New data reveals Oncodetect’s powerful prognostic performance in one of the largest TNBC MRD studies to date¹

Exact Sciences Corp. (NASDAQ: EXAS), a leading provider of cancer screening and diagnostic tests, today announced the first clinical study results from its Oncodetect^® molecular residual disease (MRD) test in breast cancer. Findings from the NSABP B-59 substudy, conducted in collaboration with the NSABP Foundation and the German Breast Group (GBG), demonstrated that the Oncodetect test strongly predicts distant recurrence following surgery in patients with early triple-negative breast cancer (TNBC)², one of the most aggressive and difficult-to-treat breast cancer subtypes.³

These data, representing one of the largest TNBC MRD datasets analyzed to date,¹ were presented by Dr. Marija Balic, MD, PhD, scientific director of the NSABP Translational Research Program, at the San Antonio Breast Cancer Symposium (SABCS). The results demonstrate Oncodetect’s ability to help identify patients at higher risk of recurrence and strengthen the growing clinical evidence supporting the test’s role in guiding post-surgical treatment decisions.

The entities intend to submit these data to a peer-reviewed journal for publication, and Exact Sciences will submit the data to MolDx in support of Medicare coverage.

Prognostic performance of the Oncodetect test in early triple-negative breast cancer

In an analysis of 147 patients from the B-59 substudy, post-surgical detection of circulating tumor DNA (ctDNA) was strongly associated with risk of distant recurrence.² Patients who remained ctDNA-positive after neoadjuvant therapy and surgery had substantially higher recurrence risk compared to ctDNA-negative patients.² The key findings include:

• Post-surgery MRD-positive status was associated with a ~30-fold higher risk of distant recurrence compared to those who were MRD-negative.²
• 95% of patients who were MRD negative after surgery remained free of distant recurrence at 3 years.²
• Neo-adjuvant therapy given before surgical resection, which is the standard of care in patients with TNBC, reduced ctDNA positivity in patients from 95% before the start of treatment to 9% after treatment. ²

These data demonstrate that ctDNA detection after surgery is a powerful prognostic indicator of recurrence risk in TNBC and may help identify patients who could benefit from additional adjuvant therapy.

“The NSABP Foundation is proud to collaborate on this impactful study,” said Dr. Norman Wolmark, chairman, NSABP Foundation. “The strength of these data, particularly the clear separation in distant recurrence curves, highlight the prognostic power of ctDNA and its potential to guide post-surgical management strategies for high-risk breast cancer.”

Inside the NSABP B-59 study

In partnership with the NSABP Foundation, the Oncodetect substudy was conducted within the NSABP-B-59/GBG-96-GeparDouze trial, which enrolled patients with TNBC receiving neoadjuvant therapy with or without atezolizumab. Blood samples were collected before treatment and after surgery to evaluate whether ctDNA positivity at the post-surgery timepoint was associated with distant recurrence-free interval, with a median follow-up of 37 months. Exact Sciences is also collaborating with the NSABP Foundation on NSABP B-64, a large prospective registry trial enrolling 1,800 participants across all breast cancer subtypes.

“This is an important milestone for our Oncodetect program and for patients facing aggressive breast cancers like TNBC,” said Dr. Rick Baehner, senior vice president, chief medical officer, Precision Oncology at Exact Sciences. “These data demonstrate how ctDNA testing can provide critical insights into recurrence risk and more precisely help inform treatment decisions.”

References

1. Data source on file. Accessed November 25, 2025.
2. Balic, Marija, Geyer, Charles Jr. et. al. Evaluation of a whole-exome sequencing tumor-informed circulating tumor DNA MRD assay in patients with early triple-negative breast cancer receiving neoadjuvant chemotherapy with or without atezolizumab: A substudy of the NSABP-B-59/GBG-96-GeparDouze Trial. Presented at: San Antonio Breast Cancer Symposium (SABCS): December 11, 2025; San Antonio, TX.
3. Obidiro O, Battogtokh G, Akala EO. Triple Negative Breast Cancer Treatment Options and Limitations: Future Outlook. Pharmaceutics. 2023 Jun 23;15(7):1796. doi: 10.3390/pharmaceutics15071796. PMID: 37513983; PMCID: PMC10384267.

About Exact Sciences

A leading provider of cancer screening and diagnostic tests, Exact Sciences (Nasdaq: EXAS) helps patients and health care providers make timely, informed decisions before, during, and after a cancer diagnosis. The company’s growing portfolio includes well-established brands such as Cologuard^® and Oncotype DX^®, along with innovative solutions like the Cancerguard^® test for multi-cancer early detection and the Oncodetect^® test for molecular residual disease and recurrence monitoring. Exact Sciences continues to invest in a robust pipeline of advanced cancer diagnostics aimed at improving outcomes. For more information, visit ExactSciences.com, follow @ExactSciences on X, or connect on LinkedIn and Facebook.

Oncodetect and Oncotype DX are trademarks of Genomic Health, Inc., a wholly owned subsidiary of Exact Sciences. Cologuard and Exact Sciences are trademarks of Exact Sciences Corporation. Oncodetect is only available in the United States.

About NSABP Foundation

The NSABP Foundation designs and conducts clinical trials to improve the care of people with breast or colorectal cancer. The Foundation manages more than 700 sites that enroll patients into clinical trials. Founded in 1958 as the legacy National Surgical Adjuvant Breast and Bowel Project (NSABP), the goal is to identify and achieve opportunities for enhanced diagnostics, more precise and less debilitating treatments, and develop clinical strategies for the prevention of cancer for those who are at risk. To learn more and to support the mission, please visit www.NSABP.org.

Forward-Looking Statement

This news release contains forward-looking statements concerning our expectations, anticipations, intentions, beliefs, or strategies regarding the future. These forward-looking statements are based on assumptions that we have made as of the date hereof and are subject to known and unknown risks and uncertainties that could cause actual results, conditions, and events to differ materially from those anticipated. Therefore, you should not place undue reliance on forward-looking statements. Risks and uncertainties that may affect our forward-looking statements are described in the Risk Factors sections of our most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q, and in our other reports filed with the Securities and Exchange Commission. We undertake no obligation to publicly update any forward-looking statement, whether written or oral, that may be made from time to time, whether as a result of new information, future developments, or otherwise.

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The Oncodetect test strongly predicts distant recurrence following surgery in patients with triple-negative breast cancer.