Interferon-γ1b therapy in idiopathic pulmonary fibrosis: A metaanalysis

Context: Despite the investigation of multiple therapeutic options, idiopathic pulmonary fibrosis (IPF) remains a devastating, progressively fatal disease. Much interest has focused on the use of interferon (IFN)-γ1b therapy, but the efficacy of this treatment has not been proven. Objective: To determine whether IFN treatment reduces mortality in patients with IPF. Design: A metaanalysis of randomized controlled trials evaluating the use of IFN-γ1b as treatment for IPF. Main outcome measure: Mortality in patients treated with IFN-γ1b was compared to mortality in patients treated with control therapies. Results: A total of three studies involving 390 patients was included in the analysis. IFN-γ1b therapy was associated with reduced mortality (hazard ratio [HR], 0.418; 95% confidence interval [CI], 0.253 to 0.690; p = 0.0003). A comparison of mortality at different time points revealed that IFN-γ1b therapy was associated with significantly reduced mortality at 1 year (0.0861; 95% CI, 0.0244 to 0.1478; p = 0.0063), 18 months (0.1682; 95% CI, 0.1065 to 0.2299; p < 0.0001), 650 days (0.1939; 95% CI, 0.1386 to 0.2492; p < 0.0001), and 2 years (0.2652; 95% CI, 0.1652 to 0.3652; p < 0.0001). Conclusion: When the results of multiple studies are combined in a metaanalysis, IFN-γ1b therapy is associated with reduced mortality.