UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13D

[Rule 13d-101]

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a)

AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a)

REATA PHARMACEUTICALS, INC.

(Name of Issuer)

CLASS A COMMON STOCK, $.001 PAR VALUE

(Title of Class of Securities)

75615P 103

(CUSIP Number)

WILLIAM E. ROSE

C/O CARDINAL INVESTMENT COMPANY, INC.

3963 MAPLE AVENUE, SUITE 200

DALLAS, TEXAS 75219

(214) 871-6809

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

May 25, 2016

(Date of Event Which Requires Filing of this Statement)

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

Note. Schedules filed in paper format shall include a signed original and five copes of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

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

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ITEM 1. SECURITY AND ISSUER.

This Schedule 13D relates to the Class A common stock, par value $0.001 per share (the “Class A Common Stock”), of Reata Pharmaceuticals, Inc., a Delaware corporation (the “Issuer”). The principal executive offices of the Issuer are located at 2801 Gateway Drive, Suite 150, Irving, Texas 75063.

ITEM 2. IDENTITY AND BACKGROUND.

The names of the persons filing this Statement (the “Reporting Persons”) include:

The principal business address for each of the Reporting Persons and Ms. Marcus is c/o Cardinal Investment Company, Inc., 3963 Maple Avenue, Suite 200, Dallas, Texas 75219.

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None of the Reporting Persons nor Ms. Marcus have, during the last five years, been convicted in a criminal proceeding or been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

ITEM 3. SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

The information set forth in Item 2, Item 5 and Item 6 is hereby incorporated by reference in its entirety.

Prior to the Issuer’s initial public offering of Class A Common Stock (the “IPO”), each of Reporting Persons held the following outstanding shares of Class B common stock of the Issuer, par value $0.001 per share (“Class B Common Stock”):

Such shares were acquired over several years in private placements using the personal funds and working capital of Edward W. Rose III, Mr. Gale and Mr. Rose and their related investment vehicles. Shares of Class B Common Stock are convertible into shares of Class A Common Stock on a one-for-one basis (a) at the holder’s election at any time after the date that is six months following the date of the closing of the initial public offering of the Shares, (b) at the holder’s election prior to that time subject to certain conditions, or (c) at the option of the Issuer’s board of directors, in its sole discretion, at any time or multiple times from time to time on or before the closing of the initial public offering.

Upon effectiveness of the Issuer’s Registration Statement on Form 8-A on May 25, 2016, filed in connection with the Issuer’s initial public offering of Class A Common Stock (the “IPO”), each of the Reporting Persons became the deemed beneficial owners of one share of Class A Common Stock for every share of Class B Common Stock owned by such Reporting Person. Upon the closing of the IPO, approximately 8% of the shares of Class B Common Stock of each of the Reporting Persons automatically converted into shares of Class A Common Stock for no additional consideration.

Additionally, Montrose LP acquired 143,000 shares of Class A Common Stock at a purchase price of $11.00 per share in the IPO with limited partnership funds, which consist of working capital of the partnership and may include borrowings under a working capital line of credit with JP Morgan Chase Bank. Puffin Partners acquired 957,000 shares of Class A Common Stock at a purchase price of $11.00 per share in the IPO with limited partnership funds, which consist of working capital of the partnership.

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ITEM 4. PURPOSE OF TRANSACTION.

The Class A Common Stock and Class B Common Stock described herein was acquired by the Reporting Persons for investment purposes. The Reporting Persons have no present plans or proposals for disposition of the shares beneficially owned by him or for acquisition of additional shares. The Reporting Persons, however, expect to evaluate on a continuing basis their goals and objectives, other business opportunities available to them, and general economic and equity market conditions, as well as the Issuer’s business operations and prospects. Based on such evaluations, the Reporting Persons may change their plans and intentions and may determine to sell or otherwise dispose of some or all of the shares beneficially owned by them or to acquire additional shares. In addition, the Reporting Persons may, from time to time, transfer shares beneficially owned by them for tax or other economic planning purposes.

