# EDGAR Filing Document

**Accession Number:** 0002070849
**File Stem:** 0000000000-25-007567
**Filing Date:** 2025-7
**Character Count:** 28838
**Document Hash:** f47b614ff1dbf31da045ee506f65690c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000000000-25-007567.hdr.sgml**: 20260508

**ACCESSION NUMBER**: 0000000000-25-007567

**CONFORMED SUBMISSION TYPE**: UPLOAD

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20250717

**FILED FOR**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BillionToOne, Inc.
- **CENTRAL INDEX KEY:** 0002070849
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-MEDICAL LABORATORIES [8071]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 811082020
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** UPLOAD
- **SEC FILE NUMBER:** 377-08131

**BUSINESS ADDRESS:**
- **STREET 1:** 1035 O'BRIEN DRIVE
- **CITY:** MENLO PARK
- **STATE:** CA
- **BUSINESS PHONE:** 650-460-2551

**MAIL ADDRESS:**
- **STREET 1:** 1035 O'BRIEN DRIVE
- **CITY:** MENLO PARK
- **STATE:** CA
- **ZIP:** 94025
**PUBLIC REFERENCE ACCESSION NUMBER**: 0000950123-25-006095

## Text-Extract

```

                                                            July 17, 2025

Oguzhan Atay
Chief Executive Officer
BillionToOne, Inc.
1035 O   Brien Drive
Menlo Park, CA 94025

       Re: BillionToOne, Inc.
           Draft Registration Statement on Form S-1
           Submitted June 20, 2025
           CIK No. 0002070849
Dear Oguzhan Atay:

       We have reviewed your draft registration statement and have the
following comments.

       Please respond to this letter by providing the requested information and
either
submitting an amended draft registration statement or publicly filing your
registration
statement on EDGAR. If you do not believe a comment applies to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why
in your
response.

      After reviewing the information you provide in response to this letter
and your
amended draft registration statement or filed registration statement, we may
have additional
comments.

Draft Registration Statement on Form S-1
Glossary, page ii

1.     Please revise the terms included in the glossary to include a brief
description of the
       relevance of the terms to your operations. As an example only, we note
that you
       define cfDNA as "[c]ell free DNA released from tumor cells". Please
briefly explain,
       or include a cross reference to your disclosures on pages 4 and 117, the
relevance of
       cfDNA for modern precision medicine. Likewise, please explain the
relevance
       of polymerase chain reactions, and define methylation and sample
accessioning.
 July 17, 2025
Page 2
Prospectus Summary
Overview, page 2

2.     We note your disclosure on page 48 that "[y]ou currently offer a number
of genetic
       tests, each of which is a laboratory developed test (LDT)". Please
revise your
       summary to prominently note, if true, that all of your current products
are LDTs,
       which are not subject to FDA regulatory approvals.
3.     We note your disclosure that "[yo]ur superior technology platform has
enabled [you]
       to build category-defining prenatal and oncology products," and that
"[you] have
       established [y]ourselves as a leader in the prenatal testing market."
Please revise to
       discuss the metric upon which you base this statement that your
technology platform
       is superior and that you are a leader in the prenatal testing market.
For example,
       explain whether you are measuring by revenue or market share, or a
combination of
       various metrics. We refer to your disclosure on page 128 that "[you] are
the second
       largest prenatal genetics laboratory in the United States by revenue."
