Exhibit 4.2

REGISTRATION RIGHTS AGREEMENT

This Registration Rights Agreement (this “Agreement”) is made and entered into as of September 30, 2013 (the “Agreement Date”), by and among CymaBay Therapeutics, Inc., a Delaware corporation (the “Company”), and the several investors who have signed a joinder agreement to become a party hereto (each a “Purchaser” and collectively, the “Purchasers”).

This Agreement is made in connection with the offering contemplated by (i) the Securities Purchase Agreement dated as of the date hereof among the Company and certain purchasers (the “Purchase Agreement”), (ii) the several Subscription Agreements between the Company, on the one hand, and certain subscribers, on the other hand (the “Subscription Agreement”), and, (iii) if applicable, the Institutional Purchase Agreement (as defined in the Subscription Agreement) by and among the Company and certain purchasers (the Purchase Agreement, Subscription Agreement and Institutional Purchase Agreement shall collectively be referred to herein as the “Applicable Agreements”).

NOW, THEREFORE, in consideration of the mutual covenants contained in this Agreement, and for other good and valuable consideration, the receipt and adequacy of which are hereby acknowledged, the Company and the Purchasers agree as follows:

1. Definitions. Capitalized terms used and not otherwise defined herein that are defined in an Applicable Agreement shall have the respective meanings given such terms in such Applicable Agreement. As used in this Agreement, the following terms shall have the following meanings:

“Advice” shall have the meaning set forth in Section 6(e).

“Affiliate” means, with respect to any person, any other person which directly or indirectly controls, is controlled by, or is under common control with, such person.

“Agreement” shall have the meaning set forth in the Preamble.

“Applicable Agreement” and “Applicable Agreements” shall have the respective meanings set forth in the Recitals.

“Applicable Securities” means all Registrable Securities in the Holders’ possession.

“Business Day” means a day, other than a Saturday or Sunday, on which banks in New York City are open for the general transaction of business.

“Commission” means the Securities and Exchange Commission.

“Common Stock” means the common stock of the Company, par value $0.0001 per share, and any securities into which such common stock may hereinafter be reclassified.

“Company” shall have the meaning set forth in the Preamble.

“Conversion Shares” shall means shares of the Company’s Common Stock issued upon conversion of the Company’s preferred stock as described in the Purchase Agreement.

“Effective Date” means the date that the applicable Registration Statement filed pursuant to Section 2(a) is first declared effective by the Commission.

“Effectiveness Deadline” means the 30th calendar day following the Filing Deadline; provided, however, that in the event that the Commission reviews such Registration Statement and has written comments with respect thereto, such deadline shall be extended to the 60th calendar day following the Filing Deadline and provided, further, however, that if the Effectiveness Deadline falls on a Saturday, Sunday or other day that the Commission is closed for business, the Effectiveness Deadline shall be extended to the next Business Day on which the Commission is open for business.

“Effectiveness Period” shall have the meaning set forth in Section 2(b).

“Event” shall have the meaning set forth in Section 2(c).

“Event Date” shall have the meaning set forth in Section 2(c).

“Exchange Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.

“Filing Deadline” means, with respect to the Registration Statement required to be filed pursuant to Section 2(a), the 30th calendar day following the Offering Termination Date and, provided, however, that if the Filing Deadline falls on a Saturday, Sunday or other day that the Commission is closed for business, the Filing Deadline shall be extended to the next Business Day on which the Commission is open for business.

“Holder” or “Holders” means the holder or holders, as the case may be, from time to time of Registrable Securities.

“Indemnified Party” shall have the meaning set forth in Section 5(c).

“Indemnifying Party” shall have the meaning set forth in Section 5(c).

“Initial Registration Statement” shall have the meaning set forth in Section 2(a).

“Losses” shall have the meaning set forth in Section 5(a).

“Nasdaq” means the Nasdaq Stock Market.

“New York Courts” means the state and federal courts sitting in the City of New York.

“New Registration Statement” shall have the meaning set forth in Section 2(a).

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“Person” means an individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind.

“Placement Agent” shall mean National Securities Corporation.

“Principal Market” means the Trading Market on which the Common Stock is primarily listed on and quoted for trading.

“Proceeding” means an action, claim, suit, investigation or proceeding (including, without limitation, an investigation or partial proceeding, such as a deposition), whether commenced or threatened.

“Prospectus” means the prospectus included in a Registration Statement (including, without limitation, a prospectus that includes any information previously omitted from a prospectus filed as part of an effective registration statement in reliance upon Rule 430A promulgated under the Securities Act), as amended or supplemented by any prospectus supplement, with respect to the terms of the offering of any portion of the Registrable Securities covered by a Registration Statement, and all other amendments and supplements to the Prospectus, including post-effective amendments, and all material incorporated by reference or deemed to be incorporated by reference in such Prospectus.

“Register,” “registered” and “registration” refer to a registration made by preparing and filing a Registration Statement or similar document in compliance with the Securities Act and pursuant to Rule 415, and the declaration or ordering of effectiveness of such Registration Statement or document.

“Registrable Securities” means all of (i) the Shares, (ii) the Warrant Shares, (iii) the Conversion Shares, and (iv) any securities issued or issuable upon any stock split, dividend or other distribution, recapitalization or similar event with respect to the foregoing; provided, that the Holder has completed and delivered to the Company a Selling Stockholder Questionnaire; and provided, further, that a Holder’s security shall cease to be Registrable Securities upon the earliest to occur of the following: (A) sale of such security by such Holder pursuant to a Registration Statement or Rule 144 under the Securities Act (in which case, only such security sold shall cease to be a Registrable Security); or (B) at such time that the Holder can sell such securities under Rule 144 (1) without limitations as to volume of sales, method of sale requirements or notice requirements and (2) without the requirement for the Company to be in compliance with the current public information requirement under Rule 144(c)(1).

“Registration Statements” means any one or more registration statements of the Company filed under the Securities Act that covers the resale of any of the Registrable Securities pursuant to the provisions of this Agreement (including without limitation the Initial Registration Statement, each New Registration Statement and any Remainder Registration Statements), amendments and supplements to such Registration Statements, including post-effective amendments, all exhibits and all material incorporated by reference or deemed to be incorporated by reference in such Registration Statements.

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“Remainder Registration Statement” shall have the meaning set forth in Section 2(a).

“Rule 144” means Rule 144 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time, or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.

“Rule 415” means Rule 415 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time, or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.

“Rule 424” means Rule 424 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time, or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.

“SEC Guidance” means (i) any publicly-available written or oral guidance, comments, requirements or requests of the Commission staff and (ii) the Securities Act.

“Securities Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

“Selling Stockholder Questionnaire” means a questionnaire in the form attached as Annex B hereto, or such other form of questionnaire as may reasonably be adopted by the Company from time to time.