Except as set forth above, the Reporting Persons have no present plans or intentions which would result in or relate to any of the transactions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D.

ITEM 5. INTEREST IN SECURITIES OF ISSUER.

The information set forth in Item 2, Item 3 and Item 6 is hereby incorporated by reference in its entirety.

(2) The Estate may be deemed to beneficially own 2,046,718 shares of Class A Common Stock, representing approximately 21.50% of the outstanding shares of Class A Common Stock.

(3) Mrs. Rose may be deemed to beneficially own 95,662 shares of Class A Common Stock, representing approximately 1.24% of the outstanding shares of Class A Common Stock.

(4) The Rose IRA may be deemed to beneficially own 95,662 shares of Class A Common Stock, representing approximately 1.24% of the outstanding shares of Class A Common Stock.

(5) The 2001 Trust may be deemed to beneficially own 235 shares of Class A Common Stock, representing approximately 0.00% of the outstanding shares of Class A Common Stock.

(6) The 2002 Trust may be deemed to beneficially own 537 shares of Class A Common Stock, representing approximately 0.01% of the outstanding shares of Class A Common Stock.

(7) Mr. Gale may be deemed to beneficially own 3,117,017 shares of Class A Common Stock, representing approximately 32.44% of the outstanding shares of Class A Common Stock.

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(8) The Gale IRA may be deemed to beneficially own 342 shares of Class A Common Stock, representing approximately 0.00% of the outstanding shares of Class A Common Stock.

(9) Puffin Partners may be deemed to beneficially own 957,000 shares of Class A Common Stock, representing approximately 12.52% of the outstanding shares of Class A Common Stock.

(10) Puffin GP may be deemed to beneficially own 957,000 shares of Class A Common Stock, representing approximately 12.52% of the outstanding shares of Class A Common Stock.

(11) Montrose LP may be deemed to beneficially own 143,000 shares of Class A Common Stock, representing approximately 1.87% of the outstanding shares of Class A Common Stock.

(12) Montrose GP may be deemed to beneficially own 143,000 share of Class A Common Stock, representing approximately 1.87% of the outstanding shares of Class A Common Stock.

(b) (1) Mr. Rose may be deemed to have sole voting power with respect to 140,926 shares of common stock (comprised of 11,618 shares of Class A Common Stock and 129,308 shares of Class B Common Stock), shared voting power with respect to 1,100,772 shares of common stock (comprised of 1,100,065 shares of Class A Common Stock and 707 shares of Class B Common Stock), sole dispositive power with respect to 140,926 shares of common stock (comprised of 11,618 shares of Class A Common Stock and 129,308 shares of Class B Common Stock), and shared dispositive power with respect to 1,100,772 shares of common stock (comprised of 1,100,065 shares of Class A Common Stock and 707 shares of Class B Common Stock).

(2) The Estate may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 2,046,718 shares of common stock (comprised of 168,720 shares of Class A Common Stock and 1,877,998 shares of Class B Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 2,046,718 shares of common stock (comprised of 168,720 shares of Class A Common Stock and 1,877,998 shares of Class B Common Stock).

(3) Mrs. Rose may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 95,662 shares of common stock (comprised of 7,886 shares of Class A Common Stock and 87,776 shares of Class B Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 95,662 shares of common stock (comprised of 7,886 shares of Class A Common Stock and 87,776 shares of Class B Common Stock).

(4) Rose IRA may be deemed to have sole voting power with respect to 0 shares of common stock, and shared voting power with respect to 95,662 shares of common stock (comprised of 7,886 shares of Class A Common Stock and 87,776 shares of Class B Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 95,662 shares of common stock (comprised 7,886 shares of Class A Common Stock and 87,776 shares of Class B Common Stock).

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(5) The 2001 Trust may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 235 shares of common stock (comprised of 20 shares of Class A Common Stock and 215 shares of Class B Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 235 shares of common stock (comprised of 20 shares of Class A Common Stock and 215 shares of Class B Common Stock).

