NKARTA, INC. AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT August 27, 2019

Exhibit 4.2

NKARTA, INC.

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT

August 27, 2019

TABLE OF CONTENTS

i

Schedule A - Schedule of Investors

ii

NKARTA, INC.

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT

THIS AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT (this “Agreement”), is made as of the 27^th day of August, 2019, by and among Nkarta, Inc., a Delaware corporation (the “Company”), and each of the investors listed on Schedule A hereto (together with any subsequent investors or transferees who become parties to this Agreement in accordance with Section 6.9 hereof, each an “Investor” and together the “Investors”).

RECITALS

WHEREAS, certain of the Investors (the “Existing Investors”) hold shares of the Company’s Series A Preferred Stock and possess certain rights pursuant to that certain Investors’ Rights Agreement, dated as of December 18, 2017 (the “Prior Agreement”);

WHEREAS, the Company and certain of the Investors are parties to that certain Series B Preferred Stock Purchase Agreement of even date herewith (as may be amended and/or restated from time to time, the “Purchase Agreement”), pursuant to which such Investors are purchasing shares of the Company’s Series B Preferred Stock (together, the “Series B Preferred Stock”) and it is a condition to the initial closing of the sale of the Series B Preferred Stock to the Investors listed on the Schedule of Purchasers attached as Exhibit A thereto that such Investors and the Company execute and deliver this Agreement; and

WHEREAS, the undersigned parties constitute (a) the Company, (b) the holders of a majority of the Registrable Securities (as defined in the Prior Agreement) outstanding as of the date hereof, and such parties desire to amend and restate the Prior Agreement in its entirety and to accept the rights created pursuant to this Agreement in lieu of the rights granted to them under the Prior Agreement; and

WHEREAS, the Company desires to induce the Investors to purchase shares of Series B Preferred Stock pursuant to the Purchase Agreement by agreeing to the terms and conditions set forth herein.

NOW, THEREFORE, the parties hereby agree as follows:

1. Definitions. For purposes of this Agreement:

“Affiliate” means, with respect to any specified Person, any other Person who, directly or indirectly, controls, is controlled by, or is under common control with such Person, including without limitation any general partner, managing member, officer, director or trustee of such Person, or any venture capital fund or registered investment company now or hereafter existing that is controlled by one or more general partners, managing members or investment adviser of, or shares the same management company or investment adviser with, such Person; provided that, where the term “Person” refers to Novo Holdings A/S, in lieu of the foregoing definition, the term “Affiliate” shall mean Novo Ventures (US) Inc. (together with Novo Holdings A/S, “Novo”), any partner, executive officer or director of Novo or any venture capital fund or other Person now or hereafter existing formed for the purpose of making investments in other Persons that is controlled by or under common control with Novo, and for the avoidance of doubt, shall not include any other affiliate of Novo; and provided further, that where the term “Person” refers to Deerfield Special Situations Fund, L.P. and Deerfield Private Design Fund IV, L.P. (collectively, “Deerfield”), in lieu of the foregoing definition, the term “Affiliate” shall mean Deerfield’s affiliates, its other equityholders, partners (including partners and affiliated partnerships managed by the same management company or managing (general) partner or by any Person that is an Affiliate with such management company or managing (general) partner), members and a trust for the benefit of such other equityholders of Deerfield.

“Board of Directors” means the board of directors of the Company.

“Common Stock” means shares of the Company’s common stock, par value $0.0001 per share.

“Competitor” means a Person engaged, directly or indirectly (including through any partnership, limited liability company, corporation, joint venture or similar arrangement (whether now existing or formed hereafter)), in a business that offers products or services that are directly or indirectly competitive with the products or services of the Company, including products or services which are in actual or demonstrably anticipated research or development by the Company, but shall not include any financial investment firm or collective investment vehicle that, together with its Affiliates, holds less than twenty percent (20%) of the outstanding equity of any Competitor and does not, nor do any of its Affiliates, have a right to designate any members of the board of directors of any Competitor. In no event shall any of Glaxo Group Limited, Novo, SR One, NEA, Samsara, RA Capital, LSP or Deerfield (collectively, the “Preferred Investors”), be deemed a Competitor.

“Damages” means any loss, damage, claim or liability (joint or several) to which a party hereto may become subject under the Securities Act, the Exchange Act, or other federal or state law, insofar as such loss, damage, claim or liability (or any action in respect thereof) arises out of or is based upon: (i) any untrue statement or alleged untrue statement of a material fact contained in any registration statement of the Company, including any preliminary prospectus or final prospectus contained therein or any amendments or supplements thereto; (ii) an omission or alleged omission to state therein a material fact required to be stated therein, or necessary to make the statements therein not misleading; or (iii) any violation or alleged violation by the indemnifying party (or any of its agents or Affiliates) of the Securities Act, the Exchange Act, any state securities law, or any rule or regulation promulgated under the Securities Act, the Exchange Act, or any state securities law.

“Derivative Securities” means any securities or rights convertible into, or exercisable or exchangeable for (in each case, directly or indirectly), Common Stock, including options and warrants.

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

“Excluded Registration” means (i) a registration relating to the sale or grant of securities to employees of the Company or a subsidiary pursuant to a stock option, stock purchase, equity incentive or similar plan; (ii) a registration relating to an SEC Rule 145 transaction; (iii) a registration on any form that does not include substantially the same information as would be required to be included in a registration statement covering the sale of the Registrable Securities; or (iv) a registration in which the only Common Stock being registered is Common Stock issuable upon conversion of debt securities that are also being registered.

“Form S-1” means such form under the Securities Act as in effect on the date hereof or any successor registration form under the Securities Act subsequently adopted by the SEC.

“Form S-3” means such form under the Securities Act as in effect on the date hereof or any registration form under the Securities Act subsequently adopted by the SEC that permits forward incorporation of substantial information by reference to other documents filed by the Company with the SEC.

2

“GAAP” means generally accepted accounting principles in the United States as in effect from time to time.

“Holder” means any holder of Registrable Securities who is a party to this Agreement.

“Immediate Family Member” means a child, stepchild, grandchild, parent, stepparent, grandparent, spouse, domestic partner, sibling, mother-in-law, father-in-law, son-in-law, daughter-in-law, brother-in-law, or sister-in-law, including, adoptive relationships, of a natural person referred to herein.

“Initiating Holders” means, collectively, Holders who properly initiate a registration request under this Agreement.

“IPO” means the Company’s first underwritten public offering of its Common Stock under the Securities Act.

“Key Employee” means any executive-level employee (including, division director and vice president-level positions) as well as any employee who, either alone or in concert with others, develops, invents, programs, or designs any Company Intellectual Property (as defined in the Purchase Agreement).

“LSP” means LSP 6 Holding C.V. and its Affiliates.

“Major Investor” means any Investor that, individually or together with such Investor’s Affiliates, holds at least (i) 1,681,131 shares of Preferred Stock (as adjusted for any stock split, stock dividend, combination, recapitalizations, reclassifications and the like effected after the date hereof) or (ii) such number of Registrable Securities issued or issuable upon conversion of 1,681,131 shares of Preferred Stock (as adjusted for any stock split, stock dividend, combination, recapitalization, reclassification and the like effected after the date hereof) provided that each RA Capital Investor shall be deemed to be a Major Investor for so long as each such RA Capital Investor holds the number of shares purchased by such RA Capital Investor under the Purchase Agreement, and provided further that, notwithstanding the foregoing, in the event that any Major Investor becomes a Defaulting Purchaser (as defined in the Purchase Agreement), such Defaulting Purchaser shall cease to be a Major Investor under this Agreement.

“NEA” means New Enterprise Associates 15 L.P. and its Affiliates.

“New Securities” means, collectively, equity securities of the Company, whether or not currently authorized, as well as rights, options, or warrants to purchase such equity securities, or securities of any type whatsoever that are, or may become, convertible or exchangeable into or exercisable for such equity securities.

“Person” means any individual, corporation, partnership, trust, limited liability company, association or other entity.

“Preferred Stock” means, collectively, shares of the Company’s Series A Preferred Stock and shares of the Company’s Series B Preferred Stock.

“RA Capital” means, collectively, RA Capital Healthcare Fund, L.P., RA Capital Nexus Fund, L.P., and ▇▇▇▇▇▇▇▇▇ Partners LLC—Series A, and their Affiliates.

3

“Registrable Securities” means (i) the Common Stock issuable or issued upon conversion of the Preferred Stock, excluding any Common Stock issued upon conversion of the Preferred Stock pursuant to the “Special Mandatory Conversion” provisions of the Restated Certificate; (ii) any Common Stock, or any Common Stock issued or issuable (directly or indirectly) upon conversion and/or exercise of any other securities of the Company acquired by the Investors after the date hereof and (iii) any Common Stock issued as (or issuable upon the conversion or exercise of any warrant, right, or other security that is issued as) a dividend or other distribution with respect to, or in exchange for or in replacement of, the shares referenced in clauses (i) and (ii) above; excluding in all cases, however, any Registrable Securities sold by a Person in a transaction in which the applicable rights under this Agreement are not assigned pursuant to Section 6.1, and excluding for purposes of Section 2 any shares for which registration rights have terminated pursuant to Section 2.13 of this Agreement.

“Registrable Securities then outstanding” means the number of shares determined by adding the number of shares of outstanding Common Stock that are Registrable Securities and the number of shares of Common Stock issuable (directly or indirectly) pursuant to then exercisable and/or convertible securities that are Registrable Securities.

