Clinical and analytical validation of FoundationOne Liquid CDx, a novel 324-gene blood-based comprehensive genomic profiling assay

• Published in: Journal of clinical oncology Vol. 38; no. 15_suppl; p. e13685
• Main Authors: Woodhouse, Ryan, Dennis, Lucas, Li, Meijuan, Burns, Christine, Ma, Pei, Meng, Wei, Dewal, Ninad, Vietz, Christine, Hegde, Priti
• Format: Journal Article
• Language: English
• Published: 20.05.2020
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2020.38.15_suppl.e13685

Abstract only e13685 Background: As the availability of precision therapies expand, a well-validated blood-based comprehensive genomic profiling (CGP) assay has the potential to provide considerable value as a complement to tissue-based testing to ensure that potentially life-extending therapies are administered to the patients most likely to benefit. Comprehensive clinical and analytical validity data for blood-based assays are crucial to enabling physicians to understand the true performance of available testing options. Methods: The FoundationOne Liquid CDx assay is a blood-based CGP assay that has been validated for a Premarket Approval (PMA) submission to the Food and Drug Administration (FDA). Validation studies included > 9,000 tests and > 30,000 unique variants across > 300 genes and > 50 cancer types, allowing for a comprehensive assessment of performance. Results: The results of these extensive studies demonstrate a 95% limit of detection (LoD) of 0.40% variant allele fraction (VAF) for select short variants (subs and indels), 0.37% VAF for select rearrangements, 21.7% tumor fraction (TF) for select copy number amplifications, and 30.4% TF for copy number losses. LoD for complex biomarkers such as microsatellite instability (MSI) and blood tumor mutational burden (bTMB) were also determined. The limit of blank (LoB) was shown to be the ideal value of zero. Reproducibility of variant calling was determined to be 99.59% with two-sided exact CI of (99.58%, 99.60%). In comparison with an orthogonal method, an overall PPA (95% CI) of 96.3% (94.8, 97.4%) and NPA (95% CI) of > 99.9% (99.9%, 100.0%) was observed. Critically, clinical validity and concordance with tissue-based CGP results across multiple tumor types were also evaluated. Conclusions: The results of these studies demonstrate that FoundationOne Liquid CDx accurately and reproducibly detects the major types of genomic alterations (short variants, rearrangements, and copy number alterations), as well as complex biomarkers, such as MSI, bTMB, and tumor fraction. These data demonstrate that the assay can identify genomic variants that may inform therapeutic decisions for cancer patients with any solid tumor using a single blood sample. Additionally, clinical validation results establish FoundationOne Liquid CDx as an additional tool for physicians in the therapeutic management of cancer patients.