4.     We note your disclosure that you estimate "an annual market opportunity
of over
       $100 billion in the United States alone," and that "[w]hile [y]our
current products
       already address an estimated annual market opportunity of over $20
billion in the
       United States, [you] believe that [y]our R&D pipeline could eventually
expand this
       annual addressable market to over $100 billion." We also note your
disclosure on
       page 97 that the $100 billion figure is comprised of an addressable
market of $1
       billion for carrier screening, $1.5 billion for aneuploidy testing, $6
billion for therapy
       selection, over $15 billion for therapy monitoring, over $30 billion for
minimal
       residual disease and over $50 billion for early detection. Please revise
to provide a
       detailed discussion of how you calculate each of these addressable
market figures, and
       discuss any material assumptions underlying these calculations, such as
the price at
       which you are able to sell your products and the available patient
population. Please
       also revise to clarify why you include products that have not yet been
launched in
       your total addressable market calculation. In your discussion, please
also explain the
       basis for your disclosure on page 97 that "[you] estimate the 14-gene
version of
       UNITY Fetal Risk Screen will expand the serviceable addressable market
for UNITY
       by 70%" and on page 128 that "[you] estimate that the [oncology] market
is less than
       20% penetrated today by all molecular diagnostics companies."
5.     We note your disclosure on page 37 that "[you] have incurred significant
losses since
       [y]our inception. For the years ended December 31, 2023 and 2024, [you]
incurred net
       losses of $82.7 million and $41.6 million, respectively. As of December
31, 2024,
       [you] had an accumulated deficit of $282.2 million." Please revise your
prospectus
       summary to discuss your significant losses and accumulated deficit for
the periods
       presented.
Our four pillars of differentiation, page 3

6.     We note your disclosure that "[yo]ur revolutionary platform achieves
absolute
       quantification at the single molecule level, enabling [you] to: (i)
accurately quantify
       genetic targets by eliminating biases introduced from next-generation
sequencing
       (NGS); (ii) precisely measure and analyze intermediate biochemical
reactions to
       optimize the performance of [y]our assays; and (iii) reduce sequencing
costs by
 July 17, 2025
Page 3

       obtaining a higher quality signal at each genomic location analyzed."
Please clarify
       these biases that are eliminated from NGS, and explain how a higher
quality signal
       can reduce sequencing costs.
Our Superior Efficiency, page 4

7.     We note your disclosure which describes your limited accumulated deficit
as of
       December 31, 2024 being a small fraction of the losses incurred by some
of your
       competitors. Please remove the comparative disclosure or revise to
provide
       substantiation for the statement.
Our solution and suite of products, page 6

8.     We note your disclosure that "[you] intend to expand [y]our oncology
test offerings
       into testing of earlier stage cancer patients, including through MRD
testing and
       potentially for early cancer detection." Please revise to provide a more
detailed
       discussion of the current stage of development of each of your product
candidates, and
       note the expected timing for their commercialization. Please also
disclose whether any
       of the product candidates are expected to require FDA regulatory
approvals.
Prenatal products, page 6

9.     We note your graphic reflecting a brief description of your prenatal
products. Please
       revise to briefly describe the Aneuploidy NIPT + RhD NIPT product.
Risk Factors
If the government and other third-party payors fail to provide coverage and
adequate payment
for our existing and future tests, our..., page 20

10.    We note your disclosure that "[t]hird-party reimbursement for [y]our
tests represents a
       significant portion of [y]our revenue, and [you] expect government and
commercial
       third-party payors to continue to be [y]our primary source of payments."
We also note
       your disclosure that "third-party payor revenue for [y]our
testing...constitutes the large
       majority of [y]our revenue." Please disclose the percentage of your
revenue
       represented by third-party reimbursements for the financial periods
presented.
11.    We note your disclosure on page 21 that "[w]hile ACOG guidelines
generally
       acknowledge that NIPT is the most sensitive screening option for, and/or
are generally
       supportive of NIPT in, average-risk pregnancies in addition to high-risk
       pregnancies...not all of [y]our current tests are covered under practice
guidelines, and
       [you] cannot predict whether [y]our future tests will be covered by such
guidelines."
       Please clarify which of your current tests are not covered under
practice guidelines.
Our revenue may be adversely affected if we are unable to successfully obtain
reimbursement
from the Medicare program and state Medicaid..., page 22

12.    We note your disclosure that "[i]t is estimated that nearly half of all
births in the
       United States are to state Medicaid program beneficiaries. Each state
s Medicaid
       program has its own coverage determinations related to [y]our testing,
and several
       state Medicaid programs do not provide coverage for [y]our testing."