“Restated Certificate” means the Company’s Amended and Restated Certificate of Incorporation, as may be amended and/or restated from time to time.

“Restricted Securities” means the securities of the Company required to be notated with the legend set forth in Section 2.12(b) hereof.

“Right of First Refusal and Co-Sale Agreement” means that certain Amended and Restated Right of First Refusal and Co-Sale Agreement, dated of even date herewith, by and among the Company, the Investors and the other parties named therein, as may be amended and/or restated from time to time.

“Samsara” means Samsara BioCapital L.P. and its Affiliates.

“SEC” means the Securities and Exchange Commission.

“SEC Rule 144” means Rule 144 promulgated by the SEC under the Securities Act.

“SEC Rule 145” means Rule 145 promulgated by the SEC under the Securities Act.

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

“Selling Expenses” means all underwriting discounts, selling commissions, and stock transfer taxes applicable to the sale of Registrable Securities, and fees and disbursements of counsel for any Holder, except for the fees and disbursements of the Selling Holder Counsel borne and paid by the Company as provided in Section 2.6.

“Series A Preferred Stock” means shares of the Company’s Series A Preferred Stock, par value $0.0001 per share.

“Series B Preferred Stock” means shares of the Company’s Series B Preferred Stock, par value $0.0001 per share.

“SR One” means SR One, Limited, and its Affiliates.

4

“Voting Agreement” means that certain Amended and Restated Voting Agreement, dated of even date herewith, by and among the Company, the Investors and the other parties named therein, as may be amended and/or restated from time to time.

2. Registration Rights. The Company covenants and agrees as follows:

2.1 Demand Registration.

(a) Form S-1 Demand. If at any time after the earlier of (i) five (5) years after the date of this Agreement or (ii) one hundred eighty (180) days after the effective date of the registration statement for the IPO, the Company receives a request from Holders of a majority of the Registrable Securities then outstanding that the Company file a Form S-1 registration statement, for an aggregate gross offering price of at least $5,000,000, then the Company shall (x) within ten (10) days after the date such request is given, give notice thereof (the “Demand Notice”) to all Holders other than the Initiating Holders, and (y) as soon as practicable, and in any event within sixty (60) days after the date such request is given by the Initiating Holders, file a Form S-1 registration statement under the Securities Act covering all Registrable Securities that the Initiating Holders requested to be registered and any additional Registrable Securities requested to be included in such registration by any other Holders, as specified by notice given by each such Holder to the Company within twenty (20) days of the date the Demand Notice is given, and in each case, subject to the limitations of Sections 2.1(c) and 2.3.

(b) Form S-3 Demand. If at any time when it is eligible to use a Form S-3 registration statement, the Company receives a request from Holders of the Registrable Securities then outstanding that the Company file a Form S-3 registration statement with respect to outstanding Registrable Securities of such Holders having an anticipated aggregate gross offering price, of at least $1,000,000, then the Company shall (i) within ten (10) days after the date such request is given, give a Demand Notice to all Holders other than the Initiating Holders, and (ii) as soon as practicable, and in any event within forty-five (45) days after the date such request is given by the Initiating Holders, file a Form S-3 registration statement under the Securities Act covering all Registrable Securities requested to be included in such registration by any other Holders, as specified by notice given by each such Holder to the Company within twenty (20) days of the date the Demand Notice is given, and in each case, subject to the limitations of Sections 2.1(c) and 2.3.

(c) Notwithstanding the foregoing obligations, if the Company furnishes to Holders requesting a registration pursuant to this Section 2.1 a certificate signed by the Company’s chief executive officer stating that in the good faith judgment of the Board of Directors it would be materially detrimental to the Company and its stockholders for such registration statement to either become effective or remain effective for as long as such registration statement otherwise would be required to remain effective, because such action would (i) materially interfere with a significant acquisition, corporate reorganization, or other similar transaction involving the Company, (ii) require premature disclosure of material information that the Company has a bona fide business purpose for preserving as confidential, or (iii) render the Company unable to comply with requirements under the Securities Act or Exchange Act, then the Company shall have the right to defer taking action with respect to such filing, and any time periods with respect to filing or effectiveness thereof shall be tolled correspondingly, for a period of not more than sixty (60) days after the request of the Initiating Holders is given; provided, however, that the Company may not invoke this right more than once in any twelve (12) month period; and provided further that the Company shall not register any securities for its own account or that of any other stockholder during such sixty (60) day period other than an Excluded Registration.

5

(d) The Company shall not be obligated to effect, or to take any action to effect, any registration pursuant to Section 2.1(a): (i) during the period that is thirty (30) days before the Company’s good faith estimate of the date of filing of, and ending on a date that is one hundred eighty (180) days after the effective date of, a Company-initiated registration, provided that the Company is actively employing in good faith commercially reasonable efforts to cause such registration statement to become effective; (ii) after the Company has effected two registrations pursuant to Section 2.1(a); or (iii) if the Initiating Holders propose to dispose of shares of Registrable Securities that may be immediately registered on Form S-3 pursuant to a request made pursuant to Section 2.1(b). The Company shall not be obligated to effect, or to take any action to effect, any registration pursuant to Section 2.1(b): (i) during the period that is thirty (30) days before the Company’s good faith estimate of the date of filing of, and ending on a date that is sixty (60) days after the effective date of, a Company-initiated registration, provided that the Company is actively employing in good faith commercially reasonable efforts to cause such registration statement to become effective; or (ii) if the Company has effected two registrations pursuant to Section 2.1(b) within the twelve (12) month period immediately preceding the date of such request. A registration shall not be counted as “effected” for purposes of this Section 2.1(d) until such time as the applicable registration statement has been declared effective by the SEC, unless the Initiating Holders withdraw their request for such registration, elect not to pay the registration expenses therefor, and forfeit their right to one demand registration statement pursuant to Section 2.6, in which case such withdrawn registration statement shall be counted as “effected” for purposes of this Section 2.1(d); provided, that if such withdrawal is during a period the Company has deferred taking action pursuant to Section 2.1(c), then the Initiating Holders may withdraw their request for registration and such registration will not be counted as “effected” for purposes of this Section 2.1(d).

2.2 Company Registration. If the Company proposes to register (including, for this purpose, a registration effected by the Company for stockholders other than the Holders) any of its securities under the Securities Act in connection with the public offering of such securities solely for cash (other than in an Excluded Registration), the Company shall, at such time, promptly give each Holder notice of such registration. Upon the request of each Holder given within twenty (20) days after such notice is given by the Company, the Company shall, subject to the provisions of Section 2.3, cause to be registered all of the Registrable Securities that each such Holder has requested to be included in such registration. The Company shall have the right to terminate or withdraw any registration initiated by it under this Section 2.2 before the effective date of such registration, whether or not any Holder has elected to include Registrable Securities in such registration. The expenses (other than Selling Expenses) of such withdrawn registration shall be borne by the Company in accordance with Section 2.6.

2.3 Underwriting Requirements.

(a) If, pursuant to Section 2.1, the Initiating Holders intend to distribute the Registrable Securities covered by their request by means of an underwriting, they shall so advise the Company as a part of their request made pursuant to Section 2.1, and the Company shall include such information in the Demand Notice. The underwriter(s) will be selected by the Company and shall be reasonably acceptable to a majority in interest of the Initiating Holders. In such event, the right of any Holder to include such Holder’s Registrable Securities in such registration shall be conditioned upon such Holder’s participation in such underwriting and the inclusion of such Holder’s Registrable Securities in the underwriting to the extent provided herein. All Holders proposing to distribute their securities through such underwriting shall (together with the Company as provided in Section 2.4(e)) enter into an underwriting agreement in customary form with the underwriter(s) selected for such underwriting; provided, however, that no Holder (or any of its assignees) shall be required to make any representations, warranties or indemnities except as they relate to such Holder’s ownership of shares and authority to enter into the underwriting agreement and to such Holder’s intended method of distribution, and the liability of such Holder shall be limited to an amount equal to the net proceeds from the offering received by such Holder. Notwithstanding any other provision of this Section 2.3, if the managing underwriter(s) advise(s) the Initiating Holders in writing that marketing factors require a limitation on the number of shares to be

6

underwritten, then the Initiating Holders shall so advise all Holders of Registrable Securities that otherwise would be underwritten pursuant hereto, and the number of Registrable Securities that may be included in the underwriting shall be allocated among such Holders of Registrable Securities, including the Initiating Holders, in proportion (as nearly as practicable) to the number of Registrable Securities owned by each Holder or in such other proportion as shall mutually be agreed to by all such selling Holders; provided, however, that the number of Registrable Securities held by the Holders to be included in such underwriting shall not be reduced unless all other securities are first entirely excluded from the underwriting. To facilitate the allocation of shares in accordance with the above provisions, the Company or the underwriters may round the number of shares allocated to any Holder to the nearest one hundred (100) shares.

