# Real-World Performance of the EasyPGX® Ready Epidermal Growth Factor Receptor Assay for Genomic Testing of Non-Small Cell Lung Cancer Samples

## TL;DR

The study evaluates a commercial test for detecting EGFR gene changes in lung cancer samples, showing it works well even with small amounts of DNA.

## Contribution

Demonstrates the effectiveness of the EasyPGX® assay for EGFR variant detection in real-world clinical samples with low DNA input.

## Key findings

- The EasyPGX® assay achieved 94.3% concordance with NGS for EGFR variant detection.
- The assay works effectively with DNA inputs as low as 5 ng, below the manufacturer's recommendation.
- Exon 19 deletions and p.L858R were the most common EGFR variants identified.

## Abstract

Background/Objectives: Activating epidermal growth factor receptor (EGFR) variants is the most common targetable alteration in non-small cell lung cancer (NSCLC). Clinical decision-making requires fast and reliable detection of EGFR variants in early and advanced NSCLC, but limited available tissue necessitates tissue-sparing approaches and optimized sample management. The objective of this study was to assess the performance of the commercial EasyPGX® ready EGFR assay using real-world clinical NSCLC samples. Methods: A consecutive cohort of 804 non-squamous NSCLC samples was prospectively analyzed with the real-time quantitative polymerase chain reaction (RT-qPCR)-based EasyPGX® ready EGFR assay (Diatech Pharmacogenetics, Jesi, Ancona, Italy) and compared to next-generation sequencing (NGS) assays. Results: NGS revealed conclusive results in 99.7% samples, of which 11.1% had at least one EGFR variant. The most common variants were exon 19 deletions and p.L858R. The RT-qPCR-based assay identified EGFR variants with high accuracy (overall concordance rate 94.3%) over a broad range of clinical sample types, variant allele frequencies, tumor cell contents and deoxyribonucleic acid (DNA) input amounts. Conclusions: This study demonstrates that the EasyPGX® ready EGFR assay is a valid approach for the rapid detection of common EGFR variants in real-world clinical NSCLC samples with DNA inputs as low as 5 ng (less than the 15 ng recommended by the manufacturer), improving sample management in small specimens with limited quantity of nucleic acids.