Hot off the breath: a big step forward for idiopathic pulmonary fibrosis
- 1Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- 2Department of Medicine, University of California, San Francisco, San Francisco, California, USA
- Correspondence to Dr Christopher J Ryerson, Department of Medicine & Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Ward 8B, 1081 Burrard Street, Vancouver, British Columbia, Canada V6Z 1Y6; .
- Received 12 June 2014
- Accepted 13 June 2014
- Published Online First 4 July 2014
Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease of unknown etiology1 with a median survival of 3 years from the time of diagnosis.2 The recent decade has seen a tremendous investment in IPF clinical research, and as a result, we have moved beyond traditional treatment approaches (prednisone and other immunomodulatory therapies) toward clinical trials of potential antifibrotic therapies.3 As recently as 2011, however, an international guideline committee concluded that there remained insufficient evidence to support the regular use of any IPF pharmacotherapy.1 Because of this, there has been no consensus standard of care for IPF patients.
This will likely change with the recent publication of three landmark studies.4–6 Two novel therapies, pirfenidone and nintedanib, were found to slow disease progression in patients with IPF, while a third therapy, acetylcysteine, was found to have no effect. We believe these studies will transform IPF management and lead to the establishment of a universal standard of care. We discuss each of the three trials below, followed by a discussion of their clinical and clinical research implications.
Pirfenidone is an orally available antifibrotic agent with multiple potential mechanisms of action. Early clinical trials suggested that pirfenidone could slow lung function decline in patients with IPF,7–9 prompting two parallel, randomised, double-blind, placebo-controlled, phase III clinical trials (the CAPACITY studies).10 There was a significant benefit in the primary endpoint of change in FVC over 72 weeks in one of the CAPACITY studies but not in the other. Pirfenidone was associated with an increased risk of gastrointestinal (eg, nausea and stomach discomfort) and dermatological (eg, photosensitivity) adverse effects, however, these were generally manageable, and most patients were able to continue at the full dose for the duration of the study. Based largely on the CAPACITY results, pirfenidone was approved …