(b) In connection with any offering involving an underwriting of shares of the Company’s capital stock pursuant to Section 2.2, the Company shall not be required to include any of the Holders’ Registrable Securities in such underwriting unless the Holders seeking to sell Registrable Securities in such offering accept the terms of the underwriting as agreed upon between the Company and its underwriters, and then only in such quantity as the underwriters in their sole discretion determine will not jeopardize the success of the offering by the Company. If the total number of securities, including Registrable Securities, requested by stockholders to be included in such offering exceeds the number of securities to be sold (other than by the Company) that the underwriters in their reasonable discretion determine is compatible with the success of the offering, then the Company shall be required to include in the offering only that number of such securities, including Registrable Securities, which the underwriters and the Company in their sole discretion determine will not jeopardize the success of the offering. If the underwriters determine that less than all of the Registrable Securities requested to be registered can be included in such offering, then the Registrable Securities that are included in such offering shall be allocated among the selling Holders in proportion (as nearly as practicable to) the number of Registrable Securities owned by each selling Holder or in such other proportions as shall mutually be agreed to by all such selling Holders. To facilitate the allocation of shares in accordance with the above provisions, the Company or the underwriters may round the number of shares allocated to any Holder to the nearest one hundred (100) shares. Notwithstanding the foregoing, in no event shall (i) the number of Registrable Securities included in the offering be reduced unless all other securities (other than securities to be sold by the Company) are first entirely excluded from the offering, or (ii) the number of Registrable Securities included in the offering be reduced below thirty percent (30%) of the total number of securities included in such offering, unless such offering is the IPO, in which case the selling Holders may be excluded further if the underwriters make the determination described above and no other stockholder’s securities are included in such offering. For purposes of the provision in this Section 2.3(b) concerning apportionment, for any selling Holder that is a partnership, limited liability company, or corporation, the partners, members, retired partners, retired members, stockholders, and Affiliates of such Holder, or the estates and Immediate Family Members of any such partners, retired partners, members, and retired members and any trusts for the benefit of any of the foregoing Persons, shall be deemed to be a single “selling Holder,” and any pro rata reduction with respect to such “selling Holder” shall be based upon the aggregate number of Registrable Securities owned by all Persons included in such “selling Holder,” as defined in this sentence.

(c) For purposes of Section 2.1, a registration shall not be counted as “effected” if, as a result of an exercise of the underwriter’s cutback provisions in Section 2.3(a), fewer than fifty percent (50%) of the total number of Registrable Securities that Holders have requested to be included in such registration statement are actually included

7

2.4 Obligations of the Company. Whenever required under this Section 2 to effect the registration of any Registrable Securities, the Company shall, as expeditiously as reasonably possible:

(a) prepare and file with the SEC a registration statement with respect to such Registrable Securities and use its commercially reasonable efforts to cause such registration statement to become effective and, upon the request of the Holders of a majority of the Registrable Securities registered thereunder, keep such registration statement effective for a period of up to one hundred twenty (120) days or, if earlier, until the distribution contemplated in the registration statement has been completed; provided, however, that (i) such one hundred twenty (120) day period shall be extended for a period of time equal to the period the Holder refrains, at the request of an underwriter of Common Stock (or other securities) of the Company, from selling any securities included in such registration, and (ii) in the case of any registration of Registrable Securities on Form S-3 that are intended to be offered on a continuous or delayed basis, subject to compliance with applicable SEC rules, such one hundred twenty (120) day period shall be extended for up to one hundred eighty (180) days, if necessary, to keep the registration statement effective until all such Registrable Securities are sold;

(b) prepare and file with the SEC such amendments and supplements to such registration statement, and the prospectus used in connection with such registration statement, as may be necessary to comply with the Securities Act in order to enable the disposition of all securities covered by such registration statement;

(c) furnish to the selling Holders such numbers of copies of a prospectus, including a preliminary prospectus, as required by the Securities Act, and such other documents as the Holders may reasonably request in order to facilitate their disposition of their Registrable Securities;

(d) use its commercially reasonable efforts to register and qualify the securities covered by such registration statement under such other securities or blue-sky laws of such jurisdictions as shall be reasonably requested by the selling Holders; provided that the Company shall not be required to qualify to do business or to file a general consent to service of process in any such states or jurisdictions, unless the Company is already subject to service in such jurisdiction and except as may be required by the Securities Act;

(e) in the event of any underwritten public offering, enter into and perform its obligations under an underwriting agreement, in usual and customary form, with the underwriter(s) of such offering;

(f) use its commercially reasonable efforts to cause all such Registrable Securities covered by such registration statement to be listed on a national securities exchange or trading system and each securities exchange and trading system (if any) on which similar securities issued by the Company are then listed;

(g) provide a transfer agent and registrar for all Registrable Securities registered pursuant to this Agreement and provide a CUSIP number for all such Registrable Securities, in each case not later than the effective date of such registration;

(h) promptly make available for inspection by the selling Holders, any managing underwriter(s) participating in any disposition pursuant to such registration statement, and any attorney or accountant or other agent retained by any such underwriter or selected by the selling Holders, all financial and other records, pertinent corporate documents, and properties of the Company, and cause the Company’s officers, directors, employees, and independent accountants to supply all information reasonably requested by any such seller, underwriter, attorney, accountant, or agent, in each case, as necessary or advisable to verify the accuracy of the information in such registration statement and to conduct appropriate due diligence in connection therewith;

8

(i) notify each selling Holder, promptly after the Company receives notice thereof, of the time when such registration statement has been declared effective or a supplement to any prospectus forming a part of such registration statement has been filed; and

(j) after such registration statement becomes effective, notify each selling Holder of any request by the SEC that the Company amend or supplement such registration statement or prospectus.

In addition, the Company shall ensure that, at all times after any registration statement covering a public offering of securities of the Company under the Securities Act shall have become effective, its ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ policy shall provide that the Company’s directors may implement a trading program under Rule 10b5-l of the Exchange Act.

2.5 Furnish Information. It shall be a condition precedent to the obligations of the Company to take any action pursuant to this Section 2 with respect to the Registrable Securities of any selling Holder that such Holder shall furnish to the Company such information regarding itself, the Registrable Securities held by it, and the intended method of disposition of such securities as is reasonably required to effect the registration of such Holder’s Registrable Securities.

2.6 Expenses of Registration. All expenses (other than Selling Expenses) incurred in connection with registrations, filings, or qualifications pursuant to Section 2, including all registration, filing, and qualification fees; printers’ and accounting fees; fees and disbursements of counsel for the Company; and the reasonable fees and disbursements, not to exceed $200,000 of one counsel for the selling Holders (“Selling Holder Counsel”), shall be borne and paid by the Company; provided, however, that the Company shall not be required to pay for any expenses of any registration proceeding begun pursuant to Section 2.1 if the registration request is subsequently withdrawn at the request of the Holders of a majority of the Registrable Securities to be registered (in which case all selling Holders shall bear such expenses pro rata based upon the number of Registrable Securities that were to be included in the withdrawn registration), unless the Holders of a majority of the Registrable Securities agree to forfeit their right to one registration pursuant to Sections 2.1(a) or 2.1(b), as the case may be; provided further that if, at the time of such withdrawal, the Holders shall have learned of a material adverse change in the condition, business, or prospects of the Company from that known to the Holders at the time of their request and have withdrawn the request with reasonable promptness after learning of such information then the Holders shall not be required to pay any of such expenses and shall not forfeit their right to one registration pursuant to Sections 2.1(a) or 2.1(b). All Selling Expenses relating to Registrable Securities registered pursuant to this Section 2 shall be borne and paid by the Holders pro rata on the basis of the number of Registrable Securities registered on their behalf.

2.7 Delay of Registration. No Holder shall have any right to obtain or seek an injunction restraining or otherwise delaying any registration pursuant to this Agreement as the result of any controversy that might arise with respect to the interpretation or implementation of this Section 2.

2.8 Indemnification. If any Registrable Securities are included in a registration statement under this Section 2:

(a) To the extent permitted by law, the Company will indemnify and hold harmless each selling Holder, and the partners, members, officers, directors, and stockholders of each such Holder; legal counsel and accountants for each such Holder; any underwriter (as defined in the Securities Act) for each such Holder; and each Person, if any, who controls such Holder or underwriter within the meaning of the Securities Act or the Exchange Act, against any Damages, and the Company will pay to each such Holder, underwriter, controlling Person, or other aforementioned Person any legal or other

9

expenses reasonably incurred thereby in connection with investigating or defending any claim or proceeding from which Damages may result, as such expenses are incurred; provided, however, that the indemnity agreement contained in this Section 2.8(a) shall not apply to amounts paid in settlement of any such claim or proceeding if such settlement is effected without the consent of the Company, which consent shall not be unreasonably withheld, nor shall the Company be liable for any Damages to the extent that they arise out of or are based upon actions or omissions made in reliance upon and in conformity with written information furnished by or on behalf of any such Holder, underwriter, controlling Person, or other aforementioned Person expressly for use in connection with such registration.

(b) To the extent permitted by law, each selling Holder, severally and not jointly, will indemnify and hold harmless the Company, and each of its directors, each of its officers who has signed the registration statement, each Person (if any), who controls the Company within the meaning of the Securities Act, legal counsel and accountants for the Company, any underwriter (as defined in the Securities Act), any other Holder selling securities in such registration statement, and any controlling Person of any such underwriter or other Holder, against any Damages, in each case only to the extent that such Damages arise out of or are based upon actions or omissions made in reliance upon and in conformity with written information furnished by or on behalf of such selling Holder expressly for use in connection with such registration; and each such selling Holder will pay to the Company and each other aforementioned Person any legal or other expenses reasonably incurred thereby in connection with investigating or defending any claim or proceeding from which Damages may result, as such expenses are incurred; provided, however, that the indemnity agreement contained in this Section 2.8(b) shall not apply to amounts paid in settlement of any such claim or proceeding if such settlement is effected without the consent of the Holder, which consent shall not be unreasonably withheld; and provided further that in no event shall the aggregate amounts payable by any Holder by way of indemnity or contribution under Sections 2.8(b) and 2.8(d) exceed the proceeds from the offering received by such Holder (net of any Selling Expenses paid by such Holder), except in the case of fraud or willful misconduct by such Holder.

