• Five-year outcomes from large, prospective phase III ADAPT study confirm value of the test to help guide treatment decisions in breast cancer patients with high clinical risk, including those with node-positive disease
• New meta-analysis of data from more than 10,000 patients with node-negative disease, including the results of TAILORx, supports the Oncotype DX Breast Recurrence Score^® test as the standard of care genomic test in early-stage, invasive breast cancer

MADISON, Wis., December 11, 2020 – Exact Sciences Corp. (NASDAQ: EXAS) today announced the presentation of new data at the virtual 2020 San Antonio Breast Cancer Symposium (SABCS) building on the clinical value of the Oncotype DX Breast Recurrence Score^® test. These data highlight the role of the test in further individualizing treatment decisions in early breast cancer.

“These latest presentations, including data from the RxPONDER trial, further highlight the unique value of the Recurrence Score^® result in providing critical information to personalize and improve the quality of treatment decisions in node-negative and node-positive early breast cancer,” said Rick Baehner, MD, chief medical officer of Precision Oncology at Exact Sciences.

Five-year outcomes from ADAPT study show that not all clinically high-risk patients with node-negative or node-positive disease need chemotherapy

First efficacy results from the ADAPT study (4,691 patients) were presented at SABCS.[i] Patients were all considered candidates for chemotherapy by traditional parameters and were stratified using the Oncotype DX test and changes in the immunohistochemical prognostic marker Ki67 after three weeks of pre-operative anti-hormonal therapy. Patients with clinically high risk node-negative disease, and node-positive disease with up to 3 positive nodes, were treated with anti-hormonal therapy alone if the Recurrence Score result was 0–11 or if the Recurrence Score result was 12-25 with a Ki67 response. This group of patients had, regardless of their age, favorable outcomes with anti-hormonal therapy alone, with 5-year distant disease-free survival of 96%.

Another analysis from the ADAPT trial also presented at SABCS evaluated 864 breast cancer patients who received neoadjuvant chemotherapy primarily based on their Recurrence Score result.[ii] These results from a large neoadjuvant trial showed that the Recurrence Score result is a strong predictor of response to chemotherapy as assessed by the rate of pathologic complete response (no residual invasive tumor).

ADAPT is one of the largest prospective, randomized studies in early-stage breast cancer and was conducted by the West German Study Group (WSG) in 80 centers across Germany. It utilized a pioneering trial design to assess individualization of (neo)adjuvant decision-making.

“Our study shows the unique value of the complementary biological information provided by the Oncotype DX test and sequential Ki67 testing. Risk stratification using the Recurrence Score result and changes in Ki67 after brief pre-operative anti-hormonal therapy allows us to identify those patients with node-negative or node-positive disease who can be spared the toxicity and side effects of chemotherapy without a negative impact on treatment outcome,” said Prof. Nadia Harbeck, Scientific Director of the WSG and Head of the Breast Centre at LMU Klinikum Munich (LMU), Germany. “This is especially important for patients who would be considered at high risk of relapse based on traditional clinical parameters.”

New patient-specific meta-analysis provides individualized estimates for both prognosis and absolute chemotherapy benefit in node-negative breast cancer

A new patient-specific meta-analysis of data from more than 10,000 patients with node-negative disease assessed individualized estimates of distant recurrence risk and absolute chemotherapy benefit based on the integration of the Recurrence Score^® result with clinicopathologic features.^[iii]

This analysis builds on the practice-changing results from the TAILORx study, which prospectively defined the groups of patients who will and will not benefit from chemotherapy.

The meta-analysis was conducted by the ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) and was presented in an oral session at SABCS by lead author Joseph A. Sparano, M.D., associate director for clinical research at Albert Einstein Cancer Center and associate chair for clinical research in the department of oncology at Montefiore Health System in New York, and leader of the TAILORx study for the ECOG-ACRIN Cancer Research Group. The data was published concurrently in the December 2020 issue of the Journal of Clinical Oncology.