“Shares” means the shares of Common Stock issued or issuable to the Purchasers pursuant to the Applicable Agreements.

“Trading Day” means (i) a day on which the Common Stock is listed or quoted and traded on its Principal Market (other than the OTC Bulletin Board), or (ii) if the Common Stock is not listed on a Trading Market (other than the OTC Bulletin Board), a day on which the Common Stock is traded in the over-the-counter market, as reported by the OTC Bulletin Board, or (iii) if the Common Stock is not quoted on any Trading Market, a day on which the Common Stock is quoted in the over-the-counter market as reported in the “pink sheets” by Pink Sheets LLC (or any similar organization or agency succeeding to its functions of reporting prices); provided, that in the event that the Common Stock is not listed or quoted as set forth in (i), (ii) and (iii) hereof, then Trading Day shall mean a Business Day.

“Trading Market” means whichever of the following on which the Common Stock is listed or quoted for trading on the date in question: the New York Stock Exchange, the NYSE MKT, Nasdaq, or the OTC Bulletin Board.

“Transaction Documents” means the Applicable Agreements, the Warrants and this Agreement.

“Warrants” means the Warrants issued pursuant to the Applicable Agreements.

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“Warrant Shares” means the shares of Common Stock issued or issuable upon exercise of the Warrants.

2. Registration.

(a) No later than the Filing Deadline, the Company shall prepare and file with the Commission a “Shelf” Registration Statement covering the resale of all of the Registrable Securities not already covered by an existing and effective Registration Statement for an offering to be made on a continuous basis pursuant to Rule 415 or if Rule 415 is not available for offers and sales of the Registrable Securities by such other means of distribution of Registrable Securities as the Holders may reasonably specify and that is permitted under the Securities Act (such Registration Statement, the “Initial Registration Statement”). The Initial Registration Statement shall be on Form S-1 or on another appropriate form in accordance herewith, and shall contain (except if otherwise required pursuant to written comments received from the Commission upon a review of such Registration Statement) the “Plan of Distribution” section attached hereto as Annex A (which may be modified to respond to comments, if any, provided by the Commission, except that no Holder shall be named as an “underwriter” without such Holder’s consent). In the event the Commission requires a Holder to be named as an “underwriter”, such Holder shall have the option to either be named as such in the Registration Statement or to exclude some or all of such Holder’s Registrable Securities from such Registration Statement to the extent necessary for such Holder to not be named as an underwriter in such Registration Statement (and such Registrable Securities excluded from the Initial Registration Statement at the option of any Holder shall be deemed “Cut Back Shares”, as defined below). Such Initial Registration Statement shall not seek to register any securities other than the Registrable Securities. Notwithstanding the registration obligations set forth in this subsection (a) and subsections (b) and (c) of this Section 2, in the event that, with respect to any particular registration, the Commission informs the Company that all of the Registrable Securities cannot, as a result of the application of Rule 415, be registered for resale as a secondary offering on a single registration statement, the Company agrees promptly to (i) inform each of the Holders thereof and use its commercially reasonable best efforts to file amendments to the Initial Registration Statement as required by the Commission and/or (ii) withdraw such Initial Registration Statement and file a new registration statement (a “New Registration Statement”), in either case covering the maximum number of Registrable Securities permitted to be registered by the Commission, on Form S-1 or such other form available to register for resale the Registrable Securities as a secondary offering; provided, however, that prior to filing such amendment or New Registration Statement, the Company shall be obligated to use its commercially reasonable best efforts to advocate with the Commission for the registration of all of the Registrable Securities in accordance with the SEC Guidance; provided, further, that, the Company shall not in connection with such amendment or New Registration Statement agree to name any Holder as an “underwriter” in such amendment or New Registration Statement without the prior written consent of such Holder. In the event the Commission requires a Holder to be named as an “underwriter”, such Holder shall have the option to either be named as such in the Registration Statement or to exclude some or all of such Holder’s Registrable Securities from such Registration Statement to the extent necessary for such Holder to not be named as an underwriter in such Registration Statement (and such Registrable Securities excluded from such Registration Statement at the option of any Holder shall be deemed “Cut Back Shares”, as

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defined below). Notwithstanding any other provision of this Agreement, if any SEC Guidance sets forth a limitation of the number of Registrable Securities permitted to be registered on a particular Registration Statement as a secondary offering (and notwithstanding that the Company used its commercially reasonable best efforts to advocate with the Commission for the registration of all or a greater number of Registrable Securities) (a “Cut-Back”), unless otherwise directed in writing by a Holder as to its Registrable Securities, the number of Registrable Securities to be registered on such Registration Statement will be reduced on a pro rata basis and such reduction shall be applied first to any Conversion Shares included in the Registrable Securities, second to any Warrant Shares included in the Registrable Securities and finally to any Shares included in the Registrable Securities, unless the SEC Guidance otherwise requires or the Holders otherwise agree (any Registrable Securities so removed from the Initial Registration Statement, the “Cut-Back Shares”). In the event the Company amends the Initial Registration Statement or files a New Registration Statement, as the case may be, under clauses (i) or (ii) above, the Company will use its commercially reasonable best efforts to file with the Commission, as promptly as allowed by the Commission or SEC Guidance provided to the Company or to registrants of securities in general, one or more registration statements on Form S-1 or such other form available to register for resale the Cut-Back Shares (a “Remainder Registration Statement”).

(b) The Company shall use its commercially reasonable best efforts to cause each Registration Statement to be declared effective by the Commission as soon as practicable and, with respect to the Initial Registration Statement or a New Registration Statement, as applicable, no later than the Effectiveness Deadline (including filing with the Commission a request for acceleration of effectiveness in accordance with Rule 461 promulgated under the Securities Act within three Business Days after the date that the Company is notified (orally or in writing, whichever is earlier) by the Commission that such Registration Statement will not be “reviewed,” or not be subject to further review and the effectiveness of such Registration Statement may be accelerated) and shall use its commercially reasonable best efforts to keep each Registration Statement continuously effective under the Securities Act until the earlier of (i) such time as all of the Registrable Securities covered by such Registration Statement have been publicly sold by the Holders, or (ii) the date that all Registrable Securities covered by such Registration Statement may be sold (A) without limitations as to volume of sales, method of sale requirements or notice requirements pursuant to Rule 144 and (B) without the requirement for the Company to be in compliance with the current public information requirement under Rule 144(c)(1), as determined by counsel to the Company pursuant to written instructions to such effect, addressed to the Company’s transfer agent, copies of which shall be provided to the Holders and the Placement Agent (the “Effectiveness Period”). The Company shall telephonically request effectiveness of a Registration Statement as of 5:00 pm Eastern Time on the Effective Date. The Company shall promptly notify the Holders via facsimile or e-mail of the effectiveness of a Registration Statement on the same Trading Day that the Company telephonically confirms effectiveness with the Commission. The Company shall, by 9:30 am Eastern Time on the Trading Day after the effective date of such Registration Statement, file a 424(b) prospectus with the Commission.

