Phase 3 trials have shown both pirfenidone and nintedanib are significantly better than placebo in reducing the progression of idiopathic pulmonary fibrosis.
In the pirfenidone study, which followed up 555 patients over 52 weeks, the drug reduced the relative risk of death or disease progression by 43% compared with placebo (King TE Jr et al. N Engl J Med. 2014;370:2083-2092). Gastrointestinal and skin-related adverse effects were more common in patients receiving pirfenidone, but they were typically mild to moderate.
Slomski A. Two Drugs Reduce Progression of Idiopathic Pulmonary Fibrosis. JAMA. 2014;311(24):2472. doi:10.1001/jama.2014.7074