Expanded coverage enables Medicare beneficiaries with Stage II-III TNBC or HER2+ breast cancer to access ultrasensitive MRD testing to monitor response to neoadjuvant therapy

Personalis, Inc. (NASDAQ:PSNL), a leader in advanced genomics for precision oncology, today announced that the Centers for Medicare & Medicaid Services' (CMS) Molecular Diagnostic Services Program (MolDX) has expanded coverage for the company's NeXT Personal minimal residual disease (MRD) test. The new coverage determination is for monitoring treatment response to neoadjuvant therapy (NAT) in patients diagnosed with Stage II-III Triple-Negative Breast Cancer (TNBC) or HER2-positive (HER2+) breast cancer.

This decision marks Personalis' fourth Medicare coverage milestone for NeXT Personal, expanding the test's clinical use in breast cancer. While previous coverage enabled post-surgical recurrence surveillance, this new milestone extends Medicare coverage into the neoadjuvant setting, allowing clinicians to utilize NeXT Personal's ultrasensitive technology to actively monitor therapy effectiveness before a patient undergoes surgery.

The coverage determination is underpinned by clinical evidence from the prospective PREDICT-DNA study, recently published in the Journal of Clinical Oncology (JCO). The study followed 227 patients with TNBC and HER2+ breast cancer across more than 24 leading US cancer centers. Data from that study demonstrated that ultrasensitive ctDNA monitoring with NeXT Personal allows accurate tracking of neoadjuvant therapy response and outperforms traditional clinical metrics in predicting long-term patient outcomes.

"Securing our fourth Medicare coverage decision for NeXT Personal is another milestone that moves our technology into active treatment management," said Chris Hall, Chief Executive Officer of Personalis. "We are focused on enabling a better outcome for patients by using our ultrasensitive MRD technology to help guide decisions throughout their clinical journey."

A key finding of the PREDICT-DNA study was the clinical necessity of the ultrasensitive range for accurately tracking patient response to neoadjuvant therapy. Nearly half of all ctDNA detections following NAT occurred at levels below 100 parts per million (PPM)—low-level traces of cancer that less sensitive MRD assays can miss.

"The clinical data published in JCO clearly show that neoadjuvant monitoring benefits from a highly quantitative, ultrasensitive test to capture treatment response dynamics. NeXT Personal's unique ability to track up to ~1,800 patient-specific variants provides the resolution physicians need to confidently track treatment response," said Richard Chen, MD, President and Chief Medical Officer at Personalis. "With neoadjuvant therapy as the standard of care in a number of breast cancer settings, we are thrilled to expand access to NeXT Personal for those patients and take another step forward in our mission to transform cancer care through personalized testing."

About Personalis, Inc.

At Personalis, we are transforming the active management of cancer through breakthrough personalized testing. We aim to drive a new paradigm for cancer management, guiding care throughout the patient journey. Our highly sensitive assays combine tumor-and-normal profiling with proprietary algorithms to deliver advanced insights even as cancer evolves over time. Our products are designed to detect minimal residual disease (MRD) and recurrence at the earliest timepoints, enable selection of targeted therapies based on ultra-comprehensive genomic profiling, and enhance biomarker strategy for drug development. Personalis is based in Fremont, California. To learn more, visit www.personalis.com and connect with us on LinkedIn and X (Twitter).

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include all statements that are not historical facts, including statements relating to: the attributes, advantages, sensitivity, and clinical relevance of the NeXT Personal test, the duration of Medicare coverage in the neoadjuvant therapy monitoring setting, our ability to drive a new paradigm for cancer management and the design of Personalis' products. Such forward-looking statements involve known and unknown risks and uncertainties and other factors that may cause actual results to differ materially from any anticipated results or expectations expressed or implied by such statements, including the risks, uncertainties and other factors that relate to Personalis' ability to demonstrate attributes, advantages or clinical validity of the NeXT Personal test, including the NeXT Personal MRD assay remaining unique in its ability to detect traces of cancer in the ultrasensitive range, and the ability of the NeXT Personal test to evaluate treatment response and predict outcomes in patients undergoing neoadjuvant therapy; future clinical data differing from the clinical data previously presented or expected results; the rate of adoption and use of the NeXT Personal test; changes in health care policy, which could increase Personalis' costs, decrease Personalis' revenue, and impact sales of and reimbursement for Personalis' tests; Personalis' ability to obtain Medicare coverage and reimbursement in additional indications and the timing thereof; the impact of competition and macroeconomic factors on Personalis' business; the partnering and/or collaboration arrangements that Personalis has entered into or may enter into in the future may not be successful, or may terminate, which could adversely impact Personalis' business or affect its ability to develop and commercialize its services and products; having a limited number of suppliers; and customer concentration. These and other potential risks and uncertainties that could cause actual results to differ materially from the results predicted in these forward-looking statements are described under the captions "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" in Personalis' Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission (SEC) on February 26, 2026, and Quarterly Report on Form 10-Q for the quarter ended March 31, 2026, filed with the SEC on May 7, 2026. All information provided in this release is as of the date of this press release, and any forward-looking statements contained herein are based on assumptions that we believe to be reasonable as of this date. Undue reliance should not be placed on the forward-looking statements in this press release, which are based on information available to us on the date hereof. Personalis undertakes no duty to update this information unless required by law.

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Personalis Secures Fourth Medicare Coverage Decision for NeXT Personal®, Expanding Breast Cancer Coverage to Pre-Surgical Treatment Monitoring