BillionToOne Adds Safety, Specificity to Cancer Liquid Biopsy Test

MENLO PARK, CA – February 10, 2026 – Molecular diagnostics company BillionToOne announced today the launch of two new applications designed to make cancer treatment safer and more precise. The new tests, Northstar PGx and Northstar Select CH, are add-ons to the company's existing Northstar Select liquid biopsy, a highly sensitive blood test for patients with advanced solid tumors. The expansion aims to give oncologists a more complete picture from a single blood draw, integrating crucial information about chemotherapy safety and filtering out potential false positives without delaying patient care.

This move signals a significant step in the evolution of liquid biopsies, moving beyond simply identifying tumor DNA to addressing other critical factors that influence treatment decisions. The integrated platform promises to streamline the complex diagnostic process for oncologists, providing deeper insights that can help tailor therapy to individual patients more effectively.

"These launches reflect our continued commitment to answering the most critical question oncologists face: which treatment fits the best for my patient," said Gary Palmer, MD, JD, Chief Medical Officer, Oncology at BillionToOne, in a statement. "The launch of pharmacogenomics and clonal hematopoiesis applications further empowers oncologists to choose the right therapy for the patients by avoiding potentially ineffective therapies."

An Integrated Advantage in a Single Draw

The foundation of the new offering is Northstar Select, a comprehensive genomic profiling (CGP) liquid biopsy that has demonstrated exceptional sensitivity. In a head-to-head clinical study, the test proved capable of uncovering over 50% more clinically actionable genetic alterations in tumors compared to other commercially available tests. This superior performance is particularly evident in detecting mutations at very low levels in the bloodstream, a common challenge in liquid biopsy diagnostics.

The key innovation is the integration of two new layers of analysis onto this powerful platform. Instead of requiring separate tests, different samples, or longer waits, oncologists can now order the Northstar PGx and Northstar Select CH applications as add-ons at the same time. All three analyses are performed from the same tube of blood, with results delivered within the same average 5-day turnaround time. This efficiency is critical in advanced cancer care, where treatment decisions are often time-sensitive.

By bundling these tests, BillionToOne aims to solve multiple clinical puzzles simultaneously. Clinicians not only get a detailed map of the tumor's genetic mutations to guide targeted therapy but also receive vital information to mitigate treatment risks and increase diagnostic confidence.

Tackling Chemotherapy Toxicity Head-On

One of the most significant challenges in oncology is managing the severe, sometimes fatal, side effects of chemotherapy. Northstar PGx directly addresses this by focusing on pharmacogenomics—the study of how genes affect a person's response to drugs.

The test analyzes variants in two specific genes, DPYD and UGT1A1. These genes are crucial for metabolizing two widely used classes of chemotherapy: fluoropyrimidines (like 5-FU and capecitabine) and irinotecan. Some patients have genetic variations that impair their ability to break down these drugs, leading to a dangerous buildup in the body and severe toxicity. Recent updates to FDA labeling and clinical guidelines from organizations like the American Society of Clinical Oncology (ASCO) now emphasize the importance of testing for these variants before starting treatment.

Northstar PGx provides a report on the patient's predicted metabolizer status, allowing oncologists to identify at-risk individuals upfront. This foreknowledge enables them to make more informed decisions, such as adjusting the chemotherapy dose, increasing monitoring, or selecting an alternative treatment altogether, thereby personalizing care and significantly enhancing patient safety.

Solving the Puzzle of Clonal Hematopoiesis

The second add-on, Northstar Select CH, tackles a pervasive and complex problem in liquid biopsy: clonal hematopoiesis (CH). CH is a common age-related condition where blood stem cells acquire mutations, causing them to produce genetically distinct blood cells. These non-cancerous mutations can be shed into the bloodstream and be mistaken for tumor DNA by highly sensitive liquid biopsy tests.

Recent studies indicate that in approximately 25% of advanced cancer patients, at least one mutation detected by liquid biopsy may originate from CH rather than the tumor. This can lead to a biological false positive, potentially resulting in a patient receiving an incorrect targeted therapy that is not only ineffective but may also come with its own toxicities. Recognizing this issue, the European Society for Medical Oncology (ESMO) now recommends profiling white blood cells to help distinguish the origin of detected mutations.

Northstar Select CH is designed to do just that with remarkable precision. It combines targeted sequencing of a patient's white blood cells with a proprietary machine-learning algorithm. This dual approach allows the system to differentiate between mutations from the tumor and those from CH with over 99% accuracy. By filtering out this biological noise, the test provides oncologists with greater confidence that the reported actionable mutations are truly from the patient's cancer, ensuring treatment decisions are based on the most accurate information possible.

Navigating a Competitive and Evolving Market

BillionToOne's integrated platform enters a rapidly growing and competitive liquid biopsy market, with major players like Guardant Health, Foundation Medicine, and Tempus AI also offering advanced genomic profiling tests. While these companies have established strong footholds with FDA-approved tests for various cancers, BillionToOne's strategy of bundling CGP with PGx and CH analysis from a single sample offers a distinct workflow advantage.

The market for precision oncology is expanding rapidly, with projections estimating it will exceed $200 billion by 2030. This growth is fueled by an increasing understanding of cancer genomics and the demand for personalized therapies. However, widespread clinical adoption hinges on more than just technological innovation; it requires robust clinical validation and, crucially, reimbursement.

On this front, BillionToOne has made significant progress. The core Northstar Select test recently met coverage criteria established by Palmetto GBA, a Medicare Administrative Contractor responsible for the Molecular Diagnostics Services Program (MolDx). Securing Medicare coverage is a pivotal step for any diagnostic test, as it removes a major barrier to access for a large patient population and often influences coverage decisions by private insurers.

While oncology experts widely embrace liquid biopsies as a transformative tool, they also emphasize the need for continued evidence generation to define their optimal use. The integration of pharmacogenomics and clonal hematopoiesis filtering represents a clear response to known clinical needs, aiming to improve the utility and reliability of liquid biopsy results. As these technologies become more embedded in clinical practice, their ability to provide a comprehensive, accurate, and timely portrait of a patient's cancer will be paramount in the ongoing effort to make treatment more personal and effective.