Progressive fibrosing interstitial lung diseases: current practice in diagnosis and management

Objective: Some patients with interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF) develop a progressive fibrosing phenotype. We investigated the diagnosis and management of non-IPF ILDs using data from a survey of physicians and from US insurance claims. Methods: Pulmonologists, rheumatologists and internists in France, Germany, Italy, Japan, Spain, UK and US who had managed ≥10 patients with non-IPF ILDs in the past year, including those with progressive fibrosing ILDs, completed an online survey. Data on US insurance and prescription claims were obtained from a repository that aggregates data on claims routed from providers or pharmacies to payers. Results: In May-June 2017, 243 pulmonologists, 203 rheumatologists and 40 internists completed an online survey. Respondents estimated that 18-32% of patients diagnosed with non-IPF ILDs develop progressive fibrosis and that time from symptom onset to death in these patients was 61-80 months. Drug treatment was given to 50-75% of patients with non-IPF progressive fibrosing ILDs. Reasons for patients not being treated included that physicians considered patients to have mild or slowly progressing disease, or did not believe that available treatments are effective or well tolerated. Corticosteroids were the preferred first-line treatment for all types of non-IPF ILD. There was considerable heterogeneity in preferences for second- and third-line treatments. US insurance claims data from 3823 patients indicated that, in 2016, 50-75% of patients with ILDs received drug treatment (mostly corticosteroids) for their ILD. Conclusions: Physicians estimate that 18-32% of patients diagnosed with non-IPF ILDs develop a progressive fibrosing phenotype and that these patients experience significant delays in the diagnosis of ILD and the detection of progressive fibrosis. Between 25% and 50% of patients with progressive fibrosing ILDs do not receive drug therapy. There is an unmet need for effective and well tolerated treatments for progressive fibrosing ILDs.