New Developments in the Therapy of Pulmonary Fibrosis

Fibrosis is a normal response to injury. When it becomes excessive, however, it can interfere with the normal function of various organs. In the lungs fibrosis can lead to interstitial pneumonias. Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia of unknown cause and poor prognosis. It is characterized by clinical, radiologic, and histologic criteria. The frequently used therapy of steroids (e.g. prednisolone) and immunosuppressants (e.g. azathioprine) has not been shown to be effective. No drugs for the therapy of IPF are approved in the United States. Bosentan, pirfenidone, and N-acetyl cysteine are currently in clinical trials with preliminary results suggesting they may prolong the life expectancy of patients with IPF. New approaches to the treatment of IPF have been proposed. They include endothelial and cytokine antagonists, and antioxidants. Preclinical and clinical studies with these drugs in IPF are reviewed in this chapter. Their antifibrotic activity has been demonstrated in cell culture as well as in vivo in bleomycin-induced fibrosis in mice or rats. Better translation of preclinical findings to clinical medicine will help in the discovery and development of new drugs for the treatment of IPF.