The patient-specific meta-analysis estimates will initially be made available to physicians in the United States, starting in December 2020, as an online educational tool called RSClin™. The tool provides a more individualized prediction of absolute chemotherapy benefit that can enhance treatment decisions, particularly for patients whose Recurrence Score result is close to the TAILORx defined cut-off point of 25. By presenting the data in a new, easy-to-understand, visual format, RSClin empowers physicians with information that may be used to facilitate treatment conversations and decision-making with patients.

“As confirmed in TAILORx, for the great majority of patients, treatment based on the Recurrence Score result alone is clear,” said Dr. Sparano. “The RSClin tool, which now incorporates data from TAILORx to reflect contemporary treatment outcomes, provides individualized estimates for both risk of distant recurrence and absolute chemotherapy benefit and continues to demonstrate the role of TAILORx in informing early-stage breast cancer treatment.”

ECOG-ACRIN conducted the analysis primarily with funding from the National Cancer Institute. Mention of commercial products does not imply endorsement by the U.S. government. Additional support was provided by the Breast Cancer Research Foundation, the Komen Foundation, and the Breast Cancer Research Stamp issued by the United States Postal Service.

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About Oncotype DX

The Oncotype DX portfolio of breast, colon and prostate cancer tests applies advanced genomic science to reveal the unique biology of a tumor in order to optimize cancer treatment decisions. In breast cancer, the Oncotype DX Breast Recurrence Score test is the only test that has been shown to predict the likelihood of chemotherapy benefit as well as recurrence in invasive breast cancer. Additionally, the Oncotype DX Breast DCIS Score test predicts the likelihood of recurrence in a pre-invasive form of breast cancer called DCIS. In prostate cancer, the Oncotype DX Genomic Prostate Score^® test predicts disease aggressiveness and further clarifies the current and future risk of the cancer prior to treatment intervention, and the Oncotype DX AR-V7 Nucleus Detect^™ test helps determine which patients with metastatic castration-resistant prostate cancer (mCRPC) are resistant to androgen receptor (AR)-targeted therapies. The Oncotype DX AR-V7 Nucleus Detect test is performed by Epic Sciences at its centralized, CLIA-certified laboratory in San Diego and offered exclusively by Exact Sciences. With more than 1 million patients tested in more than 90 countries, the Oncotype DX tests have redefined personalized medicine by making genomics a critical part of cancer diagnosis and treatment. To learn more about Oncotype DX tests, visit www.OncotypeIQ.com, www.MyBreastCancerTreatment.org or www.MyProstateCancerTreatment.org.

About Exact Sciences Corp.

A leading provider of cancer screening and diagnostic tests, Exact Sciences relentlessly pursues smarter solutions providing the clarity to take life-changing action, earlier. Building on the success of the Cologuard^® and Oncotype DX tests, Exact Sciences is investing in its product pipeline to take on some of the deadliest cancers and improve patient care. Exact Sciences unites visionary collaborators to help advance the fight against cancer. For more information, please visit the company’s website at www.exactsciences.com, follow Exact Sciences on Twitter @ExactSciences, or find Exact Sciences on Facebook.

NOTE: Oncotype, Oncotype DX, Oncotype DX Breast Recurrence Score, Oncotype DX Breast DCIS Score, Oncotype DX Genomic Prostate Score, and Oncotype DX AR-V7 Nucleus Detect are trademarks or registered trademarks of Genomic Health, Inc. Exact Sciences and Cologuard are trademarks or registered trademarks of Exact Sciences Corporation. All other trademarks and service marks are the property of their respective owners.

Forward-Looking Statements

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.

^[i] Harbeck, N. et al. Oral Presentation: GS4-04. San Antonio Breast Cancer Symposium; December 2020.

^[ii] Kuemmel, S. et al. Oral Presentation: GS4-03. San Antonio Breast Cancer Symposium; December 2020.

^[iii] Sparano, J. et al. Oral Presentation: GS4-09. San Antonio Breast Cancer Symposium; December 2020.

Media (U.S.): Stephanie Spanos, sspanos@exactsciences.com

Media (Canada, Europe, Latin America, Asia): Federico Maiardi, fmaiardi@exactsciences.com

Investors: Megan Jones, meganjones@exactsciences.com