(c) If: (i) the Initial Registration Statement is not filed with the Commission on or prior to the applicable Filing Deadline, (ii) the Initial Registration Statement (or a New

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Registration Statement, as applicable) is not declared effective by the Commission (or otherwise does not become effective) for any reason, or (iii) after its Effective Date, such Registration Statement ceases for any reason (including by reason of a stop order or other suspension of the effectiveness of such Registration Statement) to remain continuously effective as to all Registrable Securities for which it is required to be effective, and, as a result, the Holders are not permitted to utilize the Prospectus therein to resell such Registrable Securities at any time during the 180-day period commencing on the Effective Date (the “Initial Effectiveness Period”), and after the end of the Initial Effectiveness Period for an aggregate of more than 20 consecutive calendar days or 40 calendar days in any twelve (12) month period (which need not be consecutive) (any such failure or breach in clauses (i) through (iii) above being referred to as an “Event,” and, for purposes of clauses (i) through (iii), the date on which such Event occurs being referred to as the “Event Date”), then in addition to any other rights available to the Holders hereunder or under applicable law on each monthly anniversary of each such Event Date (if the applicable Event shall not have been cured by such date) until the applicable Event is cured, the Company shall pay to each Holder an amount in cash equal to 1.5% of the aggregate purchase price paid by such Holder for the Applicable Securities required to be included in such Registration Statement, provided that the amount of such liquidated damages paid to each Holder may not exceed more than 25% of the aggregate purchase price paid by such Holder for such Applicable Securities. Such payments shall be made to each Holder in cash. The liquidated damages pursuant to the terms hereof shall apply on a daily pro-rata basis for any portion of a month prior to the cure of an Event. Notwithstanding the foregoing, if two or more Events are occurring simultaneously, the Company shall only be liable for liquidated damages under this Section 2(c) as if one Event is occurring. For the avoidance of doubt, no liquidated damages shall accrue as to any Cut Back Shares until such date as the Company is able to effect the registration of such Cut Back Shares in accordance with any SEC Guidance (such date, the “Restriction Termination Date” of such Cut Back Shares). From and after the Restriction Termination Date applicable to any Cut Back Shares, all of the provisions of this Section 2 (including the liquidated damages provisions) shall again be applicable to such Cut Back Shares; provided, however, that (i) the Filing Deadline for the Registration Statement including such Cut Back Shares shall be thirty (30) Business Days after such Restriction Termination Date, and (ii) the Effectiveness Deadline with respect to such Cut Back Shares shall be the 60th day immediately after the Restriction Termination Date (or the 90th day in the event the Commission provides written comments to such Registration Statement). In the event a Purchaser fails to timely provide the Company with information reasonably requested by the Company and necessary to include shares held by such Holder in a Registration Statement in accordance with the requirements of the Securities Act, the Effectiveness Deadline for such Purchaser shall be extended without, default or liquidated damages hereunder, until the 60th day after such time as the Company files any New Registration Statement subsequent to receiving the information reasonably requested and necessary to include such Holder in such New Registration Statement (or the 90th day in the event the Commission provides written comments to such New Registration Statement).

(d) Each Holder agrees to furnish to the Company a completed Questionnaire in the form attached to this Agreement as Annex B (a “Selling Stockholder Questionnaire”) no later than ten (10) Trading Days prior to the Filing Date. Each Holder further agrees that it shall not be entitled to be named as a selling securityholder in a Registration Statement or use the

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Prospectus for offers and resales of Registrable Securities at any time, unless such Holder has returned to the Company a completed and signed Selling Stockholder Questionnaire. If a Holder of Registrable Securities returns a Selling Stockholder Questionnaire after the deadline specified in the previous sentence, the Company shall use its commercially reasonable best efforts to take such actions as are required to name such Holder as a selling security holder in a Registration Statement or any pre-effective or post-effective amendment thereto and to include (to the extent not theretofore included) in such Registration Statement the Registrable Securities identified in such late Selling Stockholder Questionnaire. Each Holder acknowledges and agrees that the information in the Selling Stockholder Questionnaire will be used by the Company in the preparation of such Registration Statement and hereby consents to the inclusion of such information in such Registration Statement.

3. Registration Procedures

In connection with the Company’s registration obligations hereunder, the Company shall:

(a) Not less than (x) five Trading Days prior to the filing of a Registration Statement and (y) three Trading Days prior to the filing of any related Prospectus or any amendment or supplement thereto (except for amendments or supplements that contain Annual Reports on Form 10-K, and Quarterly Reports on Form 10-Q and Current Reports on Form 8-K and any similar or successor reports), the Company shall furnish to counsel to the Placement Agent and counsel for the Holders copies of such Registration Statement, Prospectus or amendment or supplement thereto, as proposed to be filed.

(b) (i) Prepare and file with the Commission such amendments (including post effective amendments) and supplements to each Registration Statement and the Prospectus used in connection therewith as may be necessary to keep such Registration Statement continuously effective as to the applicable Registrable Securities for its Effectiveness Period; (ii) cause the related Prospectus to be amended or supplemented by any required Prospectus supplement (subject to the terms of this Agreement), and, as so supplemented or amended, to be filed pursuant to Rule 424; (iii) respond as promptly as reasonably practicable to any comments received from the Commission with respect to each Registration Statement or any amendment thereto and, as promptly as reasonably practicable, provide counsel to the Placement Agent and the Holders the true and complete copies of all correspondence from and to the Commission relating to such Registration Statement that pertains to the Holders as “Selling Stockholders” but not any comments that would result in the disclosure to the Holders of material and non-public information concerning the Company; and (iv) comply with the provisions of the Securities Act and the Exchange Act with respect to the disposition of all Registrable Securities covered by a Registration Statement until such time as all of such Registrable Securities shall have been disposed of (subject to the terms of this Agreement) in accordance with the intended methods of disposition by the Holders thereof as set forth in such Registration Statement as so amended or in such Prospectus as so supplemented; provided, however, that each Purchaser shall be responsible for the delivery of the Prospectus to the Persons to whom such Purchaser sells any of the Shares or the Warrant Shares (including in accordance with Rule 172 under the Securities Act), and each Purchaser agrees to dispose of Registrable Securities in compliance with the “Plan of Distribution” described in such Registration Statement and otherwise in compliance with applicable federal and state securities laws; provided, further, that the Company shall promptly

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inform the Purchasers in writing if, at any time during the Effectiveness Period, the Company does not satisfy the conditions specified in Rule 172. In the case of amendments and supplements to a Registration Statement which are required to be filed pursuant to this Agreement (including pursuant to this Section 3(b)) by reason of the Company filing a report on Form 10-K, Form 10-Q or Form 8-K or any analogous report under the Exchange Act, the Company shall include such report in such Registration Statement by amendment or supplement, and shall file such amendments or supplements with the Commission on the same day on which the Exchange Act report which created the requirement for the Company to amend or supplement such Registration Statement was filed.

