Company: BLLN
Filing Date: 2025-10-17
Form Type: S-1/A
Source: 0001193125-25-242632
Chunk: 229

Company: BillionToOne, Inc.
Filing Date: 2025-10-17
Form: S-1/A
Chunk 229
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 free survival (PFS) (HR=0.26) and OS (HR=0.18) than molecular non-responders.This was particularly remarkable given that the separation between responder and non-responderwas made within the first 90 days from baseline and was predictive of durable outcomes years in advance. Molecular responders at day 90 had a significantly improved median overall survival of over two years longer compared to patients who were found to be molecular non-responders.

| 70 |     | Ye, P. P., Viens, R., Shelburne, K. E., Langpap, et al. (2025). Molecular counting enables accurate and precise quantification of methylated ctDNA for tumor-naive cancer therapy response monitoring. Scientific 
 Reports, 15(1).                                                                                                                                                                                                   |

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Probability of Survival 100 75 50 25 0 Progression-Free Survival Log-rank P<0.0001 TMS Responder 250 500 750 1000 TMS Non-Responder Real-World Progression-Free Survival (Days) Probability of Survival 100 75 50 0 Overall Survival TMS Responder 25 Log-rank P<0.0001 TMS Non-Responder 0 250 500 750 1000 Overall Survival (Days) In addition to the aforementioned studies, we are further engaged in multiple prospective clinical validation studies spanning all solid tumor and therapy types. Our flagship NORTH study is a multi-site study with over 500 late-stage (stage III/IV) solid tumor cancer patients undergoing systemic therapies. We completed enrollment of the study in early 2025 and expect to complete sample and data collection by the end of 2025. We expect the initial results to be available in 2026. The NORTH study, along with other ongoing clinical studies, has the potential to generate sufficient clinical validity evidence for our MolDX submissions for Medicare coverage. We have also engaged with academic key opinion leaders in specific disease areas to provide more insights into the validity and utility of Northstar Response. In collaboration with University of Florida, we are conducting a 100-patientprospective study examining the clinical validity of Northstar Response focusing specifically on advanced gastrointestinal tumors. The study completed enrollment in March 2025. In collaboration with University of Miami, we are engaging in a clinical utility study to identify metastatic pancreatic ductal adenocarcinoma (mPDAC) patients who may benefit from ctDNA informed switching to second line chemotherapy based on early measures