(c) Promptly after receipt by an indemnified party under this Section 2.8 of notice of the commencement of any action (including any governmental action) for which a party may be entitled to indemnification hereunder, such indemnified party will, if a claim in respect thereof is to be made against any indemnifying party under this Section 2.8, give the indemnifying party notice of the commencement thereof. The indemnifying party shall have the right to participate in such action and, to the extent the indemnifying party so desires, participate jointly with any other indemnifying party to which notice has been given, and to assume the defense thereof with counsel mutually satisfactory to the parties; provided, however, that an indemnified party (together with all other indemnified parties that may be represented without conflict by one counsel) shall have the right to retain one separate counsel, with the fees and expenses to be paid by the indemnifying party, if representation of such indemnified party by the counsel retained by the indemnifying party would be inappropriate due to actual or potential differing interests between such indemnified party and any other party represented by such counsel in such action. The failure to give notice to the indemnifying party will not relieve it of any liability that it may have to any indemnified party otherwise than under this Section 2.8.

(d) To provide for just and equitable contribution to joint liability under the Securities Act in any case in which either: (i) any party otherwise entitled to indemnification hereunder makes a claim for indemnification pursuant to this Section 2.8 but it is judicially determined (by the entry of a final judgment or decree by a court of competent jurisdiction and the expiration of time to appeal or the denial of the last right of appeal) that such indemnification may not be enforced in such case, notwithstanding the fact that this Section 2.8 provides for indemnification in such case, or (ii) contribution under the Securities Act may be required on the part of any party hereto for which indemnification is provided under this Section 2.8, then, and in each such case, such parties will contribute to the aggregate losses, claims, damages, liabilities, or expenses to which they may be subject (after contribution from

10

others) in such proportion as is appropriate to reflect the relative fault of each of the indemnifying party and the indemnified party in connection with the statements, omissions, or other actions that resulted in such loss, claim, damage, liability, or expense, as well as to reflect any other relevant equitable considerations. The relative fault of the indemnifying party and of the indemnified party shall be determined by reference to, among other things, whether the untrue or allegedly untrue statement of a material fact, or the omission or alleged omission of a material fact, relates to information supplied by the indemnifying party or by the indemnified party and the parties’ relative intent, knowledge, access to information, and opportunity to correct or prevent such statement or omission; provided, however, that, in any such case (x) no Holder will be required to contribute any amount in excess of the public offering price of all such Registrable Securities offered and sold by such Holder pursuant to such registration statement, and (y) no Person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) will be entitled to contribution from any Person who was not guilty of such fraudulent misrepresentation; and provided further that in no event shall a Holder’s liability pursuant to this Section 2.8(d), when combined with the amounts paid or payable by such Holder pursuant to Section 2.8(b), exceed the proceeds from the offering received by such Holder (net of any Selling Expenses paid by such Holder), except in the case of willful misconduct or fraud by such Holder.

(e) Notwithstanding the foregoing, to the extent that the provisions on indemnification and contribution contained in the underwriting agreement entered into in connection with the underwritten public offering are in conflict with the foregoing provisions, the provisions in the underwriting agreement shall control.

(f) Unless otherwise superseded by an underwriting agreement entered into in connection with the underwritten public offering, the obligations of the Company and Holders under this Section 2.8 shall survive the completion of any offering of Registrable Securities in a registration under this Section 2, and otherwise shall survive the termination of this Agreement.

2.9 Reports Under Exchange Act. With a view to making available to the Holders the benefits of SEC Rule 144 and any other rule or regulation of the SEC that may at any time permit a Holder to sell securities of the Company to the public without registration or pursuant to a registration on Form S-3, the Company shall:

(a) make and keep available adequate current public information, as those terms are understood and defined in SEC Rule 144, at all times after the effective date of the registration statement filed by the Company for the IPO;

(b) use commercially reasonable efforts to file with the SEC in a timely manner all reports and other documents required of the Company under the Securities Act and the Exchange Act (at any time after the Company has become subject to such reporting requirements); and

(c) furnish to any Holder, so long as the Holder owns any Registrable Securities, forthwith upon request: (i) to the extent accurate, a written statement by the Company that it has complied with the reporting requirements of SEC Rule 144 (at any time after ninety (90) days after the effective date of the registration statement filed by the Company for the IPO), the Securities Act, and the Exchange Act (at any time after the Company has become subject to such reporting requirements), or that it qualifies as a registrant whose securities may be resold pursuant to Form S-3 (at any time after the Company so qualifies); (ii) a copy of the most recent annual or quarterly report of the Company and such other reports and documents so filed by the Company; and (iii) such other information as may be reasonably requested in availing any Holder of any rule or regulation of the SEC that permits the selling of any such securities without registration (at any time after the Company has become subject to the reporting requirements under the Exchange Act) or pursuant to Form S-3 (at any time after the Company so qualifies to use such form).

11

2.10 Limitations on Subsequent Registration Rights. From and after the date of this Agreement, the Company shall not, without the prior written consent of the Holders of at least two-thirds of the Registrable Securities then outstanding, enter into any agreement with any holder or prospective holder of any securities of the Company that (i) would provide to such holder or prospective holder the right to include securities in any registration on other than either a pro rata basis with respect to the Registrable Securities or on a subordinate basis after all Holders have had the opportunity to include in the registration and offering all shares of Registrable Securities that they wish to so include, or (ii) would allow such holder or prospective holder to initiate a demand for registration of any securities held by such holder or prospective holder; provided that this limitation shall not apply to Registrable Securities acquired by any additional Investor who becomes a party to this Agreement in accordance with Section 6.9.

2.11 “Market Stand-off” Agreement. Each Holder hereby agrees that it will not, without the prior written consent of the managing underwriter, during the period commencing on the date of the final prospectus relating to the registration by the Company of shares of its Common Stock or any other equity securities under the Securities Act for its IPO and ending on the date specified by the Company and the managing underwriter (such period not to exceed one hundred eighty (180) days), or such longer period as may be required to accommodate applicable regulatory restrictions on (1) the publication or other distribution of research reports, and (2) analyst recommendations and opinions, including, but not limited to, the restrictions contained in FINRA Rule 2711(f)(4) or NYSE Rule 472(f)(4), or any successor provisions or amendments thereto), (i) lend, offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right, or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable (directly or indirectly) for Common Stock held immediately before the effective date of the registration statement for such offering or (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of such securities, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Common Stock or other securities, in cash, or otherwise. The foregoing provisions of this Section 2.11 shall (A) apply only to the IPO, (B) not apply to the sale of any shares to an underwriter pursuant to an underwriting agreement, (C) not apply to the transfer of any shares to any trust for the direct or indirect benefit of the Holder or an Immediate Family Member of the Holder, provided that the trustee of the trust agrees to be bound in writing by the restrictions set forth herein, and provided further that any such transfer shall not involve a disposition for value, and (D) be applicable to the Holders only if all officers and directors are subject to the same restrictions and stockholders individually owning more than one percent (1%) of the Company’s outstanding Common Stock (after giving effect to conversion into Common Stock of all outstanding Preferred Stock) enter into similar agreements. The underwriters in connection with such registration are intended third-party beneficiaries of this Section 2.11 and shall have the right, power and authority to enforce the provisions hereof as though they were a party hereto. Each Holder further agrees to execute such agreements as may be reasonably requested by the underwriters in connection with such registration that are consistent with this Section 2.11 or that are necessary to give further effect thereto. To the extent that any person who is subject to market stand-off obligations is released early by the managing underwriter from such market stand-off obligations, or any or all such obligations are waived, then each Holder shall also receive a pro rata release or waiver, as applicable, based on the number of shares subject to such agreements, from its respective market stand-off obligations.

12

2.12 Restrictions on Transfer.

(a) The Preferred Stock and the Registrable Securities shall not be sold, pledged, or otherwise transferred, and the Company shall not recognize and shall issue stop-transfer instructions to its transfer agent with respect to any such sale, pledge, or transfer, except upon the conditions specified in this Agreement, which conditions are intended to ensure compliance with the provisions of the Securities Act. A transferring Holder will cause any proposed purchaser, pledgee, or transferee of the Preferred Stock and the Registrable Securities held by such Holder to agree to take and hold such securities subject to the provisions and upon the conditions specified in this Agreement.

(b) Each certificate, instrument, or book entry representing (i) the Preferred Stock, (ii) the Registrable Securities, and (iii) any other securities issued in respect of the securities referenced in clauses (i) and (ii), upon any stock split, stock dividend, combinations, recapitalizations, reclassifications and the like, shall (unless otherwise permitted by the provisions of Section 2.12(c)) be notated with a legend substantially in the following form:

THE SECURITIES REPRESENTED HEREBY HAVE BEEN ACQUIRED FOR INVESTMENT AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. SUCH SHARES MAY NOT BE SOLD, PLEDGED, OR TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR A VALID EXEMPTION FROM THE REGISTRATION AND PROSPECTUS DELIVERY REQUIREMENTS OF SAID ACT.

THE SECURITIES REPRESENTED HEREBY MAY BE TRANSFERRED ONLY IN ACCORDANCE WITH THE TERMS OF AN AGREEMENT BETWEEN THE COMPANY AND THE STOCKHOLDER, A COPY OF WHICH IS ON FILE WITH THE SECRETARY OF THE COMPANY.