Please clarify
       which state Medicaid programs do not provide coverage for your testing.
 July 17, 2025
Page 4

We and the third parties with whom we work are subject to stringent and
evolving U.S. and
foreign laws, regulations, and rules..., page 50

13.    You disclose that your employees and personnel may use generative
artificial
       intelligence and machine learning to perform their work and that "[you]
use AI/ML to
       assist [you] in making certain decisions, which is regulated by certain
privacy laws."
       Please revise to further discuss the decisions for which you currently
use AI/ML.
Use of proceeds, page 79

14.    We note your disclosure that "[you] currently intend to use the net
proceeds from this
       offering, together with [y]our existing cash and cash equivalents, for
working capital
       and other general corporate purposes, including to fund [y]our growth,
research and
       development initiatives, technology development, working capital, and
operating
       expenses." Please revise to further discuss the use of the proceeds to
fund your
       growth, research and development initiatives, and technology
development. Refer to
       Item 504 of Regulation S-K.
Management's discussion and analysis of financial condition and results of
operations
Our business model and key performance metrics, page 91

15.    Please revise to define "Blended ASP," and explain how it is calculated.
Key factors affecting our results of operations and performance, page 92

16.    We note your disclosure on page 93 that "[o]nce an ordering provider
within a clinic
       first starts to use [y]our tests, [you] often see expansion of [y]our
tests to other
       providers within the clinic. [You] believe that [y]our unique product
offerings and
       exceptional end-to-end service drive this adoption. [Yo]ur cohort
analysis indicates
       that the net test retention, as defined by the total number of tests
that are received
       from a cohort of clinics first onboarded in a particular quarter, even
after accounting
       for any account or provider churn, is over 100% after a year for the
majority of
       quarterly cohorts." Please revise to define "cohort" and further discuss
your cohort
       analysis, including an explanation of how it demonstrated net test
retention.
17.    We note your disclosure on page 93 that "[you] believe [y]our tests
provide far higher
       value than the Medicare Clinical Laboratory Fee Schedule (CLFS) rates
established
       for [y]our tests. For instance, in a peer-reviewed publication, the
break-even price for
       sgNIPT was estimated between $2,336 (healthcare cost-neutral price with
better
       outcomes) and $7,233 (equivalent cost of identifying one affected
pregnancy vs.
       sequential carrier screening). In comparison, the CLFS price for [y]our
sgNIPT was
       established at $879.47." Please revise to disclose the peer-reviewed
publication, and
       further explain why you estimated that the break-even price for sgNIPT
should be
       based on the healthcare cost-neutral price with better outcomes and/or
the
       equivalent cost of identifying one affected pregnancy vs. sequential
carrier screening.
Key components of results of operations, page 97

18.    We note your disclosure that "[t]he majority of [y]our revenue is
derived from sales of
       [y]our prenatal test, UNITY, and a smaller portion is derived from sales
of [y]our
       liquid biopsy oncology tests, Northstar," and that "[r]evenue is
comprised of revenue
 July 17, 2025
Page 5

       from [y]our sales of [y]our prenatal and oncology tests and [y]our
strategic
       partnership with Johnson & Johnson." Please revise to disclose the
percentage of your
       revenue derived from your prenatal tests as compared to your oncology
tests, and your
       strategic partnership with Johnson & Johnson.
Comparison of years ended December 31, 2023 and 2024
Revenue and gross margin, page 101

19.    With regard to your 113% increase in revenue and your increase in gross
margin from
       24% to 53%, please address the following:
           Explain the reasons underlying the increase in tests processed and
your increase in
          average selling price per test.
           To the extent material, ensure you address how changes in payor mix
impacted
          your average selling price.
           Expand your disclosures to explain how the increase in revenue
impacted gross
          margin. To the extent that it relates to your composition of fixed
versus variable
          costs, provide a discussion of the degree to which cost of revenue is
fixed versus
          variable.
