Document:

EX-10.5

 Exhibit 10.5 

REGISTRATION RIGHTS AGREEMENT 

This Registration Rights Agreement (this “Agreement”) is made and entered into effective as of March 15, 2017, among Aerpio
Pharmaceuticals, Inc., a Delaware corporation (the “Company”), the persons who have purchased the Offering Shares and have executed omnibus or counterpart signature page(s) hereto (each, a “Purchaser” and
collectively, the “Purchasers”), the persons or entities identified on Schedule 1 hereto holding Placement Agent Warrants (collectively, the “Brokers”), the persons or entities identified on Schedule 2
hereto holding Merger Shares and the persons or entities identified on Schedule 3 hereto holding Registrable Pre-Merger Shares. Capitalized terms used herein shall have the meanings ascribed to them in
Section 1 below or in the Subscription Agreement. 
 RECITALS: 

WHEREAS, the Company has offered and sold in compliance with Rule 506 of Regulation D promulgated under the Securities Act to
accredited investors in a private placement offering (the “Offering”) shares of the common stock of the Company, par value $0.0001 per share, pursuant to that certain Subscription Agreement entered into by and between the Company
and each of the subscribers for the Offering Shares set forth on the signature pages affixed thereto (the “Subscription Agreement”); and 

WHEREAS, the Company has agreed to enter into a registration rights agreement with each of the Purchasers in the Offering who purchased
the Offering Shares and with the Brokers, or their designees, who hold Placement Agent Warrants and certain other investors; and 

WHEREAS, prior to the initial closing of the Offering, a wholly-owned subsidiary of the Company has merged with and into Aerpio
Therapeutics, Inc., a Delaware corporation (“Aerpio”), and following such merger, Aerpio was converted into a Delaware limited liability company; 

NOW, THEREFORE, in consideration of the mutual promises, representations, warranties, covenants, and conditions set forth herein, the
parties mutually agree as follows: 
 1. Certain Definitions. As used in this Agreement, the following terms shall have the following
respective meanings: 
 “Approved Market” means the OTC Markets Group, the Nasdaq Stock Market, the New York Stock Exchange
or the NYSE MKT. 
 “Blackout Period” means, with respect to a registration, a period during which the Company, in the good
faith judgment of its board of directors, determines (because of the existence of, or in anticipation of, any acquisition, financing activity, receipt of clinical trial results or other transaction involving the Company, or the unavailability for
reasons beyond the Company’s control of any required financial statements, disclosure of information which is in its best interest not to publicly disclose, or any other event or condition of similar significance to the Company) that the
registration and distribution of the Registrable Securities to be covered by 

 
such registration statement, if any, or the filing of an amendment to such registration statement in the circumstances described in Section 4(h), would be seriously detrimental to the Company and
its stockholders, in each case commencing on the day the Company notifies the Holders that they are required, because of the determination described above, to suspend offers and sales of Registrable Securities and ending on the earlier of
(1) the date upon which the material non-public information resulting in the Blackout Period is disclosed to the public or ceases to be material and (2) such time as the Company notifies the selling
Holders that sales pursuant to such Registration Statement or a new or amended Registration Statement may resume; provided, however, that no Blackout Period shall extend for a period of more than thirty (30) consecutive Trading Days (except for
a Blackout Period arising from the filing of a post-effective amendment to the Registration Statement to update the prospectus therein to include the information contained in the Company’s Annual Report on Form
10-K, which Blackout Period may extend for the amount of time reasonably required to respond to comments of the staff of the Commission (the “Staff”) on such amendment) and aggregate Blackout
Periods shall not exceed sixty (60) Trading Days in any twelve (12) month period. 
 “Business Day” means any day
of the year, other than a Saturday, Sunday, or other day on which banks in the State of New York are required or authorized to close. 

“Commission” means the U. S. Securities and Exchange Commission or any other federal agency at the time administering the
Securities Act. 
 “Common Stock” means the common stock, par value $0.0001 per share, of the Company and any and all
shares of capital stock or other equity securities of: (i) the Company which are added to or exchanged or substituted for the Common Stock by reason of the declaration of any stock dividend or stock split, the issuance of any distribution or
the reclassification, readjustment, recapitalization or other such modification of the capital structure of the Company; and (ii) any other corporation, now or hereafter organized under the laws of any state or other governmental authority,
with which the Company is merged, which results from any consolidation or reorganization to which the Company is a party, or to which is sold all or substantially all of the shares or assets of the Company, if immediately after such merger,
consolidation, reorganization or sale, the Company or the stockholders of the Company own equity securities having in the aggregate more than 50% of the total voting power of such other corporation. 

“Effective Date” means the date of the final closing of the Offering. 

“Exchange Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission
promulgated thereunder. 
 “Family Member” means (a) with respect to any individual, such individual’s spouse,
any descendants (whether natural or adopted), any trust all of the beneficial interests of which are owned by any of such individuals or by any of such individuals together with any organization described in Section 501(c)(3) of the Internal Revenue
Code of 1986, as amended, the estate of any such individual, and any corporation, association, partnership or limited liability company all of the equity interests of which are owned by those above described individuals, trusts or organizations and
(b) with respect to any trust, the owners of the beneficial interests of such trust. 

  
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 “Holder” means (i) each Purchaser or any of such Purchaser’s
respective successors and Permitted Assignees who acquire rights in accordance with this Agreement with respect to any Registrable Securities directly or indirectly from a Purchaser or from any Permitted Assignee; (ii) each Broker or any of
such Broker’s respective successors and Permitted Assignees who acquire rights in accordance with this Agreement with respect to any Registrable Securities directly or indirectly from an Broker or from any Permitted Assignee; (iii) each
Registrable Pre-Merger Stockholder; and (iv) each holder of the Merger Shares or its respective successors and Permitted Assignees who acquire rights in accordance with this Agreement with respect to any
Registrable Securities directly or indirectly from such holder or from any Permitted Assignee thereof. 
 “Majority
Holders” means, at any time, Holders of a majority of the Registrable Securities then outstanding. 
 “Merger
Shares” means the shares of Common Stock issued in exchange for all of the equity securities of Aerpio that are outstanding immediately prior to the closing of the Merger. 

“Permitted Assignee” means (a) with respect to a partnership, its partners or former partners in accordance with their
partnership interests, (b) with respect to a corporation, its stockholders in accordance with their interest in the corporation, (c) with respect to a limited liability company, its members or former members in accordance with their
interest in the limited liability company, (d) with respect to an individual party, any Family Member of such party, (e) an entity or trust that is controlled by, controls, or is under common control with a transferor, or (f) a party
to this Agreement. 
 “Placement Agent Warrants” shall have the meaning set forth in the Subscription Agreement. 

“Offering Shares” means the shares of Common Stock issued to the Purchasers pursuant to the Subscription Agreement (including
any Shares of Common Stock issued pursuant to Section 22 of the Subscription Agreement) and any shares of Common Stock issued or issuable with respect to such shares upon any stock split, dividend or other distribution, recapitalization or
similar event with respect to the foregoing. 
 The terms “register,” “registered,” and
“registration” refer to a registration effected by preparing and filing a registration statement in compliance with the Securities Act, and the declaration or ordering of the effectiveness of such registration statement. 

“Registrable Pre-Merger Shares” means 1,000,000 shares of Common Stock of the Company
held by stockholders of the Company other than the holders of the Merger Shares and the Offering Shares. 
 “Registrable Pre-Merger Stockholder” means a person holding Registrable Pre-Merger Shares. 

  
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 “Registrable Securities” means (a) the Offering Shares, (b) the shares
of Common Stock issuable upon exercise of the Placement Agent Warrants, (c) the Merger Shares, and (d) if any, the Registrable Pre-Merger Shares; but, in each case, excluding any otherwise
Registrable Securities that (i) have been sold or otherwise transferred other than to a Permitted Assignee, or (ii) may be sold at the time under the Securities Act without restriction, including manner of sale, current information
requirements or volume limitations either pursuant to Rule 144 of the Securities Act or otherwise during any ninety (90) day period. 

“Registration Default Period” means the period during which any Registration Event occurs and is continuing. 

“Registration Effectiveness Date” means the date that is one hundred and fifty (150) calendar days after the Effective
Date. 
 “Registration Event” means the occurrence of any of the following events: 

(a) the Company fails to file with the Commission the Registration Statement on or before the Registration Filing Date; 

(b) the Registration Statement is not declared effective by the Commission on or before the Registration Effectiveness Date; 

(c) after the SEC Effective Date, the Registration Statement ceases for any reason to remain continuously effective or the Holders are
otherwise not permitted to utilize the prospectus therein to resell the Registrable Securities for a period of more than fifteen (15) consecutive Trading Days, excluding Blackout Periods permitted herein, and as excused pursuant to Section
3(a); or 
 (d) the Company’s common stock fails to be listed or included for quotation, as applicable, on an Approved Market by
September 15, 2017 (the “Approved Market Deadline”). 
 (e) following the Approved Market Deadline, the Registrable Securities, if
issued and outstanding, are not listed or included for quotation on an Approved Market, or trading of the Common Stock is suspended or halted on the Approved Market, which at the time constitutes the principal markets for the Common Stock, for more
than three (3) full, consecutive Trading Days; provided, however, a Registration Event shall not be deemed to occur if all or substantially all trading in equity securities (including the Common Stock) is suspended or halted on the Approved
Market for any length of time. 
 “Registration Filing Date” means the date that is sixty (60) calendar days after the
Effective Date. 
 “Registration Statement” means the registration statement that the Company is required to file pursuant
to Section 3(a) of this Agreement to register the Registrable Securities. 

  
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 “Restricted Holders” means all officers and directors of the Company and certain
stockholders of the Company who have entered into lock-up agreements with the Company upon the closing of the Merger, pursuant to which they agree to certain restrictions on the sale or disposition (including
pledge) of the Common Stock held by (or issuable to) them. 
 “Rule 144” means Rule 144 promulgated by the Commission under
the Securities Act, as such rule may be amended or supplemented from time to time, or any similar successor rule that may be promulgated by the Commission. 

“Rule 145” means Rule 145 promulgated by the Commission under the Securities Act, as such rule may be amended or supplemented
from time to time, or any similar successor rule that may be promulgated by the Commission. 
 “Rule 415” means Rule 415
promulgated by the Commission under the Securities Act, as such rule may be amended or supplemented from time to time, or any similar successor rule that may be promulgated by the Commission. 

“Securities Act” means the Securities Act of 1933, as amended, or any similar federal statute promulgated in replacement
thereof, and the rules and regulations of the Commission thereunder, all as the same shall be in effect at the time. 
 “SEC
Effective Date” means the date the Registration Statement is declared effective by the Commission. 
 “Trading
Day” means any day on which such national securities exchange, the OTC Markets Group or such other securities market or quotation system, which at the time constitutes the principal securities market for the Common Stock, is open for
general trading of securities. 
 2. Term. This Agreement shall terminate with respect to each Holder on the earlier of: (i) the
date that is five (5) years from the SEC Effective Date and (ii) the date on which all Registrable Securities held by such Holder have been transferred other than to a Permitted Assignee. Notwithstanding the foregoing, Section 3(b),
Section 6, Section 8, Section 9 and Section 11 shall survive the termination of this Agreement. 
 3.
Registration. 
 (a) Registration on Form S-1. The Company shall file with the
Commission a Registration Statement on Form S-1, or any other form for which the Company then qualifies or which counsel for the Company shall deem appropriate and which form shall be available for the resale
by the Holders of all of the Registrable Securities, and the Company shall (i) use its commercially reasonable efforts to make the initial filing of the Registration Statement no later than the Registration Filing Date, (ii) use its
commercially reasonable efforts to cause such Registration Statement to be declared effective no later than the Registration Effectiveness Date and (iii) use its commercially reasonable efforts to keep such Registration Statement effective for
a period of five (5) years after the SEC Effective Date or for such shorter period ending on the date on which all Registrable Securities have been transferred other than to a Permitted Assignee (the “Effectiveness
Period”); provided, however, that the Company shall not be obligated to effect any such registration, qualification or compliance pursuant to this Section, or keep such registration effective pursuant to the terms hereunder,
in any particular jurisdiction in which the Company would be required to qualify to do business as a foreign corporation or as a dealer in 

  
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securities under the securities laws of such jurisdiction or to execute a general consent to service of process in effecting such registration, qualification or compliance, in each case where it
has not already done so; and provided further, the Company shall be entitled to suspend the effectiveness of the Registration Statement at any time prior to the expiration of the Effectiveness Period during a Blackout Period. Notwithstanding the
foregoing, in the event that the Staff should limit the number of Registrable Securities that may be sold pursuant to the Registration Statement, the Company may remove from the Registration Statement such number of Registrable Securities as
specified by the Commission on behalf of all of the holders of Registrable Securities first from the shares of Common Stock issuable upon exercise of the Placement Agent Warrants, on a pro-rata basis
among the holders thereof (and on an as-exercised basis with respect to any Placement Agent Warrants not then exercised), second, from the other Registrable Securities, on a pro rata basis among the
holders thereof (such Registrable Securities, the “Reduction Securities”). In such event, the Company shall give the Purchasers prompt notice of the number of Registrable Securities excluded therefrom. The Company shall use its
commercially reasonable efforts at the first opportunity that is permitted by the Commission to register for resale the Reduction Securities (pro rata among the Holders of such Reduction Securities) using one or more registration statements that it
is then entitled to use. The Company shall use its commercially reasonable efforts to cause each such registration statement to be declared effective under the Securities Act as soon as possible, and shall use its commercially reasonable efforts to
keep such registration statement continuously effective under the Securities Act during the entire Effectiveness Period. Notwithstanding the foregoing, the Company shall be entitled to suspend the effectiveness of such Registration Statement at any
time prior to the expiration of the Effectiveness Period for the reasons and time periods during a Blackout Period. No liquidated damages shall accrue or be payable to any Holder pursuant to Section 3(b) with respect to any Registrable Securities
that are excluded by reason of the Staff limiting the number of Registrable Securities that may be sold pursuant to a registration statement; provided that the Company continues to use commercially reasonable efforts to register such Registrable
Securities for resale by other available means. Notwithstanding anything herein to the contrary, if the Commission limits the Company’s ability to file, or prohibits or delays the filing of a new registration statement, the Company’s
compliance with such limitation, prohibition or delay solely to the extent of such limitation, prohibition or delay shall not be deemed a failure by the Company to use commercially reasonable efforts as set forth above or elsewhere in this Agreement
and shall not require the payment of any liquidated damages by the Company under this Agreement. 
 (b) Liquidated Damages. If a
Registration Event occurs, then the Company will make payments to each Holder of Registrable Securities, as liquidated damages to such Holder by reason of the Registration Event, a cash sum calculated at a rate of twelve percent (12%) per annum of:
(i) the aggregate purchase price paid by such Holder pursuant to the Subscription Agreement, (ii) $5.00 upon exercise of Placement Agent Warrants (or in the case of unexercised Placement Agent Warrants, of the exercise price thereof), or
(iii) to a Holder of Merger Shares or Registrable Pre-Merger Shares, the product of $5.00 (as adjusted for stock splits, stock dividends, combinations, recapitalizations or similar events) multiplied by
the number of Merger Shares or Registrable Pre-Merger Shares held by such Holder, but in each case of (i)-(iii), only with respect to such Holder’s Registrable Securities that are affected by such
Registration Event and only for the period during which such Registration Event continues to affect such Registrable Securities. Notwithstanding the foregoing, the maximum amount of 

  
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liquidated damages that may be paid by the Company pursuant to this Section 3(b) shall be an amount equal to five percent (5%) of the applicable foregoing amounts described in clauses (i), (ii)
and (iii) in the preceding sentence with respect to such Holder’s Registrable Securities that are affected by all Registration Events in the aggregate. Each payment of liquidated damages pursuant to this Section 3(b) shall be due and
payable in arrears within five (5) days after the end of each full 30-day period of the Registration Default Period until the termination of the Registration Default Period and within five (5) days
after such termination. The Registration Default Period shall terminate upon the earlier of such time as the Registrable Securities that are affected by the Registration Event cease to be Registrable Securities or (i) the filing of the
Registration Statement in the case of clause (a) of the definition of Registration Event, (ii) the SEC Effective Date in the case of clause (b) of the definition of Registration Event, (iii) the ability of the Holders to effect
sales pursuant to the Registration Statement in the case of clause (c) of the definition of Registration Event, and (iv) the listing or inclusion and/or trading of the Common Stock on an Approved Market, as the case may be, in the case of
clause (d) or clause (e) of the definition of Registration Event. The amounts payable as liquidated damages pursuant to this Section 3(b) shall be payable in lawful money of the United States. Notwithstanding the foregoing, the Company
will not be liable for the payment of liquidated damages described in this Section 3(b) for any delay in registration of Registrable Securities that would otherwise be includable in the Registration Statement pursuant to Rule 415 solely as a result
of a comment received from the Staff requiring a limit on the number of Registrable Securities included in such Registration Statement in order for such Registration Statement to be able to avail itself of Rule 415, or, with respect to a Holder, if
such Holder fails to provide to the Company information concerning the Holder and manner of distribution of the Holder’s Registrable Securities that is required by SEC Rules to be disclosed in a registration statement utilized in connection
with the registration of the Registrable Securities. In the event of any such circumstance, the Company will use its commercially reasonable efforts at the first opportunity that is permitted by the Commission to register for resale the Registrable
Securities that have been cut back from being registered pursuant to Rule 415 only with respect to that portion of the Holders’ Registrable Securities that are then Registrable Securities. 

(c) Other Limitations. Notwithstanding the provisions of Section 3(b) above, if (i) the Commission does not declare the
Registration Statement effective on or before the Registration Effectiveness Date, or (ii) the Commission allows the Registration Statement to be declared effective at any time before or after the Registration Effectiveness Date, subject to the
withdrawal of certain Registrable Securities from the Registration Statement, and the reason for (i) or (ii) is the Commission’s determination that (x) the offering of any of the Registrable Securities constitutes a primary offering
of securities by the Company, (y) Rule 415 may not be relied upon for the registration of the resale of any or all of the Registrable Securities, and/or (z) a Holder of any Registrable Securities must be named as an underwriter, the
Holders understand and agree that in the case of (ii) the Company may (notwithstanding anything to the contrary contained herein) reduce, on a pro rata basis, in the manner provided above, the total number of Registrable Securities to be
registered on behalf of each such Holder, and in the case of (i) or (ii) the Holder shall not be entitled to liquidated damages with respect to the Registrable Securities not registered for the reason set forth in (i) or so reduced on a
pro rata basis as set forth above. The Company shall use its commercially reasonable efforts at the first opportunity that is permitted by the Commission to register for resale the Reduction Securities (pro rata among the Holders of such Reduction
Securities) using one or more registration statements that it is then 

  
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entitled to use. The Company shall use its commercially reasonable efforts to cause each such registration statement to be declared effective under the Securities Act as soon as possible, and
shall use its commercially reasonable efforts to keep such registration statement continuously effective under the Securities Act during the entire Effectiveness Period. Notwithstanding the foregoing, the Company shall be entitled to suspend
the effectiveness of such Registration Statement at any time prior to the expiration of the Effectiveness Period for the reasons and time periods during a Blackout Period. No liquidated damages shall accrue or be payable to any Holder pursuant to
this Section 3(c) with respect to any Registrable Securities that are excluded by reason of the Staff limiting the number of Registrable Securities that may be sold pursuant to a registration statement; provided that the Company continues to use
commercially reasonable efforts to register such Registrable Securities for resale by other available means. Notwithstanding anything herein to the contrary, if the Commission limits the Company’s ability to file, or prohibits or delays the
filing of a new registration statement, the Company’s compliance with such limitation, prohibition or delay solely to the extent of such limitation, prohibition or delay shall not be deemed a failure by the Company to use commercially
reasonable efforts as set forth above or elsewhere in this Agreement and shall not require the payment of any liquidated damages by the Company under this Agreement. 

