Investigational approaches to therapies for idiopathic pulmonary fibrosis

Abstract

Importance of the field: In fibrosing diseases, scar tissue begins to replace normal tissue, causing tissue dysfunction. For instance, in lung fibrosis, foci of what resembles scar tissue form in the lungs, impeding the ability of patients to breathe. These conditions represent a significant source of morbidity and mortality. More than 150,000 people in the USA have some form of fibrotic lung disease, and the 5-year mortality rate for these diseases can be as high as 80%. Despite this large unmet medical need, there are no FDA-approved therapies. Although our understanding of the causes and the biology of fibrosing diseases remains relatively poor, we have made impressive advances in identifying the major cell populations and many biochemical mediators that can drive this process. As a result, novel therapeutics are being developed based upon these discoveries.

Areas covered in this review: This review examines the experimental therapies currently under investigation as of late 2009 for a major class of lung fibrosis called idiopathic pulmonary fibrosis (IPF).

What the reader will gain: The reader will gain an overview of current experimental therapies for IPF.

Take home message: With the recent approval of Pirfenidone in Japan for use in IPF, and a rich pipeline of experimental therapies in various stages of clinical development, the future looks bright for new treatment options.

Figure 1. Section of a lung from a patient with idiopathic pulmonary fibrosis

The section was stained with hematoxylin and eosin. A region of relatively normal lung is at upper right; the main mass of tissue in the center and lower left is fibrotic scar tissue that has replaced normal lung tissue. Figure is courtesy of Dr. Erica Herzog, Yale University School of Medicine, Internal Medicine - Pulmonary and Critical Care Division.