ZS PHARMA, INC. 2015EMPLOYEE STOCK PURCHASE PLAN

Exhibit 10.1

ZS PHARMA, INC.

2015 EMPLOYEE STOCK PURCHASE PLAN

1. Purpose. The purpose of the Plan is to provide employees of the Company and its Designated Companies with an opportunity to purchase Common Stock through accumulated Contributions. The Company intends for the Plan to have two components: a Code Section 423 Component (“423 Component”) and a non-Code Section 423 Component (“Non-423 Component”). The Company’s intention is to have the 423 Component of the Plan qualify as an “employee stock purchase plan” under Section 423 of the Code. The provisions of the 423 Component, accordingly, will be construed so as to extend and limit Plan participation in a uniform and nondiscriminatory basis consistent with the requirements of Section 423 of the Code. In addition, this Plan authorizes the grant of an option to purchase shares of Common Stock under the Non-423 Component that does not qualify as an “employee stock purchase plan” under Section 423 of the Code; such an option will be granted pursuant to rules, procedures or sub-plans adopted by the Administrator designed to achieve tax, securities laws or other objectives for Eligible Employees and the Company. Except as otherwise provided herein, the Non-423 Component will operate and be administered in the same manner as the 423 Component.

2. Definitions.

(a) “Administrator” means the Board or any Committee designated by the Board to administer the Plan pursuant to Section 14 of the Plan.

(b) “Affiliate” means any entity, other than a Subsidiary, that is an “affiliate” within the meaning of Rule 12b-2 promulgated under Section 12 of the Exchange Act.

(c) “Applicable Laws” means the requirements relating to the administration of equity-based awards and the related issuance of shares of Common Stock under U.S. state corporate laws, U.S. federal and state securities laws, the Code, any stock exchange or quotation system on which the Common Stock is listed or quoted and the applicable securities and exchange control laws of any foreign country or jurisdiction where options are, or will be, granted under the Plan.

(d) “Beneficial Owner” means a beneficial owner as determined under Rule 13d-3 under the Exchange Act.

(e) “Board” means the Board of Directors of the Company.

(f) “Business Combination” means (x) a merger or consolidation involving the Company or its stock or (y) an acquisition by the Company, directly or through one or more subsidiaries, of another entity or its stock or assets.

(g) “Change in Control” means the occurrence of any of the following events:

(i) 50% Ownership Change: Any Person, the Company, or an Affiliate makes an acquisition of Outstanding Voting Stock and is, immediately thereafter, the

Beneficial Owner of 50% or more of the then Outstanding Voting Stock, unless such acquisition is made directly from the Company in a transaction approved by a majority of the Incumbent Directors; or any group is formed that is the beneficial owner of 50% or more of the Outstanding Voting Stock; or

(ii) Major Mergers and Acquisitions: Consummation of a Business Combination unless, immediately following such Business Combination, (i) all or substantially all of the individuals and entities that were the beneficial owners of the Outstanding Voting Stock immediately before such Business Combination beneficially own, directly or indirectly, more than 50% of the then outstanding shares of voting stock of the Parent Corporation Resulting From Such Business Combination in substantially the same relative proportions as their ownership, immediately before such Business Combination, of the Outstanding Voting Stock, (ii) no Person (other than any corporation resulting from such Business Combination) beneficially owns, directly or indirectly, 50% or more of the then outstanding shares of voting stock of the Parent Corporation Resulting From Such Business Combination and (iii) a majority of the members of the board of directors of the Parent Corporation Resulting From Such Business Combination were Incumbent Directors of the Company immediately before consummation of such Business Combination; or

(iii) Major Asset Dispositions: Consummation of a Major Asset Disposition unless, immediately following such Major Asset Disposition, (i) individuals and entities that were beneficial owners of the Outstanding Voting Stock immediately before such Major Asset Disposition beneficially own, directly or indirectly, more than 70% of the then outstanding shares of voting stock of the Company (if it continues to exist) and of the entity that acquires the largest portion of such assets (or the entity, if any, that owns a majority of the outstanding voting stock of such acquiring entity) and (ii) a majority of the members of the Board (if it continues to exist) and of the entity that acquires the largest portion of such assets (or the entity, if any, that owns a majority of the outstanding voting stock of such acquiring entity) were Incumbent Directors of the Company immediately before consummation of such Major Asset Disposition; or

(iv) Liquidation or Dissolution: The Company’s stockholders approve a liquidation or dissolution of the Company.

(h) “Code” means the U.S. Internal Revenue Code of 1986, as amended. Reference to a specific Section of the Code or U.S. Treasury Regulation thereunder will include such Section or regulation, any valid regulation or other official applicable guidance promulgated under such Section, and any comparable provision of any future legislation or regulation amending, supplementing or superseding such Section or regulation.

(i) “Committee” means the Compensation Committee of the Board, and any successor committee thereto or such other committee of the Board as may be designated by the Board to administer this Plan in whole or in part, including any subcommittee of the Board as designated by the Board in accordance with Section 14 hereof.

(j) “Common Stock” means the common stock, par value $0.001 per share, of the Company.

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(k) “Company” means ZS Pharma, Inc., a Delaware corporation, or any successor thereto.

(l) “Compensation” means an Eligible Employee’s base straight time gross earnings, commissions (to the extent such commissions are an integral, recurring part of compensation), incentive compensation, bonuses, payments for overtime and shift premium, but exclusive of payments for equity compensation income and other similar compensation. The Administrator, in its discretion, may, on a uniform and nondiscriminatory basis, establish a different definition of Compensation for a subsequent Offering Period.

(m) “Contributions” means the payroll deductions and other additional payments that the Company may permit to be made by a Participant to fund the exercise of options granted pursuant to the Plan.

(n) “Designated Company” means any Subsidiary or Affiliate that has been designated by the Administrator from time to time in its sole discretion as eligible to participate in the Plan. For purposes of the 423 Component, only the Company and its Subsidiaries may be Designated Companies; provided, that at any given time, a Subsidiary that is a Designated Company under the 423 Component shall not be a Designated Company under the Non-423 Component.

(o) “Director” means a member of the Board.

(p) “EEA” shall have the meaning set forth in Section 8(c) of the Plan.

(q) “EEA Limit” shall have the meaning set forth in Section 8(c) of the Plan.

