Under the Securities Exchange Act of 1934
(Amendment No. 3)*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. o

* The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934, as amended (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(1)   Based on 40,588,004 shares of Common Stock outstanding as of March 1, 2019, as reported in the Issuer’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on March 7, 2019.

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(1)   Based on 40,588,004 shares of Common Stock outstanding as of March 1, 2019, as reported in the Issuer’s Annual Report on Form 10-K filed with the SEC on March 7, 2019.

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Item 1.   Security and Issuer.

This Amendment No. 3 (the “Amendment”) to Schedule 13D amends the Schedule 13D filed by the Reporting Persons (as defined below) with the SEC on March 27, 2017, as previously amended on June 28, 2018 and March 28, 2019 (the “Original Schedule 13D” and, together with the Amendment, the “Schedule 13D”) and relates to the common stock, par value $0.0001 per share (the “Common Stock”), of Aerpio Pharmaceuticals, Inc., a Delaware corporation (the “Issuer”).  The address of the Issuer’s principal executive office is 9987 Carver Road, Cincinnati, OH 45242.

Except as otherwise described herein, the information contained in the Original Schedule 13D remains in effect. Capitalized terms used but not defined in this Amendment shall have the respective meanings set forth with respect thereto in the Original Schedule 13D.

Item 2.   Identity and Background.

No changes.

Item 3.   Source and Amounts of Funds or Other Consideration.

No changes.

Item 4.   Purpose of Transaction.

The information set forth in Item 5(c) of this Amendment is incorporated herein by reference. Otherwise, there are no changes to the disclosure provided under this Item 4 in the Original Schedule 13D.

Item 5.   Interest in Securities of the Issuer.

No changes except as described below.

(a)                                 Based on 40,588,004 shares of Common Stock outstanding as of March 1, 2019, as reported in the Issuer’s Annual Report on Form 10-K filed with the SEC on March 7, 2019, the Common Stock held by the Reporting Persons constitutes 12.1% of the outstanding shares of Common Stock of the Issuer.

(b)                                 With respect to the number of shares of Common Stock as to which each Reporting Person has:

(i)                                     sole power to vote or to direct the vote with respect to such shares of Common Stock, please see row 7 of the applicable cover sheet to this Amendment for such Reporting Person;

(ii)                                  shared power to vote or to direct the vote with respect to such shares of Common Stock, please see row 8 of the applicable cover sheet to this Amendment for such Reporting Person;

(iii)                               sole power to dispose or direct the disposition of such shares of Common Stock, please see row 9 of the applicable cover sheet to this Amendment for such Reporting Person; and

(iv)                              shared power to dispose or to direct the disposition of such shares of Common Stock, please see row 10 of the applicable cover sheet to this Amendment for such Reporting Person.

(c)                                  Other than the open market sales referred to below or previously reported in the Original Schedule 13D, none of (i) the Reporting Persons or, (ii) to the Reporting Persons’ knowledge, the persons set forth on Schedule I hereto has effected any transaction in the Common Stock during the past 60 days.

On April 10, 2019, the Reporting Persons sold 140,230 shares of Common Stock at a weighted average price of $1.09 per share (price range: $1.02 - $1.15).

On April 9, 2019, the Reporting Persons sold 32,991 shares of Common Stock at a weighted average price of $1.01 per share (price range: $0.98 - $1.03).

On April 8, 2019, the Reporting Persons sold 27,525 shares of Common Stock at a weighted average price of $1.02 per share (price range: $1.00 - $1.08).

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On April 5, 2019, the Reporting Persons sold 24,661 shares of Common Stock at a weighted average price of $1.02 per share (price range: $0.99 - $1.05).

On April 4, 2019, the Reporting Persons sold 47,900 shares of Common Stock at a weighted average price of $1.01 per share (price range: $0.98 - $1.02).

On April 3, 2019, the Reporting Persons sold 58,033 shares of Common Stock at a weighted average price of $0.96 per share (price range: $0.93 - $1.01).

On April 2, 2019, the Reporting Persons sold 51,754 shares of Common Stock at a weighted average price of $0.97 per share (price range: $0.93 - $1.00).

On April 1, 2019, the Reporting Persons sold 116,909 shares of Common Stock at a weighted average price of $0.95 per share (price range: $0.90 - $0.99).

On March 29, 2019, the Reporting Persons sold 63,100 shares of Common Stock at a weighted average price of $0.91 per share (price range: $0.88 - $0.96)

The Reporting Persons undertake to provide the Issuer, any stockholder of the Issuer, or the Staff of the SEC, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this Item 5(c).

(d)                                 Not applicable.

(e)                                  Not applicable.

Item 6.   Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

No changes.

Item 7.   Material to be Filed as Exhibits.

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Signature

After reasonable inquiry and to the best of the undersigned’s knowledge and belief, the undersigned hereby certify that the information set forth in this statement is true, complete and correct.

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Exhibit 99.1

Joint Filing Agreement

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree to the joint filing with each other on behalf of each of them of such a statement on Schedule 13D (including amendments thereto) with respect to the Common Stock beneficially owned by each of them of Aerpio Pharmaceuticals, Inc.  This Joint Filing Agreement shall be included as an Exhibit to such Schedule 13D.

IN WITNESS WHEREOF, the undersigned hereby execute this Joint Filing Agreement as of the 11th day of April, 2019.