           Address whether there is any related trend information underlying
your revenue
          and gross margin results. Refer to Item 303(b)(2)(ii) of Regulation
S-K.
Liquidity and capital resources
Oberland Capital note purchase agreement, page 106

20.    Please expand your disclosures to address the following:
           Expand your disclosures to quantify the royalty participation
payments and clarify
           when they become applicable and payable. In this regard, we note you
earned
           more than $100 million in revenue during the year ended December 31,
2024.
           Quantify the internal rate of return Oberland will earn over the
course of the loan.
           Clarify whether or not you are in compliance with each material
financial
           covenant.
       See Sections I.D and IV.C of the SEC Interpretive Release No. 33-8350.
Business
Our Product Portfolio, page 131

21.    We note that you refer to various studies, publications and
collaborations throughout
       this section. As an example only, we note your disclosure on page 130
that
       "[you] have demonstrated the analytical and clinical validity, as well
as the clinical
       utility, of [y]our Northstar Select test through rigorous reviews," and
that "[i]n
       validation studies, Northstar Response showed a consistent ability to
detect
       quantitative changes in tumor fraction across more than 10 different
cancer types, in
       some cases as much as six months earlier than indicated by imaging
scans. Northstar
       Response has been analytically and clinically validated in three
peer-reviewed
       publications, including in collaborations with the University of
California, San Diego
       and the University of Florida." We also note your disclosure on page 143
that
       "[you] have extensive publications on [y]our smNGS platform and
products". Please
       revise to discuss each of these studies, publications and collaborations
in further
 July 17, 2025
Page 6

       detail. In particular, please disclose the date(s) and location(s) of
the studies and trials,
       the sponsor(s), the number of participants, including how participants
were selected,
       the results of the studies and trials, including how results were
measured, key
       assumptions, any serious adverse events, and whether statistical
significance was
       demonstrated, including supporting p-values, as appropriate. Please also
disclose
       whether any of the parties involved, including the sponsors in the
studies and/or trials,
       are affiliates or partners of BillionToOne. Consider providing the
disclosures in
       tabular format for ease of reference.
22.    We note your disclosure throughout this section referring to the
demonstrated
       analytical and clinical validity of your products. For example, we note
your disclosure
       on page 130 that "[you] have demonstrated the analytical and clinical
validity, as well
       as the clinical utility, of [y]our Northstar Select test through
rigorous reviews." You
       also state on page 134 that the "UNITY Fetal Risk Screen   s accuracy
has been
       validated in multiple peer-reviewed studies." Please revise to define
analytical and
       clinical validity and clarify how you have demonstrated the validity and
utility of your
       products without receipt of FDA or equivalent regulatory approvals.
Safety and
       efficacy are determinations that are solely within the authority of FDA
or similar
       foreign regulators. Where applicable, please clarify that certain of
your products have
       not been approved by the FDA or or similar foreign regulators and remove
any
       statements of safety and efficacy for such products. You may present
clinical trial end
       points and objective data resulting from trials or studies without
concluding efficacy.
23.    Please revise the table illustrating the UNITY Fetal Risk Screen's
testing menu to
       further explain the two columns included in the table.
UNITY Fetal Antigen CTA NIPT, page 136

24.    We note your disclosure that "[i]n December 2023, [you] announced a
global
       partnership with Johnson & Johnson to provide [y]our UNITY Fetal Antigen
clinical
       trial assay (CTA) in their AZALEA Phase 3 clinical trial of nipocalimab
in
       pregnancies at risk for severe HDFN", and that "[i]n April 2023, the FDA
granted an
       Investigational Device Exemption (IDE) for the assays    use in the
trial." Please revise
       to disclose the material terms of your agreement(s) with Johnson &
Johnson, and file
       any such agreement(s) as exhibits to your registration statement or
provide your
       analysis as to why you are not required to file any such agreement(s).
Refer to Item
       601(b)(10) of Regulation S-K. Please also revise to discuss the timing
for any FDA
       submission and/or approvals required in connection with this Phase 3
trial, including
       the granting of a companion diagnostics indication.
