/IV IPF ) and a relative decline in forced vital capacity ( FVC ) of ≥10% within the previous 6 (±2) months were enrolled. Outcomes were evaluated in a 12‐month follow‐up pulmonary function test. Treatment was considered ineffective if the decline in FVC was ≥10% and effective if the decline was &lt;10%. We compared clinical characteristics, effectiveness and PFS between patients receiving inhaled NAC plus pirfenidone ( n = 24) and those receiving pirfenidone alone (control; n = 10). Results Data from 34 IPF patients (age range, 59–82 years) were analysed. At the 12‐month follow‐up examination, treatment was deemed effective in 8 of 17 (47%) patients receiving NAC plus pirfenidone and in 2 of 10 (20%) receiving pirfenidone alone. The annual rate of change in FVC was −610 mL in the NAC plus pirfenidone group and −1320 mL in the pirfenidone group ( P &lt; 0.01). PFS was longer (304 days) in the NAC plus pirfenidone group than in the pirfenidone group (168 days; P = 0.016). Conclusions Combination treatment with inhaled NAC and oral pirfenidone reduced the rate of annual FVC decline and improved PFS in patients with advanced IPF .