On April 21, 2026 Personalis, Inc. (Nasdaq: PSNL), a leader in advanced genomics for precision oncology, reported the successful presentation of clinical data at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting. The data, spanning one oral podium presentation and three posters, underscore the use of the NeXT Personal ultrasensitive ctDNA assay in monitoring treatment response, identifying early recurrence, and tracking the emergence of therapy resistance.
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Neoadjuvant Monitoring in Colorectal Cancer. A highlight was the oral podium presentation of the NEOPRISM-CRC trial, delivered by Dr. Jiang from the University College London, which utilized NeXT Personal to monitor patients with high-risk stage II-III dMMR/MSI-H colorectal cancer (CRC) receiving neoadjuvant pembrolizumab. In addition to 100% sensitivity for disease at baseline, the study identified three distinct groups of patient response to neoadjuvant treatment: super molecular responders, dynamic molecular responders, and poor molecular responders. Notably, 100% of "super molecular responders"—those who cleared ctDNA by the second cycle of treatment—also achieved pathological complete response (pCR). Conversely, of "poor molecular responders"—patients with relatively stable ctDNA levels during neoadjuvant treatment—100% did not achieve pCR. These findings could provide clinicians with a critical window to adjust treatment strategies prior to surgery. Post-surgery, the test achieved a 100% negative predictive value (NPV) and 100% specificity for disease relapse.
"The data presented at AACR (Free AACR Whitepaper) confirm ultrasensitive ctDNA detection with NeXT Personal as a promising therapy monitoring tool in neoadjuvant colorectal cancer treatment," said Dr. Richard Chen, President and Chief Medical Officer at Personalis. "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."
Ultrasensitivity in Real-World Data. In a large-scale analysis of nearly 25,000 plasma samples from 10,000 real-world patients, NeXT Personal demonstrated consistent ultrasensitive performance with a median limit of detection of 1.92 PPM. The study also revealed that 39% of all positive MRD detections occurred in the ultrasensitive range below 100 PPM, with 14.6% below 10 PPM—detections that could be missed with less sensitive assays. This study also highlights the robust ultrasensitive performance of the NeXT Personal assay in real-world testing conditions across more than 14 cancer types, stage I-IV disease, and a variety of challenging sample types.
Innovation in Therapy Resistance Tracking. Personalis also debuted analytical validation and real-world data for a new opt-in feature of its NeXT Personal MRD test: Real-Time Variant Tracker. This feature allows for the simultaneous monitoring of MRD and the longitudinal tracking of specific resistance-associated mutations, such as ESR1. With a specificity of >99.9%, resistance and other clinical mutations were identified in 38% of MRD-positive patients across the real-world cohort, offering a new tool for tracking treatment resistance as it emerges.
Monitoring Immunotherapy Response in NSCLC. The DARWIN 2 study results in metastatic non-small cell lung cancer (NSCLC) demonstrated NeXT Personal’s ability to stratify risk in patients receiving immunotherapy. Patients who achieved a durable molecular complete response (dmCR) remained 100% progression-free at three years, whereas patients who failed to achieve molecular clearance were five times more likely to experience disease progression.
Together, these studies illustrate Personalis’ commitment to improving cancer management through ultrasensitive MRD testing throughout the patient journey.
(Press release, Personalis, APR 21, 2026, View Source [SID1234664650])