July 3, 2024

Thomas A. Keuer
President and Chief Operating Officer
ARCA biopharma, Inc.
10170 Church Ranch Way, Suite 100
Westminster, CO 80021

       Re: ARCA biopharma, Inc.
           Amendment No. 1 to Registration Statement on Form S-4
           Filed June 18, 2024
           File No. 333-279387
Dear Thomas A. Keuer:

     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 June 11, 2024 letter.

Amendment No. 1 to Registration Statement on Form S-4
Oruka's Pipeline, page 214

1.     We note your response to prior comment 11 and your revised disclosure on
page 214. We
       note that the pipeline table does not provide an indication for ORKA-003
or
       "Combinations." Given the status of development and limited disclosure
regarding the
       programs for ORKA-003 and "Combinations," it does not appear appropriate
to highlight
       these programs in your pipeline table. If these programs are material to
your business to
       warrant inclusion in your pipeline table, please expand your disclosure
in your Business
       section to provide a more fulsome discussion of these programs,
including descriptions of
       preclinical studies or other development activities conducted.
Alternatively, please
       remove these programs from the pipeline table or advise.
2.     Please revise your pipeline table to include columns of equal width for
each of Phase 1,
       Phase 2 and Phase 3 of clinical testing.
 July 3, 2024
Page 2

       Please contact Jenn Do at 202-551-3743 or Kevin Kuhar at 202-551-3662 if
you have
questions regarding comments on the financial statements and related matters.
Please contact
Tamika Sheppard at 202-551-8346 or Joshua Gorsky at 202-551-7836 with any other
questions.



                                                         Sincerely,

                                                         Division of
Corporation Finance
                                                         Office of Life
Sciences
cc:   Brent D. Fassett