The Holders consent to the Company making a notation in its records and giving instructions to any transfer agent of the Restricted Securities in order to implement the restrictions on transfer set forth in this Section 2.12.

(c) The holder of such Restricted Securities, by acceptance of ownership thereof, agrees to comply in all respects with the provisions of this Section 2. Before any proposed sale, pledge, or transfer of any Restricted Securities, unless there is in effect a registration statement under the Securities Act covering the proposed transaction, the Holder thereof shall give notice to the Company of such Holder’s intention to effect such sale, pledge, or transfer. Each such notice shall describe the manner and circumstances of the proposed sale, pledge, or transfer in sufficient detail and, if reasonably requested by the Company, shall be accompanied at such Holder’s expense by either (i) a written opinion of legal counsel who shall, and whose legal opinion shall, be reasonably satisfactory to the Company, addressed to the Company, to the effect that the proposed transaction may be effected without registration under the Securities Act; (ii) a “no action” letter from the SEC to the effect that the proposed sale, pledge, or transfer of such Restricted Securities without registration will not result in a recommendation by the staff of the SEC that action be taken with respect thereto; or (iii) any other evidence reasonably satisfactory to counsel to the Company to the effect that the proposed sale, pledge, or transfer of the Restricted Securities may be effected without registration under the Securities Act, whereupon the Holder of such Restricted Securities shall be entitled to sell, pledge, or transfer such Restricted Securities in accordance with the terms of the notice given by the Holder to the Company. The Company will not require such a legal opinion or “no action” letter (x) in any transaction in compliance with SEC Rule 144; or (y) in any transaction in which such Holder distributes Restricted Securities to an Affiliate of such Holder for no consideration; provided that each transferee agrees in writing to be subject to the terms of this Section 2.12. Each certificate, instrument, or book entry representing the Restricted Securities transferred as above provided shall be notated with, except if such transfer is made pursuant to SEC Rule 144, the appropriate restrictive legend set forth in Section 2.12(b), except that such certificate instrument, or book entry shall not be notated with such restrictive legend if, in the opinion of counsel for such Holder and the Company, such legend is not required in order to establish compliance with any provisions of the Securities Act.

13

2.13 Termination of Registration Rights. The right of any Holder to request registration or inclusion of Registrable Securities in any registration pursuant to Sections 2.1 or 2.2 shall terminate upon the earliest to occur of:

(a) the closing of a Deemed Liquidation Event, as such term is defined in the Restated Certificate; and

(b) the fifth anniversary of the IPO.

3. Information Rights.

3.1 Delivery of Financial Statements. The Company shall deliver to each Major Investor, provided that the Board of Directors has not reasonably determined that such Major Investor is a Competitor:

(a) as soon as practicable, but in any event within thirty (30) days of the end of each month, an unaudited income statement and statement of cash flows for such month, and an unaudited balance sheet and statement of stockholders’ equity as of the end of such month, all prepared in accordance with GAAP (except that such financial statements may (i) be subject to normal year-end audit adjustments and (ii) not contain all notes thereto that may be required in accordance with GAAP);

(b) as soon as practicable, but in any event within forty-five (45) days after the end of each of the first three (3) quarters of each fiscal year of the Company, unaudited statements of income and cash flows for such fiscal quarter, and an unaudited balance sheet and a statement of stockholders’ equity as of the end of such fiscal quarter, all prepared in accordance with GAAP (except that such financial statements may (i) be subject to normal year-end audit adjustments; and (ii) not contain all notes thereto that may be required in accordance with GAAP);

(c) as soon as practicable, but in any event within one hundred twenty (120) days after the end of each fiscal year of the Company (i) a balance sheet as of the end of such year, (ii) statements of income and of cash flows for such year, and (iii) a statement of stockholders’ equity as of the end of such year, all such financial statements audited and certified by independent public accountants of nationally recognized standing selected by the Company;

(d) as soon as practicable, but in any event thirty (30) days before the end of each fiscal year, a comprehensive budget and business plan for the next fiscal year (collectively, the “Budget”), approved by the Board of Directors (including a majority of the then-serving Preferred Directors (as such term is defined in the Restated Certificate)) and prepared on a monthly basis, including balance sheets, income statements, and statements of cash flow for such months and, promptly after prepared, any other budgets or revised budgets prepared by the Company;

(e) with respect to the financial statements called for in Section 3.1(a), Section 3.1(b) and Section 3.1(c), an instrument executed by the chief financial officer and chief executive officer of the Company certifying that such financial statements were prepared in accordance with GAAP consistently applied with prior practice for earlier periods (except as otherwise set forth in Section 3.1(a), Section 3.1(b) and Section 3.1(c)) and fairly present the financial condition of the Company and its results of operation for the periods specified therein; and

14

(f) such other information relating to the financial condition, business, prospects, or corporate affairs of the Company as any Major Investor may from time to time reasonably request; provided, however, that the Company shall not be obligated under this Section 3.1 to provide information (i) that the Company reasonably determines in good faith to be a trade secret or confidential information (unless covered by an enforceable confidentiality agreement, in a form acceptable to the Company), or (ii) the disclosure of which would adversely affect the attorney-client privilege between the Company and its counsel.

If, for any period, the Company has any subsidiary whose accounts are consolidated with those of the Company, then in respect of such period the financial statements delivered pursuant to the foregoing sections shall be the consolidated and consolidating financial statements of the Company and all such consolidated subsidiaries.

Notwithstanding anything else in this Section 3.1 to the contrary, the Company may cease providing the information set forth in this Section 3.1 during the period starting with the date thirty (30) days before the Company’s good-faith estimate of the date of filing of a registration statement if it reasonably concludes it must do so to comply with the SEC rules applicable to such registration statement and related offering; provided that the Company’s covenants under this Section 3.1 shall be reinstated at such time as the Company is no longer actively employing its commercially reasonable efforts to cause such registration statement to become effective.

3.2 Inspection. The Company shall permit each Major Investor (provided that the Board of Directors has not reasonably determined that such Major Investor is a Competitor), at such Major Investor’s expense, to visit and inspect the Company’s properties; examine its books of account and records; and discuss the Company’s affairs, finances, and accounts with its officers, during normal business hours of the Company as may be reasonably requested by the Major Investor; provided, however, that the Company shall not be obligated pursuant to this Section 3.2 to provide access to any information that it reasonably and in good faith considers to be a trade secret or confidential information (unless covered by an enforceable confidentiality agreement, in form acceptable to the Company) or the disclosure of which would adversely affect the attorney-client privilege between the Company and its counsel.

3. 3 Termination of Information Rights. The covenants set forth in Sections 3.1 and 3.2 shall terminate and be of no further force or effect (i) immediately before the consummation of the IPO, (ii) when the Company first becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon the closing of a Deemed Liquidation Event, as such term is defined in the Restated Certificate, whichever event occurs first.

3.4 Confidentiality. Each Investor agrees, severally and not jointly, that such Investor will keep confidential and will not disclose, divulge, or use for any purpose (other than to monitor its investment in the Company) any confidential information obtained from the Company pursuant to the terms of this Agreement prior to the Company’s IPO (including notice of the Company’s intention to file a registration statement), unless such confidential information (a) is known or becomes known to the public in general (other than as a result of a breach of this Section 3.4 by such Investor), (b) is or has been independently developed or conceived by the Investor without use of the Company’s confidential information, or (c) is or has been made known or disclosed to the Investor by a third party without a breach of any obligation of confidentiality such third party may have to the Company; provided, however, that an Investor may disclose confidential information (i) to its attorneys, accountants, consultants, and other professionals to the extent necessary to obtain their services in connection with monitoring its investment in the Company, (ii) to any prospective purchaser of any Registrable Securities from such Investor, if such prospective purchaser agrees to be bound by the provisions of this Section 3.4 and is not a Competitor of the Company, (iii) to any existing or prospective Affiliate, partner, member, stockholder, or wholly owned

15

subsidiary of such Investor or any subsequent partnership under common investment management in the ordinary course of business, or otherwise as part of such Investor’s normal reporting or review procedure, or in connection with such Investor’s or its Affiliates’ normal fundraising, marketing, informational or reporting activities, provided that such Investor informs such Person that such information is confidential and directs such Person to maintain the confidentiality of such information, or (iv) as may otherwise be required by law, regulation, rule, court order or subpoena, provided that the Investor promptly notifies the Company of such disclosure and takes reasonable steps to minimize the extent of any such required disclosure. The Company understands and acknowledges that in the ordinary course of business each Investor, and any of their respective representatives currently may be invested in, may invest in or may consider investments in companies that have issued securities that are publicly traded (each, a “Public Company”). Accordingly, the Company covenants and agrees that before providing material non-public information about a Public Company (“Public Company Information”) to each Investor, as applicable, the Company will use commercially reasonable efforts to provide prior written notice to the compliance personnel at each such Investor, as applicable, describing such information in reasonable detail. The Company shall not disclose Public Company Information to an Investor without written authorization from the applicable compliance personnel, provided, however, that, the Company will be permitted to disclose agreements entered into with Public Companies in the ordinary course of business, such as routine customer, supplier, advertising and publishing agreements without such written authorization. Further, the Company understands and acknowledges that the confidential information may be used by Deerfield, RA Capital, and Novo or any of their respective representatives in connection with evaluating investment opportunities, trading securities in the public markets and participating in private investment transactions, but specifically excluding disclosing or otherwise providing confidential information (or any derivatives, extracts or summaries thereof) to anyone other than Deerfield, RA Capital, and Novo or any of their respective representatives in violation of this Agreement.