(6) The 2002 Trust may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 537 shares of common stock (comprised of 45 of Class A Common Stock and 492 shares of Class B Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared voting power with respect to 537 shares of common stock (comprised of 45 shares of Class A Common Stock and 492 shares of Class B Common Stock).

(7) Mr. Gale may be deemed to have sole voting power with respect to 17,295 shares of common stock (comprised of 1,426 shares of Class A Common Stock and 15,869 shares of Class B Common Stock), shared voting power with respect to 3,099,722 shares of common stock (comprised of 1,133,635 shares of Class A Common Stock and 1,966,087 shares of Class B Common Stock), sole dispositive power with respect to 17,295 shares of common stock (comprised of 1,426 shares of Class A Common Stock and 15,869 shares of Class B Common Stock), and shared dispositive power with respect to 3,099,722 shares of common stock (comprised of 1,133,635 shares of Class A Common stock and 1,966,087 shares of Class B Common Stock).

(8) The Gale IRA may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 342 shares of common stock (comprised of 29 shares of Class A Common Stock and 313 shares of Class B Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 342 shares of common stock (comprised of 29 shares of Class A Common Stock and 313 shares of Class B Common Stock).

(9) Puffin Partners may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 957,000 shares of common stock (comprised of 957,000 shares of Class A Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 957,000 shares of common stock (comprised of 957,000 shares of Class A Common Stock).

(10) Puffin GP may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 957,000 shares of common stock (comprised of 957,000 shares of Class A Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 957,000 shares of common stock (comprised of 957,000 shares of Class A Common Stock).

(11) Montrose LP may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 143,000 shares of common stock (comprised of 143,000 shares of Class A Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 143,000 shares of common stock (comprised of 143,000 shares of Class A Common Stock).

(12) Montrose GP may be deemed to have sole voting power with respect to 0 shares of common stock, shared voting power with respect to 143,000 shares of common stock (comprised of 143,000 shares of Class A Common Stock), sole dispositive power with respect to 0 shares of common stock, and shared dispositive power with respect to 143,000 shares of common stock (comprised of 143,000 shares of Class A Common Stock).

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(c) The information provided in Item 4 above is hereby incorporated by reference.

(d) The right to receive dividends from, and proceeds from the sale of, the shares of Class A Common Stock and Class B Common Stock held of record and/or beneficially owned by Puffin Partners, Puffin GP, Montrose LP, and Montrose GP is governed by their respective limited partnership agreements and limited liability regulations, as applicable, of each of such entities, and such dividends or proceeds may be distributed with respect to numerous general and limited partnership or membership interests.

The right to receive dividends from, and proceeds from the sale of, the shares of Class A Common Stock and Class B Common Stock held of record and/or beneficially owned by the Estate is governed by will, testamentary and testate law.

(e) Not applicable.

ITEM 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE ISSUER.

The information set forth in Item 2, Item 3 and Item 5 is hereby incorporated by reference in its entirety.

Each of Mr. Rose, the Estate, Mr. Gale, the Gale IRA, the 2001 Trust and the 2002 Trust signed a Lock-Up Agreement, as extended by that certain Lock-up Extension (the “Lock-Up Agreements”), in the forms attached as exhibits hereto, pursuant to which such person or entity agreed with the underwriters in the IPO, on behalf of itself and its affiliates, for a period of 180 days following May 25, 2016, subject to certain exceptions, it and they will not, directly or indirectly, offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale, or otherwise dispose of or hedge any of the Issuer’s shares of common stock, any options or warrants to purchase any shares of the Issuer’s common stock, or any securities convertible into, or exchangeable for or that represent the right to receive shares of the Issuer’s common stock. Citigroup Global Markets Inc. and Cowen and Company, LLC, on behalf of the underwriters, may, in their sole discretion, at any time without prior notice, release all or any portion of the shares from the restrictions in any such agreement. Each of the Reporting Persons is subject to the provisions of the Lock-Up Agreements.