(r) “Eligible Employee” means any individual who is a common law employee providing services to the Company or a Designated Company and is customarily employed for at least twenty (20) hours per week and more than five (5) months in any calendar year by the Employer, or any lesser number of hours per week and/or number of months in any calendar year established by the Administrator (if required under Applicable Law) for purposes of any separate Offering or for an Eligible Employee participating in the Non-423 Component. For purposes of the Plan, the employment relationship will be treated as continuing intact while the individual is on sick leave or other leave of absence that the Employer approves or is legally protected under Applicable Laws. Where the period of leave exceeds three (3) months and the individual’s right to reemployment is not guaranteed either by statute or by contract, the employment relationship will be deemed to have terminated three (3) months and one (1) day following the commencement of such leave. The Administrator, in its discretion, from time to time may, prior to an Enrollment Date for all options to be granted on such Enrollment Date in an Offering, determine (for each Offering under the 423 Component, on a uniform and nondiscriminatory basis or as otherwise permitted by Treasury Regulation Section 1.423-2) that the definition of Eligible Employee will or will not include an individual if he or she: (i) has not completed at least two (2) years of service since his or her last hire date (or such lesser period of time as may be determined by the Administrator in its discretion), (ii) customarily works not more than twenty (20) hours per week (or such lesser period of time as may be determined by the Administrator in its discretion), (iii) customarily works not more than five (5) months per

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calendar year (or such lesser period of time as may be determined by the Administrator in its discretion), (iv) is a highly compensated employee within the meaning of Section 414(q) of the Code, or (v) is a highly compensated employee within the meaning of Section 414(q) of the Code with compensation above a certain level or is an officer or subject to the disclosure requirements of Section 16(a) of the Exchange Act; provided, that the exclusion is applied with respect to each Offering under the 423 Component in an identical manner to all highly compensated employees of the Employer whose employees are participating in that Offering. Each exclusion shall be applied with respect to an Offering under a 423 Component in a manner complying with U.S. Treasury Regulation Section 1.423-2(e)(2)(ii). Such exclusions may be applied with respect to an Offering under the Non-423 Component without regard to the limitations of Treasury Regulation Section 1.423-2.

(s) “Employer” means the employer of the applicable Eligible Employee(s).

(t) “Enrollment Date” means the first Trading Day of each Offering Period.

(u) “Enrollment Window” is defined in Section 5(a) of the Plan.

(v) “EU Prospectus Directive” shall have the meaning set forth in Section 8(c) of the Plan.

(w) “Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended, including the rules and regulations promulgated thereunder.

(x) “Exercise Date” means the first Trading Day on or after June 30 and December 31 of each Purchase Period.

(y) “Fair Market Value” of a share of Common Stock means, as of a particular date, (1) if shares of Common Stock are listed on a national securities exchange, the closing sales price per share of Common Stock on the consolidated transaction reporting system for the principal national securities exchange on which shares of Common Stock are listed on that date, or, if there shall have been no such sale so reported on that date, on the last preceding date on which such a sale was so reported, (2) if the Common Stock is not so listed, the average of the closing bid and asked price on that date, or, if there are no quotations available for such date, on the last preceding date on which such quotations shall be available, as reported by an inter-dealer quotation system, or (3) if none of the above are applicable, the Fair Market Value of a share of Common Stock as determined in good faith by the Committee.

(z) “Fiscal Year” means the fiscal year of the Company.

(aa) “423 Component” is defined in Section 1 of the Plan.

(bb) “Group” shall have the meaning given the term for purposes of Section 13(d)(3) of the Exchange Act.

(cc) “Incumbent Director” means a director of the Company (x) who was a director of the Company on the effective date of the ZS Pharma, Inc. 2014 Incentive Plan or (y) who becomes a director after such date and whose election, or nomination for election by the

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Company’s stockholders, was approved by a vote of a majority of the Incumbent Directors at the time of such election or nomination, except that any such director will not be deemed an Incumbent Director if his or her initial assumption of office occurs as a result of an actual or threatened solicitation of proxies by or on behalf of a Person other than the Board.

(dd) “Major Asset Disposition” means the sale or other disposition in one transaction or a series of related transactions of all or substantially all of the assets of the Company and its subsidiaries on a consolidated basis.

(ee) “New Exercise Date” means a new Exercise Date if the Administrator shortens any Offering Period then in progress.

(ff) “Non-423 Component” is defined in Section 1 of the Plan.

(gg) “Offering” means an offer under the Plan of an option that may be exercised during an Offering Period as further described in Section 4 of the Plan. For purposes of the Plan, the Administrator may designate separate Offerings under the Plan (the terms of which need not be identical) in which Eligible Employees of one or more Employers will participate, even if the dates of the applicable Offering Periods of each such Offering are identical and the provisions of the Plan will separately apply to each Offering. To the extent permitted by U.S. Treasury Regulation Section 1.423-2(a)(1), the terms of each Offering need not be identical; provided, that the terms of the Plan and an Offering together satisfy U.S. Treasury Regulation Section 1.423-2(a)(2) and (a)(3).

(hh) “Offering Periods” means the periods of approximately eighteen (18) months or such other period or periods set by the Administrator during which an option may be granted pursuant to the Plan and may be exercised, as determined under Section 4 of the Plan. The duration and timing of Offering Periods may be changed pursuant to Sections 4 and 20 of the Plan.

(ii) “Other Extraordinary Event” is defined in Section 19(a) of the Plan.

(jj) “Outstanding Voting Stock” means outstanding voting securities of the Company entitled to vote generally in the election of directors; and any specified percentage or portion of the Outstanding Voting Stock (or of other voting stock) is determined based on the combined voting power of such securities.

(kk) “Parent” means a “parent corporation,” whether now or hereafter existing, as defined in Section 424(e) of the Code.

(ll) “Parent Corporation Resulting From Such Business Combination” means the Company if its stock is not acquired or converted in the Business Combination and otherwise means the entity which as a result of such Business Combination owns the Company or all or substantially all the Company’s assets either directly or through one or more subsidiaries.

(mm) “Participant” means an Eligible Employee that participates in the Plan.

(nn) “Person” means an individual, entity or group.

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(oo) “Plan” means this ZS Pharma, Inc. 2015 Employee Stock Purchase Plan.

(pp) “Proceeding” is defined in Section 30 of the Plan.

(qq) “Purchase Period” means, unless changed by the Administrator, the approximately six (6) month period commencing after one Exercise Date and ending with the next Exercise Date, except that the first Purchase Period of any Offering Period will commence on the Enrollment Date and end with the next Exercise Date.

