Abstract 325: Validation of Aventa FusionPlus: An LDT NGS assay for comprehensive cancer genomic profiling
Authors: Melnyk Shadi , Belton Jon , Nomikou Sofia , Powell Katelyn , Heiney Daniel , Khalife Roy , Jones Damien , Schmitt Anthony , Wilson Catherine , Won Melissa , Magliocco Anthony , Roberts Chris 
Published: March 2024

Next-generation sequencing (NGS) assays play a pivotal role in illuminating the genomic landscape of cancer by providing insights into gene regulation and biomarker detection for the purpose of guiding therapeutic decisions to advance personalized medicine. We validated the Aventa FusionPlus Test, a Laboratory-Developed Test (LDT) that integrates HiC technology to enhance detection of actionable gene fusions and rearrangements in solid tumors, including those that are missed by current standard of care tests. This is a DNA-based test that is robust to DNA degradation in FFPE specimens, in contrast with RNA-seq and long-read technologies. The test utilizes the Element Biosciences AVITI sequencing platform to achieve high quality sequencing data at low cost per sample.

The Aventa FusionPlus test enables gene-level detection of structural variants near or within 361 medically actionable or diagnostically relevant cancer genes. The 3D structure and long-range linkages captured by the test amplify the signal counts for each rearrangement. The test integrates the Arima-HiC+ FFPE sample prep and the Arima Library Prep Kit workflow. After dewaxing and rehydrating the FFPE tissue, the chromatinized DNA is fragmented and the fragmented ends are filled in with a biotinylated nucleotide. Next, spatially proximal fragmented ends of DNA are ligated, capturing the 3D structure of the genome. The proximally-ligated DNA is then purified and further fragmented, and the biotinylated ligation fragments are enriched. DNA libraries are prepared from these enriched fragments and sequenced in “paired-end” mode. Genes involved in genomic rearrangements were detected using the Arima-SV pipeline along with manual curation.

The test achieved robust detection of structural variants, with accuracy of 98.8% relative to reference methods. FFPE tumor specimens from 10 different tissue types and a wide range of tumor content (20%-100%) were included. No correlation between tumor cellularity and sensitivity was observed, suggesting that samples with as low as 20% tumor cellularity can be tested. When comparing to RNA-based and other targeted reference methods, we found additional fusions nearby oncogenes missed by these reference methods. As an example, in a breast cancer case, a fusion of genomic regions neighboring BRAF and MYC oncogenes on chromosomes 7 and 8 respectively, was missed by the reference method but was successfully detected by the Aventa FusionPlus test.

The Aventa FusionPlus test is a highly sensitive, specific, and accurate method for comprehensive cancer genomic profiling. The enhanced understanding of gene fusions and rearrangements positions the test as a valuable tool for clinical decision-making in oncology.

Citation Format: Shadi Melnyk, Jon Belton, Sofia Nomikou, Katelyn Powell, Daniel Heiney, Roy Khalife, Damien Jones, Anthony Schmitt, Catherine Wilson, Melissa Won, Anthony Magliocco, Chris Roberts. Validation of Aventa FusionPlus: An LDT NGS assay for comprehensive cancer genomic profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 325.