By Diagnostics World Staff
March 6, 2025 | A retrospective study from Personalis for its NeXT Personal test, an ultra-sensitive circulating tumor DNA (ctDNA) test for cancer patients and survivors, has been published in Annals of Oncology (DOI: 10.1016/j.annonc.2025.01.021). The study was conducted with researchers from The Institute of Cancer Research, London and The Royal Marsden NHS Foundation Trust in the UK.
“We believe the strength of this data paves the way for Medicare reimbursement for NeXT Personal in breast cancer,” said Richard Chen, Chief Medical Officer and EVP of R&D at Personalis.
The NeXT Personal assay uses whole-genome sequencing of the patient’s tumor to identify a unique fingerprint of about 1,800 variants. A personalized test is then created for the patient that can recognize that fingerprint from a blood sample with ultra-high sensitivity down to about 1 part per million (PPM) of ctDNA.
In the current study, NeXT Personal was used to analyze blood samples from a cohort of 78 patients with early-stage breast cancer. The cohort included patients with triple-negative breast cancer (TNBC), HER2+, and HR+ breast cancers. Researchers tested plasma samples spanning both pre-treatment and post-treatment settings to assess the prognostic performance, the ability to detect MRD and distal and local recurrence in early-stage breast cancer, and compared performance with the current generation of exome-powered MRD assays, the authors write in the paper.
They found that NeXT Personal showed high sensitivity for detecting early-stage breast cancer with ~39% of all detections occurring in the ultra-sensitive range below 100 PPM, demonstrating the test’s ability to detect exceedingly small traces of cancer in the blood. The test detected 100% of the patients that had breast cancer recurrence, a median of ~15 months and up to 5 years ahead of standard of care radiographic imaging. Importantly, 100% of patients who tested negative with NeXT Personal throughout the study period remained disease-free.
“A whole genome-powered MRD assay detected breast cancer relapse with a long lead time over clinical relapse, and was strongly associated with relapse-free survival,” the authors wrote in their conclusions. “Rates of ctDNA detection at diagnosis were higher than those reported with exome-based tumour-informed assays.”
“NeXT Personal demonstrated the best MRD performance we have seen in this study cohort,” said first author, Dr. Isaac Garcia-Murillas, Senior Staff Scientist in the Molecular Oncology Group at The Institute of Cancer Research, London. “With the ultra-sensitive performance of NeXT Personal, we see strong opportunities to impact breast cancer care and management, especially for the escalation and de-escalation of treatment.”