(rr) “Purchase Price” means an amount equal to eighty-five percent (85%) of the Fair Market Value of a share of Common Stock on the Enrollment Date or on the Exercise Date, whichever is lower; provided, that the Purchase Price may be determined for subsequent Offering Periods by the Administrator subject to compliance with Section 423 of the Code (or any successor rule or provision or any other Applicable Law, regulation or stock exchange rule) or pursuant to Section 20 of the Plan.

(ss) “Subsidiary” means a “subsidiary corporation,” whether now or hereafter existing, as defined in Section 424(f) of the Code.

(tt) “Trading Day” means a day on which the national stock exchange upon which the Common Stock is listed is open for trading.

(uu) “U.S. Treasury Regulations” means the Treasury regulations of the Code. Reference to a specific Treasury Regulation or Section of the Code shall include such Treasury Regulation or Section, any valid regulation promulgated under such Section, and any comparable provision of any future legislation or regulation amending, supplementing or superseding such Section or regulation.

3. Eligibility.

(a) First Offering Period. In order to participate in the first Offering Period, an Eligible Employee must complete a subscription agreement during the applicable Enrollment Window before the first Offering Period begins.

(b) Subsequent Offering Periods. Any Eligible Employee must complete a subscription agreement during the prescribed Enrollment Window before any given subsequent Offering Period in order to participate in the Plan, subject to the requirements of Section 5 of the Plan.

(c) Non-U.S. Employees. Eligible Employees who are citizens or residents of a non-U.S. jurisdiction (without regard to whether they also are citizens or residents of the United States or resident aliens (within the meaning of Section 7701(b)(1)(A) of the Code)) may be excluded from participation in the Plan or an Offering if the participation of such Eligible Employees is prohibited under the laws of the applicable jurisdiction or if complying with the laws of the applicable jurisdiction would cause the Plan or an Offering to violate Section 423 of the Code. In the case of the Non-423 Component, an Eligible Employee may be excluded from participation in the Plan or an Offering if the Administrator has determined that participation of such Eligible Employee is not advisable or practicable.

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(d) Limitations. Any provisions of the Plan to the contrary notwithstanding, no Eligible Employee will be granted an option under the Plan (i) to the extent that, immediately after the grant, such Eligible Employee (or any other person whose stock would be attributed to such Eligible Employee pursuant to Section 424(d) of the Code) would own capital stock of the Company or any Parent or Subsidiary of the Company and/or hold outstanding options to purchase such stock possessing five percent (5%) or more of the total combined voting power or value of all classes of the capital stock of the Company or of any Parent or Subsidiary of the Company, or (ii) to the extent that his or her rights to purchase stock under all employee stock purchase plans (as defined in Section 423 of the Code) of the Company or any Parent or Subsidiary of the Company accrues at a rate that exceeds twenty-five thousand dollars ($25,000) worth of stock (determined at the Fair Market Value of the stock at the time such option is granted) for each calendar year in which such option is outstanding at any time, as determined in accordance with Section 423 of the Code and the regulations thereunder.

4. Offering Periods.

(a) Frequency and Duration. The Administrator may establish Offering Periods of such frequency and duration as it may from time to time determine as appropriate.

(b) First Offering Period. The first Offering Period under the Plan shall commence with the first Trading Day following the later of July 1, 2015 and the date following the date on which the stockholders of the Company approve the Plan and shall end on the first Trading Day on or after December 31, 2016.

(c) Successive Offering Periods. Unless the Administrator determines otherwise, a new Offering Period shall commence on the first Trading Day following the last Exercise Date of the immediately preceding Offering Period.

(d) Additional Offering Periods. At the discretion of the Committee, additional Offering Periods may be conducted under the Plan. Such additional Offering Periods may, but need not, qualify under Section 423 of the Code. The Administrator shall determine the commencement and duration of each additional Offering Period, and additional Offering Periods may be consecutive or overlapping. The other terms and conditions of each additional Offering Period shall be those set forth in this Plan document, with such changes or additional features as the Administrator determines necessary to comply with Section 423 of the Code (or any successor rule or provision or any other Applicable Law, regulation or stock exchange rule). The Administrator shall have the power to change the duration of Offering Periods (including the commencement dates thereof) with respect to future Offerings without stockholder approval.

(e) Offering Period Limit. No Offering Period may last more than twenty-seven (27) months.

(f) Applicable Offering Period. For purposes of calculating the Purchase Price, the applicable Offering Period shall be determined as follows:

(A) Once a Participant is enrolled in the Plan for an Offering Period, such Offering Period shall continue to apply to him or her until the earliest of (x) the end of such Offering Period, (y) the end of his or her participation under Section 10 of the Plan or (z) re-enrollment for a subsequent Offering Period under Paragraph (B), below.

(B) In the event that the Fair Market Value of a share of Common Stock on the first trading day of the Offering Period for which the Participant is enrolled is higher than on the first trading day of any subsequent Offering Period, the Participant shall automatically be re-enrolled for such subsequent Offering Period.

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5. Participation.

(a) First Offering Period. An Eligible Employee will be entitled to participate in the first Offering Period pursuant to Section 3(a) of the Plan only if such individual submits a subscription agreement authorizing Contributions in a form determined by the Administrator (which may be similar to the form attached hereto as Exhibit A) to the Company’s designated plan administrator (i) no earlier than the effective date of the Form S-8 registration statement that registers the offer and sale of Common Stock under this Plan and (ii) no later than ten (10) business days following the effective date of such S-8 registration statement or such other period of time as the Administrator may determine (the “Enrollment Window”).

(b) Subsequent Offering Periods. An Eligible Employee may participate in the Plan pursuant to Section 3(b) of the Plan by (i) submitting to the Company’s stock administration office (or its designee), on or before a date determined by the Administrator prior to an applicable Enrollment Date, a properly completed subscription agreement authorizing Contributions in the form provided by the Administrator for such purpose, or (ii) following an electronic or other enrollment procedure determined by the Administrator.

6. Contributions.

(a) At the time a Participant enrolls in the Plan pursuant to Section 5 of the Plan, he or she will elect to have Contributions (in the form of payroll deductions or otherwise, to the extent permitted by the Administrator) made on each pay day during the Offering Period in an amount not exceeding fifteen percent (15%) of the Compensation, which he or she receives on each pay day during the Offering Period (for illustrative purposes, should a pay day occur on an Exercise Date, a Participant will have any payroll deductions made on such day applied to his or her account under the then-current Purchase Period or Offering Period). The Administrator, in its sole discretion, may permit all Participants in a specified Offering to contribute amounts to the Plan through payment by cash, check or other means set forth in the subscription agreement prior to each Exercise Date of each Purchase Period. A Participant’s subscription agreement will remain in effect for successive Offering Periods unless terminated as provided in Section 10 hereof.

