Personalis Pioneers Advancement in MRD Testing with the Launch of its Real-Time Variant Tracker™

Key Terms

molecular residual disease (mrd) medical

Molecular residual disease (MRD) is the tiny number of cancer cells that remain in a patient after treatment, detected by highly sensitive genetic or molecular tests that can find one cancer cell among thousands or millions of normal cells. MRD matters to investors because it helps predict the chance of relapse and influences whether additional treatment is given; MRD signals are increasingly used as early clinical trial or regulatory endpoints, so positive or negative MRD results can materially affect the market value of diagnostics and therapies—similar to an early warning that shapes future decisions.

circulating tumor dna (ctdna) medical

Circulating tumor DNA (ctDNA) are tiny fragments of genetic material shed by cancer cells into the bloodstream, detectable with a blood test often called a liquid biopsy. For investors, ctDNA matters because it can enable earlier, less invasive detection of cancer, track how well treatments are working, and guide drug development and diagnostic products—factors that can drive demand, regulatory decisions, and company valuations in oncology-related markets.

esr1 medical

ESR1 is a gene that makes the estrogen receptor alpha protein, a cellular “lock” that the hormone estrogen (the “key”) fits into to tell cells how to grow, divide and behave. Mutations or changes in ESR1 can change how cancers—especially breast and other hormone-driven tumors—respond to hormone-blocking drugs, so investors track ESR1-linked tests, drugs and trial results because they directly affect treatment choices, market size and regulatory chances in oncology and women’s health.

hr+/her2- medical

A cancer subtype where tumor cells have hormone receptors for estrogen and/or progesterone (HR+) but lack excess HER2 protein (HER2−). Think of receptors as locks: HR+ tumors have locks that can be targeted by hormone-blocking drugs, while HER2− means a different lock is absent, so HER2-targeted medicines won’t work. For investors this classification matters because it determines which therapies are appropriate, how large the patient market is, and which clinical trials and regulatory paths are relevant.

biopharma medical

Biopharma companies discover and develop medicines and treatments derived from biological sources—such as proteins, cells, or genetic material—rather than from purely synthetic chemicals. For investors, biopharma matters because successful products can deliver large, protected revenues but require long, costly development and strict regulatory approval, creating a higher-risk, potentially higher-reward profile; think of them as chefs transforming living ingredients into precision medicines.

New NeXT Personal® extension empowers clinicians to identify emerging resistance and therapeutically targetable mutations during disease monitoring and surveillance

FREMONT, Calif.--(BUSINESS WIRE)-- Personalis, Inc. (Nasdaq: PSNL), a leader in advanced genomics for cancer, today announced the early access launch of Real-Time Variant Tracker, a powerful new option added to its ultrasensitive NeXT Personal molecular residual disease (MRD) test designed to detect small traces of circulating tumor DNA (ctDNA) in the blood that represent residual or recurrent cancer.

Clinicians using the NeXT Personal MRD test will now be able to opt-in for additional reporting on detected resistance and therapeutically targetable mutations that can inform new opportunities to optimize patient management. This includes ESR1 mutations, which can be an indication to switch therapy for HR+/HER2- breast cancer patients, and hundreds of other clinically relevant mutations for solid tumors.

“Personalis pioneered the shift toward ultrasensitive MRD, and today we are once again taking another innovative step forward,” said Chris Hall, Chief Executive Officer and President of Personalis. “Real-Time Variant Tracker marks a new milestone in our mission to enable physicians to fight cancer with a truly personalized approach.”

This new capability enables clinicians using the NeXT Personal MRD test to additionally monitor for:

• Emerging or evolving therapy resistance mutations that could impact clinical management
• Therapeutically targetable mutations associated with approved therapies

“The ability to detect evolving, clinically relevant mutations in genes like ESR1 during MRD monitoring and surveillance gives physicians a new tool to help optimize care,” said Richard Chen, M.D., M.S., Chief Medical Officer and Executive Vice President of R&D at Personalis. “We are continuing to innovate to empower physicians with the precision tools they need to better manage patients through their entire journey.”

Availability

The Real-Time Variant Tracker option for NeXT Personal is available to physicians who participate in the Early Access Program (EAP). The EAP is designed for clinical and academic leaders using NeXT Personal who are looking to integrate this new capability into their clinical practice and research. The ability to track mutations is also available to Personalis’ biopharma partners.

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, capabilities, sensitivity, availability and clinical relevance of Personalis’ assays and products including the NeXT Personal test and the Real-Time Variant Tracker option, the ability for Real-Time Variant Tracker to identify emerging resistance and actionable targets, remain unique in its ability to monitor mutations, and inform new opportunities to optimize patient management, participation of physicians in the EAP and adoption of mutation tracking by Personalis’ biopharma partners, and the success of Personalis’ continued innovation in the MRD space. 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 and the Real-Time Variant Tracker option, the NeXT Personal MRD assay remaining unique in its ability to detect traces of cancer in the ultrasensitive range and its ability to monitor mutations; future clinical data differing from the clinical data previously presented or expected results; the rate of adoption and use of the NeXT Personal test and the Real-Time Variant Tracker option; changes in health care policy, which could increase Personalis’ costs, decrease Personalis’ revenue, and impact sales of and reimbursement for Personalis’ tests; 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, 2024, filed with the Securities and Exchange Commission (SEC) on February 27, 2025, as updated by Personalis’ Quarterly Report on Form 10-Q for the quarter ended September 30, 2025, filed with the SEC on November 4, 2025. 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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Investor Relations:

Caroline Corner

investors@personalis.com

415-202-5678

Media Contact

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Source: Personalis, Inc.