Data supporting the detection of minimal residual disease (MRD) has highlighted potential to provide an early predictor of tumor recurrence in patients who have had breast cancer.
Liquid biopsy company Inivata announced the new data in support of its new RaDaR assay for the detection of MRD in those with high-risk hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2) breast cancer.
The company said its liquid biopsy platform unlocks essential genomic information from a simple blood draw, which may be used by clinicians to guide personalized cancer treatment to monitor response to treatment and to detect relapse.
The RaDaR assay is a personalized, tumor-informed, technology that tracks a set of up to 48 tumor-specific variants in cell-free DNA (cfDNA) within a cancer patient’s blood plasma.
It was designed to detect MRD following curative intent or definitive treatment and early signs of relapse and has been validated for clinical use in lung, head and neck and breast cancers.
The data, published in the Journal of Clinical Oncology, was presented in part at the 2022 ASCO annual meeting in Chicago in June.
In collaboration with the Dana-Farber Cancer Institute, the CHiRP study (circulating tumor DNA and late recurrence in high-risk HR+, HER2-negative breast cancer) was supported by Astra Zeneca and looked at patients at least five years after diagnosis, which is when more than half of metastatic recurrences are known to occur.
David Eberhard, chief medical officer at Inivata, said, “To our knowledge, this is the first data to be released on plasma ctDNA analysis for MRD detection in late adjuvant HR+ breast cancer patients, building on our existing evidence base in breast cancer as well as other indications.”
He said the results support the potential benefits of the clinical utility of the RaDaR assay in improving patient outcomes.
“The data will be useful in informing the future study of liquid biopsy to personalize treatment and prevent, or delay, late recurrence of early-stage breast cancer,” he added.
The RaDaR assay used patient-specific primer panels to analyze ctDNA in blood samples of the 83-patient cohort. Samples were collected every six to 12 months, starting with a median time of 8.4 years from a range of 4.9 to 20 years after initial diagnosis and followed for clinical tumor recurrence. Median follow-up was from the first blood sample.
During the study, 10% of patients had positive MRD results and in all six cases of distant metastasis in the cohort, ctDNA was previously identified using the RaDaR assay with a median lead time of a year. No patients had a positive MRD test and that included two patients who have not yet experienced recurrence and none had known metastatic recurrence at the time of the first plasma sample.
Clinical oncology fellow at the Dana-Farber Institute, Maria Lipsyc-Sharf, said, “The results of the CHiRP study mark an important step in helping us understand the baseline prevalence and role of ctDNA in the late adjuvant setting of HR+ breast cancer.”
She said the data demonstrates how important targeting multiple variants using an individualized assay, such as the RaDaR assay can be in identifying MRD-positive patients.
She added: “It is exciting to see this data highlighting the promise of this method and I am hopeful that with further studies, earlier detection of disease may enable earlier intervention and more positive outcomes for patients at greater risk.”
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