Company: BLLN
Filing Date: 2025-08-11
Form Type: DRS/A
Source: 0000950123-25-007483
Chunk: 185

Company: BillionToOne, Inc.
Filing Date: 2025-08-11
Form: DRS/A
Chunk 185
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 our results of operations and performance” for more information regarding how these 
 total addressable markets are calculated, including material assumptions.                                                                                                                            |

| 43 |     | While we have not yet started development in this area, the research work that we have done for Northstar Response and MRD is a necessary precursor for early detection development. In particular, we believe that a                                 
 sensitive tissue-free MRD test, which we have already de-risked by the recent launch of an can be ultra-sensitive response monitoring assay (Northstar Response v2), which can detect tumor DNA in blood down to a limit of detection (LOD) of 0.01%, 
 technically equivalent to an early detection test for cancer. Both MRD and early-detection assays are designed to detect minute amounts of cancer DNA in blood (e.g., at levels of 0.01% or even lower). Given the trade off between specificity and  
 sensitivity (LOD), this higher specificity can be, in principle, achieved by changing the calling threshold. The difference with an early detection assay is that it is used in a broader population than MRD, therefore, it needs to have a higher   
 threshold for specificity. As a part of our Five-year strategic plan, we have included the necessary R&D funding for development of an early detection test that builds upon our earlier work. 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.                 |

133

The need for comprehensive prenatal testing solutions

In 2023, the U.S. Center for Disease Control and Prevention (CDC) reported approximately 3.7 million births in the United States, with about one in every 33 infants
affected by congenital anomalies. These anomalies can be due to chromosomal abnormalities or single gene inherited disorders. While existing cfDNA prenatal tests can detect chromosomal abnormalities, they are unable to screen for these inherited
single gene conditions, such as sickle cell disease, cystic fibrosis, alpha-thalassemia, beta-thalassemia and spinal muscular atrophy (SMA). These five recessive conditions are common, clinically actionable, and recommended for universal screening
by ACOG, with one in six pregnant individuals in the United States being a carrier for recessive conditions.

Inherited single gene conditions can be identified
through carrier screening of the parents,