United States securities and exchange commission logo

                               December 7, 2020

       Steven D. Harr, M.D.
       President and Chief Executive Officer
       Sana Biotechnology, Inc.
       188 East Blaine Street, Suite 400
       Seattle, Washington 98102

                                                        Re: Sana Biotechnology,
                                                            Draft Registration
Statement on Form S-1
                                                            Submitted November
10, 2020
                                                            CIK No. 0001770121

       Dear Dr. Harr:

              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

       Prospectus Summary
       Overview, page 1

   1.                                                   Please tell us the
basis for your belief stated in the first paragraph that engineered cells
                                                        will have a therapeutic
potential that will be "at least as disruptive" as biologics. Please
                                                        also tell us why you
believe it is appropriate to cite the amount of global revenues for all
                                                        branded biologic drugs
when you do not have any product candidates in development
                                                        beyond the preclinical
stage and which address only certain indications.
   2.                                                   We note your disclosure
on page 1 that you "expect to file multiple INDs per year." Given
                                                        the unpredictability of
drug development, please remove this statement and a similar
 Steven D. Harr, M.D.
FirstName LastNameSteven
Sana Biotechnology, Inc. D. Harr, M.D.
December   NameSana
             2020    Biotechnology, Inc.
Page 2    7, 2020 Page 2
FirstName LastName
         statement in the Business section as such statements are speculative.
3.       We note your disclosure on page 1 and in the Business section that you
have shown that
         you can specifically target numerous cell surface receptors that, when
combined with
         delivery vehicles to form fusosomes, allow cell-specific delivery
across multiple different
         cell types. Please revise the second paragraph of the Summary and the
statements in the
         Business section to clarify that you have not conducted clinical
development efforts to
4.       Please revise your pipeline table on page 2 to include a separate
column for
         preclinical, Phase 1, Phase 2 and Phase 3 and to provide the
indications that you are
         actually pursuing as opposed to the "potential" indications. It
appears that you have
         included every in-house program in your pipeline table. Please explain
to us why each
         program is sufficiently material to your business to warrant inclusion
in your pipeline
         table or revise your table as appropriate.
Our in vivo Cell Engineering Platform and Programs, page 4

5.       We note your disclosure here and in the Business section that your
fusogen technology
         should allow you to rapidly create multiple therapies targeting a
variety of diseases with
         each successful fusogen and accelerate development of subsequent
therapies targeting that
         same cell type. Please revise these statements and any similar
statements to remove any
         implication that you will be able to accelerate the development of
your product
         candidates. Please also revise the statements here and in the Business
section that success
         with any initial therapy targeting a given cell type meaningfully
"de-risks" development of
         subsequent therapies targeting that same cell type and any similar
statements that imply
         that you will be successful in mitigating the risk associated with
drug development.
6.       We note your disclosure that your preclinical data demonstrate that
you can make an
         "effective" CAR T cell in vivo with a single intravenous injection.
Efficacy is
         a determination that is solely within the authority of the FDA or
similar foreign regulators.
         You may present clinical trial end points and objective data resulting
from trials without
         concluding efficacy. Please revise this statement accordingly.
Risks Associated with Our Business, page 11

7.       Please expand the second to last bullet point in this section or add
another bullet point to
         address the risks associated with the licensed technology and the
related agreements you
         have with Harvard, UCSF, Washington University, Cobalt, Oscine and
Cytocardia as
         discussed in the risk factor on page 61.
Implications of Being an Emerging Growth Company, page 12

8.       Please supplementally 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
 Steven D. Harr, M.D.
Sana Biotechnology, Inc.
December 7, 2020
Page 3
         not they retain copies of the communications.
Risk Factors, page 18

9.       Given the length of your risk factor section, please revise to comply
with Regulation S-K
         Item 105 by relocating risks that could generically apply to any
registrant or offering to
         the end of the section under the caption    General Risk Factors.
Risks Related to Intellectual Property and Information Technology
We may be dependent on intellectual property licensed or sublicensed to us
from..., page 66

10.      We note your disclosure that government agencies have provided
assistance in connection
         with the development of certain intellectual property rights owned by
or licensed to you,
         and these government agencies may have retained rights in the
intellectual property.
         Please revise this risk factor to identify the intellectual property
or technologies and what
         rights in the intellectual property the government agencies have
Use of Proceeds, page 91

11.      Please revise to identify the specific product candidates for which
you intend to use the
         proceeds of this offering and how far in their development you intend
to get using the
         proceeds of this offering.
Management's Discussion and Analysis of Financial Condition and Results of
Stock Based Compensation, page 118

12.      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. Please discuss with the staff how to
submit your response.
13.      You state on page 120 that you used the backsolve method for inferring
the equity value
         implied by a recent financing transaction. Tell us why you believe
that the
         contemporaneous financing transactions were arms' length transactions.
Business, page 121

