Company: BLLN
Filing Date: 2025-06-20
Form Type: DRS
Source: 0000950123-25-006095
Chunk: 170

Company: BillionToOne, Inc.
Filing Date: 2025-06-20
Form: DRS
Chunk 170
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 care for early-stage cancer is the surgical removal of the tumor. However, a small number of cancer cells may remain and
can lead to future metastasis. MRD testing post-surgery enables healthcare providers to administer adjuvant therapy when needed and can also be used to monitor cancer recurrence over time. There are two approaches to MRD testing today,
tumor-informed and tumor-naive. Tumor-informed approaches involve sequencing the cancer tissue to identify mutations which can then be tracked in blood at subsequent points in time. Tumor-informed approaches can have up to 40% failure rates due to
the limited amount of tissue that can be obtained in early-stage cancers or tissue sequencing failing to identify a sufficient number of variants that can be used for MRD tracking. Moreover, the mutations that are tracked may not represent the
evolution of the tumor, resulting in false negatives. Tumor-naïve approaches measure the levels of ctDNA in a patient’s blood and do not require an upfront tissue sample, but to date, their lower
sensitivity has been a limiting factor in their adoption. We believe that our smNGS platform will allow our planned MRD test to address the sensitivity challenges of existing tumor-naïve assays.

Our proprietary smNGS platform enables us to create differentiated, ultrasensitive tests that approach the physical limit of detection
(LOD). Our product portfolio touches everyone from the beginning of life, with prenatal genetic testing, to the end of life, with cancer therapy selection and response monitoring testing.

To date, we have launched multiple differentiated products across these large addressable markets. We performed more than smNGS-based tests in the last 12 months
ended June 30, 2025, with significant room to further grow test volume in both markets.

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Prenatal products

Traditional non-invasive prenatal screening focuses on assessing a fetus’ risk for larger chromosomal changes, such as Down
syndrome. However, several common and severe conditions are the result of much smaller genetic changes. Identifying these tiny changes within cfDNA is technically challenging and requires precise quantification to separate the contribution of
relatively sparse fetal signal from the significant maternal background DNA, especially for recessive conditions such as SCD, alpha thalassemia, beta-thalassemia, CF, and SMA. Since traditional non-invasive
prenatal tests (NIPTs) are unable to screen for these recessively-inherited, single-gene conditions, diagnosing these disorders in