Employment of the Envisia Genomic Classifier in Conjunction With Cryobiopsy in Patients With Undiagnosed Interstitial Lung Disease

Abstract

Background

The Envisia Genomic Classifier (EGC) is a clinically validated molecular diagnostic test identifying usual interstitial pneumonia (UIP), increasing the diagnostic confidence for idiopathic pulmonary fibrosis in patients with interstitial lung disease (ILD).

Research Question

What is the association of the EGC and lung cryobiopsy on clinical management decisions in patients with fibrotic ILD?

Study Design and Methods

Retrospective analysis of patients at multimedical centers. We assessed the change in management strategy after EGC and cryobiopsy. We evaluated the association between genomic UIP classification and disease progression using the American Thoracic Society definition of progressive pulmonary fibrosis (method 1), or combined end point of death from any cause, lung transplant, or ≥ 10% relative decline in FVC (method 2).

Results

In patients that were EGC positive for UIP (gcUIP+), 78.6% were diagnosed with idiopathic pulmonary fibrosis. Cryobiopsy and EGC test results changed management strategy for 59.5% of patients in the cohort that were gcUIP+, and 21.4% of patients that had indeterminate cryobiopsy interpretations were gcUIP+, leading to a change in treatment strategy of an additional 16.7%. There was a decrease in follow-up without treatment from 64.3% to 11.9% (P < .001). Utilization of immunosuppressive drugs decreased from 23.8% to 9.5% (P = .06), and there was an increase in treatment with antifibrotics drugs from 11.9% to 71.4% (P < .001). A Kaplan-Meier curve of disease progression did not reach statistical significance on multivariable analysis (method 1: hazard ratio, 1.4; 95% CI, 0.4-4.2; P = .55; method 2: hazard ratio, 1.3; 95% CI, 0.8-2.1; P = .29). In analysis of EGC positivity for UIP, patients who were not prescribed antifibrotics showed disease progression compared with patients who were EGC negative for UIP (hazard ratio, 1.8; 95% CI, 0.99-3.4; P = .053)

Interpretation

This study suggests that combined EGC and cryobiopsy are associated with change in therapeutic strategy in patients with undiagnosed ILD. The EGC might serve as a predictor for disease progression in patients not treated with antifibrotics.