IPF is a form of progressive pulmonary fibrosis, or abnormal scarring of the lungs. As the scarring progresses, transfer of oxygen into the bloodstream is increasingly impaired, leading to irreversible loss of lung function as well as high morbidity and mortality rates. Average life expectancy is estimated to be three to five years from diagnosis, with approximately two-thirds of patients dying within five years of diagnosis. Survival rates are comparable to those for some of the deadliest cancers.
IPF is designated as an orphan disease in the U.S., with U.S. prevalence and incidence of IPF estimated to be 135,000 cases (for IPF defined based on ICD-9 code) and 21,000 new cases per year, respectively, based on Raghu et al. (Am J Respir Crit Care Med (2006)) and on data from the United Nations Population Division. We believe that, with the availability of technology to enable more accurate diagnoses, the number of new cases of IPF diagnosed each year will increase.