Company: BLLN
Filing Date: 2025-06-20
Form Type: DRS
Source: 0000950123-25-006095
Chunk: 182

Company: BillionToOne, Inc.
Filing Date: 2025-06-20
Form: DRS
Chunk 182
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 the need for weekly intensive monitoring by a specialist, invasive procedures, and regular
blood draws, significantly reducing healthcare costs and her anxiety. This early identification through the UNITY Fetal Antigen NIPT provided critical information that guided the management of her pregnancy, ensuring it progressed without
complications related to alloimmunization. This case highlights the value of UNITY Fetal Antigen NIPT in streamlining prenatal care, minimizing unnecessary interventions and risks, and removing the fear of the unknown for the patient.

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Northstar patient case study: Northstar Select identified a new ESR1 mutation at a very low VAF in a metastatic breast cancer patient after signs of progression using Northstar Response

A patient was diagnosed with HR positive/HER2 negative metastatic breast
cancer and was heavily pretreated with anastrozole/ribociclib. During the patient’s routine follow-up three years later, the patient began Northstar Response monitoring, which indicated low baseline tumor
burden (TMS=63). Longitudinal monitoring revealed progressively increasing TMS scores with a 390-fold increase found five months afterwards (TMS=67,000).

Subsequent comprehensive profiling with Northstar Select revealed an ESR1 S463P mutation at a VAF of 0.09%, significantly below any competing therapy selection
test’s limit of detection, confirming the emergence of a resistance mutation to aromatase inhibitor therapy, a common challenge in treating HR-positive metastatic breast cancer. ESR1 S463P
mutations have an FDA-approved therapy, elacestrant, in this indication and provided this patient with an opportunity for treatment.

This case highlights how utilizing both Northstar Select and Response can help physicians first timely detect disease progression and identify more actionable mutations
at greater sensitivity, leading to earlier interventions and better treatment options for patients.

Northstar patient case study: Synergistic use of Northstar Select and Response demonstrated true precision oncology and personalized medicine

A patient with metastatic colorectal cancer, awaiting first-line treatment with pembrolizumab monotherapy, presented with a baseline
TMS of 210,000, indicating a very high tumor burden. After the first cycle of

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treatment, initial molecular response was observed and TMS decreased by over 50%, while therapy profiling with Northstar Select identified a druggable BRAF V600E mutation. Continuing with
monotherapy IO alone, TMS increased above 100,000, which prompted the provider to increase treatment intensity by adding chemotherapy.