Cardinal Investment Company, Inc., an affiliate of the Reporting Persons, is a party to that certain Seventh Amended and Restated Registration Rights Agreement dated as of November 10, 2010 (the “Registration Rights Agreement”), pursuant to which holders of more than 67% of the registerable shares of the Issuer, at any time at least six months after the completion of the IPO, may twice request that the Issuer effect the registration of at least 50% of the registerable shares held by all holders of registration rights, or a lesser number of shares if the aggregate price to the public of the offering (net of underwriter discounts) will be at least $5 million. Furthermore, if Form S-3 is available for an offering by the initiating holders, the initiating holders may request that the Issuer effect an unlimited number of registrations on Form S-3 at an aggregate offering price of at least $1,000,000 per registration on Form S-3. In addition, the holders of registrable securities have piggyback registration rights if the Issuer determines to register any equity securities for its own account or the account of another security holder (other than in the IPO). The Issuer will pay the registration expenses, other than underwriting fees, discounts or commissions, of the shares registered pursuant to the registrations described above, but limited to four registrations on Form S-3. The Registration Rights Agreement terminates with respect to any holder who is permitted to sell, within a 90-day period, all of such holder’s registrable shares in compliance with Rule 144.

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To the Reporting Persons’ knowledge, there are no other contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Issuer.

The descriptions contained in this Statement on Schedule 13D of the Lock-Up Agreements and the Registration Rights Agreement are summaries only and are qualified in their entireties by the actual terms of each such agreement, which are incorporated herein by this reference. See Item 7 “Material to be Filed as Exhibits.”

ITEM 7. MATERIAL TO BE FILED AS EXHIBITS.

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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SIGNATURE

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

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Exhibit 7.1

Lock-up Agreement

Reata Pharmaceuticals, Inc.

Public Offering of Common Stock

            , 201    

Citigroup Global Markets Inc.

Cowen and Company, LLC

As Representatives of the several Underwriters,

c/o Citigroup Global Markets Inc.

388 Greenwich Street

New York, New York 10013

Ladies and Gentlemen:

This letter is being delivered to you in connection with the proposed Underwriting Agreement (the “Underwriting Agreement”) between Reata Pharmaceuticals, Inc., a Delaware corporation (the “Company”), Citigroup Global Markets Inc. and Cowen and Company, LLC (together, the “Representatives”) as representatives of a group of Underwriters named therein, relating to an underwritten public offering of Class A Common Stock, $0.001 par value per share (the “Common Stock”), of the Company (the “Offering”).

In order to induce you and the other Underwriters to enter into the Underwriting Agreement, the undersigned will not, without the prior written consent of the Representatives, offer, sell, contract to sell, pledge or otherwise dispose of (or enter into any transaction which is designed to, or might reasonably be expected to, result in the disposition (whether by actual disposition or effective economic disposition due to cash settlement or otherwise) by the undersigned or any affiliate of the undersigned or any person in privity with the undersigned or any affiliate of the undersigned), directly or indirectly, including the filing (or participation in the filing) of a registration statement (other than the registration statement relating to the Offering) with the Securities and Exchange Commission in respect of, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations of the Securities and Exchange Commission promulgated thereunder with respect to, any shares of capital stock of the Company or any securities convertible into, or exercisable or exchangeable for such capital stock, or publicly announce an intention to effect any such transaction, for a period from the date hereof until 180 days after the date of the Underwriting Agreement (the “Lock-Up Period”). If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing restrictions shall be equally applicable to any issuer-directed shares of Common Stock the undersigned may purchase in the Offering.

