August 23, 2019

John Evans
Chief Executive Officer
Beam Therapeutics Inc.
26 Landsdowne Street
Cambridge, MA 02139

       Re: Beam Therapeutics Inc.
           Draft Registration Statement on Form S-1
           Submitted July 29, 2019
           CIK No. 0001745999

Dear Mr. Evans:

       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 response.

      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
comments.

Draft Registration Statement on Form S-1

Prospectus Summary, page 1

1.     Please provide support for the statements below. In this regard, please
explain how you
       have "demonstrated" certain abilities when none of your product
candidates are in clinical
       stages of development:
         "we have demonstrated the ability to create the naturally-occurring
'Makassr' variant of
           hemoglobin," on pages 4 and 131;
         "[w]e have demonstrated the ability of base editors to perform
simultaneous multiplex
           editing with very high efficiencies and without any detectable
chromosomal
           rearrangements," on pages 4 and 123;
         "[o]our AATD base editing program has demonstrated the ability to
directly correct
 John Evans
FirstName LastNameJohn Evans
Beam Therapeutics Inc.
Comapany NameBeam Therapeutics Inc.
August 23, 2019
Page 2
August 23, 2019 Page 2
FirstName LastName
             the E342K point mutation, potentially addressing both the lung and
liver components
             of the disease," on page 4;
             "[o]ur base editors have demonstrated the ability to repair the
two most prevalent
             mutations that cause the disease," on page 4; and
             "[o]ur base editing approach, delivered through AAV viral vectors,
has demonstrated
             the ability to repair the G1961E point mutation," on page 5.
Our Portfolio, page 2

2.       Please add columns in your portfolio table here and on pages 113 and
124 to show all
         phases of the FDA approval process.
Implications of being an emerging growth company, page 7

3.       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.
Use of Proceeds, page 86

4.       We note your disclosure that you intend to use net proceeds for
continued research and
         development of your portfolio of base editing programs, for
IND-enabling studies and the
         potential initiation of clinical studies, and for continued
advancement of your platform
         technologies and discovery-stage research for other potential
programs. Please specify
         how far in the development of each of the listed clinical trials or
programs you expect to
         reach with the proceeds of the offering. If any material amounts of
other funds are
         necessary to accomplish the specified purposes, state the amounts and
sources of other
         funds needed for each specified purpose and the sources. Refer to
Instruction 3 to Item
         504 of Regulation S-K.
Management's Discussion and Analysis of Financial Condition and Results of
Operations
Critical accounting policies and significant judgments
Share-based compensation, page 105

5.       Once you have an estimated offering price range, please explain to us
the reasons for any
         differences between recent valuations of your common shares leading up
to the planned
         initial public offering and the midpoint of your estimated offering
price range. This
         information will help facilitate our review of your accounting for
equity issuances,
         including stock compensation.

Business, page 112

6.       We note your description of the Collaboration and License Agreement
with Verve on page
         F-38. If this agreement is material, please file it as an exhibit to
the registration statement
 John Evans
Beam Therapeutics Inc.
August 23, 2019
Page 3
         and describe its material terms in the business section. In addition,
disclose the milestone
         and royalties payments under the agreement referenced on page F-39.
Approach 1: Recreate naturally-occurring protective HPFH mutations to evaluate
HbF, page 129

7.       Please provide support for your statement that your "base editor
program uses a precise,
         direct editing strategy that is validated by human genetics." We note
that you have not
         conducted any clinical trials, yet state that your strategy has been
validated by human
         genetics.
License Agreement with The President and Fellows of Harvard College, page 147

8.       We note your reference to "low double digits" describing royalties or
other types of
         payments on pages 149 and 153. Please revise your disclosure to narrow
the royalty range
         in each of the referenced cases to no more than ten percentage points
(for example,
         between twenty and thirty percent).
License Agreement with Editas Medicine, Inc. , page 149

9.       Please disclose the aggregate milestone payments under the Editas
agreement. We note
         your reference to milestone payments on page 150.
8. Blink Therapeutics, page F-27

10.      Please provide us an analysis supporting your accounting treatment for
the share exchange
         with Blink Therapeutics, which resulted in a $49.5 million loss, as
well as expenses
         associated with the other exchange transactions described on page
F-28. In particular,
         explain your consideration of guidance governing common control
transactions. Refer us
         to the technical literature upon which you relied.
Notes to Consolidated Financial Statements
9. Redeemable convertible preferred stock, page F-28

11.      Please provide us an analysis supporting your accounting treatment for
the reclassification
         of the tranche liability, associated with "committed" investors, to
the carrying value of the
         Series A-2 Preferred shares, as well as the $5.7 million loss
recognized upon the issuance
         of Series A-2 Preferred shares to "additional" investors. Refer us to
the technical literature
         upon which you relied.
Part II
Exhibit index, page II-5
FirstName LastNameJohn Evans
Comapany NameBeam Therapeutics Inc.
12.     Please file the employment agreements with your named executive
officers described on
Augustpage2019 or tell3 why you believe they are not required to be filed.
         23, 186 Page us
FirstName LastName
 John Evans
FirstName LastNameJohn Evans
Beam Therapeutics Inc.
Comapany NameBeam Therapeutics Inc.
August 23, 2019
Page 4
August 23, 2019 Page 4
FirstName LastName
        You may contact Franklin Wyman at (202) 551-3660 or Sharon Blume at
(202) 551-
3474 if you have questions regarding comments on the financial statements and
related
matters. Please contact Tonya K. Aldave at (202) 551-3601 or Dietrich King at
(202) 551-
8071 with any other questions.



                                                         Sincerely,

                                                         Division of
Corporation Finance
                                                         Office of Healthcare &
Insurance
cc:      Marc A. Rubenstein, Esq.