(b) In the event Contributions are made in the form of payroll deductions, such payroll deductions for a Participant will commence on the first pay day following the Enrollment Date and will end on the last pay day prior to the Exercise Date of such Offering Period to which such authorization is applicable, unless sooner terminated by the Participant as provided in Section 10 hereof; provided, that for the first Offering Period, payroll deductions will commence on the first pay day on or following the end of the Enrollment Window.

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(c) All Contributions made for a Participant will be credited to his or her account under the Plan, and Contributions will be made in whole percentages of Compensation only. A Participant may not make any additional payments into such account.

(d) A Participant may discontinue his or her participation in the Plan as provided in Section 10 of the Plan. Except as may be permitted by the Administrator, as determined in its sole discretion, a Participant may not change the rate of his or her Contributions during an Offering Period.

(e) Notwithstanding the foregoing, to the extent necessary to comply with Section 423(b)(8) of the Code and Section 3(d) hereof, a Participant’s Contributions may be decreased to zero percent (0%) at any time during a Purchase Period. Subject to Section 423(b)(8) of the Code and Section 3(d) hereof, Contributions will recommence at the rate originally elected by the Participant effective as of the beginning of the first Purchase Period scheduled to end in the following calendar year, unless terminated by the Participant as provided in Section 10 of the Plan.

(f) Notwithstanding any provisions to the contrary in the Plan, the Administrator may allow Eligible Employees to participate in the Plan via cash contributions instead of payroll deductions if (i) payroll deductions are not permitted under applicable local law, (ii) the Administrator determines that cash contributions are permissible under Section 423 of the Code or (iii) for Participants participating in the Non-423 Component.

(g) At the time the option is exercised, in whole or in part, or at the time some or all of the Common Stock issued under the Plan is disposed of (or any other time that a taxable event related to the Plan occurs), the Participant must make adequate provision for the Company’s or the Employer’s federal, state, local or any other tax liability payable to any authority including taxes imposed by jurisdictions outside of the U.S., national insurance, social security or other tax withholding obligations, if any, which arise upon the exercise of the option or the disposition of the Common Stock (or any other time that a taxable event related to the Plan occurs). At any time, the Company or the Employer may, but will not be obligated to, withhold from the Participant’s compensation the amount necessary for the Company or the Employer to meet applicable withholding obligations, including any withholding required to make available to the Company or the Employer any tax deductions or benefits attributable to sale or early disposition of Common Stock by the Eligible Employee. In addition, the Company or the Employer may, but will not be obligated to, withhold from the proceeds of the sale of Common Stock or any other method of withholding the Company or the Employer deems appropriate to the extent permitted by U.S. Treasury Regulation Section 1.423-2(f).

7. Grant of Option. On the Enrollment Date of each Offering Period, each Eligible Employee participating in such Offering Period will be granted an option to purchase on each Exercise Date during such Offering Period (at the applicable Purchase Price) up to a number of shares of Common Stock determined by dividing such Eligible Employee’s Contributions accumulated prior to such Exercise Date and retained in the Eligible Employee’s account as of the Exercise Date by the applicable Purchase Price; provided, that in no event will an Eligible Employee be permitted to purchase during each Purchase Period more than 5,000 shares of Common Stock and, during each Offering Period, more than 15,000 shares of Common Stock

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(subject, in each case, to any adjustment pursuant to Section 19 of the Plan); provided, further, that such purchase will be subject to the limitations set forth in Sections 3(d) and 13 of the Plan. The Eligible Employee may accept the grant of such option (i) with respect to the first Offering Period by submitting a properly completed subscription agreement in accordance with the requirements of Section 5 of the Plan on or before the last day of the Enrollment Window, and (ii) with respect to any subsequent Offering Period under the Plan, by electing to participate in the Plan in accordance with the requirements of Section 5 of the Plan. The Administrator may, for future Offering Periods, increase or decrease, in its absolute discretion, the maximum number of shares of Common Stock that an Eligible Employee may purchase during each Purchase Period of an Offering Period. Exercise of the option will occur as provided in Section 8, unless the Participant has withdrawn pursuant to Section 10 of the Plan. To the extent not otherwise exercised in full, the option will expire on the last day of the Offering Period.

8. Exercise of Option.

(a) Unless a Participant withdraws from the Plan as provided in Section 10 of the Plan, his or her option for the purchase of shares of Common Stock will be exercised automatically on the Exercise Date, and the maximum number of full shares subject to the option will be purchased for such Participant at the applicable Purchase Price with the accumulated Contributions from his or her account. No fractional shares of Common Stock will be purchased; any Contributions accumulated in a Participant’s account, which are not sufficient to purchase a full share will be retained in the Participant’s account for the subsequent Purchase Period or Offering Period, subject to earlier withdrawal by the Participant as provided in Section 10. Any other funds left over in a Participant’s account after the Exercise Date will be returned to the Participant. During a Participant’s lifetime, a Participant’s option to purchase shares hereunder is exercisable only by him or her.

(b) If the Administrator determines that, on a given Exercise Date, the number of shares of Common Stock with respect to which options are to be exercised may exceed (i) the number of shares of Common Stock that were available for sale under the Plan on the Enrollment Date of the applicable Offering Period, or (ii) the number of shares of Common Stock available for sale under the Plan on such Exercise Date, the Administrator may in its sole discretion (x) provide that the Company will make a pro rata allocation of the shares of Common Stock available for purchase on such Enrollment Date or Exercise Date, as applicable, in as uniform a manner as will be practicable and as it will determine in its sole discretion to be equitable among all Participants exercising options to purchase Common Stock on such Exercise Date, and continue all Offering Periods then in effect or (y) provide that the Company will make a pro rata allocation of the shares available for purchase on such Enrollment Date or Exercise Date, as applicable, in as uniform a manner as will be practicable and as it will determine in its sole discretion to be equitable among all participants exercising options to purchase Common Stock on such Exercise Date, and terminate any or all Offering Periods then in effect pursuant to Section 20 of the Plan. The Company may make a pro rata allocation of the shares available on the Enrollment Date of any applicable Offering Period pursuant to the preceding sentence, notwithstanding any authorization of additional shares for issuance under the Plan by the Company’s stockholders subsequent to such Enrollment Date.