(c) Notify the Holders (which notice shall, pursuant to clauses (i) through (iii) hereof, be accompanied by an instruction to suspend the use of the Prospectus until the requisite changes have been made) as promptly as reasonably possible (in the case of (i) and (ii) below, not more than one Trading Day after such issuance or receipt and in the case of (iii) below, not less than three Trading Days prior to the financial statements in any Registration Statement becoming ineligible for inclusion therein) (i) of the issuance by the Commission or any other federal or state governmental authority of any stop order suspending the effectiveness of a Registration Statement covering any or all of the Registrable Securities or the initiation of any Proceedings for that purpose; (ii) of the receipt by the Company of any notification with respect to the suspension of the qualification or exemption from qualification of any of the Registrable Securities for sale in any jurisdiction, or the initiation or threatening of any Proceeding for such purpose; and (iii) of the occurrence of any event or passage of time that makes the financial statements included in a Registration Statement ineligible for inclusion therein or any statement made in such Registration Statement or Prospectus or any document incorporated or deemed to be incorporated therein by reference untrue in any material respect or that requires any revisions to such Registration Statement, Prospectus or other documents so that, in the case of such Registration Statement or the Prospectus, as the case may be, it will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein (in the case of any Prospectus, form of prospectus or supplement thereto, in light of the circumstances under which they were made), not misleading.

(d) Use its commercially reasonable best efforts to avoid the issuance of, or, if issued, obtain the withdrawal of (i) any order suspending the effectiveness of a Registration Statement, or (ii) any suspension of the qualification (or exemption from qualification) of any of the Registrable Securities for sale in any jurisdiction, as soon as reasonably practicable.

(e) If requested by a Holder, furnish to such Holder, without charge, at least one conformed copy of each Registration Statement and each amendment thereto and all exhibits to the extent requested by such Person (including those previously furnished or incorporated by reference) promptly after the filing of such documents with the Commission; provided, that the Company shall have no obligation to provide any document pursuant to this clause that is available on the Commission’s EDGAR system.

(f) Prior to any resale of Registrable Securities by a Holder, use its commercially reasonable best efforts to register or qualify, unless an exemption from registration and qualification applies, the Registrable Securities for offer and sale under the securities or Blue Sky laws of such jurisdictions within the United States as any Holder reasonably requests in

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writing, to keep each such registration or qualification (or exemption therefrom) effective during the Effectiveness Period and to do any and all other acts or things reasonably necessary to enable the disposition in such jurisdictions of the Registrable Securities covered by the Registration Statements; provided, that the Company shall not be required to qualify generally to do business in any jurisdiction where it is not then so qualified or to take any action that would subject the Company to general service of process in any jurisdiction where it is not then so subject or subject the Company to any material tax in any such jurisdiction where it is not then so subject.

(g) If requested by the Holders, cooperate with the Holders to facilitate the timely preparation and delivery of certificates representing Registrable Securities to be delivered to a transferee pursuant to the Registration Statements, which certificates shall be free, to the extent permitted by the Applicable Agreements, and under law, of all restrictive legends, and to enable such Registrable Securities to be in such denominations and registered in such names as any such Holders may reasonably request.

(h) Following the occurrence of any event contemplated by Section 3(c), as promptly as reasonably practicable (taking into account the Company’s good faith assessment of any adverse consequences to the Company and its stockholders of the premature disclosure of such event), prepare a supplement or amendment, including a post-effective amendment, to the affected Registration Statements or a supplement to the related Prospectus or any document incorporated or deemed to be incorporated therein by reference, and file any other required document so that, as thereafter delivered, no Registration Statement nor any Prospectus will contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein (in the case of any Prospectus, form of prospectus or supplement thereto, in light of the circumstances under which they were made), not misleading. If the Company notifies the Holders in accordance with clauses (i) through (iii) of Section 3(c) above to suspend the use of any Prospectus until the requisite changes to such Prospectus have been made, then the Holders shall suspend use of such Prospectus. The Company will use its commercially reasonable best efforts to ensure that the use of the Prospectus may be resumed as promptly as is practicable. The Company shall be entitled to exercise its right under this Section 3(h) to suspend the availability of a Registration Statement and Prospectus, subject to the payment of partial liquidated damages otherwise required pursuant to Section 2(c), for a period not to exceed thirty (40) calendar days (which need not be consecutive days) in any twelve (12) month period.

(i) In order to enable the Holders to sell Shares or Warrant Shares under Rule 144, until such time that the Holder can sell under Rule 144 (A) without limitations as to volume of sales, method of sale requirements or notice requirements and (B) without the requirement for the Company to be in compliance with the current public information requirement under Rule 144(c)(1), timely file (or obtain extensions in respect thereof and file within the applicable grace period) all reports required to be filed by the Company after the date hereof pursuant to Section 13(a) or 15(d) of the Exchange Act. During such period, if the Company is not required to file reports pursuant to Section 13(a) or 15(d) of the Exchange Act, it will prepare and furnish to the Holders and make publicly available in accordance with Rule 144(c) promulgated under the Securities Act annual and quarterly financial statements, together with a discussion and analysis of such financial statements in form and substance substantially similar to those that would

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otherwise be required to be included in reports required by Section 13(a) or 15(d) of the Exchange Act, as well as any other information required thereby, in the time period that such filings would have been required to have been made under the Exchange Act. The Company further covenants that it will take such further action as any Holder may reasonably request, all to the extent required from time to time to enable such Person to sell Shares and Warrant Shares without registration under the Securities Act within the limitation of the exemptions provided by Rule 144 promulgated under the Securities Act, including compliance with the provisions of any Applicable Agreement relating to the transfer of the Shares and Warrant Shares.

4. Registration Expenses. All fees and expenses incident to the Company’s performance of or compliance with its obligations under this Agreement (excluding any underwriting discounts and selling commissions for any Holder), and reasonable fees and disbursements of a single special counsel for the Holders not to exceed $15,000 shall be borne by the Company whether or not any Registrable Securities are sold pursuant to a Registration Statement. The fees and expenses referred to in the foregoing sentence shall include, without limitation, (i) all registration and filing fees (including, without limitation, fees and expenses (A) with respect to filings required to be made with any Trading Market on which the Common Stock is then listed for trading, and (B) in compliance with applicable state securities or Blue Sky laws (including, without limitation, fees and disbursements of counsel for the Company in connection with Blue Sky qualifications or exemptions of the Registrable Securities, and determination of the eligibility of the Registrable Securities for investment under the laws of such jurisdictions as requested by the Holders)), (ii) printing expenses (including, without limitation, expenses of printing certificates for Registrable Securities and of printing prospectuses if the printing of prospectuses is reasonably requested by the Holders of a majority of the Registrable Securities included in a Registration Statement), (iii) messenger, telephone and delivery expenses, (iv) fees and disbursements of counsel for the Company, (v) Securities Act liability insurance, if the Company so desires such insurance, and (vi) fees and expenses of all other Persons retained by the Company in connection with the consummation of the transactions contemplated by this Agreement. In addition, the Company shall be responsible for all of its internal expenses incurred in connection with the consummation of the transactions contemplated by this Agreement (including, without limitation, all salaries and expenses of its officers and employees performing legal or accounting duties), the expense of any annual audit and the fees and expenses incurred in connection with the listing of the Registrable Securities on any securities exchange as required hereunder. In no event shall the Company be responsible for any broker or similar commissions of any Holder or any legal fees or other costs of the Holders.

