Figure 1.

Investigational therapies for idiopathic pulmonary fibrosis (IPF): targeting aberrant responses to injury. This schematic indicates the sequential profibrotic processes implicated in the currently prevailing paradigm of IPF pathogenesis, in which recurrent or persistent injury to the alveolar epithelium is believed to drive aberrant wound-healing responses, resulting in fibrosis rather than repair. Drug candidates evaluated in recently completed or ongoing phase II and III clinical trials in IPF are placed in the context of the profibrotic process(es) they are believed to target. Although fibrosis in IPF appears to predominantly expand the interstitial compartment, the aberrant repair processes driving IPF progression, and the fibrosis they produce, may occur in both the interstitium and the airspaces. For purposes of figure clarity, we have depicted the development of fibrosis in the airspaces in this figure. NAC = N-acetylcysteine. Inspired by Reference 6.