4. Rights to Future Stock Issuances.

4.1 Right of First Offer. Subject to the terms and conditions of this Section 4.1 and applicable securities laws, if the Company proposes to offer or sell any New Securities, the Company shall first offer such New Securities to each Major Investor. A Major Investor shall be entitled to apportion the right of first offer hereby granted to it, in such proportions as it deems appropriate, among (i) itself, (ii) its Affiliates and (iii) its beneficial interest holders, such as limited partners, members or any other Person having “beneficial ownership,” as such term is defined in Rule 13d-3 promulgated under the Exchange Act, of such Major Investor (“Investor Beneficial Owners”); provided that each such Affiliate or Investor Beneficial Owner (x) is not a Competitor, unless such party’s purchase of New Securities is otherwise consented to by the Board of Directors, and (y) agrees to enter into this Agreement and each of the Voting Agreement and Right of First Refusal and Co-Sale Agreement as an “Investor” under each such agreement, or any amended and/or restated version of such agreements, as the case may be (provided that any Competitor shall not be entitled to any rights as a Major Investor under Sections 3.1, 3.2 and 4.1 hereof).

(a) The Company shall give notice (the “Offer Notice”) to each Major Investor, stating (i) its bona fide intention to offer such New Securities, (ii) the number of such New Securities to be offered, and (iii) the price and terms, if any, upon which it proposes to offer such New Securities.

(b) By notification to the Company within twenty (20) days after the Offer Notice is given, each Major Investor may elect to purchase or otherwise acquire, at the price and on the terms specified in the Offer Notice, up to that number of such New Securities which equals the proportion that the Common Stock then held by such Major Investor (including all shares of Common Stock then issuable (directly or indirectly) upon conversion and/or exercise, as applicable, of the Preferred Stock and any other Derivative Securities then held by such Major Investor) bears to the total Common Stock of the

16

Company then outstanding (assuming full conversion and/or exercise, as applicable, of all Preferred Stock and any other Derivative Securities then outstanding). At the expiration of such twenty (20) day period, the Company shall promptly notify each Major Investor that elects to purchase or acquire all the shares available to it (each, a “Fully Exercising Investor”) of any other Major Investor’s failure to do likewise. During the ten (10) day period commencing after the Company has given such notice, each Fully Exercising Investor may, by giving notice to the Company, elect to purchase or acquire, in addition to the number of shares specified above, up to that portion of the New Securities for which Major Investors were entitled to subscribe but that were not subscribed for by the Major Investors. In the event there are two (2) or more such Fully Exercising Investors that elect to purchase or acquire such New Securities that were not subscribed for by the Major Investors for a total number of New Securities in excess of the number proposed to be offered or sold by the Company, the remaining New Securities available to be purchased or acquired under this Section 4.1(b) shall be allocated to such Fully Exercising Investors pro rata based on the number of shares of New Securities such Fully Exercising Investors have elected to purchase or acquire pursuant to this Section 4.1(b) (without giving effect to any New Securities that any such Fully Exercising Investor has elected to purchase or acquire pursuant to this sentence). The closing of any sale pursuant to this Section 4.1(b) shall occur within the later of one hundred and twenty (120) days of the date that the Offer Notice is given and the date of initial sale of New Securities pursuant to Section 4.1(c).

(c) If all New Securities referred to in the Offer Notice are not elected to be purchased or acquired as provided in Section 4.1(b), the Company may, during the ninety (90) day period following the expiration of the periods provided in Section 4.1(b), offer and sell the remaining unsubscribed portion of such New Securities to any Person or Persons at a price not less than, and upon terms no more favorable to the offeree than, those specified in the Offer Notice. If the Company does not enter into an agreement for the sale of the New Securities within such period, or if such agreement is not consummated within thirty (30) days of the execution thereof, the right provided hereunder shall be deemed to be revived and such New Securities shall not be offered unless first reoffered to the Major Investors in accordance with this Section 4.1.

(d) The right of first offer in this Section 4.1 shall not be applicable to (i) Exempted Securities (as defined in the Restated Certificate); (ii) shares of Common Stock issued in the IPO; and (iii) the issuance of shares of Series B Preferred Stock issued pursuant to Section 1.2 of the Purchase Agreement.

4.2 Termination. The covenants set forth in Section 4.1 shall terminate and be of no further force or effect (i) immediately before the consummation of the IPO, (ii) when the Company first becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon the closing of a Deemed Liquidation Event, as such term is defined in the Restated Certificate, whichever event occurs first.

5. Additional Covenants.

5.1 Board Matters.

(a) The Board of Directors shall convene for meetings at least quarterly, unless otherwise approved by the Board of Directors including a majority of the then-serving Preferred Directors.

(b) Upon request, the Company shall promptly reimburse in full, each non-employee director of the Company for his or her reasonable, customary and documented out-of-pocket expenses incurred in the course of business conducted on behalf of the Company (including without limitation attendance of meetings of the Board of Directors).

17

(c) Each Preferred Director shall be entitled to serve on each committee of the Board of Directors.

5.2 Matters Requiring Preferred Director Approval. The Company hereby covenants and agrees with each of the Investors that it shall not, without approval of the Board of Directors, which approval must include the affirmative vote of at least a majority of the then-serving Preferred Directors:

(a) approve any annual operating plan, budgets or any changes thereto;

(b) approve the making of any expenditures exceeding by more than $1,000,000 in the aggregate the budget approved by the Board of Directors specifically for such expenditures;

(c) approve any new expenditures individually or in the aggregate exceeding $1,000,000;

(d) appoint, dismiss or change the Company’s auditor or general outside counsel;

(e) sell, transfer, lease, assignment, encumber, license or dispose of any assets or intellectual property of the Company (whether by a single transaction or a series of related transactions) the aggregate fair market value of which exceeds $1,000,000;

(f) purchase or acquire any assets or intellectual property (whether by a single transaction or a series of related transactions) the aggregate purchase price or cost to acquire of which exceeds $1,000,000;

(g) consummate an initial public offering of equity securities of the Company or any of its subsidiaries;

(h) make any change to the principal business of the Company, enter into new lines of business, or exit a current line of business;

(i) make, or permit any subsidiary to make, any loan or advance to, or own any stock or other securities of, any subsidiary or other corporation, partnership, or other entity unless it is wholly owned by the Company;

(j) make, or permit any subsidiary to make, any loan or advance to any Person, including, without limitation, any employee or director of the Company or any subsidiary, except advances and similar expenditures in the ordinary course of business or under the terms of an employee stock or option plan approved by the Board of Directors;

(k) guarantee, directly or indirectly, or permit any subsidiary to guarantee, directly or indirectly, any indebtedness except for trade accounts of the Company or any subsidiary arising in the ordinary course of business;

(l) make any investment inconsistent with any investment policy approved by the Board of Directors;

18

(m) otherwise enter into or be a party to any transaction with any director, officer, or employee of the Company or any “associate” (as defined in Rule 12b-2 promulgated under the Exchange Act) of any such Person, except for transactions contemplated by this Agreement and the Purchase Agreement; transactions resulting in payments to or by the Company in an aggregate amount less than $250,000 per year; or transactions made in the ordinary course of business and pursuant to reasonable requirements of the Company’s business and upon fair and reasonable terms that are approved by a majority of the Board of Directors;

(n) in-license any material intellectual property;

(o) create any subsidiary of the Company;

(p) make any material change in the accounting policies or principles of the Company, except with prior approval of the Company’s auditors;

(q) enter into a joint venture; or

(r) file for bankruptcy, insolvency, or other similar proceedings.

5.3 Director’s & Officer’s Liability. The Company has and shall maintain, from financially sound and reputable insurers, Directors and Officers liability insurance in an amount not less than $3,000,000, unless otherwise approved by the Investors.

5.4 Indemnification Matters. The Company shall use its best efforts to provide that its Restated Certificate and bylaws provide for indemnification of officers and directors of the Company to the maximum extent permitted by law. The Company shall enter into a customary indemnification agreement in form satisfactory to the Investors with each non-employee member of the Board of Directors. The Company hereby acknowledges that one (1) or more of the directors nominated to serve on the Board of Directors by the Investors (each an “Investor Director”) may have certain rights to indemnification, advancement of expenses and/or insurance provided by one or more of the Investors and certain of their Affiliates (collectively, the “Investor Indemnitors”). The Company hereby agrees (a) that it is the indemnitor of first resort (i.e., its obligations to any such Investor Director are primary and any obligation of the Investor Indemnitors to advance expenses or to provide indemnification for the same expenses or liabilities incurred by such Investor Director are secondary), (b) that it shall be required to advance the full amount of expenses incurred by such Investor Director and shall be liable for the full amount of all expenses, judgments, penalties, fines and amounts paid in settlement by or on behalf of any such Investor Director to the extent legally permitted and as required by the Company’s Certificate of Incorporation or Bylaws of the Company (or any agreement between the Company and such Investor Director), without regard to any rights such Investor Director may have against the Investor Indemnitors, and, (c) that it irrevocably waives, relinquishes and releases the Investor Indemnitors from any and all claims against the Investor Indemnitors for contribution, subrogation or any other recovery of any kind in respect thereof. The Company further agrees that no advancement or payment by the Investor Indemnitors on behalf of any such Investor Director with respect to any claim for which such Investor Director has sought indemnification from the Company shall affect the foregoing and the Investor Indemnitors shall have a right of contribution and/or be subrogated to the extent of such advancement or payment to all of the rights of recovery of such Investor Director against the Company. The Investor Directors and the Investor Indemnitors are intended third-party beneficiaries of this Section 5.4 and shall have the right, power and authority to enforce the provisions of this Section 5.4 as though they were a party to this Agreement.

