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                              April 24, 2024

       Erik Ostrowski
       Interim Chief Executive Officer
       AVROBIO, Inc.
       100 Technology Square
       Sixth Floor
       Cambridge, MA 02139

                                                        Re: AVROBIO, Inc.
                                                            Amendment No. 2 to
Registration Statement on Form S-4
                                                            Filed April 15,
2024
                                                            File No. 333-277048

       Dear Erik Ostrowski:

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

              Please respond to this letter by amending your registration
statement and providing the
       requested information. 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 any amendment to your registration statement and
the information you
       provide in response to this letter, we may have additional comments.
Unless we note otherwise,
       any references to prior comments are to comments in our April 8, 2024
letter.

       Amendment No. 2 to Registration Statement on Form S-4

       Risk Factors
       Tectonic currently relies and expects to rely in the future on the use
of manufacturing suites in
       third-party facilities..., page 146

   1.                                                   We note that Tectonic
currently relies on WuXi Biologics (Hong Kong) Limited as the
                                                        sole manufacturer of
its supply of TX45 product candidate used in its clinical trials. Please
                                                        tell us your
consideration of whether the proposed BIOSECURE Act, if passed and
                                                        enacted into law, may
impact the combined company   s business and operations, and if so,
                                                        how. Include risk
factor disclosure as appropriate.
       The Merger
       Background of the Merger, page 179
 Erik Ostrowski
AVROBIO, Inc.
April 24, 2024
Page 2

2.    We note your response to prior comment 5. Your description of the
background of the
      Merger Agreement is still not sufficient to clearly explain the bases for
all material terms
      of the Merger agreement that were negotiated through proposals and
counter-proposals.
      Please further revise this section to explain the reason(s) why the
various parties proposed
      and counter-proposed valuations for AVROBIO and Tectonic. Specifically:
          Clearly explain the material bases for the proposed valuations for
AVROBIO. In this
           regard, you explain that proposed valuation amounts "includ[e] a
targeted $65 million
           of net cash at closing," but you do not explain the reason(s) for
proposed valuations
           in excess of the targeted net cash amount. To the extent that the
parties ascribed value
           to AVROBIO in excess of its targeted ending net cash position based
on
           AVROBIO's public company listing or for any other material reason,
please so state.
          Explain the basis for the proposed valuations for Tectonic. In this
regard, we note
           that the reason(s) why Tectonic proposed an initial valuation for
Tectonic of $150
           million in the Tectonic November 11, 2023 Proposal are unclear. It
is similarly
           unclear why AVROBIO countered with a proposed valuation for Tectonic
of $130
           million on November 15, 2023 at the direction of the Transaction
Committee, and
           why the parties ultimately agreed to the $140 million valuation for
Tectonic proposed
           in the Tectonic November 21, 2023 proposal.

       Please contact Jenn Do at 202-551-3743 or Mary Mast at 202-551-3613 if
you have
questions regarding comments on the financial statements and related matters.
Please contact
Lauren Hamill at 303-844-1008 or Chris Edwards at 202-551-6761 with any other
questions.



                                                            Sincerely,
FirstName LastNameErik Ostrowski
                                                            Division of
Corporation Finance
Comapany NameAVROBIO, Inc.
                                                            Office of Life
Sciences
April 24, 2024 Page 2
cc:       Adam Johnson
FirstName LastName