Interferon gamma-1b in the treatment of idiopathic pulmonary fibrosis

OBJECTIVE: To examine the clinical aspects of idiopathic pulmonary fibrosis (IPF) and the efficacy and safety of interferon gamma-1b (IFN gamma-1b) in its treatment. DATA SOURCES: Epidemiologic, preclinical, and clinical studies published in the English language were identified by a MEDLINE search (1966-January 2005) using the search terms idiopathic pulmonary fibrosis, cryptogenic fibrosing alveolitis, and interferon. Additional citations were identified from the reference lists of related publications. STUDY SELECTION AND DATA EXTRACTION: Selected preclinical studies describing the pathophysiologic basis for IFN gamma-1b therapy and all clinical studies were included. Additional trials describing other treatment modalities and the determinants of response to therapy in patients with IPF were also reviewed. DATA SYNTHESIS: IFN gamma-1b targets the fibrotic rather than inflammatory processes of IPF The efficacy of IFN gamma-1b in patients with IPF is inconsistent with regard to changes in pulmonary function and mortality, although a modest survival benefit was observed in the largest clinical trial. Adverse events related to IFN gamma-1b are frequent although transient. Several cases of respiratory failure occurring subsequent to the administration of IFN gamma-1b are documented. CONCLUSIONS: To date, although trials suggest that earlier-stage IPF may be responsive to IFN gamma-1b, study results overall are inconsistent; further investigation is needed.