Patient Case Studies, page 144

25.    We note your presentation of "patient case studies." Please revise to
provide a brief
       description explaining why you are highlighting the case studies and
whether the
       results of the highlighted patients are representative of your patients
to provide
       context for investors.
 July 17, 2025
Page 7
Intellectual Property, page 151

26.    Please expand your disclosure relating to your patent portfolio and
identify for each
       material patent and patent application, as applicable, the scope and
technology of each
       such patent or patent application, the type of patent protection,
jurisdiction, and
       expiration dates. Consider adding tabular disclosure in addition to the
narrative for
       ease of use.
Certain relationships and related party transactions, page 185

27.    Please revise this section to include the rate(s) at which your series D
redeemable
       convertible preferred stock, series C-1 redeemable convertible preferred
stock, and
       series C redeemable convertible preferred stock will convert into class
A common
       stock.
Notes to Financial Statements
(2) Summary of Significant Accounting Policies
Revenue, page F-12

28.    We note you present disaggregated revenue by Oncology, Prenatal and
Clinical trial
       support services. Please tell us your consideration of presenting
disaggregated revenue
       by third-payor groups, patients, and commercial payors. See ASC
606-10-50-5
       through 7.
10. Long-term Debt, page F-27

29.    As disclosed on page F-28, we note that the Oberland Note Purchase
Agreement
       requires you to maintain certain trailing six-month net revenue levels
and trailing six-
       month gross margin ratios, and other covenants. We also note, as
indicated on page
       106 that this agreement also has a royalty participation. Please expand
your
       disclosures to provide the schedule of such net revenue levels, quantify
the royalty
       rate and clarify whether or not you were in compliance with each
material covenant as
       of the latest balance sheet presented.
General

30.    Refer to the gatefold graphic with key metrics including annualized
revenue run-rate
       and year-over-year revenue growth. Please revise to describe how you
calculate
       annualized revenue run-rate, year-over-year revenue growth and
profitability. We may
       have additional comments upon review of the complete graphic populated
with the
       data. Please also define LTM in the graphics and ensure that your
filing, including the
       graphics with text and letter from your co-founder and CEO, are
text-searchable.
31.    You have included an estimate for your U.S. annual market opportunity in
the
       gatefold graphic. Please revise to provide a balanced presentation by
briefly
       describing the material assumptions.
32.    We note your disclosure on page 27 that "[you] rely on a limited number
of suppliers,
       or, in some cases, sole- or single-source suppliers, for certain
sequencers, reagents,
       blood tubes and other equipment, instruments and materials that [you]
use in [y]our
       laboratory operations;" on page 94 that "[you] prioritize entering into
contracts with
       major commercial insurance companies and other third-party payors;" and
on page
 July 17, 2025
Page 8

       148 that "[o]utside of [y]our direct sales efforts in oncology, [you]
have signed
       collaboration agreements with a select number of pharmaceutical
companies and
       institutions to support clinical development of novel precision oncology
therapeutics."
       Please revise to further discuss these suppliers and collaborations,
disclose the terms
       of any material contracts, other than contracts entered into in the
ordinary course of
       business, and file any such material contracts as exhibits to your
registration
       statement. Refer to Item 601(b)(10) of Regulation S-K.
33.    We note that you make various statements throughout the registration
statement
       regarding your field and the performance of your products including, but
not limited
       to, the following:

             Gatefold Graphic 3: "Cancers at this low level of VAF are often
missed by other
           cancer tests."
             Letter from Our Co-Founder & CEO: "While others in our industry
poured
           hundreds of millions of dollars into fully automated labs that
locked down their
           assays and made further improvements hugely expensive, we identified
           bottlenecks systematically, automating our facilities step-by-step."
             Page 2: "Our products reveal actionable insights from a simple
blood draw that
           are fundamentally changing how diseases are diagnosed and treated,
leading to a
           paradigm shift in personalized medicine;" "Our Northstar Select test
is used to
           guide therapy selection and has been shown to detect over 50% more
actionable
           solid tumor mutations than conventional liquid biopsies."
