Company: BLLN
Filing Date: 2025-10-07
Form Type: S-1
Source: 0001193125-25-233697
Chunk: 221

Company: BillionToOne, Inc.
Filing Date: 2025-10-07
Form: S-1
Chunk 221
---
ification to treatment monitoring with a Tumor Methylation Score (TMS). TMS is a quantitative metric that measures the extent of cancer-specific DNA methylation signal that is present in blood and reflects whether the tumor is growing or shrinking in a cancer patient when measured longitudinally. Using a DNA methylation-based approach in conjunction with our smNGS platform, we bring a new level of precision that can help determine molecular progression or therapy response at multiple time-points over the course of a patient’s treatment. Tumor Methylation ScoreTM Time Points Baseline Decrease Decrease Decrease Increase !Consider imaging sooner or ordering Northstar Select. Northstar Response is highly accurate at measuring changes in tumor burden across cancer types Our pan-cancerNorthstar Response assay has been analytically validated across more than 10 tumor types and has been evaluated in several clinical studies. In one study, we demonstrated that our assay could detect minute changes in cfDNA burden as small as 0.02% (e.g., an elevation of tumor fraction from 0.02% to 0.04%) demonstrating high sensitivity for a tissue-free, blood only test. The assay also achieves a coefficient of variation (CV) of less than 10% for a typical sample with 1% tumor fraction, which is at least two times lower than conventional tumor-naive, targeted-panel methods that measure VAF. It has demonstrated a strong correlation with clinical outcomes in patients with lung, colorectal, and pancreatic cancers.

| 66 |     | 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).                                                                                                                                                                                                                     |

156

1000 Tumor Methylation Score 0 750 500 250 Breast Analytical LOD is at 0.01% Colorectal 0% 0.1% 0.2% 0.3% 0.4% 0.5% 900 600 300 0 0% 0.1% 0.2% 0.3% 0.4% 0.5% Contrived Tumor Fraction

Northstar Response assay measures changes in tumor burden across 12+ cancer types Brain Breast Colorectal Endometrial Liver Lung Ovarian Pancreas Prostate Renal Sarcoma Stomach