Data Support Envisia Classifier Helping to More Quickly and Accurately Diagnose IPF, Veracyte Says
Veracyte announced new data further supporting its Envisia Genomic Classifier as a useful tool in helping doctors to diagnosis idiopathic pulmonary fibrosis (IPF) with greater confidence and without the need for surgery to biopsy lung tissue.
Findings from three different studies were presented at the annual meeting of the American College of Chest Physicians (CHEST 2019), held Oct. 19-23 in New Orleans, and showed that the test is a valuable complement to high-resolution computed tomography (HRCT) scans, the gold standard for distinguishing IPF from other interstitial lung diseases (ILDs).
“The new Envisia classifier data being presented at CHEST add to the growing body of evidence showing that the test complements HRCT and clinical factors for a more confident diagnosis,” Bonnie H. Anderson, Veracyte’s chairman and CEO, said in a press release.
The Envisia classifier is the first commercially available test designed to help distinguish IPF from other ILDs without surgery. It is reported to combine RNA sequencing — a sensitive technique that measures gene activity — and machine learning, to detect with high accuracy interstitial pneumonia (UIP), an altered pattern of lung structure essential in an IPF diagnosis.
Sadia Benzaquen, MD, chair of pulmonary/critical care at Einstein Healthcare Network, presented a study demonstrating that the Envisia classifier used with HRCT identified twice as many UIP patients as HRCT alone. Using scans from 46 patients, researchers saw that combining the classifier with HRCT results correctly identified UIP in 17 patients, while HRCT alone identified nine patients. This corresponded to a sensitivity of 81% and specificity of 88%.
When coupled to local radiology, adding the classifier to HRCT further improved, and showed a sensitivity of 95%, the release states.
A second study, presented by Jonathan Chung, MD at the University of Chicago Medicine, compared the evaluations of two multidisciplinary medical teams asked to diagnose 94 patients enrolled in the Bronchial Sample Collection for a Novel Genomic Test (BRAVE) study.
Researchers found a high (greater than 86 percent) concordance between IPF and non-IPF diagnoses made using the classifier as compared to biopsy results. This agreement was even higher (90%) among patients who had HRCT results inconsistent with UIP.
Using Envisia classifier significantly raised the confidence of doctors in making an IPF diagnosis to 94%, compared to 53% confidence with biopsy results.
The final study, conducted at Tulane University, also showed that if doctors analyze clinical and HRCT findings first, followed by cryobiopsy (a procedure sometimes performed during bronchoscopy) and then Envisia results, their confidence rose from 36% to 71% when diagnosing IPF in patients with inconclusive UIP findings on HRCT scans.
“The diagnosis of IPF often remains a challenge for physicians and patients, particularly given the risk involved with invasive diagnostic procedures and the urgency of getting patients onto appropriate treatment in order to slow disease progression,” said Joseph Lasky, MD, a professor of medicine at Tulane.
“Our findings suggest that the Envisia classifier enhances diagnostic confidence, and thereby helps alleviate this challenge by serving as a valuable complement to HRCT and clinical factors,” Lasky added.
Veracyte noted in its release that a Pulmonary Fibrosis Foundation survey has reported that 55 percent of IPF/ILD patients are misdiagnosed at least once, and 1 in 5 patients wait three or more years before being accurately diagnosed.
“Given the long-standing challenges associated with differentiating IPF from other ILDs, we believe the Envisia classifier can significantly improve patient care by expediting accurate diagnosis, reducing risk and decreasing cost,” Anderson said.