Personalis Announces Two Abstracts Accepted for Presentation at ASCO 2023 - Seite 2

Details of the Personalis abstracts are outlined below, and further details about the poster presentations can be found here.

Poster details

Title: Ultra-sensitive, tumor-informed ctDNA profiling in patients with gastroesophageal cancer and treated with pembrolizumab and longitudinal ctDNA kinetics.
Overview: In collaboration with Duke Cancer Institute and the University of North Carolina, samples from a phase II clinical trial (NCT03342937) involving patients with metastatic esophagogastric cancer were tested using Personalis’ NeXT Personal platform to assess ctDNA levels and their utility for longitudinal disease monitoring and surveillance of dynamic tumor evolution. We found that ctDNA levels dynamically varied from 5.3 to 302,000 PPM, with NeXT Personal showing an ultra-sensitive limit of detection between 1.5 and 4.6 PPM. Results showed that a reduction in ctDNA during treatment corresponded with better outcomes. And, ctDNA analysis revealed the evolution of a potentially therapeutically relevant variant in one patient during treatment.

Title: Association of ultra-sensitive ctDNA assay to identify actionable variants and response to immune checkpoint inhibitor (ICI) therapy in metastatic melanoma.
Overview: Detection of MRD via ctDNA can identify therapeutic response/resistance months in advance of imaging, and monitoring clinically actionable variant dynamics in ctDNA may be important for guiding treatment. However, efforts to use ctDNA have been hindered by low sensitivity, with most assays having a limit of detection of ~100 PPM. In this study, we collaborated with the University Medical Centre Hamburg-Eppendorf. Samples collected from melanoma patients receiving ICI were collected over several years and, using NeXT Personal, ctDNA findings were correlated with clinical outcomes. Levels of ctDNA ranged from 2.3-100,000 PPM, with NeXT Personal showing an ultra-sensitive limit of detection of 1.97 PPM. Importantly, 37% of detections were below 100 PPM. In response to ICI, average ctDNA levels fell more than 3-fold and the frequency of multiple therapeutically relevant variants changed, such that tumors appeared less sensitive to ICI.