BillionToOne has expanded its liquid biopsy portfolio with the launch of Northstar Origin, a new test designed to help physicians determine where a cancer originated when the primary tumor cannot be identified with confidence. The company has introduced the test as an add-on to its Northstar Select genomic profiling platform, allowing clinicians to obtain additional information from the same blood sample already collected for treatment selection.
The launch addresses a difficult diagnostic problem in oncology. Patients with cancer of unknown primary, commonly referred to as CUP, can undergo extensive imaging, pathology and other diagnostic procedures without physicians being able to establish where the disease began. BillionToOne’s new test is intended to provide another molecular signal that can support clinical decisions in these cases.
The development also highlights the expanding role of the cancer biomarker market in precision oncology, where information obtained from blood or tumor samples is increasingly being used to guide diagnosis and treatment. Northstar Origin analyzes circulating cell-free DNA and combines methylation patterns with genetic information to predict the tissue where a cancer is most likely to have originated.
Northstar Origin Uses Blood-Based Signals to Identify Cancer Origin
Northstar Origin is designed for patients whose diagnosis remains uncertain after conventional clinical evaluation. Instead of requiring a separate tissue biopsy or another blood collection, the test can be added to a Northstar Select analysis using the sample already obtained for genomic profiling.
This could be particularly relevant in community oncology settings, where physicians may not always have immediate access to the specialized pathology expertise, multidisciplinary tumor boards or other resources available at major academic cancer centers.
Cancer of unknown primary represents a relatively small but clinically important portion of new cancer diagnoses. According to data cited by BillionToOne, approximately 3% to 5% of new cancer cases are classified as CUP. The company also points to uncertainty in community oncology, where as many as 10% of patients may receive an uncertain diagnosis when detailed pathology resources are not readily available.
The clinical challenge is significant because identifying the tissue of origin can influence treatment selection. Different cancers can respond differently to chemotherapy, targeted therapies and other treatments. When the origin remains uncertain, oncologists may have fewer options for selecting a treatment strategy tailored to the underlying disease.
Northstar Origin attempts to address this gap by analyzing molecular characteristics found in blood. Its approach combines methylation profiling with information from tissue-specific somatic variants identified through the Northstar Select panel.
Methylation refers to chemical changes that influence how genes are regulated. Different tissues can have characteristic methylation patterns, and these patterns can provide clues about where a tumor originated. By combining this information with genetic signals, BillionToOne aims to give physicians a more comprehensive molecular assessment without requiring an additional sample.
The company developed the classifier using 6,025 blood samples from patients with advanced cancer before testing it against a separate validation group of 1,578 patients.
In that validation cohort, Northstar Origin’s top prediction matched the reported tissue of origin in 87% of cases. The correct origin appeared among the test’s top three predictions in 91% of cases.
Those results indicate potential value as a diagnostic aid, although they do not by themselves establish that using the test improves patient outcomes. BillionToOne said it intends to conduct prospective studies to evaluate its clinical utility and expand the classifier to cover additional tumor types.
The distinction between diagnostic accuracy and clinical utility will be important as the test enters the market. A molecular prediction can provide useful information, but physicians must ultimately determine whether that information changes treatment decisions and benefits the patient.
BillionToOne Expands Genomic Profiling Platform Amid Precision Oncology Growth
The Northstar Origin launch is accompanied by a broader expansion of BillionToOne’s Northstar Select genomic profiling panel. The company has increased the number of genes covered by the panel from 84 to 102, widening the range of genetic information that can potentially be assessed from a patient’s blood sample.
The combined offering gives the company a broader position in liquid biopsy, where blood-based testing is being developed for applications ranging from therapy selection to cancer monitoring and diagnosis. For oncologists, the ability to obtain multiple types of information from one blood draw could help reduce additional testing requirements for some patients.
This approach may have particular relevance as precision oncology becomes more dependent on molecular information. Tumors can contain genetic alterations that influence how they respond to treatment, while molecular characteristics can also provide clues about disease origin. Bringing these signals together could give physicians a more detailed picture of an individual patient’s cancer.
For patients with CUP, the potential benefit is especially relevant. Conventional diagnosis can involve repeated investigations as doctors attempt to establish the primary site. If a blood-based test can provide a reliable additional indication, it could potentially reduce some of the uncertainty surrounding treatment planning.
However, the technology is positioned as a complement to existing diagnostic methods rather than a replacement for pathology, imaging or clinical assessment. Physicians still need to consider the patient’s symptoms, medical history, imaging findings and pathological evidence when determining the most appropriate diagnosis and treatment.
BillionToOne’s expansion also reflects the commercial opportunity emerging around liquid biopsy. Blood-based cancer testing can offer logistical advantages compared with tissue sampling, particularly when obtaining a tumor specimen is difficult or when a patient’s existing sample can support multiple analyses.
The company’s Chief Medical Officer for oncology, Ethan Dmitrovsky, has said that Northstar Origin is intended to help address differences in diagnostic resources between community oncology practices and academic medical centers. Allen Chen, the company’s vice president of oncology clinical development and medical affairs, has similarly highlighted the challenges physicians face when conventional testing does not establish the primary tumor.
The next stage for BillionToOne will be demonstrating how the test performs in routine clinical practice. Prospective evidence will be important in determining whether its predictions consistently lead to more informed treatment choices and better patient management.
For the wider cancer biomarker industry, the launch illustrates how liquid biopsy is moving beyond a single-purpose diagnostic test. Companies are increasingly looking at how one blood sample can provide information about tumor genetics, disease characteristics and potential treatment options.
Northstar Origin therefore enters the market at a point when oncologists are seeking ways to make complex cancer diagnosis more efficient without adding unnecessary procedures. Its ability to provide a tissue-of-origin prediction from an existing blood sample could make it a useful addition to molecular testing, particularly for patients whose cancer remains difficult to classify.
Whether that promise translates into broader clinical adoption will depend on further validation, physician confidence and evidence that molecular predictions can meaningfully improve treatment decisions. For now, BillionToOne’s latest launch adds another application to the growing field of blood-based cancer testing and strengthens the company’s position in the developing liquid biopsy market.
