September 11, 2018

Stephen Hoffman
Chief Executive Officer
Aerpio Pharmaceuticals, Inc.
9987 Carver Road
Cincinnati, OH 45242

       Re: Aerpio Pharmaceuticals, Inc.
           Post-Effective Amendment No. 1 to Form S-1 on Form S-3
           Filed August 31, 2018
           File No. 333-217320

Dear Dr. Hoffman:

       We have reviewed your post-effective amendment 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.

Post-Effective Amendment No. 1 to Form S-1 on Form S-3 Registration Statement
filed August
31, 2018

General

1.     We note that you included December 31, 2016 audited financial statements
in the Form S-
       1 declared effective July 23, 2017 and that this is the first
post-effective amendment to the
       registration statement. We also note that you sought to add financial
statements for the
       year ended December 31, 2017 to your prospectus on May 25, 2018 without
the filing of
       the requisite post-effective amendment. If an offering continues for
more than nine
       months, you are required to update your registration statement by
post-effective
       amendment if the information in the prospectus is more than 16 months
old. Please tell us
       whether you engaged in the offer or sale of your securities between May
1, 2018
 Stephen Hoffman
Aerpio Pharmaceuticals, Inc.
September 11, 2018
Page 2
       and the present. Refer to Section 10(a)(3) of the Securities Act and
Rule 427. For
       additional guidance, please refer to Questions 113.01 and 113.02 of the
Securities Act
       Forms Compliance and Disclosure Interpretations.
        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.

       Please contact Irene Paik at 202-551-6553 or Erin Jaskot at 202-551-3442
with any
questions.



                                                            Sincerely,
FirstName LastNameStephen Hoffman
                                                            Division of
Corporation Finance
Comapany NameAerpio Pharmaceuticals, Inc.
                                                            Office of
Healthcare & Insurance
September 11, 2018 Page 2
cc:       Danielle Lauzon, Esq. - Goodwin Procter LLP
FirstName LastName