SecProbe.io

March 6, 2018
Arthur Tzianabos
President and Chief Executive Officer
Homology Medicines, Inc.
45 Wiggins Avenue
Bedford, MA 01730
Re:Homology Medicines, Inc.
Registration Statement on Form S-1
Filed March 2, 2018
File No. 333-223409
Dear Dr. Tzianabos:
            We have reviewed your registration statement and have the following comment.
            Please respond to this letter by amending your registration statement and providing the
requested information.  If you do not believe our comment applies to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why in your
response.
            After reviewing any amendment to your registration statement and the information you
provide in response to this comment, we may have additional comments.
Form S-1 filed March 2, 2018
Notes to Consolidated Financial Statements
Note 16. Collaboration and License Agreement, page F-27
1.Please revise to separately quantify your potential development, regulatory and
commercial milestone payments under the Novartis agreement.
            We remind you that the company and its management are responsible for the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.
            Refer to Rules 460 and 461 regarding requests for acceleration.  Please allow adequate
time for us to review any amendment prior to the requested effective date of the registration
statement.

 FirstName LastNameArthur Tzianabos
 Comapany NameHomology Medicines, Inc.
 June 16, 2017 Page 2
 FirstName LastName
Arthur Tzianabos
Homology Medicines, Inc.
March 6, 2018
Page 2
            You may contact Keira Nakada at 202-551-3659 or Angela Connell at 202-551-3426 if
you have questions regarding comments on the financial statements and related matters.  Please
contact Jeffrey Gabor at 202-551-2544 or Erin Jaskot at 202-551-3442 with any other questions.
Division of Corporation Finance
Office of Healthcare & Insurance
cc: Wesley Holmes