5. Indemnification.

(a) Indemnification by the Company. The Company shall, notwithstanding any termination of this Agreement, indemnify, defend and hold harmless each Holder, the officers, directors, agents, partners, members, managers, shareholders, Affiliates and employees of each of them, each Person who controls any such Holder (within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act) and the officers, directors, partners, members, managers, shareholders, agents and employees of each such controlling Person, to the fullest extent permitted by applicable law, from and against any and all losses, claims, damages, liabilities, costs (including, without limitation, reasonable costs of preparation and investigation

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and reasonable attorneys’ fees) and expenses (collectively, “Losses”), as incurred, that arise out of or are based upon (i) any untrue or alleged untrue statement of a material fact contained in any Registration Statement, any Prospectus or any form of prospectus or in any amendment or supplement thereto (it being understood that the Holder has approved Annex A hereto for this purpose) or in any preliminary prospectus, or arising out of or relating to any omission or alleged omission to state a material fact required to be stated therein or necessary to make the statements therein (in the case of any Prospectus or form of prospectus or supplement thereto, in light of the circumstances under which they were made) not misleading, or (ii) any violation or alleged violation by the Company of the Securities Act, Exchange Act, any state securities law, any Blue Sky laws of any jurisdiction in which Registrable Securities are offered or any rule or regulation thereunder relating to the offer or sale of the Registrable Securities pursuant to a Registration Statement or any violation of this Agreement, except to the extent, but only to the extent, that (A) such untrue statements, alleged untrue statements, omissions or alleged omissions are based solely upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, or to the extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities and was reviewed and approved in writing by such Holder expressly for use in such Registration Statement, such Prospectus or such form of Prospectus or in any amendment or supplement thereto (it being understood that each Holder has approved Annex A hereto for this purpose), (B) in the case of an occurrence of an event of the type specified in Section 3(c)(i) through (iii), the use by a Holder of an outdated or defective Prospectus after the Company has notified such Holder in writing that the Prospectus is outdated or defective and prior to the receipt by such Holder of the Advice contemplated and defined in Section 6(e), or (C) any such Losses arise out of the Holder’s (or any other indemnified Person’s) failure to send or give a copy of the Prospectus or supplement (as then amended or supplemented), if required, pursuant to Rule 172 under the Securities Act (or any successor rule) to the Persons asserting an untrue statement or alleged untrue statement or alleged untrue statement or omission or alleged omission at or prior to the written confirmation of the sale of Registrable Securities to such Person if such statement or omission was corrected in such Prospectus or supplement. The Company shall notify the Holders promptly of the institution, threat or assertion of any Proceeding arising from or in connection with the transactions contemplated by this Agreement of which the Company is aware. Such indemnity shall remain in full force and effect regardless of any investigation made by or on behalf of an Indemnified Party and shall survive the transfer of the Registrable Securities by the Holders.

(b) Indemnification by Holders. Each Holder shall, notwithstanding any termination of this Agreement, severally and not jointly, indemnify and hold harmless the Company, its directors, officers, agents and employees, each Person who controls the Company (within the meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors, officers, agents or employees of such controlling Persons, to the fullest extent permitted by applicable law, from and against all Losses, as incurred, arising out of or based solely upon any untrue or alleged untrue statement of a material fact contained in any Registration Statement, any Prospectus, or any form of prospectus, or in any amendment or supplement thereto or in any preliminary prospectus, or arising out of or relating to any omission or alleged omission of a material fact required to be stated therein or necessary to make the statements therein (in the case of any Prospectus, or any form of prospectus or supplement

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thereto, in light of the circumstances under which they were made) not misleading (i) to the extent, but only to the extent that, such untrue statements or omissions are based solely upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, (ii) to the extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities and was reviewed and approved by such Holder expressly for use in the Registration Statements (it being understood that the Holder has approved Annex A hereto for this purpose), such Prospectus or such form of Prospectus or in any amendment or supplement thereto or (iii) in the case of an occurrence of an event of the type specified in Section 3(c)(i) through (iii), the use by such Holder of an outdated or defective Prospectus after the Company has notified such Holder in writing that the Prospectus is outdated or defective and prior to the receipt by such Holder of the Advice contemplated in Section 6(e). In no event shall the liability of any selling Holder hereunder be greater in amount than the dollar amount of the net proceeds received by such Holder upon the sale of the Registrable Securities giving rise to such indemnification obligation.

(c) Conduct of Indemnification Proceedings. If any Proceeding shall be brought or asserted against any Person entitled to indemnity hereunder (an “Indemnified Party”), such Indemnified Party shall promptly notify the Person from whom indemnity is sought (the “Indemnifying Party”) in writing, and the Indemnifying Party shall have the right to assume the defense thereof, including the employment of counsel reasonably satisfactory to the Indemnified Party and the payment of all reasonable fees and expenses incurred in connection with defense thereof; provided, that the failure of any Indemnified Party to give such notice shall not relieve the Indemnifying Party of its obligations or liabilities pursuant to this Agreement, except (and only) to the extent that it shall be finally determined by a court of competent jurisdiction (which determination is not subject to appeal or further review) that such failure shall have proximately and materially adversely prejudiced the Indemnifying Party.

