Fasihul A Khan1,2, Iain Stewart1,2,3, Samuel Moss1,2,3, Laura Fabbri1,2,3, Karen A Robinson4, Simon R Johnson1,2, R Gisli Jenkins1,2,3. 1. Division of Respiratory Medicine, School of Medicine, University of Nottingham, Nottingham, United Kingdom. 2. Nottingham Biomedical Research Centre, National Institute for Health Research, Nottingham, United Kingdom. 3. National Heart and Lung Institute, Imperial College London, London, United Kingdom; and. 4. Johns Hopkins University, Baltimore, Maryland.
Abstract
Rationale: Novel therapies for idiopathic pulmonary fibrosis (IPF) are in development, but there remains uncertainty about the optimal trial endpoint. An earlier endpoint would enable assessment of a greater number of therapies in adaptive trial designs. Objectives: To determine whether short-term changes in FVC, DlCO, and six-minute-walk distance could act as surrogate endpoints to accelerate early-phase trials in IPF. Methods: Individual participant data (IPD) from IPF clinical trials were included in a two-step random-effects meta-analysis to determine whether baseline or 3-month changes in FVC, DlCO, and 6-minute-walk distance were associated with mortality or disease progression in placebo arms. Three-month and 12-month FVC decline endpoints were compared with treatment arm data from antifibrotic studies by meta-regression. Measurements and Main Results: IPD were available from 12 placebo cohorts totaling 1,819 participants, with baseline and 3-month changes in all physiological variables independently associated with poorer outcomes. Treatment data were available from six cohorts with 1,684 participants. For each 2.5% relative decline in FVC over 3 months, there was an associated 15% (adjusted hazard ratio, 1.15; 95% confidence interval [CI], 1.06-1.24; I2 = 59.4%) and 20% (adjusted hazard ratio, 1.20; 95% CI, 1.12-1.28; I2 = 18.0%) increased risk for mortality in untreated and treated individuals, respectively. An FVC change treatment effect was observed between treatment and placebo arms at 3 months (difference in FVC change of 42.9 ml; 95% CI, 24.0-61.8 ml; P < 0.001). Conclusions: IPD meta-analysis demonstrated that 3-month changes in physiological variables, particularly FVC, were associated with mortality among individuals with IPF. FVC change over 3 months may hold potential as a surrogate endpoint in IPF adaptive trials.
Rationale: Novel therapies for idiopathic pulmonary fibrosis (IPF) are in development, but there remains uncertainty about the optimal trial endpoint. An earlier endpoint would enable assessment of a greater number of therapies in adaptive trial designs. Objectives: To determine whether short-term changes in FVC, DlCO, and six-minute-walk distance could act as surrogate endpoints to accelerate early-phase trials in IPF. Methods: Individual participant data (IPD) from IPF clinical trials were included in a two-step random-effects meta-analysis to determine whether baseline or 3-month changes in FVC, DlCO, and 6-minute-walk distance were associated with mortality or disease progression in placebo arms. Three-month and 12-month FVC decline endpoints were compared with treatment arm data from antifibrotic studies by meta-regression. Measurements and Main Results: IPD were available from 12 placebo cohorts totaling 1,819 participants, with baseline and 3-month changes in all physiological variables independently associated with poorer outcomes. Treatment data were available from six cohorts with 1,684 participants. For each 2.5% relative decline in FVC over 3 months, there was an associated 15% (adjusted hazard ratio, 1.15; 95% confidence interval [CI], 1.06-1.24; I2 = 59.4%) and 20% (adjusted hazard ratio, 1.20; 95% CI, 1.12-1.28; I2 = 18.0%) increased risk for mortality in untreated and treated individuals, respectively. An FVC change treatment effect was observed between treatment and placebo arms at 3 months (difference in FVC change of 42.9 ml; 95% CI, 24.0-61.8 ml; P < 0.001). Conclusions: IPD meta-analysis demonstrated that 3-month changes in physiological variables, particularly FVC, were associated with mortality among individuals with IPF. FVC change over 3 months may hold potential as a surrogate endpoint in IPF adaptive trials.
Entities:
Keywords:
6-minute-walk test; gas transfer for carbon monoxide; interstitial lung disease; mortality; spirometry