The provisions of the immediately preceding paragraph shall not apply to or prohibit any of the following: (i) transfers, dispositions, or distributions of shares of capital stock of the Company by the undersigned (or any security convertible into or exercisable or exchangeable for shares of common stock) (a) as a bona fide gift, (b) to limited partners, members, stockholders or trust beneficiaries of the undersigned or to any investment fund or other entity controlled or managed by the undersigned, (c) by will or other testamentary document or by intestacy, and (d) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned (for the purposes of this letter, “immediate family” shall mean any relationship by blood, current or former marriage or adoption, not more remote than first cousin) in a transaction not involving a disposition for value, provided that, in the case of any transfer, disposition or distribution pursuant to the above four subclauses, each donee, transferee or distributee shall sign and deliver a lock-up letter in the form of this letter, and with respect to (a), (b) and (d) above, no filing under Section 16(a) of the Exchange Act, or other public announcement, reporting a reduction in beneficial ownership of shares of capital stock of the Company, shall be required or shall be voluntarily made by the undersigned or any other person in connection therewith during the Lock-Up Period; (ii) the exercise of options to

purchase shares of capital stock of the Company granted under any stock incentive plan or stock purchase plan described in the prospectus filed in connection with the Offering, provided that the underlying shares issuable upon exercise thereof shall continue to be subject to the restrictions on transfer set forth in this letter; (iii) transfers of shares of capital stock of the Company to the Company in connection with the termination of the undersigned’s employment with the Company; (iv) establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of shares of capital stock of the Company, provided that such plan does not provide for the transfer of such capital stock during the Lock-Up Period and no filing with the SEC or other public announcement shall be required or shall be voluntarily made by the undersigned or any other person in connection therewith during the Lock-Up Period; (v) transfers or dispositions of shares of Common Stock purchased in the Offering from the Underwriters (other than issuer-directed shares of Common Stock purchase in the Offering by an officer or director of the Company) or on the open market following the Offering; or (vi) transfers of shares of capital stock of the Company pursuant to a bona fide third-party tender offer for all outstanding shares of the Company, merger, consolidation or other similar transaction made to all holders of the Company’s securities involving a change of control of the Company that has been approved by the board of directors of the Company, provided that (a) the shares of capital stock of the Company held by the undersigned that are not transferred pursuant to such tender offer, merger, consolidation or other similar transaction shall remain subject to all of the restrictions set forth in this letter, (b) if such transaction is not completed, all shares of capital stock of the Company held by the undersigned shall remain subject to the provisions of this letter, and (c) for purposes of this paragraph, “change of control” shall mean the consummation of any bona fide third party tender offer for any and all of the Company’s share capital or any merger, consolidation or other similar transaction the result of which is that any “person” (as defined in Section 13(d)(3) of the Exchange Act), or group of persons, other than the Company, becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 of the Exchange Act) of 50% of the total voting power of the voting securities of the Company.

If the undersigned is an officer or director of the Company, (i) the Representatives agree that, at least three business days before the effective date of any release or waiver of the foregoing restrictions in connection with a transfer of any shares of capital stock of the Company, the Representatives will notify the Company of the impending release or waiver, and (ii) the Company has agreed in the Underwriting Agreement to announce the impending release or waiver by press release through a major news service at least two business days before the effective date of the release or waiver. Any release or waiver granted by the Representatives hereunder to any such officer or director shall only be effective two business days after the publication date of such press release. The provisions of this paragraph will not apply if (a) the release or waiver is effected solely to permit a transfer not for consideration and (b) the transferee has agreed in writing to be bound by the same terms described in this letter to the extent and for the duration that such terms remain in effect at the time of the transfer.

If any percentage of the shares of capital stock of the Company (or any security convertible into or exercisable or exchangeable for shares of such capital stock) held by any person or entity (other than the undersigned) that (1) is the holder of 2% or more of the outstanding shares of the Company’s capital stock (calculated on a fully-diluted, post-Offering basis) or (2) is a director or officer of the Company, that is subject to a lock-up agreement related to the Offering similar in form to this Lock-Up Agreement is released from any restrictions set forth in such lock-up agreement during the Lock-Up Period, the same percentage of shares of capital stock and such other securities held by the undersigned shall be immediately and fully released on the same terms from the lock-up restrictions set forth herein (the “Pro-rata Release”); provided, however, that such Pro-rata Release shall not occur (a) unless and until the Representatives have first waived such restrictions with respect to an aggregate number of shares of capital stock and such other securities representing more than 2 % of the Company’s total outstanding shares of Common Stock calculated as of immediately following the closing of the Offering and assuming conversion, exercise and exchange of all securities convertible into or exercisable or exchangeable for Common Stock, or (b) in the event of a release in connection with any underwritten public offering, whether or not such offering or sale is wholly or partially a secondary offering of the Company’s Common Stock during the Lock-Up Period (the “Underwritten Sale”); provided, however, that the undersigned, to the extent the undersigned has a contractual right to demand or require the registration of the undersigned’s Common Stock or such other securities or otherwise “piggyback” on a registration statement filed by the Company for the offer and sale of securities, is offered the opportunity to participate on a basis consistent with such contractual rights in such Underwritten Sale. In the event that the undersigned is released from any of its obligations under this letter or, by virtue of this letter, becomes entitled to offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or