An Indemnified Party shall have the right to employ separate counsel in any such Proceeding and to participate in the defense thereof, but the fees and expenses of such counsel shall be at the expense of such Indemnified Party or Parties unless: (1) the Indemnifying Party has agreed in writing to pay such fees and expenses; (2) the Indemnifying Party shall have failed promptly to assume the defense of such Proceeding and to employ counsel reasonably satisfactory to such Indemnified Party in any such Proceeding; or (3) the named parties to any such Proceeding (including any impleaded parties) include both such Indemnified Party and the Indemnifying Party, and such Indemnified Party shall have been advised by counsel that a conflict of interest exists if the same counsel were to represent such Indemnified Party and the Indemnifying Party (in which case, if such Indemnified Party notifies the Indemnifying Party in writing that it elects to employ separate counsel at the expense of the Indemnifying Party, the Indemnifying Party shall not have the right to assume the defense thereof and such counsel shall be at the expense of the Indemnifying Party); provided, that the Indemnifying Party shall not be liable for the fees and expenses of more than one separate firm of attorneys at any time for the Indemnified Party. The Indemnifying Party shall not be liable for any settlement of any such Proceeding effected without its written consent, which consent shall not be unreasonably withheld, delayed or conditioned. No Indemnifying Party shall, without the prior written consent of the Indemnified Party, effect any settlement of any pending Proceeding in respect of which any Indemnified Party is a party, unless such settlement includes an unconditional release of such Indemnified Party from all liability on claims that are the subject matter of such Proceeding.

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Subject to the terms of this Agreement, all fees and expenses of the Indemnified Party (including reasonable fees and expenses to the extent incurred in connection with investigating or preparing to defend such Proceeding in a manner not inconsistent with this Section) shall be paid to the Indemnified Party, as incurred, within 10 Trading Days of written notice thereof to the Indemnifying Party; provided, that the Indemnified Party shall promptly reimburse the Indemnifying Party for that portion of such fees and expenses applicable to such actions for which such Indemnified Party is finally judicially determined to not be entitled to indemnification hereunder and such settlement does not require the Indemnified Party to pay any amount or take any action in connection therewith. The failure to deliver written notice to the Indemnifying Party within a reasonable time of the commencement of any such action shall not relieve such Indemnifying Party of any liability to the Indemnified Party under this Section 5, except to the extent that the Indemnifying Party is prejudiced in its ability to defend such action.

Such indemnity shall survive the transfer of Registrable Securities by the Holder pursuant to Section 6(i).

(d) Contribution. If a claim for indemnification under Section 5(a) or 5(b) is unavailable to an Indemnified Party (by reason of public policy or otherwise), then each Indemnifying Party, in lieu of indemnifying such Indemnified Party, shall contribute to the amount paid or payable by such Indemnified Party as a result of such Losses, in such proportion as is appropriate to reflect the relative fault of the Indemnifying Party and Indemnified Party in connection with the actions, statements or omissions that resulted in such Losses as well as any other relevant equitable considerations. The relative fault of such Indemnifying Party and Indemnified Party shall be determined by reference to, among other things, whether any action in question, including any untrue or alleged untrue statement of a material fact or omission or alleged omission of a material fact, has been taken or made by, or relates to information supplied by, such Indemnifying Party or Indemnified Party, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such action, statement or omission. The amount paid or payable by a party as a result of any Losses shall be deemed to include, subject to the limitations set forth in this Agreement, any reasonable attorneys’ or other reasonable fees or expenses incurred by such party in connection with any Proceeding to the extent such party would have been indemnified for such fees or expenses if the indemnification provided for in this Section 5 was available to such party in accordance with its terms.

The parties hereto agree that it would not be just and equitable if contribution pursuant to this Section 5(d) were determined by pro rata allocation or by any other method of allocation that does not take into account the equitable considerations referred to in the immediately preceding paragraph. Notwithstanding the provisions of this Section 5(d), no Holder shall be required to contribute, in the aggregate, any amount in excess of the amount by which the net proceeds actually received by such Holder from the sale of the Registrable Securities subject to the Proceeding exceeds the amount of any damages that such Holder has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any Person who was not guilty of such fraudulent misrepresentation.

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The indemnity and contribution agreements contained in this Section 5 are in addition to any liability that the Indemnifying Parties may have to the Indemnified Parties and are not in diminution or limitation of the indemnification provisions under any Applicable Agreement.

6. Miscellaneous.

(a) Remedies. In the event of a breach by the Company or by a Holder of any of their obligations under this Agreement, each Holder or the Company, as the case may be, in addition to being entitled to exercise all rights granted by law and under this Agreement, including recovery of damages, will be entitled to specific performance of its rights under this Agreement. The Company and each Holder agree that monetary damages would not provide adequate compensation for any losses incurred by reason of a breach by it of any of the provisions of this Agreement and hereby further agrees that, in the event of any action for specific performance in respect of such breach, it shall waive the defense that a remedy at law would be adequate.

(b) No Other Registration Rights. Except as contemplated by Sections 6(g) and (i), the Company shall not enter into any agreement with any holder or prospective holder of any securities of the Company that would grant such holder rights to demand the registration of shares of the Company’s capital stock, or to include such shares in a registration statement that would reduce the number of shares includable by the Holders.

(c) Entire Agreement. This Agreement is intended by the parties as a final expression of their agreement and intended to be a complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the subject matter contained herein. This Agreement supersedes all prior agreements and understandings between the parties with respect to such subject matter, except for, and as provided in the Transaction Documents.

(d) Compliance. Each Holder covenants and agrees that it will comply with the prospectus delivery requirements of the Securities Act as applicable to it (unless an exemption therefrom is available) in connection with sales of Registrable Securities pursuant to a Registration Statement and, in such event, shall sell the Registrable Securities only in accordance with a method of distribution described in such Registration Statement.

(e) Discontinued Disposition. Each Holder further agrees by its acquisition of Registrable Securities that, upon receipt of a notice from the Company of the occurrence of any event of the kind described in Section 3(c)(i) through (iii), such Holder will forthwith discontinue disposition of such Registrable Securities under a Registration Statement until it is advised in writing (the “Advice”) by the Company that the use of the applicable Prospectus (as it may have been supplemented or amended) may be resumed. The Company may provide appropriate stop orders to enforce the provisions of this paragraph. The Company agrees and acknowledges that any periods during which the Holder is required to discontinue the disposition of the Registrable Securities hereunder shall be subject to the provisions of Section 2(c) as qualified by Section 3(a). The Company shall use its commercially reasonable best efforts to cause the use of the Prospectus may be resumed as promptly as possible.

