Three-Month FVC Change: A Trial Endpoint for Idiopathic Pulmonary Fibrosis Based on Individual Participant Data...

Area of Science:

• Pulmonary Medicine
• Clinical Trial Design
• Biostatistics

Background:

• Idiopathic pulmonary fibrosis (IPF) requires novel therapies, but optimal clinical trial endpoints are unclear.
• Earlier endpoints are needed to facilitate adaptive trial designs and evaluate more treatments.

Purpose of the Study:

• To assess if short-term changes in forced vital capacity (FVC), diffusing capacity for carbon monoxide (DlCO), and six-minute-walk distance (6MWD) can serve as surrogate endpoints in IPF trials.
• To accelerate early-phase clinical assessments of novel IPF therapeutics.

Main Methods:

• Individual participant data (IPD) from IPF clinical trials were analyzed using a two-step random-effects meta-analysis.
• The association between baseline and 3-month changes in FVC, DlCO, and 6MWD with mortality and disease progression was evaluated in placebo arms.
• Meta-regression compared 3-month and 12-month FVC decline endpoints with antifibrotic treatment data.

Main Results:

• IPD from 12 placebo cohorts (1,819 participants) showed baseline and 3-month physiological variable changes correlated with adverse outcomes.
• A 2.5% relative decline in FVC over 3 months increased mortality risk by 15-20% in both untreated and treated individuals.
• A significant treatment effect on FVC change was observed at 3 months between treatment and placebo arms (42.9 ml difference).

Conclusions:

• A meta-analysis of IPD indicates that 3-month physiological changes, particularly FVC decline, are linked to mortality in IPF patients.
• Forced vital capacity (FVC) change over 3 months shows potential as a valid surrogate endpoint for adaptive clinical trials in IPF.