Under the Securities Exchange Act of 1934
(Amendment No. 2)*

(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. 2 (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 (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 except as described below.

(a) – (c) and (f) This Schedule 13D is being filed by Novartis Bioventures Ltd. (“NBV”) and Novartis AG (“Novartis”). NBV and Novartis are hereinafter sometimes collectively referred to as the “Reporting Persons.”  The name, business address, present principal occupation or employment and citizenship of the executive officers and members of the Board of Directors of each of the Reporting Persons is set forth on Schedule I hereto and is incorporated herein by reference. The principal business address of both NBV and Novartis is Lichtstrasse 35, CH-4056 Basel, Switzerland.

(d) - (e) Neither the Reporting  Persons nor, to the best knowledge of each of them, any of the executive officers and members of the Board of Directors of each of the Reporting Persons set forth on Schedule I hereto during  the last  five  years,  (i) has been  convicted  in a criminal  proceeding  (excluding traffic violations or similar  misdemeanors) or (ii) was a party to a civil proceeding of a judicial or administrative  body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment,  decree or final order enjoining future violations of, or prohibiting or mandating  activities subject to, federal or state securities laws or finding any violation with respect to such laws.

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.

All shares of Common Stock reported acquired by the Reporting Persons in this Schedule 13D were acquired for the purpose of investment and were not intended to and have not effected any change in the control of the Issuer.

The Reporting Persons from time to time review their investment in the Issuer on the basis of various factors, including the liquidity and diversification objectives of the Reporting Persons, other investment opportunities the Reporting Persons may have, the Issuer’s business, financial condition, results of operations and prospects, general economic and industry conditions, the securities markets in general and those for the Issuer’s shares of Common Stock in particular, as well as other developments. Based upon such review, the Reporting Persons will take such actions as the Reporting Persons may deem appropriate in light of the circumstances existing from time to time. The Reporting Persons have determined to reduce their holdings in the Issuer as part of the Reporting Persons’ liquidity and diversification strategy, particularly in light of the Reporting Persons’ level of holdings in the Issuer. As reported in this Amendment, the Reporting Persons have sold shares of the Common Stock during the past 60 days. Except as described above, none of the Reporting Persons currently has any plan or proposal that relates to or would result in any of the actions specified in clauses (a) through (j) of Item 4 of Schedule 13D.

Item 5.         Interest in Securities of the Issuer.

No changes except as described below.

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(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 13.5% 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, 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 March 28, 2019, the Reporting Persons sold 88,835 shares of Common Stock at a weighted average price of $0.94 per share (price range: $0.92 - $1.00)

On March 27, 2019, the Reporting Persons sold 50,749 shares of Common Stock at a weighted average price of $0.99 per share (price range: $0.99 - $1.02).

On March 26, 2019, the Reporting Persons sold 177,762 shares of Common Stock at a weighted average price of $1.01 per share (price range: $1.00 - $1.06).

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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SCHEDULE I

DIRECTORS AND EXECUTIVE OFFICERS OF
NOVARTIS AG AND NOVARTIS BIOVENTURES LTD.

Directors and Executive Officers of Novartis AG

The name, function, citizenship and present principal occupation or employment of each of the directors and executive officers of Novartis AG are set forth below. Unless otherwise indicated below, (i) each occupation set forth opposite an individual’s name refers to employment with Novartis AG and (ii) the business address of each director and executive officer of Novartis AG is Novartis Campus, Lichtstrasse 35, CH-4056, Basel, Switzerland.

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Directors and Officers of Novartis Bioventures Ltd.

The name, address, citizenship and present principal occupation or employment of each of the directors and executive officers of Novartis Bioventures Ltd. are set forth below. Unless otherwise indicated below, (i) each occupation set forth opposite an individual’s name refers to employment with Novartis Bioventures Ltd. and (ii) the business address of each director and executive officer of Novartis Bioventures Ltd. is Novartis Campus, Lichtstrasse 35, CH-4056, Basel, Switzerland.

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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 28th day of March, 2019.

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