(d) If the Company receives a written notice from the Holders of at least 50% of the Registrable Securities then outstanding that they
desire to distribute the Registrable Securities held by them (or a portion thereof) by means of an underwritten offering or a block trade, the Company shall use commercially reasonable efforts to promptly engage one or more underwriter(s) or
investment bank(s) to conduct such an offering of the Registrable Securities (a “Secondary Offering”). The underwriter(s) or investment bank(s) will be selected by the Company and shall be reasonably acceptable to the Holders of a
majority of the Registrable Securities providing such notice. All Holders proposing to distribute their securities through such Secondary Offering shall enter into an underwriting agreement or other agreement(s), including any lock-up or market standoff agreements, in customary form with the underwriter(s) or investment bank(s) selected for such Secondary Offering as may be mutually agreed upon among the Company, the underwriter(s) or
investment bank(s) and the selling Holders. In connection with a Secondary Offering, the Company shall enter into and perform its obligations under an underwriting agreement or other agreement(s), in usual and customary form as may be mutually
agreed upon among the Company, the underwriter(s) or investment bank(s) and the selling Holders. Notwithstanding any other provision of this Section 3(d), if the underwriter(s) or investment bank(s) advise(s) such Holders in writing that marketing
factors require a limitation on the number of shares to be offered in the Secondary Offering, then the number of Registrable Securities that may be included in such Secondary Offering shall be allocated among such Holders of Registrable Securities,
in proportion (as nearly as practicable) to the number of Registrable Securities owned by each such Holder or in such other proportion as shall mutually be agreed to by all such selling Holders; provided, however, that the number of
Registrable Securities held by the Holders to be included in such Secondary Offering shall not be reduced unless all other securities are first entirely excluded from the Secondary Offering. 

  
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 4. Registration Procedures. The Company will keep each Holder reasonably advised as to the
filing and effectiveness of the Registration Statement. At its expense with respect to the Registration Statement, the Company will: 
 (a)
prepare and file with the Commission with respect to the Registrable Securities, a Registration Statement in accordance with Section 3(a) hereof, and use its commercially reasonable efforts to cause such Registration Statement to become effective
and to remain effective for the Effectiveness Period; 
 (b) not name any Holder in the Registration Statement as an underwriter
without that Holder’s prior written consent; 
 (c) if the Registration Statement is subject to review by the Commission, promptly
respond to all comments and diligently pursue resolution of any comments to the satisfaction of the Commission; 
 (d) prepare and file with
the Commission such amendments and supplements to such Registration Statement as may be necessary to keep such Registration Statement effective during the Effectiveness Period; 

(e) not less than ten (10) Trading Days prior to filing a Registration Statement or any related prospectus or any amendment or supplement
thereto, the Company shall furnish to the Holders copies of all such documents proposed to be filed (other than those incorporated by reference) and duly consider any comments received by the Holders; 

(f) furnish, without charge, to each Holder of Registrable Securities covered by such Registration Statement (i) a reasonable number of
copies of such Registration Statement (including any exhibits thereto other than exhibits incorporated by reference), each amendment and supplement thereto as such Holder may reasonably request, (ii) such number of copies of the prospectus
included in such Registration Statement (including each preliminary prospectus and any other prospectus filed under Rule 424 of the Securities Act) as such Holders may reasonably request, in conformity with the requirements of the Securities Act,
and (iii) such other documents as such Holder may reasonably require to consummate the disposition of the Registrable Securities owned by such Holder, but only during the Effectiveness Period; provided that the Company shall have no obligation
to furnish any document pursuant to this clause that is available on the EDGAR system; 
 (g) use its commercially reasonable efforts to
register or qualify such registration under such other applicable securities laws of such jurisdictions within the United States as any Holder of Registrable Securities covered by such Registration Statement reasonably requests and as may be
necessary for the marketability of the Registrable Securities (such request to be made by the time the applicable Registration Statement is deemed effective by the Commission) and do any and all other acts and things necessary to enable such Holder
to consummate the disposition in such jurisdictions of the Registrable Securities owned by such Holder; provided, that the Company shall not be required to (i) qualify generally to do business in any jurisdiction where it would not
otherwise be required to qualify but for this paragraph, (ii) subject itself to taxation in any such jurisdiction, or (iii) consent to general service of process in any such jurisdiction where it has not already done so; 

  
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 (h) as promptly as practicable after becoming aware of such event, notify each Holder of
Registrable Securities, the disposition of which requires delivery of a prospectus relating thereto under the Securities Act, of the happening of any event, which comes to the Company’s attention, that will after the occurrence of such event
cause the prospectus included in such Registration Statement, if not amended or supplemented, to contain an untrue statement of a material fact or an omission to state a material fact required to be stated therein or necessary to make the statements
therein, in the light of the circumstances under which they were made, not misleading and the Company shall promptly thereafter prepare and furnish to such Holder a supplement or amendment to such prospectus (or prepare and file appropriate reports
under the Exchange Act) so that, as thereafter delivered to the purchasers of such Registrable Securities, such prospectus shall not contain an untrue statement of a material fact or omit to state any material fact required to be stated therein or
necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, unless suspension of the use of such prospectus otherwise is authorized herein or in the event of a Blackout Period, in which
case no supplement or amendment need be furnished (or Exchange Act filing made) until the termination of such suspension or Blackout Period; provided that any and all information provided to the Holder pursuant to such notification shall remain
confidential to each Holder until such information otherwise becomes public, unless disclosure by a Holder is required by law; 
 (i) comply,
and continue to comply during the Effectiveness Period, in all material respects with the Securities Act and the Exchange Act and with all applicable rules and regulations of the Commission with respect to the disposition of all securities covered
by such Registration Statement; 
 (j) as promptly as practicable after becoming aware of such event, notify each Holder of Registrable
Securities being offered or sold pursuant to the Registration Statement of the issuance by the Commission of any stop order or other suspension of effectiveness of the Registration Statement; 

(k) use its commercially reasonable efforts to cause all the Registrable Securities covered by the Registration Statement to be quoted on the
OTC Markets Group or such other principal securities market or quotation system on which securities of the same class or series issued by the Company are then listed or traded or quoted; 

(l) provide a transfer agent and registrar, which may be a single entity, for the shares of Common Stock at all times and cooperate with the
Holders to facilitate the timely preparation and delivery of the Registrable Securities to be delivered to a transferee pursuant to the Registration Statement (whether electronically or in certificated form) which Registrable Securities shall be
free, to the extent permitted by the Subscription Agreement, of all restrictive legends, and to enable such Registrable Securities to be in such denominations and registered in such names as any such Holders may request; 

(m) cooperate with the Holders of Registrable Securities being offered pursuant to the Registration Statement to issue and deliver, or cause
its transfer agent to issue and deliver, certificates representing Registrable Securities to be offered pursuant to the Registration Statement within a reasonable time after the delivery of certificates representing the Registrable Securities to the
transfer agent or the Company, as applicable, and enable such certificates to be in such denominations or amounts as the Holders may reasonably request and registered in such names as the Holders may request; 

  
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 (n) notify the Holders, the Placement Agents and their counsel as promptly as reasonably possible
and (if requested by any such Person) confirm such notice in writing no later than one (1) Trading Day following the day: (i)(A) when a Prospectus or any prospectus supplement or post-effective amendment to a Registration Statement is proposed
to be filed; (B) when the Commission notifies the Company whether there will be a “no review,” “review” or a “completion of a review” of such Registration Statement and whenever the Commission comments in writing
on such Registration Statement (in which case the Company shall provide true and complete copies thereof and all written responses thereto to each of the Holders that pertain to the Holders as a selling stockholder, but not information which the
Company believes would constitute material and non-public information); and (C) with respect to each Registration Statement or any post-effective amendment, when the same has been declared effective,
provided, however, that such notice under this clause (C) shall be delivered to each Holder; (ii) of any request by the Commission or any other federal or state governmental authority for amendments or supplements to a Registration
Statement or prospectus or for additional information that pertains to the Holders as selling stockholders; or (iii) of the receipt by the Company of any notification with respect to the suspension of the qualification or exemption from
qualification of any of the Registrable Securities for sale in any jurisdiction, or the initiation or threatening of any proceeding for such purpose; 

(o) during the Effectiveness Period, refrain from bidding for or purchasing any Common Stock or any right to purchase Common Stock or
attempting to induce any person to purchase any such security or right if such bid, purchase or attempt would in any way limit the right of the Holders to sell Registrable Securities by reason of the limitations set forth in Regulation M of the
Exchange Act; and 
 (p) take all other commercially reasonable actions necessary to enable, expedite, or facilitate the Holders to dispose
of the Registrable Securities by means of the Registration Statement during the term of this Agreement. 
 5. Obligations of the
Holders. 
 (a) Each Holder agrees that, upon receipt of any notice from the Company of the happening of any event of the kind described
in Section 4(h) hereof or of the commencement of a Blackout Period, such Holder shall discontinue the disposition of Registrable Securities included in the Registration Statement until such Holder’s receipt of the copies of the supplemented or
amended prospectus contemplated by Section 4(h) hereof or notice of the end of the Blackout Period, and, if so directed by the Company, such Holder shall deliver to the Company (at the Company’s expense) all copies (including, without
limitation, any and all drafts), other than permanent file copies, then in such Holder’s possession, of the prospectus covering such Registrable Securities current at the time of receipt of such notice. 

  
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 (b) The Holders of the Registrable Securities shall provide such information as may reasonably be
requested by the Company in connection with the preparation of any registration statement, including amendments and supplements thereto, in order to effect the registration of any Registrable Securities under the Securities Act pursuant to Section
3(a) of this Agreement and in connection with the Company’s obligation to comply with federal and applicable state securities laws, including a completed questionnaire in the form attached to this Agreement as Annex A (a “Selling
Securityholder Questionnaire”) or any update thereto not later than three (3) Business Days following a request therefore from the Company. 

(c) Each Holder, by its acceptance of the Registrable Securities, agrees to cooperate with the Company as reasonably requested by the Company
in connection with the preparation and filing of any Registration Statement hereunder, unless such Holder has notified the Company in writing of its election to exclude all of its Registrable Securities from such Registration Statement. 

6. Registration Expenses. The Company shall pay all expenses in connection with any registration obligation provided herein, including,
without limitation, all registration, filing, stock exchange fees, printing expenses, all fees and expenses of complying with applicable securities laws, and the fees and disbursements of counsel for the Company and of the Company’s independent
accountants and reasonable fees and disbursements of a single counsel of the Holders selected by the Company and reasonably acceptable to the Holders of at least a majority of the Registrable Securities, in an amount not to exceed $30,000;
provided, that, in any underwritten registration or other Secondary Offering, the Company shall have no obligation to pay any underwriting discounts, selling commissions or transfer taxes attributable to the Registrable Securities being sold
by the Holders thereof, which underwriting discounts, selling commissions and transfer taxes shall be borne by such Holders. Except as provided in this Section 6 and Section 8 of this Agreement, the Company shall not be responsible for the
expenses of any attorney or other advisor employed by a Holder. 
 7. Assignment of Rights. No Holder may assign its rights under
this Agreement to any party without the prior written consent of the Company; provided, however, that any Holder may assign its rights under this Agreement without such consent to a Permitted Assignee as long as (a) such transfer
or assignment is effected in accordance with applicable securities laws; (b) such transferee or assignee agrees in writing to become bound by and subject to the terms of this Agreement; and (c) such Holder notifies the Company in writing
of such transfer or assignment, stating the name and address of the transferee or assignee and identifying the Registrable Securities with respect to which such rights are being transferred or assigned. The Company may assign this Agreement or any
rights or obligations hereunder without the prior written consent of the other party hereto. 
 8. Indemnification. 

(a) In the event of the offer and sale of Registrable Securities under the Securities Act, the Company shall, and hereby does, indemnify and
hold harmless, to the fullest extent permitted by law, each Holder, its directors, officers, partners, and each other person, if any, who controls or is under common control with such Holder within the meaning of Section 15 of the Securities
Act, against any losses, claims, damages or liabilities, joint or several, and expenses to which the Holder or any such director, officer, partner or controlling person may become subject under the Securities Act or otherwise, insofar as such
losses, claims, damages, liabilities or expenses (or actions or proceedings, whether commenced or threatened, in respect 

  
 12 

 
thereof) arise out of or are based upon any untrue statement of any material fact contained in any registration statement prepared and filed by the Company under which Registrable Securities were
registered under the Securities Act, any preliminary prospectus, final prospectus or summary prospectus contained therein, or any amendment or supplement thereto, or any omission to state therein a material fact required to be stated or necessary to
make the statements therein in light of the circumstances in which they were made not misleading, and the Company shall reimburse the Holder, and each such director, officer, partner and controlling person for any legal or any other expenses
reasonably incurred by them in connection with investigating, defending or settling any such loss, claim, damage, liability, action or proceeding; provided, however, that the Company shall not be liable in any such case (i) to the
extent that any such loss, claim, damage, liability (or action or proceeding in respect thereof) or expense arises out of or is based upon (x) an untrue statement in or omission from such registration statement, any such preliminary prospectus,
final prospectus, summary prospectus, amendment or supplement in reliance upon and in conformity with written information included in the Selling Securityholder Questionnaire, attached hereto as Annex A, furnished by a Holder or its representative
to the Company expressly for use in the preparation thereof or (y) the failure of a Holder to comply with the covenants and agreements contained in Section 5 hereof respecting the sale of Registrable Securities; or (ii) if the person
asserting any such loss, claim, damage, liability (or action or proceeding in respect thereof) who purchased the Registrable Securities that are the subject thereof did not receive a copy of an amended preliminary prospectus or the final prospectus
(or the final prospectus as amended or supplemented) at or prior to the written confirmation of the sale of such Registrable Securities to such person because of the failure of such Holder to so provide such amended preliminary or final prospectus
and the untrue statement or omission of a material fact made in such preliminary prospectus was corrected in the amended preliminary or final prospectus (or the final prospectus as amended or supplemented). Such indemnity shall remain in full force
and effect regardless of any investigation made by or on behalf of the Holders, or any such director, officer, partner or controlling person and shall survive the transfer of such shares by the Holder. 

(b) As a condition to including Registrable Securities in any registration statement filed pursuant to this Agreement, each Holder agrees,
severally and not jointly, to be bound by the terms of this Section 8 and to indemnify and hold harmless, to the fullest extent permitted by law, the Company, each of its directors, officers, partners, and each underwriter, if any, and each
other person, if any, who controls the Company within the meaning of Section 15 of the Securities Act, against any losses, claims, damages or liabilities, joint or several, to which the Company or any such director or officer or controlling
person may become subject under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions or proceedings, whether commenced or threatened, in respect thereof) arise out of or are based upon any untrue
statement of a material fact or any omission of a material fact required to be stated in any registration statement, any preliminary prospectus, final prospectus, summary prospectus, amendment or supplement thereto or necessary to make the
statements therein not misleading, to the extent, but only to the extent, that such untrue statement or omission is included or omitted in reliance upon and in conformity with written information included in the Selling Securityholder Questionnaire,
attached hereto as Annex A, furnished by the Holder or its representative to the Company expressly for use in the preparation thereof, and such Holder shall reimburse the Company, and its directors, officers, partners, and any such controlling
persons for any legal or other expenses reasonably incurred by them in connection with investigating, defending, or 

  
 13 

 
settling any such loss, claim, damage, liability, action, or proceeding; provided, however, that indemnity obligation contained in this Section 8(b) shall in no event exceed the
amount of the net proceeds received by such Holder as a result of the sale of such Holder’s Registrable Securities pursuant to such registration statement, except in the case of fraud or willful misconduct. Such indemnity shall remain in full
force and effect, regardless of any investigation made by or on behalf of the Company or any such director, officer or controlling person and shall survive the transfer by any Holder of such shares. 

(c) Promptly after receipt by an indemnified party of notice of the commencement of any action or proceeding involving a claim referred to in
this Section 8 (including any governmental action), such indemnified party shall, if a claim in respect thereof is to be made against an indemnifying party, give written notice to the indemnifying party of the commencement of such action;
provided, that the failure of any indemnified party to give notice as provided herein shall not relieve the indemnifying party of its obligations under this Section, except to the extent that the indemnifying party is actually prejudiced by
such failure to give notice. In case any such action is brought against an indemnified party, unless in the reasonable judgment of counsel to such indemnified party a conflict of interest between such indemnified party and indemnifying parties may
exist or the indemnified party may have defenses not available to the indemnifying party in respect of such claim, the indemnifying party shall be entitled to participate in and to assume the defense thereof, with counsel reasonably satisfactory to
such indemnified party and, after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party shall not be liable to such indemnified party for any legal or other expenses
subsequently incurred by the latter in connection with the defense thereof, unless in such indemnified party’s reasonable judgment a conflict of interest between such indemnified and indemnifying parties arises in respect of such claim after
the assumption of the defenses thereof or the indemnifying party fails to defend such claim in a diligent manner, other than reasonable costs of investigation. Neither an indemnified party nor an indemnifying party shall be liable for any settlement
of any action or proceeding effected without its consent. No indemnifying party shall, without the consent of the indemnified party, consent to entry of any judgment or enter into any settlement, which does not include as an unconditional term
thereof the giving by the claimant or plaintiff to such indemnified party of a release from all liability in respect of such claim or litigation. Notwithstanding anything to the contrary set forth herein, and without limiting any of the rights set
forth above, in any event any party shall have the right to retain, at its own expense, counsel with respect to the defense of a claim. Each indemnified party shall furnish such information regarding itself or the claim in question as an
indemnifying party may reasonably request in writing and as shall be reasonably required in connection with defense of such claim and litigation resulting therefrom. 

(d) If an indemnifying party does not or is not permitted to assume the defense of an action pursuant to Section 8(c) or in the case of the
expense reimbursement obligation set forth in Sections 8(a) and 8(b), the indemnification required by Sections 8(a) and 8(b) shall be made by periodic payments of the amount thereof during the course of the investigation or defense, as and when
bills are received or expenses, losses, damages, or liabilities are incurred. 

  
 14 

 (e) If the indemnification provided for in Section 8(a) or 8(b) is held by a court of competent
jurisdiction to be unavailable to an indemnified party with respect to any loss, liability, claim, damage or expense referred to herein, the indemnifying party, in lieu of indemnifying such indemnified party hereunder, shall contribute to the amount
paid or payable by such indemnified party as a result of such loss, liability, claim, damage or expense (i) in such proportion as is appropriate to reflect the proportionate relative fault of the indemnifying party on the one hand and the
indemnified party on the other (determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or omission relates to information supplied by the indemnifying party or the indemnified party and the
parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such untrue statement or omission), or (ii) if the allocation provided by clause (i) above is not permitted by applicable law or provides
a lesser sum to the indemnified party than the amount hereinafter calculated, then in such proportion as is appropriate to reflect not only the proportionate relative fault of the indemnifying party and the indemnified party, but also the relative
benefits received by the indemnifying party on the one hand and the indemnified party on the other, as well as any other relevant equitable considerations. Notwithstanding any other provision of this Section 8(e), no Holder shall be required to
contribute any amount in excess of the amount by which the net proceeds received by such Holder from the sale of the Registrable Securities pursuant to the Registration Statement exceeds the amount of damages that such Holder has otherwise been
required to pay by reason of such untrue or alleged untrue statement of a material fact or omission, except in the case of fraud or willful misconduct. No indemnified party guilty of fraudulent misrepresentation (within the meaning of Section 11(f)
of the Securities Act) shall be entitled to contribution from any indemnifying party who was not guilty of such fraudulent misrepresentation. 

9. Rule 144. The Company shall file with the Commission “Form 10 information” (as defined in Rule 144(i)(3) under the
Securities Act) reflecting its status as an entity that is no longer an issuer described in Rule 144(i)(1)(i) promptly following the closing of the Merger. Following the Effective Date, the Company will use its commercially reasonable efforts to
timely file all reports required to be filed by the Company after the date hereof under the Exchange Act and the rules and regulations adopted by the Commission thereunder, and if the Company is not required to file reports pursuant to such
sections, it will prepare and furnish to the Purchasers and make publicly available in accordance with Rule 144(c) such information as is required for the Purchasers to sell shares of Common Stock under Rule 144. 