5.5 Successor Indemnification. If the Company or any of its successors or assignees consolidates with or merges into any other Person and is not the continuing or surviving corporation or entity of such consolidation or merger, then to the extent necessary, proper provision shall be made so that the successors and assignees of the Company assume the obligations of the Company with respect to indemnification of members of the Board of Directors as in effect immediately before such transaction, whether such obligations are contained in the Company’s Bylaws, its Certificate of Incorporation, or elsewhere, as the case may be.

19

5.6 Prevention of Corruption. The Company shall use commercially reasonable efforts to (i) ensure that the Company and any of its affiliates operate to the same standards of conduct set forth in “Prevention of Corruption – Third Party Guidelines” of GlaxoSmithKline plc (“GSK”) found at: ▇▇▇▇▇://▇▇▇.▇▇▇.▇▇▇/▇▇▇▇▇/▇▇▇▇/▇▇▇▇-▇▇▇▇▇-▇▇▇▇▇-▇▇▇▇▇▇▇▇▇▇.▇▇▇ and (ii) notify the Preferred Investors if it becomes aware of any activities or proposed activities to be conducted by itself or any of its Affiliates that may be contrary to GSK’s publicly announced ethical standards or the principles set forth in the “Prevention of Corruption – Third Party Guidelines” of which the Company is aware or has been notified.

5.7 Publicity. The Company shall not use the name of Samsara, LSP, SR One, Novo, NEA, GSK, Deerfield, RA Capital, or Amgen Ventures LLC in any trade publication, marketing materials or otherwise to the general public, in each case without the prior written consent of such Investor, which consent may be withheld in its sole discretion; provided that (i) the parties anticipate that there will be a mutually-agreed press release announcing the closing of the transactions contemplated in the Purchase Agreement; (ii) following the public announcement contemplated in clause (i), the Company may confirm that Samsara, LSP, SR One, Novo, NEA, GSK, Deerfield, RA Capital, and Amgen Ventures LLC are investors in the Company (but not the amount or terms thereof) in a form of disclosure that has been previously approved by such Investors; and (iii) the Company may list or disclose Samsara’s, LSP’s, SR One’s, Novo’s, NEA’s, GSK’s, Deerfield’s, RA Capital’s and Amgen Ventures LLC’s names when identifying such Investor on the Company’s website or in Company presentations.

5.8 Employee Agreements. The Company will cause each person now or hereafter employed by it or by any subsidiary (or engaged by the Company or any subsidiary as a consultant/independent contractor) with access to confidential information and/or trade secrets to enter into a nondisclosure and proprietary rights assignment agreement in substantially the form provided or made available to Investors and/or their counsel on or before the date hereof. In addition, the Company shall not amend, modify, terminate, waive, or otherwise alter, in whole or in part, any of the above-referenced agreements or any restricted stock agreement between the Company and any employee, without the consent of the Board of Directors, including a majority of the then-serving Preferred Directors.

5.9 Employee Stock. Unless otherwise approved by the Board of Directors, all future employees and consultants of the Company who purchase, receive options to purchase, or receive awards of shares of the Company’s capital stock after the date hereof shall be required to execute restricted stock or option agreements, as applicable, providing for (i) vesting of shares over a four (4) year period, with the first twenty-five percent (25%) of such shares vesting following twelve (12) months of continued employment or service, and the remaining shares vesting in equal monthly installments over the following thirty-six (36) months, and (ii) a market stand-off provision substantially similar to that in Section 2.11. In addition, unless otherwise approved by the Board of Directors, including a majority of the then-serving Preferred Directors, the Company shall retain a “right of first refusal” on transfers of Common Stock held by current or former service providers to the Company until the Company’s IPO, no restricted stock agreements or stock option agreements shall contain any provisions providing for acceleration of vesting, and the Company shall have the right to repurchase unvested shares at cost upon termination of employment of a holder of restricted stock.

5.10 Qualified Small Business Stock. The Company shall use commercially reasonable efforts to cause the shares of Series B Preferred Stock issued pursuant to the Purchase Agreement, as well as any shares into which such shares are converted, within the meaning of Section 1202(f) of the Internal Revenue Code (the “Code”), to constitute “qualified small business stock” as defined in Section 1202(c)

20

of the Code; provided, however, that such requirement shall not be applicable if the Board of Directors of the Company, including a majority of the then-serving Preferred Directors, determines, in its good-faith business judgment, that such qualification is inconsistent with the best interests of the Company. The Company shall submit to its stockholders (including the Investors) and to the Internal Revenue Service any reports that may be required under Section 1202(d)(1)(C) of the Code and the regulations promulgated thereunder. In addition, within twenty (20) business days after any Investor’s written request therefor, the Company shall, at its option, either (i) deliver to such Investor a written statement indicating whether (and what portion of) such Investor’s interest in the Company constitutes “qualified small business stock” as defined in Section 1202(c) of the Code or (ii) deliver to such Investor such factual information in the Company’s possession as is reasonably necessary to enable such Investor to determine whether (and what portion of) such Investor’s interest in the Company constitutes “qualified small business stock” as defined in Section 1202(c) of the Code.

5.11 FCPA. The Company represents that it shall not (and shall not permit any of its subsidiaries or affiliates or any of its or their respective directors, officers, managers, employees, independent contractors, representatives or agents to) directly or indirectly, offer, promise, authorize or make any payment to, or otherwise contribute any item of value to, any third party, including any “foreign official” (as such term is defined in the U.S. Foreign Corrupt Practices Act of 1977, as amended (the “FCPA”)), foreign political party or official thereof or candidate for foreign political office, in each case, in violation of the FCPA, the U.K. Bribery Act, or any other applicable anti-bribery or anti-corruption law. The Company further represents that it shall (and shall cause each of its subsidiaries and affiliates to) cease all of its or their respective activities, as well as remediate any actions taken by the Company, its subsidiaries or affiliates, or any of their respective directors, officers, managers, employees, independent contractors, representatives or agents in violation of the FCPA, the U.K. Bribery Act, or any other applicable anti-bribery or anti-corruption law. The Company further represents that it shall (and shall cause each of its subsidiaries and affiliates to) maintain systems of internal controls (including, but not limited to, accounting systems, purchasing systems and billing systems) and written policies to ensure compliance with the FCPA, the U.K. Bribery Act, or any other applicable anti-bribery or anti-corruption law and to ensure that all books and records of the Company and its subsidiaries accurately and fairly reflect, in reasonable detail, all transactions and dispositions of funds and assets. Upon request, the Company agrees to provide responsive information and/or certifications concerning its compliance with applicable anti-bribery and anti-corruption laws. The Company shall promptly notify each Investor if the Company becomes aware of any Enforcement Action (as defined in the Purchase Agreement). The Company shall, and shall cause any direct or indirect subsidiary or entity controlled by it, whether now in existence or formed in the future, to comply with the FCPA. The Company shall use its best efforts to cause any direct or indirect subsidiary, whether now in existence or formed in the future, to comply in all material respects with all applicable laws.

5.12 Right to Conduct Activities. The Company hereby agrees and acknowledges that certain Investors are professional investment funds or organizations, and as such review the business plans and related proprietary information of many enterprises and invest in numerous portfolio companies, some of which may be deemed competitive with the Company’s business (as currently conducted or as currently proposed to be conducted), and that certain Investors each have affiliated entities that may be deemed competitive with the Company’s business (as currently conducted or as currently proposed to be conducted). The Company hereby agrees that, to the extent permitted under applicable law, such Investors or their respective Affiliates shall not be liable to the Company for any claim arising out of, or based upon, (i) the investment by such Investors or their respective Affiliates in any entity competitive with the Company, or (ii) actions taken by any partner, officer, employee or other representative of such Investors or their respective Affiliates to assist any such competitive company, whether or not such action was taken as a member of the board of directors of such competitive company or otherwise, and whether or not such action has a detrimental effect on the Company; provided, however, that the foregoing shall not relieve (x) any of the Investors from liability associated with the unauthorized disclosure of the Company’s confidential information obtained pursuant to this Agreement, or (y) any director or officer of the Company from any liability associated with his or her fiduciary duties to the Company.

21

5.13 Harassment Policy. The Company shall, within one hundred twenty (120) days following the date of this Agreement, adopt and thereafter maintain in effect (i) a Code of Conduct governing appropriate workplace behavior and (ii) an Anti-Harassment and Discrimination Policy prohibiting discrimination and harassment at the Company. Such policy shall be reviewed and approved by the Board of Directors.