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(f) Piggy-Back Registrations. If at any time during the Effectiveness Period there is not an effective Registration Statement covering all of the Registrable Securities and the Company shall determine to prepare and file with the Commission a registration statement relating to an offering for its own account or the account of others under the Securities Act of any of its equity securities, other than on Form S-4 or Form S-8 (each as promulgated under the Securities Act) or their then equivalents relating to equity securities to be issued solely in connection with any acquisition of any entity or business or equity securities issuable in connection with stock option or other employee or director benefit plans, then the Company shall send to each Holder written notice of such determination and, if within 15 calendar days after receipt of such notice, any such Holder shall so request in writing, the Company shall include in such registration statement all or any part of such Registrable Securities such Holder requests to be registered, subject to customary underwriter cutbacks applicable to all holders of registration rights on a pro rata basis (along with other holders of piggyback registration rights with respect to the Company); provided, however, that no such reduction shall reduce the amount of Registrable Securities of the selling Holders included in the registration statement below 30% of the total amount of securities included in such registration statement, unless such registration does not include shares of any other selling stockholders, in which event any or all of the Registrable Securities of the Holders may be excluded in accordance with the immediately preceding clause; provided, further that (i) the Company shall not be required to register any Registrable Securities pursuant to this Section 6(f) that are (A) eligible for resale under Rule 144 without limitations as to volume of sales, method of sale requirements or notice requirements and without the requirement for the Company to be in compliance with the current public information requirements under Rule 144(c)(1), or (B) the subject of a then effective Registration Statement, and (ii) if at any time after giving written notice of its intention to register any securities and prior to the effective date of the registration statement filed in connection with such registration, the Company shall determine for any reason not to register or to delay registration of such securities, the Company may, at its election, give written notice of such determination to such Holder and, thereupon, (Y) in the case of a determination not to register, shall be relieved of its obligation to register any Registrable Securities pursuant to this Section 6(f) in connection with such registration (but not from its obligation to pay expenses in accordance with Section 4 hereof), and (Z) in the case of a determination to delay registering, shall be permitted to delay registering any Registrable Securities being registered pursuant to this Section 6(f) for the same period as the delay in registering such other securities. Nothing contained in this Section 6(f) shall limit the Company’s liabilities and/or obligations under this Agreement, including, without limitation, the obligation to pay liquidated damages under Section 2(c).

(g) Amendments and Waivers. The provisions of this Agreement, including the provisions of this sentence, may not be amended, modified or supplemented unless the same shall be in writing and signed by the Company and Holders holding 50% of the then outstanding Registrable Securities, and waivers or consents to departures from the provisions hereof may not be given, unless the same shall be in writing and signed by the Company and Holders holding 50% of the then outstanding Registrable Securities; provided however, that execution of a

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Joinder Agreement by additional Purchasers after the Agreement Date shall not be deemed to be an amendment to this Agreement. If a Registration Statement does not register all of the Registrable Securities pursuant to a waiver or amendment done in compliance with the previous sentence, then the number of Registrable Securities to be registered for each Holder shall be reduced pro rata among all Holders. Notwithstanding the foregoing, a waiver or consent to depart from the provisions hereof with respect to a matter that relates exclusively to the rights of Holders and that does not directly or indirectly affect the rights of other Holders may be given by Holders of all of the Registrable Securities to which such waiver or consent relates; provided, however, that the provisions of this sentence may not be amended, modified, or supplemented except in accordance with the provisions of the first sentence of this Section 6(g).

(h) Notices. Any and all notices or other communications or deliveries required or permitted to be provided hereunder shall be in writing and shall be deemed given and effective on the earliest of (a) the date of transmission, if such notice or communication is delivered via facsimile (provided the sender receives a machine-generated confirmation of successful transmission) at the facsimile number specified in this Section 6(h) prior to 5:00 p.m., eastern time, on a Trading Day, (b) the next Trading Day after the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number specified in this Section 6(h) on a day that is not a Trading Day or later than 5:00 p.m., eastern time, on any Trading Day, (c) the Trading Day following the date of mailing, if sent by U.S. nationally recognized overnight courier service with next day delivery specified, or (d) upon actual receipt by the party to whom such notice is required to be given. The address for such notices and communications shall be as follows:

or such other address as may be designated in writing hereafter, in the same manner, by such Person.

(i) Successors and Assigns. This Agreement shall inure to the benefit of and be binding upon the successors and permitted assigns of each of the parties and shall inure to the benefit of each Holder. Nothing in this Agreement, express or implied, is intended to confer

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upon any party other than the parties hereto or their respective successors and assigns any rights, remedies, obligations, or liabilities under or by reason of this Agreement, except as expressly provided in this Agreement. The Company may not assign its rights or obligations hereunder without the prior written consent of all the Holders of the then outstanding Registrable Securities (other than by merger or to an entity which acquires the Company including by way of acquiring all or substantially all of the Company’s assets). The rights of the Holders hereunder, including the right to have the Company register Registrable Securities pursuant to this Agreement, may be assigned by each Holder to transferees or assignees of all or any portion of the Registrable Securities, but only if (i) such Holder complies with all laws applicable thereto, (ii) the transferee or assignee signs the form of Joinder Agreement attached hereto agreeing to be bound by all of the provisions of this Agreement and (iii) such Holder provides written notice of assignment to the Company promptly after such assignment is effected.

(j) Execution and Counterparts. This Agreement may be executed in any number of counterparts, each of which when so executed shall be deemed to be an original and, all of which taken together shall constitute one and the same Agreement and shall become effective when counterparts have been signed by each party and delivered to the other party, it being understood that both parties need not sign the same counterpart. For purposes of the preceding sentence, each Purchaser shall become a party to this Agreement by executing and delivering to the Company a Joinder Agreement in the form attached hereto. In the event that any signature is delivered by facsimile transmission or by e-mail delivery of a “.pdf” format data file, such signature shall create a valid and binding obligation of the party executing (or on whose behalf such signature is executed) with the same force and effect as if such facsimile or “.pdf” signature were the original thereof.

(k) Governing Law. All questions concerning the construction, validity, enforcement and interpretation of this Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York, without regard to the principles of conflicts of law thereof. Each party agrees that all Proceedings concerning the interpretations, enforcement and defense of the transactions contemplated by this Agreement and any other Transaction Documents (whether brought against a party hereto or its respective Affiliates, employees or agents) shall be commenced exclusively in the New York Courts. Each party hereto hereby irrevocably submits to the exclusive jurisdiction of the New York Courts for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein (including with respect to the enforcement of any of the Transaction Documents), and hereby irrevocably waives, and agrees not to assert in any Proceeding, any claim that it is not personally subject to the jurisdiction of any such New York Court, or that such Proceeding has been commenced in an improper or inconvenient forum. Each party hereto hereby irrevocably waives personal service of process and consents to process being served in any such Proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law.

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(l) Cumulative Remedies. The remedies provided herein are cumulative and not exclusive of any remedies provided by law.

(m) Severability. If any term, provision, covenant or restriction of this Agreement is held by a court of competent jurisdiction to be invalid, illegal, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions set forth herein shall remain in full force and effect and shall in no way be affected, impaired or invalidated, and the parties hereto shall use their reasonable efforts to find and employ an alternative means to achieve the same or substantially the same result as that contemplated by such term, provision, covenant or restriction. It is hereby stipulated and declared to be the intention of the parties that they would have executed the remaining terms, provisions, covenants and restrictions without including any of such that may be hereafter declared invalid, illegal, void or unenforceable.

(n) Headings. The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.

