Company: BLLN
Filing Date: 2025-09-17
Form Type: DRS/A
Source: 0001193125-25-206347
Chunk: 23

Company: BillionToOne, Inc.
Filing Date: 2025-09-17
Form: DRS/A
Chunk 23
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 tests. More recently, in 2024, the FDA passed a final rule to regulate LDTs as medical devices, but in 2025, a federal district court found that this rule exceeded FDA’s regulatory                
 authority, vacating the final rule. The FDA has decided not to appeal the decision. As a result, 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 Testing”                                                                                                                                                                                                                 |

| 15 |     | 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. |

| 16 |     | Riku, S., Herman, M., et al. (2022). Reflex single-gene non-invasive prenatal testing is associated with markedly better detection of fetuses affected with single-gene recessive disorders at lower cost. Journal of 
 Medical Economics.                                                                                                                                                                                                    |

7

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. 17 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