Envisia Genomic Test Shows Promise in Differentiating IPF
Veracyte has presented new data demonstrating the diagnostic performance and utility of its Envisia Genomic Classifier to help distinguish idiopathic pulmonary fibrosis (IPF) from other interstitial lung diseases (ILDs).
The company is now planning to make the Envisia classifier available to international markets by the end of this year, enabling laboratories to perform the test locally.
New findings reinforcing the test’s utility and solid diagnostic performance were presented across several abstracts at the American Thoracic Society 2021 International Conference, held online, May 14–19.
IPF is a common form of ILD, characterized by inflammation and scarring of the lungs, which impacts breathing. Identifying IPF among other ILDs can be challenging and may require invasive surgical biopsies.
The Envisia Genomic Classifier works by comparing genomic patterns in patient samples collected through a non-surgical procedure called a transbronchial biopsy, in which a bronchoscope — a long flexible tube — is inserted through the mouth or nose to collect pieces of lung tissue. The test is designed to distinguish usual interstitial pneumonia (UIP), a typical IPF diagnostic pattern, from non-UIP.
One of the abstracts presented, titled “Envisia Genomic Classifier Demonstrates Consistent Performance Across Gender, Age Group, and Smoking Status,” assessed the test’s ability to detect UIP among ILD patients with clinical signs less commonly associated with IPF, including those younger than 65, women, and those who have never smoked.
An analysis of 144 samples from ILD patients in two independent validation groups showed that across all groups, the Envisia genomic classifier had a 90.6% specificity and 62.5% sensitivity compared to standard histology, or tissue, testing. Sensitivity is a test’s ability to identify true positives, while specificity refers to its ability to detect true negatives.
The test was equally effective when evaluated in specific patient groups stratified by gender, age, and smoking status.
“These findings demonstrate robust performance of the Envisia Genomic Classifier across subsets of patients who are typically less likely to have a UIP pattern or IPF,” Luca Richeldi, MD, PhD, of Università Cattolica del Sacro Cuore, who presented the data, said in a press release.
“This is the first time that study data have been stratified to look at clinical characteristics in this way, and I think physicians will be reassured to learn that the Envisia classifier’s sensitivity and specificity extend to patients who are less likely to have IPF and therefore typically harder to diagnose confidently,” he added.
Another abstract, titled “Envisia Genomic Classifier Helps Improve Multidisciplinary Diagnoses of Complex Interstitial Lung Diseases,” presented by Lisa Lancaster, MD, of Vanderbilt University Medical Center, tested the impact of the genomic test to help identify undiagnosed ILD patients.
A total of 61 patients with suspected ILD with available computed tomography images and a confirmed histology diagnosis were evaluated by a pulmonologist, radiologist, and pathologist. Analyses found the addition of the Envisia genomic classifier and histopathology, especially among those with a UIP pattern, significantly decreased the number of unclassifiable ILDs.
Another abstract, titled “Bridging the Envisia Genomic Classifier to the nCounter Platform: A Proof-of-Concept Study,” presented by Huimin Jiang, PhD, at Veracyte, suggested the test may soon be accessible to physicians in global markets via the molecular testing platform nCounter Analysis System. The company acquired exclusive global diagnostics rights to this system back in 2019, with plans to facilitate global access.
“Making our validated genomic tests available on the nCounter system will enable physicians and patients around the world to access timely, critical diagnostic information that can change the path of patients’ disease and lives,” said Bonnie Anderson, Veracyte’s chairman and CEO. “We are excited to execute on this plan, beginning with the Envisia classifier.”
Researchers tested the Envisia classifier’s performance on the nCounter system by processing 33 transbronchial biopsy samples of varying RNA quality on an RNA-sequencing platform and the nCounter system, using a validated classifier set of 190 genes. A high correlation between the nCounter and RNA-sequencing platforms was demonstrated.
“Bridging the [Envisia genomic classifier] to the nCounter test platform is in progress, with minimal expected algorithm modification,” the investigators wrote. “We thus expect the Envisia nCounter test clinical performance to maintain at approximately 91% specificity and 63% sensitivity.”
Another abstract, titled “Cryobiopsy and Genomic Classifier (Envisia) in the Diagnosis of Usual Interstitial Pneumonia,” presented by Reza Ronaghi, MD, a pulmonologist from the University of California, Los Angeles, evaluated the test’s ability to identify ILDs when combined with transbronchial lung cryobiopsy. This less-invasive biopsy uses a flexible cryoprobe to rapidly freeze an area of the lung, which is then extracted to be evaluated.
Previous data showed that transbronchial lung cryobiopsy had an overall diagnosis yield ranging from 70%–90%, with variable complication rates. The addition of the Envisia classifier in a group of 41 eligible patients increased the diagnostic yield by 8% to an overall of 98%, thereby suggesting the addition of “Envisia to cryobiopsy is safe and increases the diagnostic yield for both UIP and non-UIP ILD,” the researchers wrote.
Finally, another abstract, titled “Role of the Envisia Genomic Classifier in Establishing a Diagnosis of Idiopathic Pulmonary Fibrosis,” was presented by Mohammed Abdalla, MD, from Pulmonary and Critical Care Medicine at the Medical College of Wisconsin.
In this study, the records of 18 patients who had undergone both transbronchial lung cryobiopsy and Envisia genomic classification were examined. A clinical diagnosis of IPF was confirmed in three patients and ruled out in 15, with the Envisia classifier attaining a specificity of 87% and a sensitivity of 100%.
“Envisia showed utility in both confirming and ruling out a clinical diagnosis of IPF when introduced into an academic medical center,” the researchers wrote.