10. Independent Nature of Each Purchaser’s Obligations and Rights. The obligations of each Purchaser and each Broker under this
Agreement are several and not joint with the obligations of any other Purchaser or Broker, and each Purchaser and each Broker shall not be responsible in any way for the performance of the obligations of any other Purchaser or any Broker under this
Agreement. Nothing contained herein and no action taken by any Purchaser or Broker pursuant hereto, shall be deemed to constitute such Purchasers and/or Brokers as a partnership, an association, a joint venture, or any other kind of entity, or
create a presumption that the Purchasers and/or Brokers are in any way acting in concert or as a group with respect to such obligations or the transactions contemplated by this Agreement. Each Purchaser and each Broker shall be entitled to
independently protect and enforce its rights, including without limitation the rights arising out of this Agreement, and it shall not be necessary for any other Purchaser or Broker to be joined as an additional party in any proceeding for such
purpose. 

  
 15 

 11. Miscellaneous. 

(a) Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the United States of America and the
State of Delaware, both substantive and remedial, without regard to Delaware conflicts of law principles. Any judicial proceeding brought against either of the parties to this Agreement or any dispute arising out of this Agreement or any matter
related hereto shall be brought in the state or federal courts located in the State of Delaware and, by its execution and delivery of this Agreement, each party to this Agreement accepts the jurisdiction of such courts. The foregoing consent to
jurisdiction shall not be deemed to confer rights on any person other than the parties to this Agreement. 
 (b) Remedies. Except as
otherwise specifically set forth herein with respect to a Registration Event, in the event of a breach by the Company or by a Holder of any of their respective obligations under this Agreement, each Holder or the Company, as the case may be, in
addition to being entitled to exercise all rights granted by law and under this Agreement, including recovery of damages, shall be entitled to specific performance of its rights under this Agreement. Except as otherwise specifically set forth herein
with respect to a Registration Event, the Company and each Holder agree that monetary damages would not provide adequate compensation for any losses incurred by reason of a breach by it of any of the provisions of this Agreement and hereby further
agrees that, in the event of any action for specific performance in respect of such breach, it shall not assert or shall waive the defense that a remedy at law would be adequate. 

(c) Subsequent Registration Rights. Except with respect to the Registration Rights Agreement to be entered into among the Company and
certain of the Holders hereto who were former stockholders of Aerpio, until the Registration Statement required hereunder is declared effective by the Commission, the Company shall not enter into any agreement granting any registration rights with
respect to any of its securities to any Person without the written consent of Holders representing no less than a majority of the outstanding Registrable Securities. 

(d) Successors and Assigns. Except as otherwise provided herein, the provisions hereof shall inure to the benefit of, and be binding
upon, the successors, Permitted Assignees, executors and administrators of the parties hereto. 
 (e) No Inconsistent Agreements. The
Company has not entered, as of the date hereof, and shall not enter, on or after the date of this Agreement, into any agreement with respect to its securities that would have the effect of impairing the rights granted to the Holders in this
Agreement or otherwise conflicts with the provisions hereof. 
 (f) Entire Agreement. This Agreement and the documents, instruments
and other agreements specifically referred to herein or delivered pursuant hereto constitute the full and entire understanding and agreement between the parties with regard to the subjects hereof. 

(g) Notices, etc. All notices, consents, waivers, and other communications which are required or permitted under this Agreement shall be
in writing will be deemed given to a party (a) upon receipt, when personally delivered; (b) one (1) Business Day after deposit with an nationally recognized overnight courier service with next day delivery specified, costs

  
 16 

 
prepaid) on the date of delivery, if delivered to the appropriate address by hand or by nationally recognized overnight courier service (costs prepaid); (c) the date of transmission if sent by
facsimile or e-mail with confirmation of transmission by the transmitting equipment if such notice or communication is delivered prior to 5:00 P.M., New York City time, on a Trading Day, or the next Trading
Day after the date of transmission, if such notice or communication is delivered on a day that is not a Trading Day or later than 5:00 P.M., New York City time, on any Trading Day, provided confirmation of facsimile is mechanically or electronically
generated and kept on file by the sending party and confirmation of email is kept on file, whether electronically or otherwise, by the sending party and the sending party does not receive an automatically generated message from the recipients email
server that such e-mail could not be delivered to such recipient; (d) the date received or rejected by the addressee, if sent by certified mail, return receipt requested, postage prepaid; or
(e) seven days after the placement of the notice into the mails (first class postage prepaid), to the party at the address, facsimile number, or e-mail address furnished by the such party, 

If to the Company, to: 
 Aerpio
Pharmaceuticals, Inc. 
 9987 Carver Road, Suite 420 

Cincinnati, OH 45242 
 Attn:
Joseph Gardner, Chief Executive Officer 
 Telephone Number:
513-985-1921 
 Facsimile: 513-985-0999 
 E-mail Address: jgardner@aerpio.com

 with copy to: 
 Goodwin
Procter, LLP 
 100 Northern Avenue 

Boston, MA 02210 
 Attention:
Kingsley Taft and Danielle Lauzon 
 Facsimile: 617-523-1231

 Telephone Number: 617-570-1000 

E-mail Address: ktaft@goodwinlaw.com and dlauzon@goodwinlaw.com 

if to a Purchaser or Broker, to: 

such Purchaser or Broker at the address set forth on the signature page hereto; 

or at such other address as any party shall have furnished to the other parties in writing in accordance with this Section 11(f). 

(h) Delays or Omissions. No delay or omission to exercise any right, power or remedy accruing to any Holder, upon any breach or default
of the Company under this Agreement, shall impair any such right, power or remedy of such Holder nor shall it be construed to be a waiver of any such breach or default, or an acquiescence therein, or of any similar breach or default thereunder
occurring; nor shall any waiver of any single breach or default be deemed a waiver of any other breach or default theretofore or thereafter occurring. Any waiver, permit, 

  
 17 

 
consent or approval of any kind or character on the part of any Holder of any breach or default under this Agreement, or any waiver on the part of any Holder of any provisions or conditions of
this Agreement, must be in writing and shall be effective only to the extent specifically set forth in such writing. All remedies, either under this Agreement, or by law or otherwise afforded to any holder, shall be cumulative and not alternative.

 (i) Counterparts. This Agreement may be executed in any number of counterparts, and with respect to any Purchaser, by execution of
an Omnibus Signature Page to this Agreement and the Subscription Agreement, each of which shall be enforceable against the parties actually executing such counterparts, and all of which together shall constitute one instrument. In the event that any
signature is delivered by facsimile transmission or by an e-mail, which contains a portable document format (.pdf) file of an executed signature page, such signature shall create a valid and binding obligation
of the party executing (or on whose behalf such signature is executed) with the same force and effect as if such facsimile or e-mail of a .pdf signature page were an original thereof. 

(j) Severability. In the case any provision of this Agreement shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or impaired thereby. 
 (k) Amendments. Except as
otherwise provided herein, the provisions of this Agreement may be amended at any time and from time to time, and particular provisions of this Agreement may be waived, with and only with an agreement or consent in writing signed by the Company and
the Majority Holders; provided that this Agreement may not be amended and the observance of any term hereof may not be waived with respect to any Holder without the written consent of such Holder unless such amendment or waiver applies to all
Holders in the same fashion. The Purchasers and Brokers acknowledge that by the operation of this Section, the Majority Holders may have the right and power to diminish or eliminate all rights of the Purchasers and/or Brokers under this Agreement.

 [COMPANY SIGNATURE PAGE FOLLOWS] 

  
 18 

 This Registration Rights Agreement is hereby executed as of the date first above written. 

 

			
	THE COMPANY:
	
	Aerpio Pharmaceuticals, Inc.
		
	By:	 	 /s/ Joseph H. Gardner

	 Name:
	 	 Joseph H. Gardner

	 Title:
	 	 President and CEO

 PURCHASERS 

See Omnibus Signature Pages to Subscription 

Agreement 
  

							
	 BROKER (INDIVIDUAL):
	 		 	 BROKER (ENTITY):

			
	  
	 		 	 
	 Print Name
	 		 	 Print Name of Entity

				
	  
	 		 	 By:
	 	  

	 Signature
	 		 	 Name:
	 	
		 		 	 Title:
	 	
			
	REGISTRABLE PRE-MERGER STOCKHOLDER (INDIVIDUAL):	 		 	REGISTRABLE PRE-MERGER STOCKHOLDER (ENTITY):
			
	  
	 		 	  

	 Print Name
	 		 	 Print Name of Entity

				
	  
	 		 	 By:
	 	  

	 Signature
	 		 	 Name:
	 	
		 		 	 Title:
	 	
			
	HOLDER OF MERGER SHARES (INDIVIDUAL):	 		 	HOLDER OF MERGER SHARES (ENTITY):
			
	  
	 		 	  

	 Print Name
	 		 	 Print Name of Entity

				
	  
	 		 	 By:
	 	  

	 Signature
	 		 	 Name:
	 	
		 		 	 Title:
	 	
				
	 All Holders: Address
	 		 		 	
	 	 		 		 	
	 	 		 		 	
	 	 		 		 	

 Annex A 

Aerpio Pharmaceuticals, Inc. 

Selling Securityholder Notice and Questionnaire 

The undersigned beneficial owner of Registrable Securities of Aerpio Pharmaceuticals, Inc., a Delaware corporation (the
“Company”), understands that the Company has filed or intends to file with the U.S. Securities and Exchange Commission a registration statement (the “Registration Statement”) for the registration and resale under
Rule 415 of the Securities Act of 1933, as amended, of the Registrable Securities, in accordance with the terms of the Registration Rights Agreement (the “Registration Rights Agreement”) to which this document is annexed. A copy of
the Registration Rights Agreement is available from the Company upon request at the address set forth below. All capitalized terms not otherwise defined herein shall have the meanings ascribed thereto in the Registration Rights Agreement. 

Certain legal consequences arise from being named as a selling security holder in the Registration Statement and the related prospectus.
Accordingly, holders and beneficial owners of Registrable Securities are advised to consult their own securities law counsel regarding the consequences of being named or not being named as a selling security holder in the Registration Statement and
the related prospectus. 
 NOTICE 

The undersigned beneficial owner (the “Selling Securityholder”) of Registrable Securities hereby elects to include the
Registrable Securities owned by it in the Registration Statement. 
 The undersigned hereby provides the following information to the
Company and represents and warrants that such information is accurate: 
 QUESTIONNAIRE 

 

	1.	Name: 

  

			
	(a)	    	Full Legal Name of Selling Securityholder
		
		    	  

		    	  

		
	(b)	    	Full Legal Name of Registered Holder (holder of record) (if not the same as (a) above) through which Registrable Securities are held:
		
		    	  

		    	  

			
	(c)	    	If you are not a natural person, full Legal Name of Natural Control Person (which means a natural person who directly or indirectly alone or with others has power to vote or dispose of the securities covered by this
Questionnaire):
		
		    	  

		    	  

  

	2.	Address for Notices to Selling Securityholder: 

  

	
	 
	 
	 
	
Telephone:                 
                                         
                                  Fax:      
                                         
                                         
                              

	
Email:                  
                                         
                                         
                                         
                                         
                                         
                     

	 Contact
Person:                                        
                                         
                                         
                                         
                                         
                       

  

	3.	Broker-Dealer Status: 

  

	 	(a)	Are you a broker-dealer? 

Yes    ☐    No    ☐ 

 

	 	(b)	If “yes” to Section 3(a), did you receive your Registrable Securities as compensation for investment banking services to the Company? 

Yes    ☐    No    ☐ 

 

	 	Note:	If “no” to Section 3(b), the Commission’s staff has indicated that you should be identified as an underwriter in the Registration Statement. 

 

	 	(c)	Are you an affiliate of a broker-dealer? 

Yes    ☐    No    ☐ 

 

	 	(d)	If you are an affiliate of a broker-dealer, do you certify that you purchased the Registrable Securities in the ordinary course of business, and at the time of the purchase of the Registrable Securities to be resold,
you had no agreements or understandings, directly or indirectly, with any person to distribute the Registrable Securities? 

Yes    ☐    No    ☐ 

 

	 	Note:	If “no” to Section 3(d), the Commission’s staff has indicated that you should be identified as an underwriter in the Registration Statement. 

 

	4.	Beneficial Ownership of Securities of the Company Owned by the Selling Securityholder: 

Except as set forth below in this Item 4, the undersigned is not the beneficial or registered owner of any securities of the Company.

			
	(a)	    	Please list the type (common stock, warrants, etc.) and amount of all securities of the Company (including any Registrable Securities) beneficially owned1 by the Selling
Securityholder:
		
		    	  

		    	  

  

	5.	Relationships with the Company: 

  

	
	Except as set forth below, neither you nor (if you are a natural person) any member of your immediate family, nor (if you are not a natural person) any of your affiliates2,
officers, directors or principal equity holders (owners of 5% of more of the equity securities of the undersigned) has held any position or office or has had any other material relationship with the Company (or its predecessors or affiliates) during
the past three years.
	
	State any exceptions here:
	
	  

	  

  
  

	1 	Beneficially Owned: A “beneficial owner” of a security includes any person who, directly or indirectly, through any contract, arrangement, understanding, relationship or
otherwise has or shares (i) voting power, including the power to direct the voting of such security, or (ii) investment power, including the power to dispose of, or direct the
disposition of, such security. In addition, a person is deemed to have “beneficial ownership” of a security of which such person has the right to acquire beneficial ownership at any time within 60 days, including, but not limited
to, any right to acquire such security: (i) through the exercise of any option, warrant or right, (ii) through the conversion of any security or (iii) pursuant to the power to revoke, or the automatic termination of, a trust,
discretionary account or similar arrangement. 

 It is possible that a security may have more than one “beneficial
owner,” such as a trust, with two co-trustees sharing voting power, and the settlor or another third party having investment power, in which case each of the three would be the “beneficial owner” of the securities in the trust. The
power to vote or direct the voting, or to invest or dispose of, or direct the investment or disposition of, a security may be indirect and arise from legal, economic, contractual or other rights, and the determination of beneficial ownership depends
upon who ultimately possesses or shares the power to direct the voting or the disposition of the security. 
 The final determination of the
existence of beneficial ownership depends upon the facts of each case. You may, if you believe the facts warrant it, disclaim beneficial ownership of securities that might otherwise be considered “beneficially owned” by you. 

 

	2 	Affiliate: An “affiliate” is a company or person that directly, or indirectly through one or more intermediaries, controls you, or is controlled by you, or is under
common control with you. 

 The undersigned agrees to promptly notify the Company of any inaccuracies or changes in the
information provided herein that may occur subsequent to the date hereof at any time while the Registration Statement remains effective. 

By signing below, the undersigned consents to the disclosure of the information contained herein in its answers to Items 1 through 5 and the
inclusion of such information in the Registration Statement and the related prospectus and any amendments or supplements thereto. The undersigned understands that such information will be relied upon by the Company in connection with the preparation
or amendment of the Registration Statement and the related prospectus and any amendments or supplements thereto. 
 IN WITNESS WHEREOF the
undersigned, by authority duly given, has caused this Selling Securityholder Notice and Questionnaire to be executed and delivered either in person or by its duly authorized agent. 

 

					
	BENEFICIAL OWNER (individual)	 		  	BENEFICIAL OWNER (entity)
			
	  
	 		  	  

	Signature	 		  	Name of Entity
			
	  
	 		  	  

	Print Name	 		  	Signature
			
	  
	 		  	Print
Name:                                        
                                         
           
	Signature (if Joint Tenants or Tenants in Common)	 		  	
		 		  	Title:                                     
                                         
                           

 PLEASE E-MAIL OR FAX A COPY OF THE COMPLETED AND EXECUTED SELLING SECURITYHOLDER
NOTICE AND QUESTIONNAIRE, AND RETURN THE ORIGINAL BY OVERNIGHT MAIL, TO: 
 CKR Law LLP 

1330 Avenue of the Americas, 14th Floor 

New York, NY 10022 
 Attention:
Eleanor Osmanoff 
 Facsimile: (212) 259-8200 

E-mail Address: eosmanoff@ckrlaw.comEX-10.6

 Exhibit 10.6 

SUBSCRIPTION AGREEMENT 
 This Subscription
Agreement (this “Agreement”) has been executed by the purchaser set forth on the signature page hereof (the “Purchaser”) in connection with the private placement offering (the
“Offering”) by Aerpio Pharmaceuticals, Inc. (f/k/a Zeta Acquisition Corp. II), a Delaware corporation (the “Company”) of a minimum of $35,000,000 (the “Minimum Offering”)
of shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (“Common Stock”), at a purchase price of $5.00 per Share (the “Purchase Price”), plus up
to an additional $5,000,000 of Shares at the Purchase Price to cover over-subscriptions (the “Over-Subscription Option”), in the event the Offering is oversubscribed. This subscription is being submitted to you in accordance
with and subject to the terms and conditions described in this Agreement, the Confidential and Non-Binding Summary Term Sheet of the Company previously provided to the Purchaser relating to the Offering (as
the same may be amended or supplemented, the “Term Sheet”), and any other Disclosure Materials (as defined below). The minimum subscription is $50,000.00 (10,000 Shares). The Company may accept subscriptions for less than
$50,000 in its sole discretion. 
 The Shares being subscribed for pursuant to this Agreement have not been registered under the Securities Act of 1933, as
amended (the “Securities Act”). The Offering is being made on a reasonable best efforts basis to “accredited investors,” as defined in Regulation D under the Securities Act in reliance upon the exemption from
securities registration afforded by Section 4(a)(2) of the Securities Act and Rule 506 of Regulation D. 
 The Shares are being offered and sold
in connection with a reverse triangular merger (the “Merger”) between a subsidiary of the Company and Aerpio Therapeutics, Inc., a Delaware corporation (“Aerpio”), pursuant to which Aerpio will
become a wholly owned subsidiary of the Company, and all of the outstanding capital stock of Aerpio will be exchanged for shares of the Company’s Common Stock (the “Merger Shares”), and outstanding Aerpio stock options
will be converted into options to purchase the Company’s Common Stock at the same ratio at which shares of outstanding Aerpio capital stock are exchanged, as further described in the Term Sheet, and certain other transactions on the terms and
conditions described in the Term Sheet. Such other transactions include (i) immediately following the Merger, the conversion of Aerpio to a Delaware limited liability company (the “LLC Conversion”), (ii) immediately
following the LLC Conversion, the surrender for cancellation by certain pre-Merger stockholders of the Company of 4,000,000 of the 5,000,000 shares of the Company’s Common Stock held by them (the
“Cancellation”) and (iii) immediately following the Cancellation, the Offering. 
 The undersigned acknowledges receipt of a
copy of the Registration Rights Agreement, substantially in the form of Exhibit A hereto (the “Registration Rights Agreement”), pursuant to which, among other things, the Company agrees to register under the Securities
Act for resale the Shares, the shares of Common Stock issuable upon exercise of the Placement Agent Warrants (as such term is defined below), the Merger Shares and the 1,000,000 shares of Common Stock held by other stockholders of the Company. 

Each closing of the Offering (a “Closing,” and the date on which such Closing occurs hereinafter referred to as the
“Closing Date”) shall take place at the offices of CKR Law LLP, at 1330 Avenue of the Americas, New York, New York 10019 (or such other place as is mutually agreed to by the Company and the Placement Agents (as defined
below)). Stockholders of Aerpio prior to the Merger shall purchase a minimum aggregate amount of $17,500,000 of the Offering (the “Minimum Insider Investment”). 

 

 The first Closing will not occur unless: 

 

	 	a.	funds deposited in escrow as described in Section 2b below are equal to at least the Minimum Offering (including the Minimum Insider Investment), and corresponding documentation with respect to such
amounts, have been delivered by the Purchaser and other “Purchasers” under Subscription Agreements of like tenor with this Agreement (collectively, the “Purchasers”) as described in Section 2a below;

  

	 	b.	the Merger, LLC Conversion and Cancellation have been effected; and 

  

	 	c.	the other conditions set forth in Sections 7 and 8 shall have been satisfied. 

