Interferon Gamma-1b in the Treatment of Idiopathic Pulmonary Fibrosis

Abstract

Objective: To examine the clinical aspects of idiopathic pulmonary fibrosis (IPF) and the efficacy and safety of interferon gamma-1b (IFNγ−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 IFNγ−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: IFNγ−1b targets the fibrotic rather than inflammatory processes of IPF. The efficacy of IFNγ−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 IFNγ−1b are frequent although transient. Several cases of respiratory failure occurring subsequent to the administration of IFNγ−1b are documented. CONCLUSIONS: To date, although trials suggest that earlier-stage IPF may be responsive to IFNγ−1b, study results overall are inconsistent; further investigation is needed.