Data presented at the American Association for Cancer Research meeting highlights the use of circulating tumor DNA for monitoring colorectal and lung cancers.
Personalis presented clinical data at the American Association for Cancer Research (AACR) Annual Meeting demonstrating the use of its NeXT Personal assay for monitoring treatment response, identifying early recurrence, and tracking the emergence of therapy resistance.
The data, which included an oral podium presentation and three posters, focused on the clinical application of liquid biopsy technology in patients with colorectal and lung cancers.
Monitoring Neoadjuvant Therapy in Colorectal Cancer
A highlight of the meeting was the presentation of the NEOPRISM-CRC trial, which used the assay to monitor patients with high-risk stage II-III colorectal cancer receiving neoadjuvant pembrolizumab. The study, delivered by Dr Jiang from University College London, reported 100% sensitivity for disease at baseline.
Researchers identified three distinct groups of patient responses during neoadjuvant treatment: super molecular responders, dynamic molecular responders, and poor molecular responders. According to the data, 100% of super molecular responders—those who cleared circulating tumor DNA (ctDNA) by the second cycle of treatment—achieved a pathological complete response (pCR). Conversely, 100% of poor molecular responders, who showed stable ctDNA levels, did not achieve pCR.
Following surgery, the test reached a 100% negative predictive value and 100% specificity for disease relapse.
“The data presented at AACR confirm ultrasensitive ctDNA detection with NeXT Personal as a promising therapy monitoring tool in neoadjuvant colorectal cancer treatment,” says Richard Chen, president and chief medical officer at Personalis, in a release. “By measuring molecular response with high resolution, we are providing the tools needed to explore ctDNA-guided management of colorectal cancer patients receiving neoadjuvant therapy.”
Real-World Performance and Sensitivity
In a large-scale analysis of approximately 25,000 plasma samples from 10,000 real-world patients, the assay demonstrated a median limit of detection of 1.92 parts per million (PPM). The study found that 39% of all positive minimal residual disease (MRD) detections occurred in the ultrasensitive range below 100 PPM, while 14.6% were below 10 PPM.
The findings suggest these low-level detections might be missed by less sensitive assays. The study included more than 14 cancer types and various disease stages, highlighting the assay’s performance across diverse precision oncology samples.
Tracking Therapy Resistance
Personalis also presented data for a new feature of its MRD test called Real-Time Variant Tracker. This tool allows for the simultaneous monitoring of MRD and the longitudinal tracking of specific resistance-associated mutations, such as ESR1.
The analytical validation showed a specificity of greater than 99.9%. In the real-world cohort, resistance and other clinical mutations were identified in 38% of MRD-positive patients, providing a new method for tracking treatment resistance as it develops.
Immunotherapy Response in Lung Cancer
Results from the DARWIN 2 study in metastatic non-small cell lung cancer showed the assay’s ability to stratify risk in patients receiving immunotherapy.
Patients who achieved a durable molecular complete response remained 100% progression-free at three years. In contrast, patients who did not achieve molecular clearance were five times more likely to experience disease progression.
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