 Thereafter, the Company may
conduct one or more additional Closings for the sale of the Shares until the termination of the Offering. Unless terminated earlier by the Company, the Offering shall continue until March 3, 2017, which period may be extended by the Company
until a date not later than March 17, 2017, without notice to any Purchaser, past, current or prospective. 
 The Term Sheet and any supplement or
amendment thereto, and any disclosure schedule or other information document, delivered to the Purchaser prior to Purchaser’s execution of this Agreement, and any such document delivered to the Purchaser after Purchaser’s execution of this
Agreement and prior to the Closing of the Purchaser’s subscription hereunder (including, without limitation, a substantially complete draft of the Current Report on Form 8-K describing the Merger, the
Offering and the related transactions, including “Form 10 information” (as defined in Rule 144(i)(3) under the Securities Act), to be filed by the Company with the Securities and Exchange Commission (the “SEC”)
within four Business Days after the closing of the Merger and the initial Closing of the Offering (the “Super 8-K”)), are collectively referred to as the “Disclosure
Materials.” (“Business Day” means a day, other than a Saturday or Sunday, on which banks in New York City are open for the general transaction of business.) 

 

	 	1.	Subscription. The undersigned Purchaser hereby subscribes to purchase the number of Shares set forth on the Omnibus Signature Page attached hereto, for the aggregate Purchase Price as set forth on such Omnibus
Signature Page, subject to the terms and conditions of this Agreement and on the basis of the representations, warranties, covenants and agreements contained herein. 

 

	 	2.	Subscription Procedure. To complete a subscription for the Shares, the Purchaser must fully comply with the subscription procedure provided in paragraphs a. through c. of this Section on or before the Closing
Date. 

  

	 	a.	Subscription Documents. On or before the Closing Date, the Purchaser shall review, complete and execute the Omnibus Signature Page to this Agreement and the Registration Rights Agreement, Investor Profile,
Anti-Money Laundering Form and Investor Certification, attached hereto following the Omnibus Signature Page (collectively, the “Subscription Documents”), if applicable, additional forms and questionnaires distributed to the
Purchaser and deliver the Subscription Documents and such additional forms and questionnaires to CKR Law LLP (“CKR”), at the address set forth under the caption “How to subscribe for Shares in the private offering of
Aerpio.” below. Executed documents may be delivered to CKR by facsimile or .pdf sent by electronic mail (e-mail), if the Purchaser delivers the original copies of the documents to CKR as
soon as practicable thereafter. 

  
 2 

	 	b.	Purchase Price. Simultaneously with the delivery of the Subscription Documents to CKR as provided herein, and in any event on or prior to the Closing Date, the Purchaser shall deliver to Delaware Trust Company,
in its capacity as escrow agent (the “Escrow Agent”), under an escrow agreement among the Company, the Placement Agents (as defined below) and the Escrow Agent (the “Escrow Agreement”) the full
Purchase Price by certified or other bank check or by wire transfer of immediately available funds, pursuant to the instructions set forth under the caption “How to subscribe for Shares in the private offering of Aerpio” below. Such
funds will be held for the Purchaser’s benefit in the escrow account established for the Offering (the “Escrow Account”) and will be returned promptly, without interest or offset, if this Agreement is not
accepted by the Company or the Offering is terminated pursuant to its terms prior to the Closing. 

  

	 	c.	Company Discretion. The Purchaser understands and agrees that the Company in its sole discretion reserves the right to accept or reject this or any other subscription for Shares, in whole or in part,
notwithstanding prior receipt by the Purchaser of notice of acceptance of this subscription. The Company shall have no obligation hereunder until the Company shall execute and deliver to the Purchaser an executed copy of this Agreement. If this
subscription is rejected in whole, or the Offering is terminated, all funds received from the Purchaser will be returned without interest or offset, and this Agreement shall thereafter be of no further force or effect. If this subscription is
rejected in part, the funds for the rejected portion of this subscription will be returned without interest or offset, and this Agreement will continue in full force and effect to the extent this subscription was accepted. 

 

	 	3.	Placement Agents. Raymond James & Associates, Inc., National Securities Corporation and Katalyst Securities LLC, each a broker-dealer licensed with FINRA, have been engaged on a co-exclusive basis as placement agents (the “Placement Agents”) for the Offering on a reasonable best efforts basis. The Placement Agents will be paid at each Closing from the proceeds in the
Escrow Account, a cash commission of seven percent (7%) of the gross Purchase Price paid by Purchasers in the Offering introduced by them (“Cash Fee”) and will receive warrants to purchase a number of shares of Common Stock
equal to seven percent (7%) of the number of Shares sold to the investors in the Offering introduced by the Placement Agents, with a term of three (3) years from the relevant Closing Date, and an exercise price of $5.00 per share (the
“Placement Agent Warrants”); provided, however, that with respect to the Purchase Price paid by existing shareholders of Aerpio or their Affiliates (as defined below), the Placement Agents will be paid a Cash Fee of six
percent (6%) and will receive no Placement Agent Warrants. Any sub-agent of a Placement Agent that introduces investors to the Offering will be entitled to share in the Cash Fees and Placement Agent Warrants
attributable to those investors as described above, pursuant to the terms of an executed sub-agent agreement. The Company will also pay certain expenses of the Placement Agents in connection with the Offering.

  
 3 

	 	4.	Representations and Warranties of the Company. Except as set forth in the Super 8-K, which disclosures (other than disclosures under “risk factors” or similar
disclosures, unless otherwise specified below) qualify these representations and warranties in their entirety, the Company hereby represents and warrants to the Purchaser, as of the date hereof and on each Closing Date after giving effect to the
Merger, the LLC Conversion and the Cancellation (unless otherwise specified), the following: 

  

	 	a.	Organization and Qualification. The Company and each of its subsidiaries is a corporation or other business entity duly organized, validly existing and in good standing under the laws of the jurisdiction of its
formation, and has the requisite corporate power to own its properties and to carry on its business as now being conducted. The Company and each of its subsidiaries is duly qualified as a foreign corporation to do business and is in good standing in
every jurisdiction in which the nature of the business conducted by it makes such qualification necessary, except to the extent that the failure to be so qualified or be in good standing would not have a material adverse effect on the assets,
business, financial condition, results of operations or future prospects of the Company and its subsidiaries (in each case as described in the Super 8-K) taken as a whole (a “Material Adverse
Effect”). Each subsidiary of the Company is identified on Schedule 4a attached hereto. 

  

	 	b.	Authorization, Enforcement, Compliance with Other Instruments. (i) The Company has the requisite corporate power and authority to enter into and perform its obligations under this Agreement, the Registration
Rights Agreement, the Escrow Agreement and each of the other agreements and documents that are exhibits hereto or thereto or are contemplated hereby or thereby or necessary or desirable to effect the transactions contemplated hereby or thereby (the
“Transaction Documents”) and to issue the Shares, in accordance with the terms hereof and thereof; (ii) the execution and delivery by the Company of each of the Transaction Documents and the consummation by it of the
transactions contemplated hereby and thereby, including, without limitation, the issuance of the Shares, have been, or will be at the time of execution of such Transaction Document, duly authorized by the Company’s Board of Directors, and no
further consent or authorization is, or will be at the time of execution of such Transaction Document, required by the Company, its respective Board of Directors or its stockholders; (iii) each of the Transaction Documents will be duly executed
and delivered by the Company; and (iv) the Transaction Documents when executed will constitute the valid and binding obligations of the Company enforceable against the Company in accordance with their terms, except as such enforceability may be
limited by general principles of equity or applicable bankruptcy, insolvency, reorganization, moratorium, liquidation or similar laws relating to, or affecting generally, the enforcement of creditors’ rights and remedies and, with respect to
any rights to indemnity or contribution contained in the Registration Rights Agreement, as such rights may be limited by state or federal laws or public policy underlying such laws. 

 

	 	c.	 Capitalization. The authorized capital stock of the Company consists of 100,000,000 shares of Common Stock
and 10,000,000 shares of preferred stock. After giving effect to the Merger, the LLC Conversion and the Cancellation, but immediately before the initial Closing of the Offering, the Company will have 19,000,000 shares of Common Stock and no

  
 4 

	 	
preferred stock issued and outstanding. All of the outstanding shares of Common Stock and of the capital stock of each of the Company’s subsidiaries have been duly authorized, validly issued
and are fully paid and nonassessable. Immediately after giving effect to the Closing of the Minimum Offering, the pro forma outstanding capitalization of the Company will be as set forth under “Pro Forma Capitalization” in
Schedule 4c. After giving effect to the Merger: (i) no shares of capital stock of the Company or any of its subsidiaries will be subject to preemptive rights or any other similar rights or any liens or encumbrances (other than as
contemplated by Section 7(f) hereof) suffered or permitted by the Company; (ii) except as set forth on Schedule 4c(ii) there will be no outstanding options, warrants, scrip, rights to subscribe to, calls or commitments of any
character whatsoever relating to, or securities or rights convertible into, any shares of capital stock of the Company or any of its subsidiaries, or contracts, commitments, understandings or arrangements by which the Company or any of its
subsidiaries is or may become bound to issue additional shares of capital stock of the Company or any of its subsidiaries; (iii) there will be no outstanding debt securities of the Company or any of its subsidiaries other than
indebtedness as set forth in Schedule 4c(iii); (iv) other than pursuant to the Registration Rights Agreement or as set forth in Schedule 4c(iv), there will be no agreements or arrangements under which the Company or
any of its subsidiaries is obligated to register the sale of any of their securities under the Securities Act; (v) there will be no outstanding registration statements of the Company or any of its subsidiaries, and there will be no
outstanding comment letters from the SEC or any other regulatory agency; (vi) except as provided in this Agreement or as set forth in Schedule 4c(vi), there will be no securities or instruments of the Company or any of its
subsidiaries containing anti-dilution or similar provisions, including the right to adjust the exercise, exchange or reset price under such securities, that will be triggered by the issuance of the Shares as described in this Agreement; and
(vii) no co-sale right, right of first refusal or other similar right will exist with respect to the Shares or the issuance and sale thereof. Upon request, the Company will make available to the Purchaser
true and correct copies of the Company’s Certificate of Incorporation, as in effect as of the first Closing Date, and the Company’s By-laws, as in effect as of the first Closing Date, and the terms
of all securities exercisable for Common Stock and the material rights of the holders thereof in respect thereto other than stock options issued to officers, directors, employees and consultants. 

 

	 	d.	Issuance of Shares. The Shares are duly authorized and, when issued and paid for in accordance with the terms hereof, shall be duly issued, fully paid and nonassessable, and are free and clear of all taxes, liens
and charges with respect to the issue thereof. The shares of Common Stock underlying the Placement Agent Warrants (the “Underlying Shares”) have been duly authorized and reserved for issuance, and upon exercise of the
Placement Agent Warrants in accordance with their terms, including payment of the exercise price therefor, will be validly issued, fully paid and nonassessable, and are free and clear from all taxes, liens and charges with respect to the issue
thereof. 

  

	 	e.	 No Conflicts. The execution, delivery and performance of each of the Transaction Documents by the Company,
and the consummation by the Company of the transactions contemplated hereby and thereby will not (i) result in a violation of the Certificate of Incorporation or the By-laws (or equivalent constitutive
document) of the Company or any of 

  
 5 

	 	
its subsidiaries or (ii) violate or conflict with, or result in a breach of any provision of, or constitute a default (or an event which with notice or lapse of time or both would become a
default) under, or give to others any rights of termination, amendment, acceleration or cancellation of, any agreement, indenture or instrument to which the Company or any subsidiary is a party, except for those which would not reasonably be
expected to have a Material Adverse Effect, or (iii) result in a violation of any law, rule, regulation, order, judgment or decree (including U.S. federal and state securities laws and regulations) applicable to the Company or any subsidiary or
by which any property or asset of the Company or any subsidiary is bound or affected, except for those which would not reasonably be expected to have a Material Adverse Effect. Neither the Company nor any subsidiary is in violation of any term of or
in default under its Certificate of Incorporation or By-laws or any other constitutive documents. Except for those violations or defaults which would not reasonably be expected to have a Material Adverse
Effect, neither the Company nor any subsidiary is in violation of any term of or in default under any material contract, agreement, mortgage, indebtedness, indenture, instrument, judgment, decree or order or any statute, rule or regulation
applicable to the Company or any subsidiary. The business of the Company and its subsidiaries is not being conducted, and shall not be conducted in violation of any law, ordinance, or regulation of any governmental entity, except for any violation
which would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect. Except as specifically contemplated by this Agreement and as required under the Securities Act and any applicable state securities laws,
neither the Company nor any of its subsidiaries is required to obtain any consent, authorization or order of, or make any filing or registration with, any court or governmental agency in order for it to execute, deliver or perform any of its
obligations under or contemplated by this Agreement or the other Transaction Documents in accordance with the terms hereof or thereof. Except as set forth on Schedule 4e, neither the execution and delivery by the Company of the
Transaction Documents, nor the consummation by the Company of the transactions contemplated hereby or thereby, will require any notice, consent or waiver under any contract or instrument to which the Company or any subsidiary is a party or by which
the Company or any subsidiary is bound or to which any of their assets is subject, except for any notice, consent or waiver the absence of which would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect.
All consents, authorizations, orders, filings and registrations which the Company or any of its subsidiaries is required to obtain pursuant to the preceding two sentences have been or will be obtained or effected on or prior to the Closing.

  

	 	f.	 Absence of Litigation. Except as set forth on Schedule 4f, there is no action, suit,
claim, inquiry, notice of violation, proceeding (including any partial proceeding such as a deposition) or investigation before or by any court, public board, governmental or administrative agency, self-regulatory organization, arbitrator,
regulatory authority, stock market, stock exchange or trading facility (an “Action”) now pending or, to the knowledge of the Company, threatened, against or affecting the Company or any of its subsidiaries or any of their
respective officers or directors, which would be reasonably likely to (i) adversely affect the validity or enforceability of, or the authority or ability of the Company to perform its obligations under, this Agreement or any of the other
Transaction Documents, or (ii) have 

  
 6 

	 	
a Material Adverse Effect. For the purpose of this Agreement, the knowledge of the Company means the knowledge of the officers of the Company (for the avoidance of doubt, after giving effect to
the Merger) and Aerpio (both actual or knowledge that they would have had upon reasonable investigation). 

  

	 	g.	Acknowledgment Regarding Purchaser’s Purchase of the Shares. The Company acknowledges and agrees that each Purchaser is acting solely in the capacity of an arm’s length purchaser with respect to the
Transaction Documents and the transactions contemplated hereby and thereby. The Company further acknowledges that no Purchaser is acting as a financial advisor or fiduciary of the Company (or in any similar capacity) with respect to the Transaction
Documents and the transactions contemplated thereby and any advice given by any Purchaser or any of their respective representatives or agents in connection with the Transaction Documents and the transactions contemplated thereby is merely
incidental to the Purchaser’s purchase of the Shares. 

  

	 	h.	No General Solicitation. Neither the Company, nor any of its Affiliates, nor, to the knowledge of the Company, any person acting on its or their behalf, has engaged in any form of general solicitation or general
advertising (within the meaning of Regulation D) in connection with the offer or sale of the Shares. “Affiliate” means, with respect to any person, any other person that, directly or indirectly through one or more
intermediaries, controls, is controlled by or is under common control with such person, as such terms are used in and construed under Rule 144 under the Securities Act (“Rule 144”). With respect to a Purchaser, any
investment fund or managed account that is managed on a discretionary basis by the same investment manager as such Purchaser will be deemed to be an Affiliate of such Purchaser. 

 

	 	i.	No Integrated Offering. Neither the Company, nor any of its Affiliates, nor to the knowledge of the Company, any person acting on its or their behalf has, directly or indirectly, made any offers or sales of any
security or solicited any offers to buy any security, under circumstances that would require registration of the Shares under the Securities Act or cause this offering of the Shares to be integrated with prior offerings by the Company for purposes
of the Securities Act. 

  

	 	j.	Employee Relations. Neither Company nor any subsidiary is involved in any labor dispute nor, to the knowledge of the Company, is any such dispute threatened. Neither Company nor any subsidiary is party to any
collective bargaining agreement. The Company’s and/or its subsidiaries’ employees are not members of any union, and the Company believes that its and its subsidiaries’ relationship with their respective employees is good.

  

	 	k.	 Intellectual Property Rights. After giving effect to the Merger, except as set forth on Schedule
4k, the Company and each of its subsidiaries owns, possesses, or has rights to use, all Intellectual Property necessary for the conduct of the Company’s and its subsidiaries’ business as now conducted, except as such failure to
own, possess or have such rights would not reasonably be expected to result in a Material Adverse Effect and there are no unreleased liens or security interests which have been filed, or which the Company has received notice of, against any of the
patents owned to the Company. Furthermore, (A) to the Company’s 

  
 7 

	 	
knowledge, there is no infringement, misappropriation or violation by third parties of any such Intellectual Property, except as such infringement, misappropriation or violation would not result
in a Material Adverse Effect; (B) there is no pending or, to the Company’s knowledge, threatened, action, suit, proceeding or claim by others challenging the Company’s or any of its subsidiaries’ rights in or to any such
Intellectual Property, and the Company is unaware of any facts which would form a reasonable basis for any such claim; (C) the Intellectual Property owned by the Company and its subsidiaries, and to the Company’s knowledge, the
Intellectual Property licensed to the Company and its subsidiaries, has not been adjudged invalid or unenforceable, in whole or in part, and there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by
others challenging the validity, enforceability or scope of any such Intellectual Property, and, to the Company’s knowledge, there are no facts which would form a reasonable basis for any such claim; (D) there is no pending or, to the
Company’s knowledge, threatened action, suit, proceeding or claim by others that the Company or any of its subsidiaries infringes, misappropriates or otherwise violates any Intellectual Property or other proprietary rights of others, neither
the Company nor any of its subsidiaries has received any written notice of such claim, and, to the Company’s knowledge, there are no other facts which would form a reasonable basis for any such claim, except in each case for any action, suit,
proceeding or claim as would not be reasonably expected to have a Material Adverse Effect; and (E) to the Company’s knowledge, no employee of the Company or any of its subsidiaries is in in violation of any term of any employment contract,
patent disclosure agreement, invention assignment agreement, non-competition agreement, non-solicitation agreement, nondisclosure agreement or any restrictive covenant
to or with a former employer where the basis of such violation relates to such employee’s employment with the Company or any of its subsidiaries or actions undertaken by the employee while employed with the Company or any of its subsidiaries,
except as such violation would not reasonably be expected to have a Material Adverse Effect. Except as would not reasonably be expected to have a Material Adverse Effect, (1) the Company and its subsidiaries have disclosed to the U.S. Patent
and Trademark Office (USPTO) all information known to the Company to be relevant to the patentability of its inventions in accordance with 37 C.F.R. Section 1.56, and (2) neither the Company nor any of its subsidiaries made any
misrepresentation or concealed any information from the USPTO in any of the patents or patent applications owned or licensed to the Company, or in connection with the prosecution thereof, in violation of 37 C.F.R. Section 1.56. Except as would
not reasonably be expected to have a Material Adverse Effect and to the Company’s knowledge, (x) there are no facts that are reasonably likely to provide a basis for a finding that the Company or any of its subsidiaries does not have clear
title to the patents or patent applications owned or licensed to the Company or other proprietary information rights as being owned by the Company or any of its subsidiaries, (y) no valid issued U.S. patent would be infringed by the activities
of the Company or any of its subsidiaries relating to products currently or proposed to be manufactured, used or sold by the Company or any of its subsidiaries and (z) there are no facts with respect to any issued patent owned that would cause
any claim of any such patent not to be valid and enforceable with applicable regulations. “Intellectual Property” shall mean all patents, patent applications, trade and service marks, trade and service mark registrations,
trade names, copyrights, licenses, inventions, trade secrets, domain names, technology and know-how. 

  
 8 

	 	l.	Environmental Laws. 

