Personalis, ABRCC and Criterium Announce Major Prospective Clinical Trial

Personalis, Inc. (Nasdaq: PSNL) has announced it has partnered with the Academic Breast Cancer Consortium (ABRCC) and Criterium to carry out a prospective clinical trial, B-STRONGER-1 (Breast Cancer-Minimal Residual Disease Detection and Therapy Monitoring in Patients with Early Stage TNBC-Phase I), to evaluate the clinical performance of the NeXT Personal® test for detecting minimal residual disease (MRD) during and after treatment and recurrent cancer in patients with early-stage resectable triple-negative breast cancer (TNBC).

TNBC accounts for approximately 15%-20% of breast cancers diagnosed worldwide and is associated with worse outcomes compared to other breast cancer subtypes. Recurrence may be difficult to detect with other MRD assays, as TNBC in its earlier stages tends to ‘shed’ less circulating tumor DNA (ctDNA), a key marker for residual or recurrent cancer.

“The relatively high rate of recurrence in early stage TNBC patients makes detection of MRD after treatment important for assessing therapy response and providing opportunities for earlier intervention,” said Richard Chen, MS, MD, Chief Medical Officer and Executive Vice President of R&D at Personalis. “However, in early-stage cancers like this, detection can be challenging because of lower ctDNA shedding rates. We specifically designed NeXT Personal to detect ctDNA with very high sensitivity. With the B-STRONGER-1 trial with ABRCC, Criterium and Dr. Chalasani, we hope to demonstrate that this high sensitivity enables earlier and more accurate detection of MRD in early stage TNBC patients.”

Currently, a patient’s likelihood of developing a recurrent tumor is largely determined through pathological assessment of tissue samples collected from both the site of the primary tumor and regional lymph nodes following treatment—a process broadly referred to as pathological complete response (pCR) testing.

“While a valuable tool in estimating the risk of recurrence, pCR doesn’t help us to monitor for recurrence and response to treatment. More importantly, a large proportion of patients who do not have a pCR status have cancer recurrence. Currently we do not have good options in the clinic for detecting early recurrence. If we find it via imaging scans, it is too late, as this means the cancer has established a new ‘home’ already,” explained the study’s principal investigator, Pavani Chalasani, MD, Division Director for Hematology/Oncology, George Washington Cancer Center, George Washington University. "MRD testing has shown significant promise in recent years as a viable alternative, and it could become the new standard for assessing not only a patient's response to treatment, predicting their risk of recurrence, but also to detect early recurrence of disease. This early detection provides a window for the oncologist to potentially intervene and change treatment before the cancer can establish a new ‘home’."

NeXT Personal leverages next-generation sequencing technology to detect ctDNA in the bloodstream and may enable detection of micrometastases that currently evade pCR detection. The assay is designed to deliver industry-leading MRD sensitivity down to 1 part-per-million, an approximately 10- to 100-fold improvement over other available technologies. This may enable earlier detection across a broader variety of cancers and stages.

The B-STRONGER-1 study will enroll approximately 900 patients at up to 30 US sites and will be carried out in two stages. In the first stage, samples will be collected from each patient for both pCR and MRD analyses, to assess whether MRD using NeXT Personal correlates with standard of care pCR measurements. The second stage will involve a five-year follow-up to deepen the evidence on performance and establish clinical utility of NeXT Personal in early stage resectable TNBC.

About Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is aggressive and strongly correlated with hereditary BRCA1/2 mutations as well as a higher prevalence in young African American women. Despite advances in systemic therapies, currently 25–30% of early stage patients develop metastatic disease within 3–5 years of diagnosis and subsequent overall survival ranges from 8–13 months.