United States securities and exchange commission logo

                            August 27, 2020

       Norbert Bischofberger, Ph.D.
       President and Chief Executive Officer
       Kronos Bio, Inc.
       1300 So. El Camino Real, Suite 300
       San Mateo, CA 94402

                                                        Re: Kronos Bio, Inc.
                                                            Draft Registration
Statement on Form S-1
                                                            Submitted July 31,
                                                            CIK No. 0001741830

       Dear Dr. Bischofberger:

              We have reviewed your draft registration statement and have the
following comments. In
       some of our comments, we may ask you to provide us with information so
we may better
       understand your disclosure.

              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 our comments apply to your facts and
circumstances or do not
       believe an amendment is appropriate, please tell us why in your

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

       Draft Registration Statement on Form S-1 submitted July 31, 2020

       Prospectus Summary
       Overview, page 1

   1.                                                   We note several
discovery programs included in your pipeline table. Given the early-stage
                                                        development of these
programs, please provide us with your analysis as to why you
                                                        believe each of these
programs is sufficiently material to your business to warrant
                                                        inclusion in your
pipeline table.
 Norbert Bischofberger, Ph.D.
Kronos Bio,LastNameNorbert   Bischofberger, Ph.D.
August 27, NameKronos
           2020         Bio, Inc.
Page 2 27, 2020 Page 2
FirstName LastName
2.       Please revise your Pipeline table to present Phase 1 and Phase 2
trials in separate columns
         or provide us with your analysis as to why you believe the current
presentation is
         appropriate. Please revise the heading in the sixth column to read
"Phase 3 Trial" instead
         of "Registrational Trial."
3.       We note your disclosure on page 3 that you are currently in the
process of completing
         IND-enabling studies with respect to KB-0742. However, your pipeline
table suggests that
         you have already completed the IND-enabling studies. Please shorten
the arrow for KB-
         0742 as appropriate to illustrate how far along you are in the
IND-enabling studies.

SYK Program: ENTO and LANRA, page 2

4.       Please revise to limit the discussion of clinical trial results in
your prospectus summary to
         the endpoints of the trial and whether they were met. For example, we
note you
         characterize your Phase 1b/2 clinical trial results as revealing
"encouraging complete
         response (CR) rates and overall survival."
5.       We note that, following feedback from regulatory agencies, you plan to
directly proceed
         to a registrational Phase 2/3 clinical trial of ENTO in combination
with IC. Please expand
         your disclosure to state that you have not yet discussed with the FDA
the potential of your
         Phase 2/3 clinical trial to serve as a registrational trial, as you
state on page 20.
Risks Associated with our Business, page 5

6.       Please revise your bullet point regarding companion diagnostics to
explain that they will
         need to be approved by the FDA as medical devices, as you explain on
page 24.
Implications of Being an Emerging Growth Company, page 7

7.       Please provide us with 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, present to
         potential investors in reliance on Section 5(d) of the Securities Act,
whether or not they
         retain copies of the communications.
Management's Discussion and Analysis of Financial Condition and Results of
Critical Accounting Policies and Use of Estimates
Determination of Fair Value of Common Stock, page 100

8.       Once you have an estimated offering price or range, please explain to
us how you
         determined the fair value of the common stock underlying your equity
issuances and the
         reasons for any differences between the recent valuations of your
common stock leading
         up to the IPO and the estimated offering price. This information will
help facilitate our
         review of your accounting for equity issuances including stock
compensation and
         beneficial conversion features.
 Norbert Bischofberger, Ph.D.
Kronos Bio,LastNameNorbert   Bischofberger, Ph.D.
August 27, NameKronos
           2020         Bio, Inc.
Page 3 27, 2020 Page 3
FirstName LastName
Prior Development of ENTO, page 114

9.       We note your reference on page 115 to adverse events Grade 3 or
greater. Please revise to
         disclose the definition of an adverse event Grade 3 or greater. To the
extent a serious
         adverse event has occurred, please clearly disclose the event and the
number of affected
10.      Please remove your statement that the "safety results were considered
acceptable" as
         safety is a determinations that is solely within the authority of the
FDA or similar foreign
         regulators. You may state that your product candidate is well
tolerated, if true.
Therapeutic Rationale and Clinical Data in HOX/MEIS-High AML, page 115

11.      Please expand your disclosure to provide a brief narrative discussion
of the data presented
         in the graphs at the top of page 116.
12.      We note your disclosure that "sensitivity to ENTO correlated, with
high statistical
         significance, with the presence of NPM1 mutations alone or in
combination with FLT3 or
         DNMT3A mutations." Please disclose the p-value used to measure
statistical significance.
         Please also label the horizontal axis with the appropriate unit of
measure in the graphic at
         the top of page 117.
13.      We note your disclosure of CR rates for patients enrolled in Arm A.
Please clarify
         whether CR was measured in MLL-r subjects and NPM1 mutation subjects
in Arm B. If
         so, please revise to include a discussion of such results. Please
clarify whether the data
         observed in Arm B and C of the Phase 1b/2 clinical trial was
considered statistically
14.      Please disclose the basis for your statement that "the high HOX/MEIS
patients also
         experienced superior overall survival."
CDK9 Inhibitor Product Candidate: KB-0742, page 119

15.      We note your disclosure that you believe KB-0742 may possess
         selectivity for CDK9. This term suggests that the product candidate is
effective and likely
         to be approved. Please delete these references throughout your
registration statement. If
         your use of this term was intended to convey your belief that the
product is based on a
         novel technology or approach and/or is further along in the
development process, you may
         discuss how your technology differs from technology used by
competitors and, if
         applicable, that you are not aware of competing products that are
further along in the
         development process. Statements such as these should be accompanied by
         language that the statements are not intended to give any indication
that the product
         candidate has been proven effective or that it will receive regulatory
 Norbert Bischofberger, Ph.D.
Kronos Bio,LastNameNorbert   Bischofberger, Ph.D.
August 27, NameKronos
           2020         Bio, Inc.
Page 4 27, 2020 Page 4
FirstName LastName
Intellectual Property, page 128

16.      We note your disclosure that your ENTO and LARNA patent portfolio
includes additional
         foreign patents and patent applications. Please disclose the foreign
countries in which you
         have foreign patents, the type of patents and the term.
Family Relationships and Other Arrangements, page 147

17.      We note that two directors have the same surname. If applicable, state
the nature of any
         family relationship between any director, executive officer, or person
nominated or chosen
         to become a director or executive officer. See Item 401(d) of
Regulation S-K.
       You may contact Sasha Parikh at 202-551-3627 or Julie Sherman at
202-551-3640 if you
have questions regarding comments on the financial statements and related
matters. Please
contact Deanna Virginio at 202-551-4530 or Tim Buchmiller at 202-551-3635 with
any other


                                                              Division of
Corporation Finance
                                                              Office of Life
cc:      Charles J. Bair, Esq.