  

	 	(i)	The Company and each subsidiary has complied with all applicable Environmental Laws (as defined below), except for violations of Environmental Laws that, individually or in the aggregate, have not had and would not
reasonably be expected to have a Material Adverse Effect. There is no pending or, to the knowledge of the Company, threatened civil or criminal litigation, notice of violation, formal administrative proceeding, or investigation, inquiry or
information request, relating to any Environmental Law involving the Company or any subsidiary, except for litigation, notices of violations, formal administrative proceedings or investigations, inquiries or information requests that, individually
or in the aggregate, have not had and would not reasonably be expected to have a Material Adverse Effect. For purposes of this Agreement, “Environmental Law” means any national, state, provincial or local law, statute, rule
or regulation or the common law relating to the environment or occupational health and safety, including without limitation any statute, regulation, administrative decision or order pertaining to (i) treatment, storage, disposal, generation and
transportation of industrial, toxic or hazardous materials or substances or solid or hazardous waste; (ii) air, water and noise pollution; (iii) groundwater and soil contamination; (iv) the release or threatened release into the
environment of industrial, toxic or hazardous materials or substances, or solid or hazardous waste, including without limitation emissions, discharges, injections, spills, escapes or dumping of pollutants, contaminants or chemicals; (v) the
protection of wild life, marine life and wetlands, including without limitation all endangered and threatened species; (vi) storage tanks, vessels, containers, abandoned or discarded barrels, and other closed receptacles; (vii) health and
safety of employees and other persons; and (viii) manufacturing, processing, using, distributing, treating, storing, disposing, transporting or handling of materials regulated under any law as pollutants, contaminants, toxic or hazardous
materials or substances or oil or petroleum products or solid or hazardous waste. As used above, the terms “release” and “environment” shall have the meaning set forth in the Comprehensive Environmental Response, Compensation and
Liability Act of 1980, as amended. 

  

	 	(ii)	To the knowledge of the Company there is no material environmental liability with respect to any solid or hazardous waste transporter or treatment, storage or disposal facility that has been used by the Company or any
subsidiary. 

  

	 	(iii)	The Company and its subsidiaries (i) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses except to the extent that the
failure to have such permits, licenses or other approvals would not have a Material Adverse Effect and (ii) are in compliance, in all material respects, with all terms and conditions of any such permits, licenses or approvals.

  
 9 

	 	m.	Authorizations; Regulatory Compliance. The Company and each of its subsidiaries holds, and is operating in compliance with, all authorizations, licenses, permits, approvals, clearances, registrations,
exemptions, consents, certificates and orders of any governmental authority and supplements and amendments thereto (collectively, “Authorizations”) required for the conduct of its business and all such Authorizations are valid and
in full force and effect and neither the Company nor any of its subsidiaries is in material violation of any terms of any such Authorizations, except, in each case, such as would not reasonably be expected to have a Material Adverse Effect; and
neither the Company nor any of its subsidiaries has received written notice of any revocation or modification of any such Authorization, except to the extent that any such revocation or modification would not be reasonably expected to have a
Material Adverse Effect. The Company and each of its subsidiaries is in compliance with all applicable federal, state, local and foreign laws, regulations, orders and decrees, including such laws and regulations applicable to import and export,
except as would not reasonably be expected to have a Material Adverse Effect. Neither the Company nor any of its subsidiaries has received any unresolved FDA Form 483, warning letter, untitled letter or other correspondence or notice from the
U.S. Food and Drug Administration (“FDA”), or any other federal, state or local governmental or regulatory authority, alleging or asserting noncompliance with the Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 301 et seq.).
The Company and each of its subsidiaries, and to the Company’s knowledge, each of their respective directors, officers, employees and agents, is and has been in material compliance with applicable health care laws, including, to the extent
applicable, without limitation, the Federal Food, Drug and Cosmetic Act (21 U.S.C. § 301 et seq.), the federal Anti-Kickback Statute (42 U.S.C. § 1320a-7b(b)), the Health Insurance
Portability and Accountability Act of 1996 (42 U.S.C. § 1320d et seq.), as amended by the Health Information Technology for Economic and Clinical Health Act of 2009 (42 U.S.C. § 17921 et seq.), and the regulations promulgated pursuant to
such laws, and comparable state laws (collectively, “Health Care Laws”). Neither the Company nor any of its subsidiaries has received written notice of any ongoing claim, action, suit, proceeding, hearing, enforcement,
investigation, arbitration or other action from any Governmental Authority or third party alleging that any product operation or activity is in material violation of any Health Care Laws or Authorizations. Neither the Company nor any of its
subsidiaries has received written notice that any governmental authority has taken, is taking or intends to take action to limit, suspend, modify or revoke any Authorizations. The Company and each of its subsidiaries has filed, obtained, maintained
or submitted all reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments thereto as required by any Health Care Laws or Authorizations and that all such reports, documents, forms, notices,
applications, records, claims, submissions and supplements or amendments were complete, correct and not misleading on the date filed (or were corrected or supplemented by a subsequent submission). Neither the Company nor any of its subsidiaries has,
either voluntarily or involuntarily, initiated, conducted, or issued or caused to be initiated, conducted or issued, any recall, safety alert, “dear doctor” letter, or other notice or action relating to any alleged product defect or
violation and, to the Company’s knowledge, no third party has initiated or conducted any such notice or action. Neither the Company nor any of its subsidiaries is a party to any corporate integrity agreement, deferred prosecution agreement,
monitoring agreement, consent decree, settlement order, or similar agreements, or has any reporting obligations pursuant to any such agreement, plan or correction or other remedial measure entered into with any Governmental Authority.

  
 10 

	 	n.	Title. Neither the Company nor any of its subsidiaries owns any real property. Except as set forth on Schedule 4n, each of the Company and its subsidiaries has good and marketable title to all of
its personal property and assets, free and clear of any restriction, mortgage, deed of trust, pledge, lien, security interest or other charge, claim or encumbrance which would have a Material Adverse Effect. Except as set forth on Schedule
4n, with respect to properties and assets it leases, each of the Company and its subsidiaries is in compliance with such leases and holds a valid leasehold interest free of any liens, claims or encumbrances which would have a Material
Adverse Effect. 

  

	 	o.	No Material Adverse Effects, etc. Neither Company nor any subsidiary is subject to any judgment, decree, order, rule or regulation which in the judgment of the Company’s officers has had, or is reasonably
expected in the future to have, a Material Adverse Effect. Neither Company nor any subsidiary is in breach of any contract or agreement which breach, in the judgment of the Company’s officers, has had, or is reasonably expected to have a
Material Adverse Effect. 

  

	 	p.	Tax Status. The Company and each subsidiary has made and filed (taking into account any valid extensions) all federal and state income and all other tax returns, reports and declarations required by any
jurisdiction to which it is subject (except in any case in which the failure to so file would not have a Material Adverse Effect) and (unless and only to the extent that the Company or such subsidiary has set aside on its books provisions reasonably
adequate for the payment of all unpaid and unreported taxes) has paid all taxes and other governmental assessments and charges shown or determined to be due on such returns, reports and declarations, except those being contested in good faith and
has set aside on its books provision reasonably adequate for the payment of all taxes for periods subsequent to the periods to which such returns, reports or declarations apply or as would not have a Material Adverse Effect. To the knowledge of the
Company, there are no unpaid taxes in any material amount claimed to be due from the Company or any subsidiary by the taxing authority of any jurisdiction, and the officers of the Company know of no basis for any such claim. 

 

	 	q.	Certain Transactions. Except for arm’s length transactions pursuant to which the Company or any subsidiary makes payments in the ordinary course of business upon terms no less favorable than it could obtain
from third parties, none of the officers, directors, or employees of the Company or any subsidiary is presently a party to any transaction with the Company or any subsidiary (other than for services as employees, officers and directors), including
any contract, agreement or other arrangement providing for the furnishing of services to or by, providing for rental of real or personal property to or from, or otherwise requiring payments to or from any officer, director or such employee or, to
the knowledge of the Company, any corporation, partnership, trust or other entity in which any officer, director, or any such employee has a substantial interest or is an officer, director, trustee or partner. All transactions that would be required
to be disclosed by the Company pursuant to Item 404 of Regulation S-K promulgated under the Securities Act are disclosed in the SEC Reports in accordance with Item 404 or in the Super 8-K. 

  
 11 

	 	r.	Rights of First Refusal. Except as set forth on Schedule 4c(i) or Schedule 4r, the Company is not obligated to offer the securities offered hereunder on a
right of first refusal basis or otherwise to any third parties including, but not limited to, current or former stockholders of the Company, underwriters, brokers, agents or other third parties. 

 

	 	s.	Insurance. The Company and its subsidiaries have insurance policies of the type and in amounts customarily carried by organizations conducting businesses or owning assets similar to those of the Company and its
subsidiaries. There is no material claim pending under any such policy as to which coverage has been questioned, denied or disputed by the underwriter of such policy. 

 

	 	t.	SEC Reports. The Company has filed all reports, schedules, forms, statements and other documents required to be filed by the Company under the Securities Exchange Act of 1934, as amended (the “Exchange
Act”), including pursuant to Section 15(d) thereof (or that it would have been required to file by Section 15(d) of the Exchange Act if its duty to file thereunder had not been automatically suspended) (collectively, together with the
Super 8-K, the “SEC Reports”) for the two (2) years preceding the date hereof (or such shorter period since the Company was first required by law or regulation to file such
material). To the Company’s knowledge, the draft Super 8-K furnished to each Purchaser prior to the Initial Closing will not materially deviate from the Super 8-K.
The Super 8-K complies, and the other SEC Reports at the time they were filed complied, in all material respects with the Securities Act or the Exchange Act, as applicable, and the applicable rules and
regulations of the SEC thereunder. There are no contracts, agreements or other documents that are required to be described in the SEC Reports and/or to be filed as exhibits thereto that are not described, in all material respects, and/or filed as
required. There has not been any material change or amendment to, or any waiver of any material right under, any such contract or agreement that has not been described in and/or filed as an exhibit to the SEC Reports. 

 

	 	u.	Financial Statements. The financial statements of the Company included in the SEC Reports comply in all material respects with applicable accounting requirements and the rules and regulations of the SEC with
respect thereto as in effect at the time of filing. Such financial statements have been prepared in accordance with GAAP applied on a consistent basis during the periods involved, except as may be otherwise specified in such financial statements or
the notes thereto and except that unaudited financial statements may not contain all footnotes required by GAAP, and fairly present in all material respects the financial position of the Company and its consolidated subsidiaries taken as a whole as
of and for the dates thereof and the results of operations and cash flows for the periods then ended, subject, in the case of unaudited statements, to normal, year-end audit adjustments. The pro forma
financial information and the related notes, if any, included in the SEC Reports have been properly compiled and prepared in accordance with the applicable requirements of the Securities Act and the regulations promulgated thereunder and fairly
present in all material respects the information shown therein, and the assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions and circumstances referred to
therein. 

  
 12 

	 	v.	Material Changes. Since the respective date of the latest balance sheet of the Company and the latest balance sheet of Aerpio included in the financial statements contained within the SEC Reports, except as
specifically disclosed in the SEC Reports, (i) there have been no events, occurrences or developments that have had or would reasonably be expected to have a Material Adverse Effect with respect to the Company or Aerpio, (ii) there have
not been any changes in the authorized capital, assets, financial condition, business or operations of the Company or Aerpio from that reflected in the financial statements contained within the SEC Reports except changes in the ordinary course of
business which have not been, either individually or in the aggregate, materially adverse to the business, properties, financial condition or results of operations of the Company or Aerpio, (iii) neither the Company or any subsidiary nor Aerpio
has incurred any material liabilities (contingent or otherwise) other than (A) trade payables, accrued expenses and other liabilities incurred in the ordinary course of business consistent with past practice and (B) liabilities not
required to be reflected in the financial statements of the Company or of Aerpio, as applicable, pursuant to GAAP or to be disclosed in the SEC Reports, (iv) neither the Company or any subsidiary nor Aerpio has materially altered its method of
accounting or the manner in which it keeps its accounting books and records, and (v) neither the Company or any subsidiary nor Aerpio has declared or made any dividend or distribution of cash or other property to its stockholders or purchased,
redeemed or made any agreements to purchase or redeem any shares of its capital stock (other than in connection with repurchases of unvested stock issued to employees of the Company). 

 

	 	w.	Disclosure Controls. Except as disclosed in the Super 8-K under the “Risk Factors” section therein, the Company has established and maintains disclosure controls
and procedures (as defined in Rules 13a-14 and 15d-14 under the Exchange Act) and such controls and procedures are effective in ensuring that material information
relating to the Company, including its subsidiaries, is made known to the principal executive officer and the principal financial officer. 

  

	 	x.	Sarbanes-Oxley. Except as disclosed in the SEC Reports, including the Super 8-K under the “Risk Factors section therein, the Company is in compliance in all material
respects with all of the provisions of the Sarbanes-Oxley Act of 2002 which are applicable to it. 

  

	 	y.	Off-Balance Sheet Arrangements. There is no transaction, arrangement, or other relationship between the Company or any subsidiary and an unconsolidated or other off-balance sheet entity that is required to be disclosed by the Company in its SEC Reports (including, for purposes hereof, any that are required to be disclosed in a Form 10) and is not so disclosed or that
otherwise would have a Material Adverse Effect. 

  

	 	z.	 Foreign Corrupt Practices. Neither the Company and its subsidiaries, nor to the Company’s knowledge,
any agent or other person acting on behalf of the Company or its subsidiaries, has: (i) directly or indirectly, used any funds for unlawful contributions, gifts, entertainment or other unlawful expenses related to foreign or domestic political
activity, (ii) made any 

  
 13 

	 	
unlawful payment to foreign or domestic government officials or employees or to any foreign or domestic political parties or campaigns from corporate funds, (iii) failed to disclose fully
any contribution made by the Company (or made by any person acting on its behalf of which the Company is aware) which is in violation of law or (iv) violated in any material respect any provision of the Foreign Corrupt Practices Act of 1977, as
amended. 

  

	 	aa.	Brokers’ Fees. Neither of the Company nor any of its subsidiaries has any liability or obligation to pay any fees or commissions to any broker, finder or agent with respect to the transactions
contemplated by this Agreement, except for the payment of fees to the Placement Agents as described in Section 3 above. 

  

	 	bb.	Disclosure Materials. The SEC Reports and the Disclosure Materials taken as a whole do not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein (in
the case of SEC Reports) or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading. 

  

	 	cc.	Investment Company. The Company is not required to be registered as, and is not an Affiliate of, and immediately following the Closing will not be required to register as, an “investment company” within
the meaning of the Investment Company Act of 1940, as amended. 

  

	 	dd.	Reliance. The Company acknowledges that the Purchaser is relying on the representations and warranties made by the Company hereunder and that such representations and warranties are a material inducement to
the Purchaser purchasing the Shares. The Company further acknowledges that without such representations and warranties of the Company made hereunder, the Purchaser would not enter into this Agreement. 

 

	 	ee.	Use of Proceeds. The Company presently intends to use the net proceeds from the Offering primarily for research and development of its “AKB-9778” product
candidate and for general and working capital purposes. 

  

	 	5.	Representations, Warranties and Agreements of the Purchaser. The Purchaser, severally and not jointly with any other Purchaser, represents and warrants to, and agrees with, the Company the
following: 

  

	 	a.	The Purchaser has the knowledge and experience in financial and business matters necessary to evaluate the merits and risks of its prospective investment in the Company, and has carefully reviewed and understands the
risks of, and other considerations relating to, the purchase of Shares and the tax consequences of the investment, and has the ability to bear the economic risks of the investment. The Purchaser can afford the loss of its entire investment.

  

	 	b.	 The Purchaser is acquiring the Shares for investment for its own account and not with the view to, or for resale
in connection with, any distribution thereof. The Purchaser understands and acknowledges that the Offering and sale of the Shares have not been registered under the Securities Act or any state securities laws, by reason of a specific exemption from
the registration provisions of the Securities Act and applicable state securities laws, which depends upon, among other things, the bona fide nature of the investment intent as expressed

  
 14 

	 	
herein. The Purchaser further represents that it does not have any contract, undertaking, agreement or arrangement with any person to sell, transfer or grant participation to any third person
with respect to any of the Shares. The Purchaser understands and acknowledges that the Offering of the Shares will not be registered under the Securities Act nor under the state securities laws on the ground that the sale of the Shares to the
Purchaser as provided for in this Agreement and the issuance of securities hereunder is exempt from the registration requirements of the Securities Act and any applicable state securities laws. The Purchaser is an “accredited investor” as
defined in Rule 501 of Regulation D as promulgated by the SEC under the Securities Act, for the reason(s) specified on the Accredited Investor Certification attached hereto as completed by Purchaser, and Purchaser shall submit to the
Company such further assurances of such status as may be reasonably requested by the Company. The Purchaser resides in the jurisdiction set forth on the Purchaser’s Omnibus Signature Page affixed hereto. The Purchaser has not taken any of the
actions set forth in, and is not subject to, the disqualification provisions of Rule 506(d)(1) of the Securities Act. 

  

	 	c.	The Purchaser (i) if a natural person, represents that he or she is the greater of (A) 21 years of age or (B) the age of legal majority in his or her jurisdiction of residence, and has full power and authority
to execute and deliver this Agreement and all other related agreements or certificates and to carry out the provisions hereof and thereof; (ii) if a corporation, partnership, limited liability company, association, joint stock company, trust,
unincorporated organization or other entity, represents that such entity was not formed for the specific purpose of acquiring the Shares, such entity is duly organized, validly existing and in good standing under the laws of the state or
jurisdiction of its organization, the consummation of the transactions contemplated hereby is authorized by, and will not result in a violation of state law or its charter or other organizational documents, such entity has full power and authority
to execute and deliver this Agreement and all other related agreements or certificates and to carry out the provisions hereof and thereof and to purchase and hold the Shares, the execution and delivery of this Agreement has been duly authorized by
all necessary action, this Agreement has been duly executed and delivered on behalf of such entity and is a legal, valid and binding obligation of such entity; or (iii) if executing this Agreement in a representative or fiduciary capacity,
represents that it has full power and authority to execute and deliver this Agreement in such capacity and on behalf of the subscribing individual, ward, partnership, trust, estate, corporation, or limited liability company or partnership, or other
entity for whom the Purchaser is executing this Agreement, and such individual, partnership, ward, trust, estate, corporation, or limited liability company or partnership, or other entity has full right and power to perform pursuant to this
Agreement and make an investment in the Company, and represents that this Agreement constitutes a legal, valid and binding obligation of such entity. The execution and delivery of this Agreement will not violate or be in conflict with any order,
judgment, injunction, agreement or controlling document to which the Purchaser is a party or by which it is bound. 

  

	 	d.	 The Purchaser understands that the Shares are being offered and sold to it in reliance on specific exemptions
from the registration requirements of United States federal and state securities laws and that the Company is relying in part upon the truth and accuracy of, and such Purchaser’s compliance with, the representations, warranties, agreements,

  
 15 

	 	
acknowledgments and understandings of such Purchaser set forth herein in order to determine the availability of such exemptions and the eligibility of such Purchaser to acquire such securities.
The Purchaser further acknowledges and understands that the Company is relying on the representations and warranties made by the Purchaser hereunder and that such representations and warranties are a material inducement to the Company to sell the
Shares to the Purchaser. The Purchaser further acknowledges that without such representations and warranties of the Purchaser made hereunder, the Company would not enter into this Agreement with the Purchaser. 

 

	 	e.	The Purchaser understands that no public market exists for the Company’s Common Stock and that there can be no assurance that any public market for the Common Stock will exist or continue to exist. The
Company’s Common Stock is not approved for quotation on OTC Markets or any other quotation system or listed on any exchange. The Company intends to cause the Common Stock to be quoted on OTC Markets QB tier as soon as practicable following the
final Closing of the Offering; however, the Company makes no representation, warranty or covenant with respect to the initiation of or continued quotation of the Common Stock on the OTC Markets quotation or listing on any other market or exchange.