indirectly, any shares of capital stock (or any securities convertible into or exercisable or exchangeable for shares of such capital stock) prior to the date that is 180 days after the date of the Underwriting Agreement, the Representatives shall use their commercially reasonable efforts to notify the undersigned within three (3) business days; provided that the failure to give such notice shall not give rise to any claim or liability against the Representatives or the Underwriters.

If for any reason the Underwriting Agreement shall be terminated prior to the Closing Date (as defined in the Underwriting Agreement), the agreement set forth above shall likewise be terminated, and the agreement set forth above shall automatically terminate if the Underwriting Agreement has not been entered into between the Representatives and the Company prior to May 1, 2016

Exhibit 7.2

Lock-up Agreement

Reata Pharmaceuticals, Inc.

Public Offering of Common Stock

January     , 2016

Citigroup Global Markets Inc.

Cowen and Company, LLC

As Representatives of the several Underwriters,

c/o Citigroup Global Markets Inc.

388 Greenwich Street

New York, New York 10013

Ladies and Gentlemen:

This letter is being delivered to you in connection with the proposed Underwriting Agreement (the “Underwriting Agreement”) between Reata Pharmaceuticals, Inc., a Delaware corporation (the “Company”), Citigroup Global Markets Inc. and Cowen and Company, LLC (together, the “Representatives”) as representatives of a group of Underwriters named therein, relating to an underwritten public offering of Class A Common Stock, $0.001 par value per share (the “Common Stock”), of the Company (the “Offering”).

In order to induce you and the other Underwriters to enter into the Underwriting Agreement, the undersigned will not, without the prior written consent of the Representatives, offer, sell, contract to sell, pledge or otherwise dispose of (or enter into any transaction which is designed to, or might reasonably be expected to, result in the disposition (whether by actual disposition or effective economic disposition due to cash settlement or otherwise) by the undersigned or any affiliate of the undersigned or any person in privity with the undersigned or any affiliate of the undersigned), directly or indirectly, including the filing (or participation in the filing) of a registration statement with the Securities and Exchange Commission in respect of, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations of the Securities and Exchange Commission promulgated thereunder with respect to, any shares of capital stock of the Company or any securities convertible into, or exercisable or exchangeable for such capital stock, or publicly announce an intention to effect any such transaction, for a period from the date hereof until 180 days after the date of the Underwriting Agreement (the “Lock-Up Period”). If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing restrictions shall be equally applicable to any issuer-directed shares of Common Stock the undersigned may purchase in the Offering.

The provisions of the immediately preceding paragraph shall not apply to or prohibit any of the following: (i) transfers, dispositions, or distributions of shares of capital stock of the Company by the undersigned (or any security convertible into or exercisable or exchangeable for shares of common stock) (a) as a bona fide gift, (b) to limited partners, members, stockholders or trust beneficiaries of the undersigned or to any investment fund or other entity controlled or managed by the undersigned, (c) by will or other testamentary document or by intestacy, and (d) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned (for the purposes of this letter, “immediate family” shall mean any relationship by blood, current or former marriage or adoption, not more remote than first cousin) in a transaction not involving a disposition for value, provided that, in the case of any transfer, disposition or distribution pursuant to the above four subclauses, each donee, transferee or distributee shall sign and deliver a lock-up letter in the form of this letter, and with respect to (a), (b) and (d) above, no filing under Section 16(a) of the Exchange Act, or other public announcement, reporting a reduction in beneficial ownership of shares of capital stock of the Company, shall be required or shall be voluntarily made by the undersigned or any other person in connection therewith during the Lock-Up Period; (ii) the exercise of options to purchase shares of capital stock of the Company granted under any stock incentive plan or stock purchase plan