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(c) Further, with respect to any Offering under the Non-423 Component that is made to Participants of Designated Companies within the European Economic Area (the “EEA”), if a prospectus may be required to be filed in accordance with EU Prospectus Directive No. 2003/71/EC, as currently and hereinafter amended (the “EU Prospectus Directive”), then until such time as a valid prospectus is on file or a prospectus is not required or is no longer required under the EU Prospectus Directive in connection with such Offerings under the Plan, the total Purchase Price payable for the aggregate number of shares of Common Stock offered under this Plan under all Offerings that are not otherwise exempt from the EU Prospectus Directive made to Participants of Designated Companies within the EEA for any twelve (12)-month period shall not exceed EUR 5 million (the “EEA Limit”). If the Administrator determines that, on a given Enrollment Date, the total Purchase Price payable for the number of shares of Common Stock with respect to which options are to be exercised may cause the EEA Limit to be exceeded, the Administrator may in its sole discretion (x) provide that the Company will make a pro rata allocation of the shares of Common Stock available for purchase and under the EEA Limit on such Enrollment Date, as applicable, in as uniform a manner as will be practicable and as it will determine in its sole discretion to be equitable among all Participants of Designated Companies within the EEA exercising options to purchase Common Stock by reference to the Offering Period beginning on that Enrollment Date, and continue all Offering Periods then in effect or (y) provide that the Company will make a pro rata allocation of the shares of Common Stock available for purchase and under the EEA Limit on such Enrollment Date, as applicable, in as uniform a manner as will be practicable and as it will determine in its sole discretion to be equitable among all Participants of Designated Companies within the EEA exercising options to purchase Common Stock by reference to the Offering Period beginning on that Enrollment Date, and terminate any or all Offering Periods then in effect pursuant to Section 20 of the Plan.

9. Delivery. As soon as reasonably practicable after each Exercise Date on which a purchase of shares of Common Stock occurs, the Company will arrange the delivery to each Participant of the shares purchased upon exercise of his or her option in a form determined by the Administrator (in its sole discretion) and pursuant to rules established by the Administrator. The Company may permit or require that shares be deposited directly with a broker designated by the Company or to a designated agent of the Company, and the Company may utilize electronic or automated methods of share transfer. The Company may require that shares be retained with such broker or agent for a designated period of time and/or may establish other procedures to permit tracking of disqualifying dispositions of such shares. No Participant will have any voting, dividend, or other stockholder rights with respect to shares of Common Stock subject to any option granted under the Plan until such shares have been purchased and delivered to the Participant as provided in this Section 9 of the Plan.

10. Withdrawal.

(a) A Participant may withdraw all but not less than all the Contributions credited to his or her account and not yet used to exercise his or her option under the Plan at any time by (i) submitting to the Company’s stock administration office (or its designee) a written notice of withdrawal in the form determined by the Administrator for such purpose (which may be similar to the form attached hereto as Exhibit B), or (ii) following an electronic or other withdrawal procedure determined by the Administrator. All of the Participant’s Contributions

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credited to his or her account will be paid to such Participant promptly after receipt of notice of withdrawal and such Participant’s option for the Offering Period will be automatically terminated, and no further Contributions for the purchase of shares will be made for such Offering Period. If a Participant withdraws from an Offering Period, Contributions will not resume at the beginning of the succeeding Offering Period, unless the Participant re-enrolls in the Plan in accordance with the provisions of Section 5 of the Plan.

(b) A Participant’s withdrawal from an Offering Period will not have any effect upon his or her eligibility to participate in any similar plan that may hereafter be adopted by the Company or in succeeding Offering Periods that commence after the termination of the Offering Period from which the Participant withdraws.

11. Termination of Employment. Upon a Participant’s ceasing to be an Eligible Employee, for any reason, he or she will be deemed to have elected to withdraw from the Plan and the Contributions credited to such Participant’s account during the Offering Period but not yet used to purchase shares of Common Stock under the Plan will be returned to such Participant or, in the case of his or her death, to the person or persons entitled thereto under Section 15 of the Plan, and such Participant’s option will be automatically terminated. Unless determined otherwise by the Administrator in a manner that, with respect to an Offering under the 423 Component, is permitted by, and compliant with, Section 423 of the Code, a Participant whose employment transfers between entities through a termination with an immediate rehire (with no break in service) by the Company or a Designated Company shall not be treated as terminated under the Plan; however, no Participant shall be deemed to switch from an Offering under the Non-423 Component to an Offering under the 423 Component or vice versa unless (and then only to the extent) such switch would not cause the 423 Component or any Option thereunder to fail to comply with Section 423 of the Code.

12. Interest. No interest will accrue on the Contributions of a participant in the Plan, except as may be required by Applicable Law, as determined by the Company, and if so required by the laws of a particular jurisdiction, shall, with respect to Offerings under the 423 Component, apply to all Participants in the relevant Offering, except to the extent otherwise permitted by U.S. Treasury Regulation Section 1.423-2(f).

13. Stock.

(a) Subject to adjustment upon changes in capitalization of the Company as provided in Section 19 hereof, the maximum number of shares of Common Stock that will be made available for sale under the Plan will be (1) 400,000 shares of Common Stock; plus (2) an annual increase of shares of Common Stock to be added each January 1^st following the effective date of the Plan equal to a number of shares of Common Stock equal to the excess of (x) 1.5% of the total number of shares outstanding (on an as converted basis) on December 31st of the immediately preceding calendar year, less (y) the aggregate number of shares available under the Plan as of such date (and if the result of (x) less(y) is negative, the amount of this clause (2) shall equal zero), subject to adjustment pursuant to the provisions of Section 19 hereof.

(b) Until the Shares are issued (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), a Participant will only have the rights of an unsecured creditor with respect to such shares, and no right to vote or receive dividends or any other rights as a stockholder will exist with respect to such shares.

(c) Shares of Common Stock to be delivered to a Participant under the Plan will be registered in the name of the Participant or in the name of the Participant and his or her spouse.

