Company: BLLN
Filing Date: 2025-10-17
Form Type: S-1/A
Source: 0001193125-25-242632
Chunk: 24

Company: BillionToOne, Inc.
Filing Date: 2025-10-17
Form: S-1/A
Chunk 24
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 our molecular diagnostic products are not 
 currently subject to FDA approval requirements. While LDTs do not require FDA approval currently, they may be subject to state regulatory requirements. For example, many of our LDTs are approved by the New York’s Clinical Laboratory Evaluation     
 Program (CLEP), which reviews LDTs for accuracy. See “Risk Factors—Risks related to legal and regulatory matters—Our tests are currently marketed as LDTs, and future changes in FDA enforcement of LDTs could subject our operations                   
 to much more significant regulatory requirements.” See also “Business—Government regulations—New York laboratory licensing.”                                                                                                                            |

| 16 |     | While we have not yet started development in this area, the research work for MRD and our Select and Response tests is a necessary precusor to early detection development. We also believe that there is significant                           
 potential for our smNGS platform to accommodate products in this area. We believe the molecular information provided by our tests can assist in predicting the diagnostic pathway that can confirm the presence and tissue of origin of cancer. |

7

approximately 58% of pregnancies affected by these recessive conditions are undetected by traditional screening workflows. 17 Our UNITY Complete Fetal Risk Screen directly addressed these challenges and is the first test that uses cfDNA to provide precise fetal risk assessments for recessive conditions without requiring a paternal sample. In addition, it reports fetal aneuploidy and 22q11.2 microdeletion, enabling complete genetic insights from a single maternal blood draw. We estimate the prenatal market represents an annual opportunity of over $2.5 billion in the United States. 18 Oncology products ONCOLOGY Select: Cancer treatment selection Response: Cancer treatment response monitoring Minimum Residual Disease (MRD): Cancer detection & surveillance post-surgery In Development Non-invasiveliquid biopsy tests are a rapidly growing approach to detect and measure tumor DNA, driven by the increasing focus on molecular-targeted cancer treatments. However, current imaging and conventional liquid biopsy approaches present critical shortcomings, including missed actionable mutations and delays in detecting treatment response and progression. In 2023, we entered the oncology market with two complementary products that leverage our smNGS platform to address these unmet needs. Northstar Select, our ultrasensitive liquid biopsy test, provides insights into appropriate therapies for stage III or IV cancer patients. In a head-to-headstudy presented at the American Society of Clinical Oncology (ASCO) annual meeting in 2024, our test demonstrated superior