(o) Independent Nature of Purchasers’ Obligations and Rights. The obligations of each Purchaser under this Agreement are several and not joint with the obligations of any other Purchaser hereunder, and no Purchaser shall be responsible in any way for the performance of the obligations of any other Purchaser hereunder. The decision of each Purchaser to purchase the Shares and Warrants pursuant to the Transaction Documents has been made independently of any other Purchaser. Nothing contained herein or in any other agreement or document delivered at any closing, and no action taken by any Purchaser pursuant hereto or thereto, shall be deemed to constitute the Purchasers as a partnership, an association, a joint venture or any other kind of entity, or create a presumption that the Purchasers are in any way acting in concert with respect to such obligations or the transactions contemplated by this Agreement. Each Purchaser acknowledges that no other Purchaser has acted as agent for such Purchaser in connection with making its investment hereunder and that no Purchaser will be acting as agent of such Purchaser in connection with monitoring its investment in the Shares and Warrants or enforcing its rights under the Transaction Documents. Each Purchaser shall be entitled to protect and enforce its rights, including, without limitation, the rights arising out of this Agreement, and it shall not be necessary for any other Purchaser to be joined as an additional party in any Proceeding for such purpose. The Company acknowledges that each of the Purchasers has been provided with the same Registration Rights Agreement for the purpose of closing a transaction with multiple Purchasers and not because it was required or requested to do so by any Purchaser.

(p) No Inconsistent Agreements. The Company has not entered, as of the date hereof, nor shall the Company, on or after the date of this Agreement, enter into any agreement with respect to its securities, that would have the effect of impairing the rights granted to the Holders in this Agreement or otherwise conflict with the provisions hereof and (ii) the Company has not previously entered into any agreement granting any registration rights with respect to any of its securities to any Person that have not been satisfied in full.

(q) Currency. Unless otherwise indicated, all dollar amounts referred to in this Agreement are in United States Dollars. All amounts owing under this Agreement are in United States Dollars. All amounts denominated in other currencies shall be converted in the United States Dollar equivalent amount in accordance with the applicable exchange rate in effect on the date of calculation.

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(r) Further Assurances. The parties shall execute and deliver all such further instruments and documents and take all such other actions as may reasonably be required to carry out the transactions contemplated hereby and to evidence the fulfillment of the agreements herein contained.

(Signature pages follow.)

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IN WITNESS WHEREOF, the parties have executed this Registration Rights Agreement as of the date first written above.

(Company Signature Page for Registration Rights Agreement)

JOINDER AGREEMENT

For good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, and intending to be legally bound, the undersigned hereby acknowledges receipt of a true and complete copy of the Registration Rights Agreement, dated as of September     , 2013, by and among CymaBay Therapeutics, Inc. and the Purchasers party thereto, and agrees to be bound by all of the provisions thereof.

IN WITNESS WHEREOF, the undersigned has executed this Joinder Agreement as of the      day of             , 2013.

(Joinder Agreement Signature Page for Registration Rights Agreement)

Exhibit A

Plan of Distribution

The selling stockholders, which as used herein includes donees, pledgees, transferees or other successors-in-interest selling shares of common stock or interests in shares of common stock received after the date of this prospectus from a selling stockholder as a gift, pledge, partnership distribution or other transfer, may, from time to time, sell, transfer or otherwise dispose of any or all of their shares of common stock or interests in shares of common stock on any stock exchange, market or trading facility on which the shares are traded or in private transactions. These dispositions may be at fixed prices, at prevailing market prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale, or at negotiated prices.

The selling stockholders may use any one or more of the following methods when disposing of shares or interests therein:

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The selling stockholders may, from time to time, pledge or grant a security interest in some or all of the shares of common stock owned by them and, if they default in the performance of their secured obligations, the pledgees or secured parties may offer and sell the shares of common stock, from time to time, under this prospectus, or under an amendment to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest as selling stockholders under this prospectus. The selling stockholders also may transfer the shares of common stock in other circumstances, in which case the transferees, pledgees or other successors in interest will be the selling beneficial owners for purposes of this prospectus.

In connection with the sale of our common stock or interests therein, the selling stockholders may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of the common stock in the course of hedging the positions they assume. The selling stockholders may also sell shares of our common stock short and deliver these securities to close out their short positions, or loan or pledge the common stock to broker-dealers that in turn may sell these securities. The selling stockholders may also enter into option or other transactions with broker-dealers or other financial institutions or the creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction).

The aggregate proceeds to the selling stockholders from the sale of the common stock offered by them will be the purchase price of the common stock less discounts or commissions, if any. Each of the selling stockholders reserves the right to accept and, together with their agents from time to time, to reject, in whole or in part, any proposed purchase of common stock to be made directly or through agents. We will not receive any of the proceeds from this offering. Upon any exercise of the warrants by payment of cash, however, we will receive the exercise price of the warrants.

The selling stockholders also may resell all or a portion of the shares in open market transactions in reliance upon Rule 144 under the Securities Act of 1933, provided that they meet the criteria and conform to the requirements of that rule.

The selling stockholders and any underwriters, broker-dealers or agents that participate in the sale of the common stock or interests therein may be “underwriters” within the meaning of Section 2(11) of the Securities Act. Any discounts, commissions, concessions or profit they earn

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on any resale of the shares may be underwriting discounts and commissions under the Securities Act. Selling stockholders who are “underwriters” within the meaning of Section 2(11) of the Securities Act will be subject to the prospectus delivery requirements of the Securities Act.

To the extent required, the shares of our common stock to be sold, the names of the selling stockholders, the respective purchase prices and public offering prices, the names of any agents, dealer or underwriter, any applicable commissions or discounts with respect to a particular offer will be set forth in an accompanying prospectus supplement or, if appropriate, a post-effective amendment to the registration statement that includes this prospectus.

In order to comply with the securities laws of some states, if applicable, the common stock may be sold in these jurisdictions only through registered or licensed brokers or dealers. In addition, in some states the common stock may not be sold unless it has been registered or qualified for sale or an exemption from registration or qualification requirements is available and is complied with.

We have advised the selling stockholders that the anti-manipulation rules of Regulation M under the Exchange Act may apply to sales of shares in the market and to the activities of the selling stockholders and their affiliates. In addition, to the extent applicable we will make copies of this prospectus (as it may be supplemented or amended from time to time) available to the selling stockholders for the purpose of satisfying the prospectus delivery requirements of the Securities Act. The selling stockholders may indemnify any broker-dealer that participates in transactions involving the sale of the shares against certain liabilities, including liabilities arising under the Securities Act.

We have agreed to indemnify the selling stockholders against liabilities, including liabilities under the Securities Act and state securities laws, relating to the registration of the shares offered by this prospectus.

We have agreed with the selling stockholders to keep the registration statement of which this prospectus constitutes a part effective until the earlier of (1) such time as all of the shares covered by this prospectus have been disposed of pursuant to and in accordance with the registration statement or (2) the date on which all of the shares may be sold without restriction pursuant to Rule 144 of the Securities Act.

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