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14. Administration. The Plan will be administered by the Board or a Committee appointed by the Board, which Committee will be constituted to comply with Applicable Laws. The Administrator will have full and exclusive discretionary authority to construe, interpret and apply the terms of the Plan, to designate separate Offerings under the Plan, to designate Subsidiaries and Affiliates as participating in the 423 Component or Non-423 Component, to determine eligibility, to adjudicate all disputed claims filed under the Plan and to establish such procedures that it deems necessary for the administration of the Plan (including, without limitation, to adopt such procedures and sub-plans as are necessary or appropriate to permit the participation in the Plan by employees who are foreign nationals or employed outside the U.S., the terms of which sub-plans may take precedence over other provisions of this Plan, with the exception of Section 13(a) hereof, but unless otherwise superseded by the terms of such sub-plan, the provisions of this Plan shall govern the operation of such sub-plan). Unless otherwise determined by the Administrator, the employees eligible to participate in each sub-plan will participate in a separate Offering and will be in the Non-423 Component, unless such designation would cause the 423 Component to violate the requirements of Section 423 of the Code. Without limiting the generality of the foregoing, the Administrator is specifically authorized to adopt rules and procedures regarding eligibility to participate, the definition of Compensation, handling of Contributions, making of Contributions to the Plan (including, without limitation, in forms other than payroll deductions), establishment of bank or trust accounts to hold Contributions, payment of interest, conversion of local currency, obligations to pay payroll tax, determination of beneficiary designation requirements, withholding procedures and handling of stock certificates that vary with applicable local requirements. The Administrator also is authorized to determine that, to the extent permitted by U.S. Treasury Regulation Section 1.423-2(f), the terms of an option granted under the Plan or an Offering to citizens or residents of a non-U.S. jurisdiction will be less favorable than the terms of options granted under the Plan or the same Offering to employees resident solely in the U.S. Every finding, decision and determination made by the Administrator will, to the full extent permitted by law, be final and binding upon all parties.

15. Designation of Beneficiary.

(a) If permitted by the Administrator, a Participant may file a designation of a beneficiary who is to receive any shares of Common Stock and cash, if any, from the Participant’s account under the Plan in the event of such Participant’s death subsequent to an Exercise Date on which the option is exercised but prior to delivery to such Participant of such shares and cash. In addition, if permitted by the Administrator, a Participant may file a designation of a beneficiary who is to receive any cash from the Participant’s account under the Plan in the event of such Participant’s death prior to exercise of the option. If a Participant is married and the designated beneficiary is not the spouse, spousal consent will be required for such designation to be effective.

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(b) Such designation of beneficiary may be changed by the Participant at any time by notice in a form determined by the Administrator. In the event of the death of a Participant and in the absence of a beneficiary validly designated under the Plan who is living at the time of such Participant’s death, the Company will deliver such shares and/or cash to the executor or administrator of the estate of the Participant, or if no such executor or administrator has been appointed (to the knowledge of the Company), the Company, in its discretion, may deliver such shares and/or cash to the spouse or to any one or more dependents or relatives of the Participant, or if no spouse, dependent or relative is known to the Company, then to such other person as the Company may designate.

(c) All beneficiary designations will be in such form and manner as the Administrator may designate from time to time. Notwithstanding Sections 15(a) and (b) above, the Company and/or the Administrator may decide not to permit such designations by Participants in non-U.S. jurisdictions to the extent permitted by U.S. Treasury Regulation Section 1.423-2(f).

16. Transferability. Neither Contributions credited to a Participant’s account nor any rights with regard to the exercise of an option or to receive shares of Common Stock under the Plan may be assigned, transferred, pledged or otherwise disposed of in any way (other than by will, the laws of descent and distribution or as provided in Section 15 hereof) by the Participant. Any such attempt at assignment, transfer, pledge or other disposition will be without effect, except that the Company may treat such act as an election to withdraw funds from an Offering Period in accordance with Section 10 hereof.

17. Use of Funds. The Company may use all Contributions received or held by it under the Plan for any corporate purpose, and the Company will not be obligated to segregate such Contributions except under Offerings or for Participants in the Non-423 Component for which Applicable Laws require that Contributions to the Plan by Participants be segregated from the Company’s general corporate funds and/or deposited with an independent third party. Until shares of Common Stock are issued, Participants will only have the rights of an unsecured creditor with respect to such shares.

18. Reports. Individual accounts will be maintained for each Participant in the Plan. Statements of account will be given to participating Eligible Employees at least annually, which statements will set forth the amounts of Contributions, the Purchase Price, the number of shares of Common Stock purchased and the remaining cash balance, if any.

19. Adjustments, Dissolution, Liquidation, Merger or Change in Control.

(a) Adjustments. In the event that any subdivision or consolidation of outstanding shares of Common Stock, declaration of a dividend payable in shares of Common Stock or other stock split, other recapitalization or capital reorganization of the Company, any consolidation or merger of the Company with another corporation or entity, the adoption by the Company of any plan of exchange affecting the Common Stock or any distribution to holders of Common Stock of securities or property (other than normal cash dividends or dividends payable in Common Stock), the Administrator, in order to prevent dilution or enlargement of the benefits or potential benefits intended to be made available under the Plan, will, in such manner as it may

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deem equitable, adjust the number and class of Common Stock that may be delivered under the Plan, the Purchase Price per share and the number of shares of Common Stock covered by each option under the Plan that has not yet been exercised, and the numerical limits of Sections 7 and 13 of the Plan.

(b) Dissolution or Liquidation. In the event of the proposed dissolution or liquidation of the Company, any Offering Period then in progress will be shortened by setting a New Exercise Date, and will terminate immediately prior to the consummation of such proposed dissolution or liquidation, unless provided otherwise by the Administrator. The New Exercise Date will be before the date of the Company’s proposed dissolution or liquidation. The Administrator will notify each Participant in writing or electronically, prior to the New Exercise Date, that the Exercise Date for the Participant’s option has been changed to the New Exercise Date and that the Participant’s option will be exercised automatically on the New Exercise Date, unless prior to such date the Participant has withdrawn from the Offering Period as provided in Section 10 hereof.

(c) Merger or Change in Control. In the event of a merger or Change in Control, each outstanding option will be assumed or an equivalent option substituted by the successor corporation or a Parent or Subsidiary of the successor corporation. In the event that the successor corporation refuses to assume or substitute for the option, the Offering Period with respect to which such option relates will be shortened by setting a New Exercise Date on which such Offering Period shall end. The New Exercise Date will occur before the date of the Company’s proposed merger or Change in Control. The Administrator will notify each Participant in writing or electronically prior to the New Exercise Date, that the Exercise Date for the Participant’s option has been changed to the New Exercise Date and that the Participant’s option will be exercised automatically on the New Exercise Date, unless prior to such date the Participant has withdrawn from the Offering Period as provided in Section 10 hereof.

