Company: BLLN
Filing Date: 2025-10-17
Form Type: S-1/A
Source: 0001193125-25-242632
Chunk: 214

Company: BillionToOne, Inc.
Filing Date: 2025-10-17
Form: S-1/A
Chunk 214
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 validation through our large flagship study: NORTH (Northstar Oncology Response Monitoring Test Hallmark). NORTH is a multi-site study with over 500 Stage III and IV solid tumor cancer patients undergoing systemic therapies.
Enrollment of the study was completed in early 2025 and we expect to complete sample and data collection by the end of 2025, with results available in 2026. The NORTH study, along with other ongoing clinical studies, have the potential to generate
sufficient clinical validity evidence for our MolDX submissions for Medicare coverage.

Beyond late-stage cancer testing, we recognize there is a significant need
for more powerful early-stage cancer testing. We are developing additional oncology products for these cancer patients, including MRD testing. Current standard of 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.

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Our Product Portfolio 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 approximately 508,000 smNGS-based tests in the last 12 months ended June 30, 2025, with significant room