14.    Please revise the statements in this section that you are uniquely
positioned to develop
       transformative engineered cells as medicines and that you can increase
your likelihood of
FirstName LastNameSteven D. Harr, M.D.
       success. These statements are not appropriate given the number of
companies currently
Comapany    NameSana
       developing      Biotechnology,
                   product              Inc.the number of product candidates
that never receive
                            candidates and
December      2020 Page 3
FirstName LastName
 Steven D. Harr, M.D.
FirstName LastNameSteven
Sana Biotechnology, Inc. D. Harr, M.D.
December   NameSana
             2020    Biotechnology, Inc.
Page 4    7, 2020 Page 4
FirstName LastName
Our T Cell Fusosome Approach, page 138

15.      Please remove the reference to potential "first-in-class" product
candidates as this
         statement implies an expectation of regulatory approval and is
inappropriate given the
         length of time and uncertainty with respect to securing marketing
Intellectual Property, page 184

16.      Please revise to disclose the type of patent protection you have
(composition of matter,
         use or process) and the material foreign jurisdictions where you have
patents or pending
         patent applications.
Key Intellectual Property Agreements, page 187

17.      Please provide the current expiration date for the last-to-expire
licensed patent right under
         each of the agreements in this section if the royalty term for such
agreement is determined
         using such information.
Principal Stockholders, page 235

18.      Please revise your disclosure to identify the natural person or
persons who have voting
         and investment control of the shares held by F-Prime Fund VI.
2. Summary of significant accounting policies
Acquisitions, page F-8

19.      Please clarify that in an asset acquisition, amounts allocated to
IPR&D are recorded in
         research and development expense if they do not have an alternative
future use. Refer to
         ASC 730-10-25-2c.
3. Acquisitions, page F-16

20.      Please clarify, in Management's Discussion and Analysis and elsewhere
in the filing as
         appropriate, the amount of any payment expected to be paid upon the
IPO or within 12
         months after the IPO. In this respect we note the following:
             You state on page F-17 that the valuation measurement dates for
the Cobalt Success
             payment are triggered by an IPO at a time when at least one
company program using
             technology acquired from Cobalt is currently in a clinical trial,
has been submitted to
             the FDA for approval, or has been approved by the FDA. You also
state that the
             valuation measurement dates are triggered upon a change of control
when at least one
             of your programs based on fusogen technology is subject of an
active research
             For the Harvard College agreement you state on page F-20 that the
             payments of up to $76 million would double upon a change of
control. In addition,
             we note that the success payment measurement dates are triggered
by an equity
             financing of more than $25.0 million as well as the one year
anniversary of an IPO.
 Steven D. Harr, M.D.
Sana Biotechnology, Inc.
December 7, 2020
Page 5
21.   For the Cobalt Success payments, clarify the triggering points in which
Success payments
      will be made. For example, clarify if an ongoing clinical trial would
trigger a payment or
      if the ongoing clinical trial has to also be submitted to the FDA for
approval to trigger a
      payment. In addition, clarify if you currently are undergoing a program
based on the
      fusogen technology which is the subject of an active research program,
which would
      trigger a Success payment and how much. Finally, please clarify for both
the Harvard and
      Cobalt agreements that a change of control includes an IPO, if such is
the case, that could
      result in Success payments.
Financial Statements for the Years Ended December 31, 2019
Notes to Consolidated Financial Statements
11. Convertible preferred stock
Rights issued with Series A-1 and Series A-2 convertible preferred stock
Conversion, page F-26

22.   You state on page 111 that all outstanding shares of convertible
preferred stock will
      convert into shares of your common stock. On page F-53 you state that the
Series A-1,
      Series A-2, and Series B convertible preferred stock will automatically
convert into shares
      of the Company's common stock upon closing of the sale of shares of
common stock to
      the public in an underwritten public offering at a price that generates
at least $75.0 million
      in gross proceeds pursuant to an effective registration statement in
which the shares will
      be listed on a national securities exchange. You also state on page F-53
that the
      convertible preferred stock will automatically convert into shares of
common stock upon
      the vote or written consent of the holders of at least 61% of the
outstanding convertible
      preferred stock, voting together as a single class, which must include a
majority of the
      Series B preferred stock held by the investors that purchased at least
$29 million in the
      Series B financing. Please clarify in the filing why you believe all
convertible preferred
      stock will convert into common stock upon the IPO, given the above
conditions to
       You may contact Tracie Mariner at 202-551-3744 or Mary Mast at
202-551-3613 if you
have questions regarding comments on the financial statements and related
matters. Please
contact Ada D. Sarmento at 202-551-3798 or Mary Beth Breslin at 202-551-3625
with any other

FirstName LastNameSteven D. Harr, M.D.
                                                             Division of
Corporation Finance
Comapany NameSana Biotechnology, Inc.
                                                             Office of Life
December 7, 2020 Page 5
cc:       Brian J. Cuneo, Esq.
FirstName LastName