20. Amendment or Termination.

(a) The Board or the Administrator, in its sole discretion, may amend, suspend, or terminate the Plan, or any part thereof, at any time and for any reason. If the Plan is terminated, the Board or the Administrator, in its discretion, may elect to terminate all outstanding Offering Periods either immediately or upon completion of the purchase of shares of Common Stock on the next Exercise Date (which may be sooner than originally scheduled, if determined by the Administrator in its discretion), or may elect to permit Offering Periods to expire in accordance with their terms (and subject to any adjustment pursuant to Section 19 hereof). If the Offering Periods are terminated prior to expiration, all amounts then credited to Participants’ accounts that have not been used to purchase shares of Common Stock will be returned to the Participants (without interest thereon, except as otherwise required under Applicable Laws, as further set forth in Section 12 hereof) as soon as administratively practicable.

(b) Without stockholder consent and without limiting Section 20(a) hereof, the Administrator will be entitled to change the Offering Periods or Purchase Periods, designate separate Offerings, limit the frequency and/or number of changes in the amount withheld during an Offering Period, establish the exchange ratio applicable to amounts withheld in a currency

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other than U.S. dollars, permit Contributions in excess of the amount designated by a Participant in order to adjust for delays or mistakes in the Company’s processing of properly completed Contribution elections, establish reasonable waiting and adjustment periods and/or accounting and crediting procedures to ensure that amounts applied toward the purchase of Common Stock for each Participant properly correspond with Contribution amounts, and establish such other limitations or procedures as the Administrator determines in its sole discretion advisable that are consistent with the Plan.

(c) In the event the Administrator determines that the ongoing operation of the Plan may result in unfavorable financial accounting consequences, the Administrator may, in its discretion and, to the extent necessary or desirable, modify, amend or terminate the Plan to reduce or eliminate such accounting consequence including, but not limited to:

(i) amending the Plan to conform with the safe harbor definition under the Financial Accounting Standards Board Accounting Standards Codification Topic 718 (or any successor thereto), including with respect to an Offering Period underway at the time;

(ii) altering the Purchase Price for any Offering Period or Purchase Period including an Offering Period or Purchase Period underway at the time of the change in Purchase Price;

(iii) shortening any Offering Period or Purchase Period by setting a New Exercise Date, including an Offering Period or Purchase Period underway at the time of the Administrator action;

(iv) reducing the maximum percentage of Compensation a Participant may elect to set aside as Contributions; and

(v) reducing the maximum number of shares of Common Stock a Participant may purchase during any Offering Period or Purchase Period.

Such modifications or amendments will not require stockholder approval or the consent of any Plan Participants.

21. Notices. All notices or other communications by a Participant to the Company under or in connection with the Plan will be deemed to have been duly given when received in the form and manner specified by the Company at the location, or by the person, designated by the Company for the receipt thereof.

22. Conditions Upon Issuance of Shares. Shares of Common Stock will not be issued with respect to an option unless the exercise of such option and the issuance and delivery of such shares pursuant thereto will comply with all applicable provisions of law, domestic or foreign, including, without limitation, the Securities Act of 1933, as amended, the Exchange Act, the rules and regulations promulgated thereunder, and the requirements of any stock exchange upon which the shares may then be listed, and will be further subject to the approval of counsel for the Company with respect to such compliance.

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As a condition to the exercise of an option, the Company may require the person exercising such option to represent and warrant at the time of any such exercise that the shares are being purchased only for investment and without any present intention to sell or distribute such shares if, in the opinion of counsel for the Company, such a representation is required by any of the aforementioned applicable provisions of law.

23. Code Section 409A. The 423 Component of the Plan is exempt from the application of Code Section 409A and any ambiguities herein will be interpreted to so be exempt from Code Section 409A. In furtherance of the foregoing and notwithstanding any provision in the Plan to the contrary, if the Administrator determines that an option granted under the Plan may be subject to Code Section 409A or that any provision in the Plan would cause an option under the Plan to be subject to Code Section 409A, the Administrator may amend the terms of the Plan and/or of an outstanding option granted under the Plan, or take such other action the Administrator determines is necessary or appropriate, in each case, without the Participant’s consent, to exempt any outstanding option or future option that may be granted under the Plan from or to allow any such options to comply with Code Section 409A, but only to the extent any such amendments or action by the Administrator would not violate Code Section 409A. Notwithstanding the foregoing, the Company shall have no liability to a Participant or any other party if the option to purchase Common Stock under the Plan that is intended to be exempt from or compliant with Code Section 409A is not so exempt or compliant or for any action taken by the Administrator with respect thereto. The Company makes no representation that the option to purchase Common Stock under the Plan is compliant with Code Section 409A.

24. Term of Plan. The Plan will become effective upon the earlier to occur of its adoption by the Board or its approval by the stockholders of the Company. It will continue in effect for a term of ten years, unless sooner terminated under Section 20 of the Plan.

25. Stockholder Approval. The Plan will be subject to approval by the stockholders of the Company within twelve (12) months before or after the date the Plan is adopted by the Board. Such stockholder approval will be obtained in the manner and to the degree required under Applicable Laws.

26. Governing Law. The Plan shall be governed by, and construed in accordance with, the laws of the State of Delaware (except its choice-of-law provisions).

27. No Right to Employment. Participation in the Plan by a Participant shall not be construed as giving a Participant the right to be retained as an employee of the Company or a Subsidiary or Affiliate, as applicable. Furthermore, the Employer may dismiss a Participant from employment at any time, free from any liability or any claim under the Plan.

28. Severability. If any provision of the Plan is or becomes or is deemed to be invalid, illegal, or unenforceable for any reason in any jurisdiction or as to any Participant, such invalidity, illegality or unenforceability shall not affect the remaining parts of the Plan, and the Plan shall be construed and enforced as to such jurisdiction or Participant as if the invalid, illegal or unenforceable provision had not been included.

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29. Compliance with Applicable Laws. The terms of this Plan are intended to comply with all Applicable Laws and will be construed accordingly.