             Page 3: "Moreover, we believe our design-based R&D approach allows
us to
           harness this technology and accurately predict the clinical
performance of a novel
           assay before testing a single patient sample, which we believe
accelerates time-to-
           market and significantly improves our commercial launch success
rate."
             Page 5: "Conventional genetic analysis techniques, such as NGS and
digital
           droplet PCR (ddPCR), typically sacrifice either sensitivity or
multiplexing, i.e.,
           ability to interrogate many genomic loci at the same time, forcing
compromises in
           clinical utility."
             Page 6: "However, studies estimate that fewer than half of fathers
complete the
           recommended screening due to barriers related to cost, availability,
and
           willingness. As a result, approximately 58% of pregnancies affected
by these
           recessive conditions are undetected by traditional screening
workflows."
             Page 122: "For a pregnant patient, typically only 2% to 15% of the
cfDNA in a
           standard blood draw is of fetal origin. For a cancer patient,
approximately
           between 0.01% to 1% of the cfDNA is derived from a tumor, depending
on cancer
           stage. Notably, there is often only one cfDNA molecule present at
any given
           genomic location associated with disease, even in advanced cancer
patients"; "The
           scarcity of cfDNA necessitates amplification by a factor of millions
before it can
           be sequenced."
             Page 127: "AI can reduce medical chart extraction costs by over
90%, enabling
           the synthesis of smNGS molecular data and AI-extracted longitudinal
clinical data
           for each patient."
 July 17, 2025
Page 9

             Page 135: "smNGS enables >95% sensitivity and >99.9% specificity,
which
           results in an industry-leading PPV of 80% in average risk
pregnancies. More than
           70% of UNITY Aneuploidy orders now include 22q11.2 optional add-
           on testing;" "Since launching, UNITY Fetal RhD NIPT has been ordered
for over
           150,000 patients, with data published in peer-reviewed studies
demonstrating
           100% concordance with neonatal outcomes and sensitivity/specificity
of >99.9%."
             Page 138: "The amount of a particular SNV or alteration compared
to normal
           DNA detected by liquid biopsy tests are measured as a variant allele
fraction
           (VAF), with over half of all treatable alterations occurring at a
VAF <0.5%, and
           approximately one fourth occurring at <0.2%;" "First generation
liquid biopsy
           tests have an LOD that ranges between 0.25%   0.50%, whereas
Northstar Select
           has demonstrated an LOD of 0.15%, representing a 2-fold higher
sensitivity than
           these other assays. Since most treatable mutations occur at very low
VAFs and
           studies have shown that even mutations found at <0.20% VAF respond
to therapy,
           Northstar Select uncovers more treatment options for patients."
             Page 143: "We believe there is a significant market opportunity
for tumor-naive
           MRD assays, especially in certain cancer types such as lung, where
the QC failure
           rates for tissue testing can exceed 40%."

       Please revise your disclosure throughout the prospectus to provide the
basis for these
       statements. Please also ensure you disclose any relevant metrics on
which these
       statements are based and any material assumptions.
34.    Please provide us with supplemental copies of all written
communications, as defined
       in Rule 405 under the Securities Act, that you, or anyone authorized to
do so on your
       behalf, have presented or expect to present to potential investors in
reliance on Section
       5(d) of the Securities Act, whether or not you retained, or intend to
retain, copies of
       those communications.
       Please contact Tayyaba Shafique at 202-551-2110 or Jeanne Baker at
202-551-3691 if
you have questions regarding comments on the financial statements and related
matters. Please contact Juan Grana at 202-551-6034 or Lauren Nguyen at
202-551-3642 with
any other questions.

                                                             Sincerely,

                                                             Division of
Corporation Finance
                                                             Office of
Industrial Applications and
                                                             Services
cc:   Elena M. Vespoli, Esq.

```

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