Company: BLLN
Filing Date: 2025-08-11
Form Type: DRS/A
Source: 0000950123-25-007483
Chunk: 189

Company: BillionToOne, Inc.
Filing Date: 2025-08-11
Form: DRS/A
Chunk 189
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 working for an individual patient remains a significant
challenge that relies too heavily on subjective assessments. Currently, doctors use medical imaging (e.g., computed tomography (CT) scans, magnetic resonance imaging (MRIs), and positron emission tomography (PET) scans) as the primary tool to
evaluate a patient’s cancer status. However, this approach has important limitations affecting both accuracy and reliability. Tumors often contain diverse cell populations that respond differently to treatment, making overall assessment
difficult. Some patients receiving immunotherapy experience “pseudoprogression,” where imaging temporarily shows growth even though the treatment is working. Scar tissue forming around tumors can be hard to distinguish from active cancer.
Certain areas of the body, like bones and the abdominal cavity lining, naturally provide poor contrast on imaging, making cancer changes difficult to see. Lastly, interpreting scans involves significant human judgment, introducing inconsistency
between different radiologists’ assessments.

The practical limitations of imaging also create problems. Most patients undergo scans only every few months,
leading to critical delays in determining whether a treatment is effective. These delays can result in patients continuing ineffective therapies longer than necessary or missing opportunities to begin alternative treatments sooner. While increasing
scan frequency might seem like a solution, patients face real-world barriers including limited availability of imaging equipment (especially in rural areas), the physical and financial burden of traveling to specialized imaging centers, and
substantial costs that might not be fully covered by insurance. These limitations create an urgent need for better tools that can assess treatment response more accurately, consistently, and frequently to help doctors make timely and informed
decisions about patient care.

Northstar Response is designed to solve these problems. Northstar Response is a tissue-free,
pan-cancer, smNGS-based liquid biopsy test that precisely measures more than 2,200 genomic loci uniquely methylated in cancer. Based on our knowledge of all widely available tests, Northstar Response is the
only methylation-based assay that quantifies tumor burden with single molecule precision and provides insight into dynamic changes in a patient’s response to therapy. In validation studies, Northstar Response showed a consistent ability to
detect quantitative changes in tumor fraction across more than 10 different cancer types, in some cases as much as six months earlier than indicated by imaging scans. Northstar Response has been analytically and clinically validated in three
peer-reviewed publications, including in collaborations with the University of California, San Diego and the University of Florida.

Northstar Response is now
undergoing further validation through our large flagship study: NORTH