30. Jurisdiction; Waiver of Jury Trial. Any suit, action or proceeding with respect to the Plan, or any judgment entered by any court of competent jurisdiction in respect of any thereof, shall be resolved only in the courts of the State of Delaware and the appellate courts having jurisdiction of appeals in such courts. In that context, and without limiting the generality of the foregoing, the Company and each Participant shall irrevocably and unconditionally (a) submit in any proceeding relating to the Plan or any option, or for the recognition and enforcement of any judgment in respect thereof (a “Proceeding”), to the exclusive jurisdiction of the courts of the State of Delaware, the court of the United States of America for the District of Delaware, and appellate courts having jurisdiction of appeals from any of the foregoing, and agree that all claims in respect of any such Proceeding shall be heard and determined in such Delaware State court or, to the extent permitted by law, in such federal court, (b) consent that any such Proceeding may and shall be brought in such courts and waives any objection that the Company and each Participant may now or thereafter have to the venue or jurisdiction of any such Proceeding in any such court or that such Proceeding was brought in an inconvenient court and agree not to plead or claim the same, (c) waive all right to trial by jury in any Proceeding (whether based on contract, tort or otherwise) arising out of or relating to the Plan or any option, (d) agree that service of process in any such Proceeding may be effected by mailing a copy of such process by registered or certified mail (or any substantially similar form of mail), postage prepaid, to such party, in the case of a Participant, at the Participant’s address shown in the books and records of the Company or, in the case of the Company, at the Company’s principal offices, attention General Counsel, and (e) agree that nothing in the Plan shall affect the right to effect service of process in any other manner permitted by the laws of the State of Delaware.

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EXHIBIT A

ZS PHARMA, INC.

2015 EMPLOYEE STOCK PURCHASE PLAN

SUBSCRIPTION AGREEMENT

Capitalized terms used but not otherwise defined herein shall have the meaning given to such terms in the ZS Pharma, Inc. 2015 Employee Stock Purchase Plan.

1. 1. I,                     , hereby elect to participate in the ZS Pharma, Inc. (the “Company”) 2015 Employee Stock Purchase Plan (the “Plan”) and subscribe to purchase shares of the Company’s Common Stock in accordance with this 2015 Employee Stock Purchase Plan Subscription Agreement (the “Subscription Agreement”) and the Plan.

2. I hereby authorize payroll deductions from each paycheck in the amount of % of my Compensation on each payday (from 0 to 15%) during the Offering Period in accordance with the Plan. (Please note that no fractional percentages are permitted.)

3. I understand that said payroll deductions will be accumulated for the purchase of shares of Common Stock at the applicable Purchase Price determined in accordance with the Plan. I understand that if I do not withdraw from an Offering Period, any accumulated payroll deductions will be used to automatically exercise my option and purchase Common Stock under the Plan at the end of each applicable Purchase Period during the Offering Period.

4. I have received a copy of the complete Plan and its accompanying prospectus. I understand that my participation in the Plan is in all respects subject to the terms of the Plan. The Company reserves the right to modify the Plan and to impose other requirements on my participation in the Plan, on the option and on any shares of Common Stock purchased under the Plan, to the extent the Company determines it is necessary or advisable for legal or administrative reasons. I agree to be bound by such modifications regardless of whether notice is given to me of such event, subject, in any case, to my right to withdrawal from participation in the Plan. I further agree to sign any additional agreements or undertakings that may be necessary to accomplish the foregoing.

5. I understand the following paragraph applies to me if I am a U.S. taxpayer or subject to U.S. taxation: If I dispose of any shares received by me pursuant to an offering of the Plan in the United States within two (2) years after the Offering Date (the first day of the Offering Period during which I purchased such shares) or one (1) year after the Exercise Date, I will be treated for U.S. federal income tax purposes as having received ordinary income at the time of such disposition in an amount equal to the excess of the Fair Market Value of the shares at the time such shares were purchased by me over the Purchase Price. I hereby agree to notify the Company in writing within thirty (30) days after the date of any disposition of my shares and

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I will make adequate provision for U.S. federal, state or other tax withholding obligations, if any, which arise upon the disposition of the Common Stock. The Company may, but will not be obligated to, withhold from my compensation the amount necessary to meet any applicable withholding obligation including any withholding necessary to make available to the Company any tax deductions or benefits attributable to sale or early disposition of Common Stock by me. If I dispose of such shares at any time after the expiration of the two (2)-year and one (1)-year holding periods, I understand that I will be treated for U.S. federal income tax purposes as having received income only at the time of such disposition, and that such income will be taxed as ordinary income only to the extent of an amount equal to the lesser of (a) the excess of the Fair Market Value of the shares at the time of such disposition over the Purchase Price, or (b) 15% of the Fair Market Value of the shares on the first day of the Offering Period. The remainder of the gain, if any, recognized on such disposition will be taxed as capital gain.

6. The Company may, in its sole discretion, decide to deliver any documents related to current or future participation in the Plan by electronic means. I hereby consent to receive such documents by electronic delivery and agree to participate in the Plan through an on-line or electronic system established and maintained by the Company or another third party designated by the Company.

7. The Subscription Agreement shall be governed by and construed in accordance with the laws of the State of Delaware (without regard to its conflict of laws provisions). For purposes of litigating any dispute that arises directly or indirectly from the relationship of the parties, I hereby submit and consent to the exclusive jurisdiction of the State of Delaware and agree that such litigation shall be conducted only in the courts of Wilmington, Delaware, or the federal courts for the U.S. for the District of Delaware, and no other courts.

8. I hereby agree to be bound by the terms of the Plan and this Subscription Agreement. The effectiveness of this Subscription Agreement is dependent upon my eligibility to participate in the Plan.

I ACKNOWLEDGE AND UNDERSTAND THAT THIS SUBSCRIPTION AGREEMENT INCLUDING ITS APPENDICES AND MY PARTICIPATION IN THE PLAN WILL REMAIN IN EFFECT THROUGHOUT SUCCESSIVE OFFERING PERIODS UNLESS AFFIRMATIVELY TERMINATED BY ME.

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APPENDIX B

ZS PHARMA, INC.

2015 EMPLOYEE STOCK PURCHASE PLAN

NOTICE OF WITHDRAWAL

The undersigned participant in the Offering Period of the ZS Pharma, Inc. 2015 Employee Stock Purchase Plan that began on              ,          (the “Offering Date”) hereby notifies the Company that he or she hereby withdraws from the Offering Period. He or she hereby directs the Company to pay to the undersigned as promptly as practicable all the Contributions credited to his or her account at the time of withdrawal with respect to such Offering Period. The undersigned understands and agrees that his or her option for such Offering Period will be automatically terminated. The undersigned understands further that no further payroll deductions will be made for the purchase of shares in the current Offering Period and the undersigned will be eligible to participate in succeeding Offering Periods only by delivering to the Company a new Subscription Agreement.

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