described in the prospectus filed in connection with the Offering, provided that the underlying shares issuable upon exercise thereof shall continue to be subject to the restrictions on transfer set forth in this letter; (iii) transfers of shares of capital stock of the Company to the Company in connection with the termination of the undersigned’s employment with the Company; (iv) establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of shares of capital stock of the Company, provided that such plan does not provide for the transfer of such capital stock during the Lock-Up Period and no filing with the SEC or other public announcement shall be required or shall be voluntarily made by the undersigned or any other person in connection therewith during the Lock-Up Period; (v) transfers or dispositions of shares of Common Stock purchased in the Offering from the Underwriters (other than issuer-directed shares of Common Stock purchase in the Offering by an officer or director of the Company) or on the open market following the Offering; or (vi) transfers of shares of capital stock of the Company pursuant to a bona fide third-party tender offer for all outstanding shares of the Company, merger, consolidation or other similar transaction made to all holders of the Company’s securities involving a change of control of the Company that has been approved by the board of directors of the Company, provided that (a) the shares of capital stock of the Company held by the undersigned that are not transferred pursuant to such tender offer, merger, consolidation or other similar transaction shall remain subject to all of the restrictions set forth in this letter, (b) if such transaction is not completed, all shares of capital stock of the Company held by the undersigned shall remain subject to the provisions of this letter, and (c) for purposes of this paragraph, “change of control” shall mean the consummation of any bona fide third party tender offer for any and all of the Company’s share capital or any merger, consolidation or other similar transaction the result of which is that any “person” (as defined in Section 13(d)(3) of the Exchange Act), or group of persons, other than the Company, becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 of the Exchange Act) of 50% of the total voting power of the voting securities of the Company.

If the undersigned is an officer or director of the Company, (i) the Representatives agrees that, at least three business days before the effective date of any release or waiver of the foregoing restrictions in connection with a transfer of any shares of capital stock of the Company, the Representatives will notify the Company of the impending release or waiver, and (ii) the Company has agreed in the Underwriting Agreement to announce the impending release or waiver by press release through a major news service at least two business days before the effective date of the release or waiver. Any release or waiver granted by the Representatives hereunder to any such officer or director shall only be effective two business days after the publication date of such press release. The provisions of this paragraph will not apply if (a) the release or waiver is effected solely to permit a transfer not for consideration and (b) the transferee has agreed in writing to be bound by the same terms described in this letter to the extent and for the duration that such terms remain in effect at the time of the transfer.

If for any reason the Underwriting Agreement shall be terminated prior to the Closing Date (as defined in the Underwriting Agreement), the agreement set forth above shall likewise be terminated, and the agreement set forth above shall automatically terminate if the Underwriting Agreement has not been entered into between the Representatives and the Company prior to May 1, 2016.

Exhibit 7.3

March 28, 2016

Citigroup Global Markets Inc.

Cowen and Company, LLC

As Representatives of the several Underwriters,

c/o Citigroup Global Markets Inc.

388 Greenwich Street

New York, New York 10013

Ladies and Gentleman:

Reference is made to that certain lock-up agreement, the Lock-Up Agreement, by and among the undersigned and Citigroup Global Markets Inc. and Cowen and Company, LLC (together, the “Representatives”), in connection with the proposed public offering of Class A Common Stock, $0.001 par value per share, of the Reata Pharmaceuticals, Inc. The undersigned hereby agrees that the last paragraph of the Lock-Up Agreement shall be replaced with the clause below, such that the Lock-Up Agreement shall not expire until December 15, 2016:

“If for any reason the Underwriting Agreement shall be terminated prior to the Closing Date (as defined in the Underwriting Agreement), the agreement set forth above shall likewise be terminated, and the agreement set forth above shall automatically terminate if the Underwriting Agreement has not been entered into between the Representatives and the Company prior to December 15, 2016.”