  

	 	f.	The Purchaser has received, reviewed and understood the information about the Company, including all Disclosure Materials, and has had an opportunity to discuss the Company’s business, management and financial
affairs with the Company’s management. The Purchaser understands that such discussions, as well as any Disclosure Materials provided by the Company, were intended to describe the aspects of the Company’s business and prospects and the
Offering which the Company believes to be material, but were not necessarily a thorough or exhaustive description, and except as expressly set forth in this Agreement, the Company makes no representation or warranty with respect to the completeness
of such information and makes no representation or warranty of any kind with respect to any information provided by any entity other than the Company. Some of such information may include projections as to the future performance of the Company,
which projections may not be realized, may be based on assumptions which may not be correct and may be subject to numerous factors beyond the Company’s control. Additionally, the Purchaser understands and represents that it is purchasing the
Shares notwithstanding the fact that the Company may disclose in the future certain material information the Purchaser has not received, including (without limitation) financial statements of the Company and/or Aerpio for the current or prior fiscal
periods, and any subsequent period financial statements that will be filed with the SEC, that it is not relying on any such information in connection with its purchase of the Shares and that it waives any right of action with respect to the
nondisclosure to it prior to its purchase of the Shares of any such information. Each Purchaser has sought such accounting, legal and tax advice as it has considered necessary to make an informed investment decision with respect to its acquisition
of the Shares. 

  

	 	g.	 The Purchaser acknowledges that none of the Company or the Placement Agents is acting as a financial advisor or
fiduciary of the Purchaser (or in any similar capacity) with respect to the Transaction Documents and the transactions contemplated hereby and thereby, and no investment advice has been given by the Company, the Placement Agents or any of their

  
 16 

	 	
respective representatives or agents in connection with the Transaction Documents and the transactions contemplated hereby and thereby. The Purchaser further represents to the Company that the
Purchaser’s decision to enter into the Transaction Documents has been based solely on the independent evaluation by the Purchaser and its representatives. 

  

	 	h.	As of the Closing, all actions on the part of Purchaser, and its officers, directors and partners, if applicable, necessary for the authorization, execution and delivery of this Agreement and the Registration Rights
Agreement and the performance of all obligations of the Purchaser hereunder and thereunder shall have been taken, and this Agreement and the Registration Rights Agreement, assuming due execution by the parties hereto and thereto, constitute valid
and legally binding obligations of the Purchaser, enforceable in accordance with their respective terms, subject to: (i) judicial principles limiting the availability of specific performance, injunctive relief, and other equitable remedies and
(ii) bankruptcy, insolvency, reorganization, moratorium or other similar laws now or hereafter in effect generally relating to or affecting creditors’ rights. 

 

	 	i.	Purchaser represents that neither it nor, to its knowledge, any person or entity controlling, controlled by or under common control with it, nor any person having a beneficial interest in it, nor any person on whose
behalf the Purchaser is acting: (i) is a person listed in the Annex to Executive Order No. 13224 (2001) issued by the President of the United States (Executive Order Blocking Property and Prohibiting Transactions with Persons Who Commit,
Threaten to Commit, or Support Terrorism); (ii) is named on the List of Specially Designated Nationals and Blocked Persons maintained by the U.S. Office of Foreign Assets Control; (iii) is a non-U.S.
shell bank or is providing banking services indirectly to a non-U.S. shell bank; (iv) is a senior non-U.S. political figure or an immediate family member or close
associate of such figure; or (v) is otherwise prohibited from investing in the Company pursuant to applicable U.S. anti-money laundering, anti-terrorist and asset control laws, regulations, rules or orders (categories (i) through (v), each
a “Prohibited Purchaser”). The Purchaser agrees to provide the Company, promptly upon request, all information that the Company reasonably deems necessary or appropriate to comply with applicable U.S. anti-money laundering,
anti-terrorist and asset control laws, regulations, rules and orders. The Purchaser consents to the disclosure to U.S. regulators and law enforcement authorities by the Company and its Affiliates and agents of such information about the Purchaser as
the Company reasonably deems necessary or appropriate to comply with applicable U.S. anti-money laundering, anti-terrorist and asset control laws, regulations, rules and orders. If the Purchaser is a financial institution that is subject to the USA
Patriot Act, the Purchaser represents that it has met all of its obligations under the USA Patriot Act. The Purchaser acknowledges that if, following its investment in the Company, the Company reasonably believes that the Purchaser is a Prohibited
Purchaser or is otherwise engaged in suspicious activity or refuses to promptly provide information that the Company requests, the Company has the right or may be obligated to prohibit additional investments, segregate the assets constituting the
investment in accordance with applicable regulations or immediately require the Purchaser to transfer the Shares. The Purchaser further acknowledges that the Purchaser will have no claim against the Company or any of its Affiliates or agents for any
form of damages as a result of any of the foregoing actions. 

  
 17 

 If the Purchaser is Affiliated with a non-U.S. banking
institution (a “Foreign Bank”), or if the Purchaser receives deposits from, makes payments on behalf of, or handles other financial transactions related to a Foreign Bank, the Purchaser represents and warrants to the Company
that: (1) the Foreign Bank has a fixed address, other than solely an electronic address, in a country in which the Foreign Bank is authorized to conduct banking activities; (2) the Foreign Bank maintains operating records related to its
banking activities; (3) the Foreign Bank is subject to inspection by the banking authority that licensed the Foreign Bank to conduct banking activities; and (4) the Foreign Bank does not provide banking services to any other Foreign Bank
that does not have a physical presence in any country and that is not a regulated Affiliate. 
  

	 	j.	The Purchaser or its duly authorized representative realizes that because of the inherently speculative nature of businesses of the kind conducted and contemplated by the Company, the Company’s financial results
may be expected to fluctuate from month to month and from period to period and will, generally, involve a high degree of financial and market risk that could result in substantial or, at times, even total losses for investors in securities of the
Company. The Purchaser has carefully read the risk factors and other information (including the financial statements of Aerpio) included in the Super 8-K. The Purchaser has carefully considered such risk
factors before deciding to invest in the Shares. 

  

	 	k.	The Purchaser has adequate means of providing for its current and anticipated financial needs and contingencies, is able to bear the economic risk for an indefinite period of time and has no need for liquidity of the
investment in the Shares and could afford complete loss of such investment. 

  

	 	l.	The Purchaser is not subscribing for Shares as a result of or subsequent to any advertisement, article, notice or other communication, published in any newspaper, magazine or similar media or broadcast over television,
radio, or the internet, or presented at any seminar or meeting, or any solicitation of a subscription by a person not previously known to the Purchaser in connection with investments in securities generally. 

 

	 	m.	The Purchaser acknowledges that no U.S. federal or state agency or any other government or governmental agency has passed upon the Shares or made any finding or determination as to the fairness, suitability or wisdom of
any investments therein. 

  

	 	n.	 Other than consummating the transactions contemplated hereunder, the Purchaser has not directly or indirectly,
nor has any individual or entity acting on behalf of or pursuant to any understanding with such Purchaser, executed any purchases or sales, including Short Sales, of the securities of the Company during the period commencing as of the time that such
Purchaser first received a term sheet (written or oral) from the Company or any other individual or entity representing the Company setting forth the material terms of the transactions contemplated hereunder and ending immediately prior to the
execution hereof. Notwithstanding the foregoing, in the case of a Purchaser that is a multi-managed investment vehicle whereby separate portfolio managers manage separate portions of such Purchaser’s assets and the portfolio managers have no
direct knowledge of the investment decisions made by the portfolio managers managing other portions of such Purchaser’s assets, the 

  
 18 

	 	
representation set forth above shall only apply with respect to the portion of assets managed by the portfolio manager that made the investment decision to purchase the Shares covered by this
Agreement. Other than to other individuals or entities party to this Agreement, such Purchaser has maintained the confidentiality of all disclosures made to it in connection with this transaction (including the existence and terms of this
transaction). Notwithstanding the foregoing, for avoidance of doubt, nothing contained herein shall constitute a representation or warranty, or preclude any actions, with respect to the identification of the availability of, or securing of,
available shares to borrow in order to effect Short Sales or similar transactions in the future. For purposes of this Agreement, “Short Sales” means all “short sales” as defined in Rule 200 of Regulation SHO under
the Exchange Act (but shall not be deemed to include the location and/or reservation of borrowable shares of Common Stock). 

  

	 	o.	The Purchaser agrees to be bound by all of the terms and conditions of the Registration Rights Agreement and to perform all obligations thereby imposed upon it. 

 

	 	p.	The Purchaser is aware that the anti-manipulation rules of Regulation M under the Exchange Act may apply to sales of the Shares and other activities with respect to the Shares by the Purchaser. 

 

	 	q.	All of the information concerning the Purchaser set forth herein, and any other information furnished by the Purchaser in writing to the Company or a Placement Agent for use in connection with the transactions
contemplated by this Agreement, is true, correct and complete in all material respects as of the date of this Agreement, and, if there should be any material change in such information prior to the admission of the undersigned to the Company, the
Purchaser will promptly furnish revised or corrected information to the Company. 

  

	 	r.	(For ERISA plans only) The fiduciary of the Employee Retirement Income Security Act of 1974 (“ERISA”) plan (the “Plan”) represents that such fiduciary has
been informed of and understands the Company’s investment objectives, policies and strategies, and that the decision to invest “plan assets” (as such term is defined in ERISA) in the Company is consistent with the provisions of ERISA
that require diversification of plan assets and impose other fiduciary responsibilities. The Purchaser fiduciary or Plan (a) is responsible for the decision to invest in the Company; (b) is independent of the Company or any of its
Affiliates; (c) is qualified to make such investment decision; and (d) in making such decision, the Purchaser fiduciary or Plan has not relied primarily on any advice or recommendation of the Company or any of its Affiliates.

  

	 	6.	Transfer Restrictions. The Purchaser acknowledges and agrees as follows: 

  

	 	a.	The Shares have not been registered for sale under the Securities Act, in reliance on the private offering exemption in Section 4(a)(2) thereof; other than as expressly provided in the Registration Rights Agreement, the
Company does not currently intend to register the Shares under the Securities Act at any time in the future; and the undersigned will not immediately be entitled to the benefits of Rule 144 with respect to the Shares. 

  
 19 

	 	b.	The Purchaser understands that there are substantial restrictions on the transferability of the Shares and that the certificates representing the Shares shall bear a restrictive legend in substantially the following
form (and a stop-transfer order may be placed against transfer of such certificates or other instruments): 

 THE SECURITIES
REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR ANY STATE SECURITIES LAWS, AND NEITHER SUCH SECURITIES NOR ANY INTEREST THEREIN MAY BE OFFERED,
SOLD, PLEDGED, ASSIGNED OR OTHERWISE TRANSFERRED UNLESS (1) A REGISTRATION STATEMENT WITH RESPECT THERETO IS EFFECTIVE UNDER THE SECURITIES ACT AND ANY APPLICABLE STATE SECURITIES LAWS, OR (2) AN EXEMPTION FROM SUCH REGISTRATION EXISTS AND
THE COMPANY RECEIVES AN OPINION OF COUNSEL, WHICH COUNSEL AND OPINION ARE REASONABLY SATISFACTORY TO THE COMPANY, THAT SUCH SECURITIES MAY BE OFFERED, SOLD, PLEDGED, ASSIGNED OR TRANSFERRED IN THE MANNER CONTEMPLATED WITHOUT AN EFFECTIVE
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR APPLICABLE STATE SECURITIES LAWS OR (3) SOLD PURSUANT TO RULE 144 UNDER THE SECURITIES ACT. 

In addition, if any Purchaser is an Affiliate of the Company, certificates evidencing the Shares issued to such Purchaser may bear a customary
“Affiliates” legend. 
 The legend set forth above shall be removed and the Company shall issue a certificate without such legend
to the holder of the Shares upon which it is stamped, if (a) such Shares are sold pursuant to a registration statement under the Securities Act, or (b) such holder delivers to the Company an opinion of counsel, reasonably acceptable to the
Company, that a disposition of the Shares is being made pursuant to an exemption from such registration and that the Shares, after such transfer, shall no longer be “restricted securities” within the meaning of Rule 144. 

 

	 	c.	 Subject to the Company’s right to request an opinion of counsel as set forth in Section 6b,
the legend set forth in Section 6b above shall be removable and the Company shall issue or cause to be issued a certificate without such legend or any other legend to the holder of the applicable Shares upon which it is stamped or
issue or cause to be issued to such holder by electronic delivery at the applicable balance account at The Depository Trust Company (“DTC”) as provided in this Section 6c, if (i) such Shares and Underlying
Shares are registered for resale under the Securities Act (provided that, if the Purchaser is selling pursuant to an effective registration statement registering the Shares for resale, the Purchaser agrees to only sell such Shares during such time
that such registration statement is effective and not withdrawn or suspended, and only as permitted by such registration statement), or (ii) such Shares and Underlying Shares are sold or transferred in compliance with Rule 144, including
without limitation in compliance with the current public information requirements and volume and manner-of-sale restrictions of Rule 144, if applicable at the time of
such sale or transfer, and the holder and its broker have delivered customary documents reasonably 

  
 20 

	 	
requested by the Company’s transfer agent and/or Company counsel in connection with such sale or transfer. All costs and expenses related to the removal of the legends and the reissuance of
any Shares and Underlying Shares, including but not limited to costs and expenses with respect to the transfer agent, Company counsel or otherwise, shall be borne by the Company. Following the date on which the Registration Statement (as defined in
the Registration Rights Agreement) is first declared effective by the SEC, or at such other time as a legend is no longer required for certain Shares, the Company will no later than three (3) Trading Days (as defined below) following the
delivery by a Purchaser to the Company or the transfer agent (with concurrent notice and delivery of copies to the Company) of a legended certificate representing such Shares and Underlying Shares (endorsed or with stock powers attached, signatures
guaranteed, and otherwise in form necessary to affect the reissuance and/or transfer, and together with such other customary documents as the transfer agent and/or Company counsel shall reasonably request), deliver or cause to be delivered to the
transferee of such Purchaser or such Purchaser, as applicable, a book entry position or a certificate representing such Shares and Underlying Shares that is free from all restrictive and other legends. The Company may not make any notation on its
records or give instructions to the transfer agent that enlarge the restrictions on transfer set forth in this Section 6. Certificates for Shares and Underlying Shares subject to legend removal hereunder shall be transmitted by the transfer
agent to the Purchaser by crediting the account of the Purchaser’s prime broker with DTC. “Trading Day” means (i) a day on which the Common Stock is listed or quoted and traded on its principal trading market
(unless the principal trading market is the OTC Bulletin Board or the OTC Pink tier of the OTC Markets Group, Inc.), or (ii) if the Common Stock is not listed on a trading market (other than the OTC Bulletin Board or the OTC QB, OTC QX or OTC
Pink tier of the OTC Markets Group, Inc.), a day on which the Common Stock is traded in the over-the-counter market, as reported by the OTC Bulletin Board, or
(iii) if the Common Stock is not quoted on any trading market (other than the OTC QB, OTC QX or OTC Pink tier of the OTC Markets Group, Inc.), a day on which the Common Stock is quoted in the over-the-counter market as reported by the OTC QB, OTC QX or OTC Pink tier of the OTC Markets Group, Inc. (or any similar organization or agency succeeding to its functions of reporting prices); provided,
that in the event that the Common Stock is not listed or quoted as set forth in (i), (ii) and (iii) hereof, then Trading Day shall mean a Business Day. 

  

	 	d.	 If the Company shall fail for any reason or for no reason to issue to a Purchaser a certificate not bearing the
legend set forth in Section 6b within three (3) Trading Days after receipt by the Company and the Transfer Agent of all documents necessary for the removal of the legend as set forth in Section 6c at a time at which such removal
is not prohibited under applicable law (the “Deadline Date”) (such certificate, the “Unlegended Certificate”), then, in addition to all other remedies available to such Purchaser, if on or after the
Trading Day immediately following such three (3) Trading Day period, such Purchaser purchases (in an open market transaction or otherwise) shares of Common Stock to deliver in satisfaction of a sale by such Purchaser of the shares of Common
Stock to be represented by the Unlegended Certificate that such Purchaser anticipated receiving from the Company without any restrictive legend as a result of such Purchaser’s full compliance with Section 6c (a “Buy-In”), then the Company 

  
 21 

	 	
\shall, within three (3) Trading Days after receipt of a written request from the Purchaser to take the actions described in either clause (i) or (ii) below (which shall be in the
Purchaser’s sole discretion and identified in such written request), either (i) pay cash to the Purchaser in an amount equal to such Purchaser’s total purchase price (including brokerage commissions, if any) for the shares of Common
Stock so purchased (the “Buy-In Price”), at which point the Company’s obligation to deliver such Unlegended Certificate representing such number of shares of Common Stock so
purchased (and to issue such shares of Common Stock) shall terminate, or (ii) in the event that the Common Stock is at such time listed or quoted and traded on a trading market, promptly honor its obligation to deliver to such Purchaser a
certificate or certificates representing such shares of Common Stock and pay cash to the Purchaser in an amount equal to the excess (if any) of the Buy-In Price over the product of (a) such number of
shares of Common Stock, times (b) the closing price of the Common Stock on the Deadline Date as reported by the principal trading market on which the Common Stock is primarily listed or quoted for trading. The Purchaser of shares of Common
Stock shall provide the Company written notice indicating the amounts payable to such Purchaser in respect of the Buy-In, together with applicable confirmations and other evidence reasonably requested by the
Company. 

  

	 	e.	Each Purchaser understands that the Company prior to the Merger was a “shell company” as defined in Rule 12b-2 under the Exchange Act, and that upon filing with the
SEC of the Super 8-K reporting the consummation of the Merger and related transactions and the transactions contemplated by this Agreement, and otherwise containing “Form 10 information” discussed
below, the Company will reflect therein that it is no longer a shell company. Pursuant to Rule 144(i), securities issued by a current or former shell company (that is, the Shares) that otherwise meet the holding period and other requirements of Rule
144 nevertheless cannot be sold in reliance on Rule 144 until one year after the Company (a) is no longer a shell company; and (b) has filed current “Form 10 information“ (as
defined in Rule 144(i)) with the SEC reflecting that it is no longer a shell company, and provided that at the time of a proposed sale pursuant to Rule 144, the Company is subject to the reporting requirements of Section 13 or
15(d) of the Exchange Act and has filed all reports and other materials required to be filed by Section 13 or 15(d) of the Exchange Act, as applicable, during the preceding 12 months (or for such shorter period that the issuer was
required to file such reports and materials), other than Form 8-K reports. As a result, the restrictive legends on certificates for the Shares cannot be removed
except in connection with an actual sale meeting the foregoing requirements or pursuant to an effective registration statement. Notwithstanding the foregoing, the Company shall file a Form 8-A
with the SEC within one year of the final Closing if the Company is not otherwise a mandatory reporting entity pursuant to Section 15(d) of the Exchange Act. 

  

	 	7.	Conditions to Company’s Obligations at Closing. The Company’s obligation to complete the sale and issuance of the Shares and deliver the Shares to each Purchaser, individually, at each
Closing shall be subject to the following conditions to the extent not waived by the Company: 

  
 22 

	 	a.	Receipt of Payment. The Company shall have received payment, by certified or other bank check or by wire transfer of immediately available funds, in the full amount of the purchase price for the number of Shares
being purchased by such Purchaser at such Closing. 

  

	 	b.	Representations and Warranties. The representations and warranties made by the Purchaser in Section 5 hereof shall be true and correct in all material respects when made, and shall be
true and correct in all material respects on such Closing Date with the same force and effect as if they had been made on and as of said date (except in each case to the extent any such representation and warranty is qualified by materiality, in
which case, such representation and warranty shall be true and correct in all respects as so qualified). The Purchaser shall have performed in all material respects all obligations and covenants herein required to be performed by it on or prior to
such Closing Date. 

  

	 	c.	Receipt of Executed Documents. Such Purchaser shall have executed and delivered to the Company the Omnibus Signature Page, the Purchaser Questionnaire and the Selling Stockholder Questionnaire. 

 

	 	d.	Effectiveness of the Merger, LLC Conversion and Cancellation. The Merger, LLC Conversion and Cancellation shall have been effected. 

 

	 	e.	Minimum Offering. The Initial Closing shall be at least for the number of shares of Common Stock in the Minimum Offering at the Purchase Price (including the Minimum Insider Investment). 