This letter agreement will not change or supersede any other terms of the Lock-Up Agreement and all other terms and conditions set forth therein shall remain in full effect.

Exhibit 24.1

POWER OF ATTORNEY FOR EXECUTING

FORM ID, FORM 3, FORM 4 AND FORM 5, FORM 144

AND SCHEDULE 13D AND 13G

Know all by these present, that each of the undersigned hereby makes, constitutes and appoints Charles E. Gale as such undersigned’s true and lawful attorney-in-fact, with full power and authority as hereinafter described on behalf of and in the name, place and stead of such undersigned to:

Each of the undersigned acknowledges that:

Each of the undersigned hereby gives and grants the foregoing attorney-in-fact full power and authority to do and perform all and every act and thing whatsoever requisite, necessary or appropriate to be done in and about the foregoing matters as fully as such undersigned might or could do if present, hereby ratifying all that such attorney-in-fact of, for and on behalf of such undersigned, shall lawfully do or cause to be done by virtue of this Limited Power of Attorney.

This Power of Attorney shall remain in full force and effect until each of the undersigned is no longer required to file any of Form ID, Form 3, Form 4, Form 5, Form 144, Schedule 13D and Schedule 13G (including any amendments thereto) with respect to the undersigned’s holdings of and transactions in securities issued by the Company, unless earlier revoked by the undersigned in a signed writing delivered to the foregoing attorney-in-fact.

IN WITNESS WHEREOF, each of the undersigned has caused this Power of Attorney to be executed as of this 17th day of May, 2016.

2

Exhibit 24.2

POWER OF ATTORNEY FOR EXECUTING

FORM ID, FORM 3, FORM 4 AND FORM 5, FORM 144

AND SCHEDULE 13D AND 13G

Know all by these present, that each of the undersigned hereby makes, constitutes and appoints Charles E. Gale as such undersigned’s true and lawful attorney-in-fact, with full power and authority as hereinafter described on behalf of and in the name, place and stead of such undersigned to:

Each of the undersigned acknowledges that:

Each of the undersigned hereby gives and grants the foregoing attorney-in-fact full power and authority to do and perform all and every act and thing whatsoever requisite, necessary or appropriate to be done in and about the foregoing matters as fully as such undersigned might or could do if present, hereby ratifying all that such attorney-in-fact of, for and on behalf of such undersigned, shall lawfully do or cause to be done by virtue of this Limited Power of Attorney.

This Power of Attorney shall remain in full force and effect until each of the undersigned is no longer required to file any of Form ID, Form 3, Form 4, Form 5, Form 144, Schedule 13D and Schedule 13G (including any amendments thereto) with respect to the undersigned’s holdings of and transactions in securities issued by the Company, unless earlier revoked by the undersigned in a signed writing delivered to the foregoing attorney-in-fact.

IN WITNESS WHEREOF, each of the undersigned has caused this Power of Attorney to be executed as of this 17th day of May, 2016.

2

Exhibit 99.1

JOINT FILING AGREEMENT

Pursuant to Rule 13d-1(k)(1)(iii) of the Securities Exchange Act of 1934, as amended, each of the undersigned hereby consent to the joint filing on its behalf of a single Schedule 13D and any amendments thereto, with respect to the beneficial ownership by each of the undersigned of the shares of Class A Common Stock of Reata Pharmaceuticals, Inc. The undersigned hereby further agree that this Joint Filing Agreement be included as an exhibit to such statement and any such amendment. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning it contained herein and therein, but shall not be responsible for the completeness and accuracy of the information concerning the others. The undersigned hereby further agree that this Joint Filing Agreement may be executed in any number of counterparts, each of which when so executed shall be deemed to be an original, but all of which counterparts shall together constitute one and the same instrument.