 

	 	f.	Lock-Up Agreements. At the first Closing of the Offering, (a) all officers and directors of the Company, (b) key employees agreed to by the Company and Aerpio, if
any, (c) all persons holding Common Stock issued in exchange for the equity securities of Aerpio in the Merger; and (d) certain stockholders of the Company prior to the Merger (each a “Restricted Holder” and,
collectively, the “Restricted Holders”) shall have entered into agreements with the Company for a term of nine months (the “Restricted Period”), whereby they will agree to certain restrictions on the
sale or disposition (including pledge) of all (or in the case of the stockholders referred to in (d) above, 80%) of the Company’s Common Stock held by (or issuable to) them, excluding any shares purchased by them in the Offering. The lock-ups will contain customary transfer exceptions. 

  

	 	g.	No Short Selling. In addition, each Restricted Holder and any stockholders with record or beneficial ownership of 1% or more of the Common Stock of the Company, after giving effect to the Merger and the Offering,
shall have entered into agreements with the Company whereby they will agree that they will not, for a period of 12 months following the first Closing Date, directly or indirectly, effect or agree to effect any short sale (as defined in Rule 200
under Regulation SHO of the Exchange Act), whether or not against the box, establish any “put equivalent position” (as defined in Rule 16a-1(h) under the Exchange Act) with respect to the Common
Stock, borrow or pre-borrow any shares of Common Stock, or grant any other right (including, without limitation, any put or call option) with respect to the Common Stock or with respect to any security that
includes, relates to or derives any significant part of its value from the Common Stock or otherwise seek to hedge its position in the Common Stock. 

  
 23 

	 	8.	Conditions to Purchasers’ Obligations at Closing. Each Purchaser’s obligation to accept delivery of the Shares and to pay for the Shares shall be subject to the following conditions to the
extent not waived by the Placement Agents on behalf of the Purchasers: 

  

	 	a.	Representations and Warranties Correct. The representations and warranties made by the Company in Section 4 hereof shall be true and correct in all material respects (except to the extent any such
representation and warranty is qualified by materiality or reference to Material Adverse Effect, in which case, such representation and warranty shall be true and correct in all respects as so qualified) as of, and as if made on, the date of this
Agreement and as of such Closing Date, except to the extent any such representation or warranty expressly speaks as of an earlier date, in which case such representation or warranty shall be true and in all material respects correct as of such
earlier date (except in each case to the extent any such representation and warranty is qualified by materiality or reference to Material Adverse Effect, in which case, such representation and warranty shall be true and correct in all respects as so
qualified). The Company shall have performed in all material respects all obligations and covenants herein required to be performed by it on or prior to such Closing Date. 

 

	 	b.	Receipt of Executed Transaction Documents. The Company shall have executed and delivered to the Placement Agents the Registration Rights Agreement and the Escrow Agreement. 

 

	 	c.	Effectiveness of the Merger. The Merger, LLC Conversion and Cancellation shall have been effected. 

  

	 	d.	Minimum Offering. The Initial Closing shall be at least for the number of shares of Common Stock in the Minimum Offering at the Purchase Price and shall include the Minimum Insider Investment. 

 

	 	e.	Legal Opinion. Goodwin Procter LLP, counsel to the Company, shall deliver to the Placement Agents an opinion addressed to the Purchasers and the Placement Agents, dated as of such Closing Date, in form and
substance reasonably acceptable to the Placement Agents. 

  

	 	f.	Certificate. The Chief Executive Officer of the Company shall execute and deliver to the Placement Agents a certificate addressed to the Purchasers to the effect that the representations and warranties of the
Company in Section 4 hereof are true and correct in all material respects (except to the extent any such representation and warranty is qualified by materiality or reference to Material Adverse Effect, in which case, such representation and
warranty shall be true and correct in all respects as so qualified) as of, and as if made on, the date of this Agreement and as of such Closing Date and that the Company has satisfied in all material respects all of the conditions set forth in this
Section 8. 

  
 24 

	 	g.	Good Standing. The Company and each of its subsidiaries is a corporation or other business entity duly organized, validly existing, and in good standing under the laws of the jurisdiction of its formation.

  

	 	h.	Judgments. No judgment, writ, order, injunction, award or decree of or by any court, or judge, justice or magistrate, including any bankruptcy court or judge, or any order of or by any governmental authority,
shall have been issued, and no action or proceeding shall have been instituted by any governmental authority, enjoining or preventing the consummation of the transactions contemplated hereby. 

 

	 	i.	Lock-Up and No Short Selling Agreements. Each of the agreements required by Sections 7f and 7g hereto shall have been executed by the persons referred to therein and
delivered to the Company. 

  

	 	j.	Delivery of Draft of Super 8-K. A substantially complete draft of the Super 8-K, including audited and interim unaudited financial
statements of Aerpio and pro forma financial statements reflecting the Merger, all compliant with applicable SEC regulations for inclusion under Item 2.01(f) and/or 5.01(a)(8) of SEC Form 8-K, shall have been
delivered to the Placement Agents on behalf of the Purchasers. 

  

	 	9.	Indemnification. 

  

	 	a.	The Company agrees to indemnify and hold harmless the Purchaser, and its directors, officers, shareholders, members, partners, employees and agents (and any other persons with a functionally equivalent role of a person
holding such titles notwithstanding a lack of such title or any other title), each person who controls such Purchaser (within the meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors, officers,
shareholders, agents, members, partners or employees (and any other persons with a functionally equivalent role of a person holding such titles notwithstanding a lack of such title or any other title) of such controlling person, from and against all
losses, liabilities, claims, damages, costs, fees and expenses whatsoever (including, but not limited to, any and all expenses incurred in investigating, preparing or defending against any litigation commenced or threatened) based upon or arising
out of the Company’s actual or alleged false acknowledgment, representation or warranty, or misrepresentation or omission to state a material fact, or breach by the Company of any covenant or agreement made by the Company, contained herein or
in any other Disclosure Materials; provided, however, that the Company will not be liable in any such case to the extent and only to the extent that any such loss, liability, claim, damage, cost, fee or expense arises out of or is based upon the
inaccuracy of any representations made by such indemnified party in this Agreement, or the failure of such indemnified party to comply with the covenants and agreements contained herein. The liability of the Company under this paragraph shall not
exceed the total Purchase Price paid by the Purchaser hereunder, except in the case of fraud. 

  

	 	b.	 Promptly after receipt by an indemnified party under this Section 9 of notice of the commencement of any
Action, such indemnified party will, if a claim in respect thereof is to be made against the indemnifying party under this Section 9, notify the indemnifying party in 

  
 25 

	 	
writing of the commencement thereof; but the omission so to notify the indemnifying party will not relieve it from any liability which it may have to any indemnified party otherwise than under
this Section 9. In case any such Action is brought against any indemnified party, and it notifies the indemnifying party of the commencement thereof, the indemnifying party will be entitled to participate therein, and to the extent that it may
elect by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to assume the defense thereof, with counsel satisfactory to such indemnified party; provided, however, if the
defendants in any such Action include both the indemnified party and the indemnifying party and either (i) the indemnifying party or parties and the indemnified party or parties mutually agree or (ii) representation of both the
indemnifying party or parties and the indemnified party or parties by the same counsel is inappropriate under applicable standards of professional conduct due to actual or potential differing interests between them, the indemnified party or parties
shall have the right to select separate counsel to assume such legal defenses and to otherwise participate in the defense of such Action on behalf of such indemnified party or parties. Upon receipt of notice from the indemnifying party to such
indemnified party of its election so to assume the defense of such Action and approval by the indemnified party of counsel, the indemnifying party will not be liable to such indemnified party under this Section 9 for any reasonable legal or
other expenses subsequently incurred by such indemnified party in connection with the defense thereof unless (i) the indemnified party shall have employed counsel in connection with the assumption of legal defenses in accordance with the
proviso to the next preceding sentence (it being understood, however, that the indemnifying party shall not be liable for the expenses of more than one separate counsel in such circumstance), (ii) the indemnifying party shall not have employed
counsel satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of commencement of the Action or (iii) the indemnifying party has authorized the employment of counsel for the indemnified
party at the expense of the indemnifying party. No indemnifying party shall (i) without the prior written consent of the indemnified parties (which consent shall not be unreasonably withheld), settle or compromise or consent to the entry of any
judgment with respect to any pending or threatened Action in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified parties are actual or potential parties to such Action) unless such settlement,
compromise or consent includes an unconditional release of each indemnified party from all liability arising out of such Action, or (ii) be liable for any settlement of any such Action effected without its written consent (which consent shall
not be unreasonably withheld), but if settled with its written consent or if there be a final judgment of the plaintiff in any such Action, the indemnifying party agrees to indemnify and hold harmless any indemnified party from and against any loss
or liability by reason of such settlement or judgment. 

  

	 	10.	 Revocability; Binding Effect. The subscription hereunder may be revoked prior to the Closing thereon,
provided that written notice of revocation is sent and is received by the Company or a Placement Agent at least one Business Day prior to the Closing on such subscription. The Purchaser hereby acknowledges and agrees that this Agreement shall
survive the death or disability of the Purchaser and shall be binding upon and inure to the benefit of the parties and 

  
 26 

	 	
their heirs, executors, administrators, successors, legal representatives and permitted assigns. If the Purchaser is more than one person, the obligations of the Purchaser hereunder shall be
joint and several and the agreements, representations, warranties and acknowledgments herein shall be deemed to be made by and be binding upon each such person and such person’s heirs, executors, administrators, successors, legal
representatives and permitted assigns. 

  

	 	11.	Modification. This Agreement shall not be amended, modified or waived except by an instrument in writing signed by the Company and the holders of at least a majority of the then Held Shares (as defined below),
provided that Section 22 of this Agreement shall not be amended or modified except by an instrument in writing signed by the Company and the Anti-Dilution Requisite Party (as defined below). Any amendment, modification or waiver effected in
accordance with this Section 11 shall be binding upon the Purchaser and each transferee of the Shares, each future holder of all such Shares, and the Company. 

 

	 	12.	Immaterial Modifications to the Registration Rights Agreement. The Company and the Placement Agents may, at any time prior to the initial Closing, amend the Registration Rights Agreement if necessary to clarify
any provision therein, without first providing notice or obtaining prior consent of the Purchaser. 

  

	 	13.	Third-Party Beneficiary. The Placement Agents shall be express third party beneficiaries of the representations and warranties included in this Agreement. This Agreement is intended for the benefit of the parties
hereto and their respective successors and permitted assigns and is not for the benefit of, nor may any provision hereof be enforced by, any other Person, except as otherwise set forth in Section 9 and this Section. 

 

	 	14.	Notices. Any notice, consents, waivers or other communication required or permitted to be given hereunder shall be in writing and will be deemed to have been delivered: (i) upon receipt, when personally
delivered; (ii) upon receipt when sent by certified mail, return receipt requested, postage prepaid; (iii) upon receipt, when sent by facsimile (provided confirmation of transmission is mechanically or electronically generated and kept on
file by the sending party; (iv) when sent, if by e-mail, (provided that such sent e-mail is kept on file (whether electronically or otherwise) by the sending party
and the sending party does not receive an automatically generated message from the recipient’s e-mail server that such e-mail could not be delivered to such
recipient); or (v) one (1) Business Day after deposit with an overnight courier service with next day delivery specified, in each case, properly addressed to the party to receive the same. The addresses, facsimile numbers and email addresses
for such communications shall be: 

 (a) if to the Company, at 

Aerpio Pharmaceuticals, Inc. 

9987 Carver Road, Suite 420 

Cincinnati, OH 45242 

Attention: Joseph Gardner, CEO 

Facsimile: 513-985-0999 

Email: jgardner@aerpio.com 

  
 27 

 with copies (which shall not constitute notice) to: 

CKR Law LLP 
 1330 Avenue of the
Americas 
 New York, NY 10019 

Attention: Barrett S. DiPaolo 

Facsimile: 
1-212-259-8200 
 E-mail: bdipaolo@ckrlaw.com 

and 
 Goodwin Procter LLP 

100 Northern Avenue 
 Boston, MA
02210 
 Attention: Kingsley Taft and Danielle Lauzon 

Facsimile: 617-523-1231 

Email: ktaft@goodwinlaw.com and dlauzon@goodwinlaw.com 

or 
 (b) if to the Purchaser, at
the address set forth on the Omnibus Signature Page hereof 
 (or, in either case, to such other address as the party shall have furnished in
writing in accordance with the provisions of this Section). Any notice or other communication given by certified mail shall be deemed given at the time of certification thereof, except for a notice changing a party’s address which shall be
deemed given at the time of receipt thereof. 
  

	 	15.	Assignability. This Agreement and the rights, interests and obligations hereunder are not transferable or assignable by the Purchaser, and the transfer or assignment of the Shares shall be made only in accordance
with all applicable laws. 

  

	 	16.	Applicable Law. This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without reference to the principles thereof relating to the conflict of laws.

  

	 	17.	Arbitration. The parties agree to submit all controversies to arbitration in accordance with the provisions set forth below and understand that: 

 

	 	a.	Arbitration shall be final and binding on the parties. 

  

	 	b.	The parties are waiving their right to seek remedies in court, including the right to a jury trial. 

  

	 	c.	Pre-arbitration discovery is generally more limited and different from court proceedings. 

  

	 	d.	The arbitrator’s award is not required to include factual findings or legal reasoning and any party’s right to appeal or to seek modification of rulings by arbitrators is strictly limited. 

 

	 	e.	The panel of arbitrators will typically include a minority of arbitrators who were or are Affiliated with the securities industry. 

  
 28 

	 	f.	All controversies which may arise between the parties concerning this Agreement shall be determined by arbitration pursuant to the rules then pertaining to the Financial Industry Regulatory Authority in New York, New
York. Judgment on any award of any such arbitration may be entered in the Supreme Court of the State of New York or in any other court having jurisdiction of the person or persons against whom such award is rendered. Any notice of such arbitration
or for the confirmation of any award in any arbitration shall be sufficient if given in accordance with the provisions of this Agreement. The parties agree that the determination of the arbitrators shall be binding and conclusive upon them. The
prevailing party, as determined by such arbitrators, in a legal proceeding shall be entitled to collect any costs, disbursements and reasonable attorney’s fees from the other party. Prior to filing an arbitration, the parties hereby agree that
they will attempt to resolve their differences first by submitting the matter for resolution to a mediator, acceptable to all parties, and whose expenses will be borne equally by all parties. The mediation will be held in the County of New York,
State of New York, on an expedited basis. If the parties cannot successfully resolve their differences through mediation within sixty (60) days from the receipt of the written notice of a matter from the notifying party, the matter will be
resolved by arbitration. The arbitration shall take place in the County of New York, State of New York, on an expedited basis. 

  

	 	18.	Form D; Blue Sky Qualification. The Company agrees to timely file a Form D with respect to the Securities and to provide a copy thereof, promptly upon request of any Purchaser. The Company shall take such action
as the Company shall reasonably determine is necessary in order to obtain an exemption for, or to qualify the Securities for, sale to the Purchaser at such Closing under applicable securities or “Blue Sky” laws of the states of the United
States, and shall provide evidence of such actions promptly upon request of any Purchaser. 

  

	 	19.	Use of Pronouns. All pronouns and any variations thereof used herein shall be deemed to refer to the masculine, feminine, neuter, singular or plural as the identity of the person or persons referred to may
require. 

  

	 	20.	 Securities Law Disclosure; Publicity.    By 9:00 a.m., New York City time, on the
trading day immediately following the execution of the first Closing, the Company shall issue a press release (the “Press Release”) disclosing all material terms of the Offering. Within the time required by the Exchange Act,
the Company will file the Super 8-K (and including as exhibits to such Super 8-K, the material Transaction Documents (including, without limitation, this Agreement and
the Registration Rights Agreement)). Notwithstanding the foregoing, the Company shall not publicly disclose the name of any Purchaser or an Affiliate of any Purchaser, or include the name of any Purchaser or an Affiliate of any Purchaser in any
press release or filing with the SEC (other than the Registration Statement) or any regulatory agency or principal trading market, without the prior written consent of such Purchaser, except (i) as required by federal securities law in
connection with (A) any registration statement contemplated by the Registration Rights Agreement and (B) the filing of final Transaction Documents with the SEC or (ii) to the extent such disclosure is required by law, request of the
staff of the SEC or of any regulatory agency or principal trading market regulations, in which case the Company shall provide the Purchasers with prior written notice of such disclosure permitted under this
sub-clause (ii). From and after 

  
 29 

	 	
the issuance of the Press Release, no Purchaser shall be in possession of any material, non-public information received from the Company or any of its
respective officers, directors, employees or agents, that is not disclosed in the Press Release unless a Purchaser shall have executed a written agreement regarding the confidentiality and use of such information. Each Purchaser, severally and not
jointly with the other Purchasers, covenants that until such time as the transactions contemplated by this Agreement are publicly disclosed by the Company as described in this Section 20, such Purchaser will maintain the confidentiality of all
disclosures made to it in connection with such transactions (including the existence and terms of such transactions). 

  

	 	21.	Non-Public Information. Except for information (including the terms of this Agreement and the transactions contemplated hereby) that will be disclosed in the Super 8-K and filed with the SEC within four (4) Business Days of the first Closing, the Company shall not and shall cause each of its officers, directors, employees and agents, not to, provide any Purchaser with any
material, non-public information regarding the Company without the express written consent of such Purchaser. 

  

	 	22.	Anti-Dilution. The Purchaser (but not any transferees of the Shares) shall have anti-dilution protection such that if within six (6) months after the initial Closing of the Offering the Company shall issue
Additional Shares of Common Stock (as defined below) for a consideration per share, or with an exercise or conversion price per share, less than the Purchase Price (adjusted proportionately for any event described in clause (iii) of the
following paragraph) occurring after the first Closing of the Offering) (the “Lower Price”), the Purchaser shall be entitled to receive from the Company (for no additional consideration) additional Shares with respect to the
Shares purchased by such Purchaser in the Offering and still held of record and beneficially owned by such Purchaser at the time of the dilutive issuance (such shares, together with the shares issued to the other purchasers pursuant to the other
subscription agreements of like tenor used in the Offering, the “Held Shares”) in an amount such that, when added to the Held Shares held by the Purchaser, will equal the number of shares of Common Stock that such
Purchaser’s aggregate Purchase Price for such Held Shares would have purchased at the Lower Price. Either (i) holders of a majority of the then Held Shares or (ii) a representative of the holders of the then Held Shares, which
representative shall be appointed by the three (3) Purchasers who then hold the largest number of Held Shares, shall have the authority to waive these anti-dilution rights with respect to a particular issuance of securities for Purchaser and
all other purchasers party to the other subscription agreements of like tenor used in the Offering (such persons described in either clause (i) or (ii) of this sentence, the “Anti-Dilution Requisite Party”). 

“Additional Shares of Common Stock” shall mean all shares of Common Stock issued by the Company after the first Closing
of the Offering (including without limitation any shares of Common Stock issuable upon conversion or exchange of any convertible securities or upon exercise of any option, warrant or other right, on an
as-converted or as-exercised basis, as of the date of issuance of such security, option, warrant or right), other than: (i) shares of Common Stock issued or
issuable upon conversion or exchange of any convertible securities or exercise of any options or warrants outstanding as of immediately following the Merger and the initial Closing (including the Placement Agent Warrants); (ii) securities issued or
issuable to strategic investors in connection with an acquisition, collaboration, joint venture, technology license 

  
 30 

 
agreement or other strategic transaction; (iii) shares of Common Stock issued or issuable by reason of a stock dividend, stock split, split-up or
other distribution on shares of Common Stock relating to any recapitalization, reclassification or reorganization of the capital stock of the Company, or any consolidation or merger of the Company with another corporation, or the sale of all or
substantially all of its assets or other transaction effected in such a way that there is no change of control; (iv) securities of the Company issued or issuable pursuant to the acquisition of another entity or business by the Company by
merger, purchase of substantially all of the assets or other reorganization, but not including a transaction in which the Company is issuing securities primarily for the purpose of raising capital or to an entity whose primary business is investing
in securities; (v) issuances of awards to officers, directors and employees of, or consultants to, the Company pursuant to stock grants, option plans, purchase plans or other employee stock incentive programs or arrangements approved by the
Board of Directors, or upon exercise of options or warrants granted to such parties pursuant to any such plan or arrangement; and (vi) securities issued to financial institutions, institutional investors or lessors in connection with credit
arrangements, equipment financings, lease arrangements or similar transactions, in the aggregate not exceeding ten percent (10%) of the number of shares of Common Stock outstanding at the time of such issuance. 

 

	 	23.	Miscellaneous. 

  

	 	a.	This Agreement, together with the Registration Rights Agreement and any confidentiality agreement between the Purchaser and the Company, constitute the entire agreement between the Purchaser and the Company with respect
to the Offering and supersede all prior oral or written agreements and understandings, if any, relating to the subject matter hereof. The terms and provisions of this Agreement may be waived, or consent for the departure therefrom granted, only by a
written document executed by the party entitled to the benefits of such terms or provisions. 

  

	 	b.	If the Shares are certificated and any certificate or instrument evidencing any Shares or Placement Agent Warrants is mutilated, lost, stolen or destroyed, the Company shall issue or cause to be issued in exchange and
substitution for and upon cancellation thereof, or in lieu of and substitution therefor, a new certificate or instrument, but only upon receipt of evidence reasonably satisfactory to the Company and the Company’s transfer agent of such loss,
theft or destruction and the execution by the holder thereof of a customary lost certificate affidavit of that fact and an agreement to indemnify and hold harmless the Company and the Company’s transfer agent for any losses in connection
therewith or, if required by the transfer agent, a bond in such form and amount as is required by the transfer agent. The applicants for a new certificate or instrument under such circumstances shall also pay any reasonable third-party costs
associated with the issuance of such replacement Shares or Placement Agent Warrants. If a replacement certificate or instrument evidencing any Shares or Placement Agent Warrants is requested due to a mutilation thereof, the Company may require
delivery of such mutilated certificate or instrument as a condition precedent to any issuance of a replacement. 

  
 31 

	 	c.	Each of the parties hereto shall pay its own fees and expenses (including the fees of any attorneys, accountants, appraisers or others engaged by such party) in connection with this Agreement and the transactions
contemplated hereby, whether or not the transactions contemplated hereby are consummated. 

  

	 	d.	This Agreement may be executed in one or more original or facsimile or by an e-mail which contains a portable document format (.pdf) file of an executed signature page
counterparts, each of which shall be deemed an original, but all of which shall together constitute one and the same instrument and which shall be enforceable against the parties actually executing such counterparts. The exchange of copies of this
Agreement and of signature pages by facsimile transmission or in .pdf format shall constitute effective execution and delivery of this Agreement as to the parties and may be used in lieu of the original Agreement for all purposes. Signatures of the
parties transmitted by facsimile or by e-mail of a document in pdf format shall be deemed to be their original signatures for all purposes. 

 

	 	e.	Each provision of this Agreement shall be considered separable and, if for any reason any provision or provisions hereof are determined to be invalid or contrary to applicable law, such invalidity or illegality shall
not impair the operation of or affect the remaining portions of this Agreement. 

  

	 	f.	Paragraph titles are for descriptive purposes only and shall not control or alter the meaning of this Agreement as set forth in the text. 

 

	 	g.	The Purchaser understands and acknowledges that there may be multiple Closings for the Offering. 

  

	 	h.	The Purchaser hereby agrees to furnish the Company such other information as the Company may request prior to the Closing with respect to its subscription hereunder. 

 

	 	i.	The representations and warranties of the Company and the Purchaser made in this Agreement shall survive the execution and delivery hereof and the delivery of the Shares. 

 

	 	24.	Omnibus Signature Page. This Agreement is intended to be read and construed in conjunction with the Registration Rights Agreement. Accordingly, pursuant to the terms and conditions of this Agreement and the
Registration Rights Agreement, it is hereby agreed that the execution by the Purchaser of this Agreement, in the place set forth on the Omnibus Signature Page below, shall constitute agreement to be bound by the terms and conditions hereof and the
terms and conditions of the Registration Rights Agreement, with the same effect as if each of such separate but related agreement were separately signed. 

  

	 	25.	Public Disclosure. Neither the Purchaser nor any officer, manager, director, member, partner, stockholder, employee, Affiliate, Affiliated person or entity of the Purchaser shall make or issue any press releases
or otherwise make any public statements or make any disclosures to any third person or entity with respect to the transactions contemplated herein and will not make or issue any press releases or otherwise make any public statements of any nature
whatsoever with respect to the Company without the Company’s express prior approval (which may be withheld in the Company’s sole discretion), except to the extent such disclosure is required by law, request of the staff of the SEC or of
any regulatory agency or principal trading market regulations. 

  
 32 

	 	26.	Potential Conflicts. The Placement Agents, their sub-agents, legal counsel to the Company, the Placement Agents or Aerpio and/or their respective Affiliates, principals,
representatives or employees may now or hereafter own shares of the Company. 

  

	 	27.	Independent Nature of Each Purchaser’s Obligations and Rights. For avoidance of doubt, the obligations of the Purchaser under this Agreement are several and not joint with the obligations of any other
Purchaser, and the Purchaser shall not be responsible in any way for the performance of the obligations of any other Purchaser under any other Subscription Agreement. Nothing contained herein and no action taken by the Purchaser shall be deemed to
constitute the Purchaser as a partnership, an association, a joint venture, or any other kind of entity, or create a presumption that the Purchasers are in any way acting in concert or as a group with respect to such obligations or the transactions
contemplated by this Agreement and any other Subscription Agreements. The Purchaser shall be entitled to independently protect and enforce its rights, including without limitation the rights arising out of this Agreement, and it shall not be
necessary for any other Purchaser to be joined as an additional party in any proceeding for such purpose. 

 [Signature page
follows.] 
  

  
 33 

 IN WITNESS WHEREOF, the Company has duly executed this Agreement as of the 15th day of March, 2017. 

 

			
	AERPIO PHARMACEUTICALS, INC.
		
	By:	 	 /s/ Joseph H. Gardner

	Name:	 	Joseph H. Gardner
	Title:	 	President and CEO

 Aerpio Pharmaceuticals, Inc. 

OMNIBUS SIGNATURE PAGE TO 

SUBSCRIPTION AGREEMENT AND REGISTRATION RIGHTS AGREEMENT 

The undersigned, desiring to: (i) enter into the Subscription Agreement, dated as of ____________
___,1 2017 (the “Subscription Agreement”), between the undersigned,     Aerpio Pharmaceuticals, Inc., a Delaware corporation (the
“Company”), and the other parties thereto, in or substantially in the form furnished to the undersigned, (ii) enter into the Registration Rights Agreement (the “Registration Rights Agreement”),
among the undersigned, the Company and the other parties thereto, in or substantially in the form furnished to the undersigned, and (iii) purchase the Shares of the Company’s securities as set forth in the Subscription Agreement and below,
hereby agrees to purchase such Shares from the Company and further agrees to join the Subscription Agreement and the Registration Rights Agreement as a party thereto, with all the rights and privileges appertaining thereto, and to be bound in all
respects by the terms and conditions thereof. The undersigned specifically acknowledges having read the representations section in the Subscription Agreement entitled “Representations and Warranties of the Purchaser” and hereby represents
that the statements contained therein are complete and accurate with respect to the undersigned as a Purchaser. 
 IN WITNESS WHEREOF, the Purchaser hereby
executes this Agreement and the Registration Rights Agreement. 
 Dated:
                                        
 , 2017 
  

											
	                        	  	X      	  	$5.00                    	 	=      	  	$                                      
      	  	
	Number of Shares	  		  	Purchase Price per Share	 		  	Total Purchase Price	  	

  

					
	SUBSCRIBER (individual)	  		  	SUBSCRIBER (entity)
			
		  		  	
	  
 Signature
	  		  	  
 Name of Entity

			
		  		  	By:
                                         
                                         
                  
	  
 Print Name
	  		  	      Signature
			
		  		  	Print Name:
                                         
                                         
  
	Signature (if Joint Tenants or Tenants in Common)	  		  	Title:
                                         
                                         
               
			
	Address of Principal Residence:	  		  	Address of Executive Offices:
	  
	  		  	  

	  
	  		  	  

	  
	  		  	  

			
	Social Security Number(s):	  		  	IRS Tax Identification Number:
	  
	  		  	  

			
	Telephone Number:	  		  	Telephone Number:
	  
	  		  	  

			
	Facsimile Number:	  		  	Facsimile Number:
	  
	  		  	  

			
	E-mail Address:	  		  	E-mail Address:
	  
	  		  	  

  

	1 	Will reflect the Closing Date. Not to be completed by Purchaser. 

 Aerpio Pharmaceuticals, Inc. 

ACCREDITED INVESTOR CERTIFICATION 

For Individual Investors Only 

(all Individual Investors must INITIAL where appropriate): 

 

			
	Initial _______	  	I have a net worth of at least US$1 million either individually or through aggregating my individual holdings and those in which I have a joint, community property or other similar shared ownership interest with my spouse.
(For purposes of calculating your net worth under this paragraph, (a) your primary residence shall not be included as an asset; (b) indebtedness secured by
your primary residence, up to the estimated fair market value of your primary residence at the time of your purchase of the securities, shall not be included as a liability (except that if the amount of such indebtedness outstanding at the time of
your purchase of the securities exceeds the amount outstanding sixty (60) days before such time, other than as a result of the acquisition of your primary residence, the amount of such excess shall be included as a
liability); and (c) indebtedness that is secured by your primary residence in excess of the estimated fair market value of your primary residence at the time of your purchase of the securities shall be included as a
liability.) 
		
	Initial _______	  	I have had an annual gross income for the past two (2) years of at least US$200,000 (or US$300,000 jointly with my spouse) and expect my income (or joint income, as appropriate) to reach the same level in the current
year.
		
	Initial _______	  	I am a director or executive officer of                             .

 For Non-Individual Investors (Entities) 

(all Non-Individual Investors must INITIAL where appropriate): 

 

			
	Initial _______	  	The investor certifies that it is a partnership, corporation, limited liability company or business trust that is 100% owned by persons who meet at least one of the criteria for Individual Investors set forth above (in which case
each such person must complete the Accreditor Investor Certification for Individuals above as well the remainder of this questionnaire).
		
	Initial _______	  	The investor certifies that it is a partnership, corporation, limited liability company or business trust that has total assets of at least US$5,000,000 and was not formed for the purpose of investing the Company.
		
	Initial _______	  	The investor certifies that it is an employee benefit plan whose investment decision is made by a plan fiduciary (as defined in Section 3(21) of the Employee Retirement Income Security Act of 1974) that is a bank, savings
and loan association, insurance company or registered investment advisor.
		
	Initial _______	  	The investor certifies that it is an employee benefit plan whose total assets exceed US$5,000,000 as of the date of this Agreement.
		
	Initial _______	  	The undersigned certifies that it is a self-directed employee benefit plan whose investment decisions are made solely by persons who meet at least one of the criteria for Individual Investors.
		
	Initial _______	  	The investor certifies that it is a U.S. bank as defined in Section 3(a)(2) of the Securities Act, or any U.S. savings and loan association or other similar U.S. institution as defined in Section 3(a)(5) of the Securities Act
acting in its individual or fiduciary capacity.
		
	Initial _______	  	The undersigned certifies that it is a broker-dealer registered pursuant to Section 15 of the Securities Exchange Act of 1934.
		
	Initial _______	  	The investor certifies that it is an organization described in Section 501(c)(3) of the Internal Revenue Code with total assets exceeding US$5,000,000 and not formed for the specific purpose of investing in the Company.
		
	Initial _______	  	The investor certifies that it is a trust with total assets of at least US$5,000,000, not formed for the specific purpose of investing in the Company, and whose purchase is directed by a person with such knowledge and experience
in financial and business matters that such person is capable of evaluating the merits and risks of the prospective investment.
		
	Initial _______	  	The investor certifies that it is a plan established and maintained by a state or its political subdivisions, or any agency or instrumentality thereof, for the benefit of its employees, and which has total assets in excess of
US$5,000,000.

			
		
	Initial _______	  	The investor certifies that it is an insurance company as defined in Section 2(13) of the Securities Act of 1933, or a registered investment company.
		
	Initial _______	  	The investor certifies that it is an investment company registered under the Investment Company Act of 1940 or a business development company as defined in Section 2(a)(48) of that Act.
		
	Initial _______	  	The investor certifies that it is a Small Business Investment Company licensed by the U.S. Small Business Administration under Section 301(c) or (d) of the Small Business Investment Act of 1958.
		
	Initial _______	  	The investor certifies that it is a private business development company as defined in Section 202(a)(22) of the Investment Advisers Act of 1940.

 Aerpio Pharmaceuticals, Inc. 

Investor Profile 

(Must be completed by Investor) 

Section A - Personal Investor Information 

 

									
	 Investor
Name(s):                                       
                                         
                                         
                                         
                    

	
	 Individual executing Profile or
Trustee:                                       
                                         
                                         
                          

	
	 Social Security Numbers / Federal I.D.
Number:                                        
                                         
                                         
           

		
	 Date of Birth:
                                         
                   
	 	
Marital Status:               
                                       

	 Joint Party Date of Birth:
	 	  
	 		 		 	 Investment Experience (Years):

				
	
Annual Income:               
                                         
             
	 		 	 Liquid Net Worth: 
	 	
				
	
Net Worth*:                
                                         
                  
	 		 		 	
					
	 Tax Bracket:    
	 	 _____ 15% or below
	 	 _____ 25% - 27.5%
	 	 _____ Over 27.5%
	 	
	
	
Home Street Address:              
                                         
                                         
                                         
                                      

	
	 Home City, State & Zip
Code:                                        
                                         
                                         
                                       

		
	
Home Phone:                
                                         
                
	 	 Home Fax:
                                 Home
Email:                                       

	
	
Employer:                 
                                         
                                         
                                         
                                         
              

	
	 Employer Street
Address:                                       
                                         
                                         
                                         
       

	
	 Employer City, State & Zip
Code:                                        
                                         
                                         
                                 

		
	
Bus. Phone:                
                                         
                  
	 	 Bus. Fax:
                                     Bus.
Email:                                        
 

	
	 Type of
Business:                                       
                                         
                                         
                                         
                   

	
	 Outside
Broker/Dealer:                                      
                                         
                                         
                                         
            

 Section B – Certificate Delivery Instructions 

____ Please deliver certificate to the Employer Address listed in Section A. 

____ Please deliver certificate to the Home Address listed in Section A. 

____ Please deliver certificate to the following address:
                                         
                                         
                                   

Section C – Form of Payment – Check or Wire Transfer 

____ Check payable to Delaware Trust Company, as Escrow Agent for Aerpio, ACCT# _________ 

____ Wire funds from my outside account according to Section 2(b) of the Subscription Agreement. 

____ The funds for this investment are rolled over, tax deferred from __________ within the allowed 60-day window. 

____ Please check if you are a FINRA member or Affiliate of a FINRA member firm: ____ 

 

					
	  
	 		  	  

	 Investor Signature
	 		  	 Date

  

	*	For purposes of calculating your net worth in this form, (a) your primary residence shall not be included as an asset; (b) indebtedness secured by your primary residence, up to the estimated fair
market value of your primary residence at the time of your purchase of the securities, shall not be included as a liability (except that if the amount of such indebtedness outstanding at the time of your purchase of the securities exceeds the amount
outstanding sixty (60) days before such time, other than as a result of the acquisition of your primary residence, the amount of such excess shall be included as a liability); and (c) indebtedness that is secured by your primary residence
in excess of the estimated fair market value of your primary residence at the time of your purchase of the securities shall be included as a liability. 

 ANTI MONEY LAUNDERING REQUIREMENTS 

The USA PATRIOT Act 
 The USA PATRIOT Act is designed to
detect, deter, and punish terrorists in the United States and abroad. The Act imposes new anti-money laundering requirements on brokerage firms and financial institutions. Since April 24, 2002 all brokerage firms have been required to have new,
comprehensive anti-money laundering programs. 
 To help you understand these efforts, we want to provide you with some information about money laundering
and our steps to implement the USA PATRIOT Act. 
 What is money laundering? 

Money laundering is the process of disguising illegally obtained money so that the funds appear to come from legitimate sources or activities. Money laundering
occurs in connection with a wide variety of crimes, including illegal arms sales, drug trafficking, robbery, fraud, racketeering, and terrorism. 
 How
big is the problem and why is it important? 
 The use of the U.S. financial system by criminals to facilitate terrorism or other crimes could well taint
our financial markets. According to the U.S. State Department, one recent estimate puts the amount of worldwide money laundering activity at $1 trillion a year. 

What are we required to do to eliminate money laundering? 

Under rules required by the USA PATRIOT Act, our anti-money laundering program must designate a special compliance officer, set up employee training, conduct
independent audits, and establish policies and procedures to detect and report suspicious transaction and ensure compliance with such laws. As part of our required program, we may ask you to provide various identification documents or other
information. Until you provide the information or documents we need, we may not be able to effect any transactions for you. 

 ANTI-MONEY LAUNDERING INFORMATION FORM 

The following is required in accordance with the AML provision of the USA PATRIOT ACT. 

(Please fill out and return with requested documentation.) 
  

					
	 INVESTOR NAME:
	  	  
	 	
			
	 LEGAL ADDRESS:
	  	  
	 	
			
	 SSN# or TAX ID# OF INVESTOR:
	  	  
	 	
			
	 YEARLY INCOME:
	  	  
	 	
			
	 NET WORTH:
	  	  
	 	 *

  

	*	For purposes of calculating your net worth in this form, (a) your primary residence shall not be included as an asset; (b) indebtedness secured by your primary residence, up to the estimated fair
market value of your primary residence at the time of your purchase of the securities, shall not be included as a liability (except that if the amount of such indebtedness outstanding at the time of your purchase of the securities exceeds the amount
outstanding sixty (60) days before such time, other than as a result of the acquisition of your primary residence, the amount of such excess shall be included as a liability); and (c) indebtedness that is secured by your primary residence
in excess of the estimated fair market value of your primary residence at the time of your purchase of the securities shall be included as a liability. 

  

			
	INVESTMENT OBJECTIVE(S) (FOR ALL
INVESTORS):                                     
                                         
                                         
                
	
	ADDRESS OF BUSINESS OR OF
EMPLOYER:                                       
                                         
                                         
                                   
	
	                                   
                                         
                                         
                                         
                                        
                                         
  
	
	FOR INVESTORS WHO ARE INDIVIDUALS:
AGE:                                       
                                         
                                         
                         
	
	FOR INVESTORS WHO ARE INDIVIDUALS:
OCCUPATION:                                      
                                         
                                         
    
	
	FOR INVESTORS WHO ARE ENTITIES: TYPE OF
BUSINESS:                                       
                                         
                                         

 IDENTIFICATION & DOCUMENTATION AND SOURCE OF FUNDS: 

 

	1.	Please submit a copy of non-expired identification for the authorized signatory(ies) on the investment documents, showing name, date of birth, address and signature. The
address shown on the identification document MUST match the Investor’s address shown on the Investor Signature Page. 

  

									
	 Current Driver’s License
	  	or	  	Valid Passport	  	or	  	Identity Card

 (Circle one or more) 
  

	2.	If the Investor is a corporation, limited liability company, trust or other type of entity, please submit the following requisite documents: (i) Certificate of Incorporation,
By-Laws, Certificate of Formation, Operating Agreement, Trust or other similar documents for the type of entity; and (ii) Corporate Resolution or power of attorney or other similar document granting
authority to signatory(ies) and designating that they are permitted to make the proposed investment. 

  

	3.	Please advise where the funds were derived from to make the proposed investment: 

  

							
	 Investments
	  	 Savings
	  	 Proceeds of Sale
	  	 Other ____________

 (Circle one or more) 
  

			
	Signature:	 	  

	Print Name:	 	  

	Title (if applicable):	 	  

	Date:	 	  

 EXHIBIT A 

Form of Registration Rights Agreement

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