5.14 Expenses of Counsel. In the event of a transaction which is a Sale of the Company (as defined in the Voting Agreement), the reasonable fees and disbursements, not to exceed $100,000 in the aggregate, of one counsel for the Major Investors (the “Investor Counsel”) in their capacities as stockholders, shall be borne and paid by the Company. In connection with the negotiation of a transaction which, if consummated would constitute a Sale of the Company (the “Prospective Sale”), the Company shall obtain the ability to share with the Investor Counsel (and such counsel’s clients, subject to appropriate exceptions for direct conflicts of interest) and shall share certain confidential information (including initial and all subsequent drafts of the letter of intent and other transaction documents and related noncompete, employment, consulting and other compensation agreements and plans) pertaining to and memorializing the Prospective Sale. Such confidential information shall be shared with Investor Counsel promptly as available and in no case fewer than fifteen (15) days prior to the solicitation of consent by the Company’s stockholders to approve the Prospective Sale. In the event that Investor Counsel deems it appropriate, in its reasonable discretion, to enter into a joint defense agreement or other arrangement to enhance the ability of the parties to protect their communications and other reviewed materials under the attorney client privilege, the Company shall, and shall direct its counsel to, execute and deliver to Investor Counsel and its clients such an agreement in form and substance reasonably acceptable to Investor Counsel. In the event that one or more of the other party or parties to such transactions require the clients of Investor Counsel to enter into a confidentiality agreement and/or joint defense agreement in order to receive such information, then the Company shall share whatever information can be shared without entry into such agreement and shall, at the same time, in good faith work expeditiously to enable Investor Counsel and its clients to negotiate and enter into the appropriate agreement(s) without undue burden to the clients of Investor Counsel.

5.15 Critical Technology Matters.

(a) To the extent that, to the knowledge of the Company after due and reasonable inquiry: (a) any pre-existing products or services provided by the Company are re-categorized by the U.S. government as “critical technologies” within the meaning of Section 721 of the Defense Production Act of 1950, as amended, including all implementing regulations thereof (the “DPA”), or would reasonably be considered to constitute the design, fabrication, development, testing, production or manufacture of critical technologies after a re-categorization of selected technologies by the U.S. government, or (b) after execution of the Purchase Agreement, the Company engages in any activity that could reasonably be considered to constitute the design, fabrication, development, testing, production or manufacture of a critical technology within the meaning of the DPA, the Company shall promptly notify the Investors of such change in the categorization of its products or services and shall provide the Investors notice of such change as soon as reasonably practicable in advance of the Milestone Closing and/or any other financing or investment of a type contemplated by the DPA in the Company by the Investors or any other party

(b) If and only if (i) the Committee on Foreign Investment in the United States or any member agency thereof acting in such capacity (“CFIUS”) requests or requires that any Investor or the Company file a notice or declaration with CFIUS pursuant to the DPA with respect to such Investor’s

22

investment in the Company (the “Covered Transactions”) or (ii) such Investor or the Company reasonably and on the advice of legal counsel determines that a filing with CFIUS with respect to the Covered Transactions is required by or advisable to comply with applicable law, then in either case, (i) or (ii), (x) the Company and the applicable Investor(s) shall, and shall cause their respective affiliates to, cooperate with the other parties hereto and use reasonable best efforts to promptly file a CFIUS filing in the requested, required or advisable form in accordance with the DPA and promptly respond to any CFIUS request for information and/or documents with respect to such filing and/or the Covered Transactions; and (y) the Company and the applicable Investor(s) shall, and shall cause their respective affiliates to, use reasonable best efforts to obtain, as applicable, the CFIUS Satisfied Condition (as defined in the Purchase Agreement). In the event of a CFIUS Filing Event neither (A) the “Special Mandatory Conversion” provisions of the Restated Certificate nor (B) any future provisions of the Restated Certificate serving a similar purpose with respect to a future acquisition of shares by the Investors shall apply to any Investors making filings pursuant to the DPA under this Section 5.15(b)unless and until the CFIUS Satisfied Condition is achieved. For the avoidance of doubt, each such Investor shall have no obligation to accept or take any action, condition or restriction with respect to the Covered Transactions in order to achieve the CFIUS Satisfied Condition.

(c) If, in connection with a CFIUS review pursuant to the DPA, any Non-U.S. Investor is requested or required by CFIUS to sell, divest, or dispose of any of the shares of the Company it then holds (the “Investor Shares”) or otherwise reduce its holdings in the Company (such CFIUS request or requirement a “Divestiture Order” and such Non-U.S. Investor a “Divesting Non-U.S. Investor”) then (i) the Divesting Non-U.S. Investor shall comply with the Divestiture Order in full and, to the extent reasonably practicable, consult with the Company regarding the Divestiture Order, (ii) the Company shall, to the extent reasonably practicable, assist the Divesting Non-U.S. Investor in connection with such Divesting Non-U.S. Investor’s compliance with the Divestiture Order, and (iii) only after the Divesting Non-U.S. Investor has determined the proposed purchaser(s) or transferee(s) (each a “Proposed Transferee”) of the Investor Shares, the Divesting Non-U.S. Investor shall deliver to the Company a written notice (the “Notice of Proposed CFIUS Transfer”) stating the aggregate number of Investor Shares proposed to be transferred to each Proposed Transferee. So long as such proposed transfer is in compliance with the Divestiture Order and all applicable securities laws, the Company agrees not to withhold any required consent and to cooperate in facilitating such transfer. Further, notwithstanding any other provision in this Agreement or any other Ancillary Agreement among the Parties, the Company agrees that all rights of the Divesting Non-U.S. Investor associated with the Investor Shares being transferred, including without limitation, registration rights, rights of first refusal and co-sale, rights to designate a director (subject to any applicable share holdings threshold in existence at the time of transfer), shall be transferable to the Proposed Transferee.

(d) For the avoidance of doubt, none of the Company nor its respective affiliates and directors, officers, agents, stockholders and advisers shall be liable with respect to claims and damages that may result, directly or indirectly, after the date hereof, arising out of losses a party (other than the Company) may suffer relating to the required divestiture of that party’s Company capital stock, resulting from such party’s decision not to make a voluntary filing pursuant to the DPA in connection with the transactions contemplated by the Purchase Agreement.

5.16 Voting Thresholds. In the event one or more Investors becomes a Defaulting Purchaser (as defined in the Purchase Agreement) and as a result of which Investors holding shares of Series A Preferred Stock constitute the Required Holders, then the Company and each Investor hereby agree to, and shall, take all actions necessary to revise the definition of “Required Holders” in each of the Transaction Documents and the Company’s certificate of incorporation such that the voting threshold set forth in such definition requires the greater of (a) at least 66 2/3% and (b) at least that the minimum percentage of Preferred Stock then collectively held, on an as-converted basis, by NEA, Novo, SR One and at least one Major Investor that (i) holds Series B Preferred Stock and (ii) does not hold (and is not an Affiliate of a holder of) Series A Preferred Stock.

23

5.17 Termination of Covenants. The covenants set forth in this Section 5, except for Sections 5.4, 5.5 and 5.12 which shall terminate on the fifth anniversary of the IPO, shall terminate and be of no further force or effect (i) immediately before the consummation of the IPO, (ii) when the Company first becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon the consummation of a Deemed Liquidation Event, as such term is defined in the Restated Certificate, whichever event occurs first.

6. Miscellaneous.

6.1 Successors and Assigns. The rights under this Agreement may be assigned (but only with all related obligations) by a Holder to a transferee of Registrable Securities that (i) is an Affiliate, partner or stockholder of a Holder; (ii) is a Holder’s Immediate Family Member or trust for the benefit of an individual Holder or one or more of such Holder’s Immediate Family Members; or (iii) after such transfer, holds at least 250,000 shares of Registrable Securities (subject to appropriate adjustment for any stock split, stock dividend, combinations, recapitalizations, reclassifications and the like); provided, however, that (x) the Company is, within a reasonable time after such transfer, furnished with written notice of the name and address of such transferee and the Registrable Securities with respect to which such rights are being transferred; and (y) such transferee agrees in a written instrument delivered to the Company to be bound by and subject to the terms and conditions of this Agreement, including the provisions of Section 2.11. For the purposes of determining the number of shares of Registrable Securities held by a transferee, the holdings of a transferee (1) that is an Affiliate, partner or stockholder of a Holder; (2) who is a Holder’s Immediate Family Member; or (3) that is a trust for the benefit of an individual Holder or such Holder’s Immediate Family Member shall be aggregated together and with those of the transferring Holder; provided further that all transferees who would not qualify individually for assignment of rights shall, as a condition to the applicable transfer, have a single attorney-in-fact for the purpose of exercising any rights, receiving notices, or taking any action under this Agreement. The terms and conditions of this Agreement inure to the benefit of and are binding upon the respective successors and permitted assignees of the parties. Nothing in this Agreement, express or implied, is intended to confer upon any party other than the parties hereto or their respective successors and permitted assignees any rights, remedies, obligations or liabilities under or by reason of this Agreement, except as expressly provided herein.

6.2 Governing Law. This Agreement shall be governed by the internal law of the State of Delaware, without regard to any conflict of laws rules that would require the application of the laws of any other jurisdiction.

6.3 Counterparts. This Agreement may be executed in two (2) or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Counterparts may be delivered via electronic mail (including pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g., ▇▇▇.▇▇▇▇▇▇▇▇.▇▇▇) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes.

6.4 Titles and Subtitles. The titles and subtitles used in this Agreement are for convenience only and are not to be considered in construing or interpreting this Agreement.

24

6.5 Notices. All notices and other communications given or made pursuant to this Agreement shall be in writing and shall be deemed effectively given upon the earlier of actual receipt or (i) personal delivery to the party to be notified; (ii) when sent, if sent by electronic mail during the recipient’s normal business hours, and if not sent during normal business hours, then on the recipient’s next business day; (iii) five (5) days after having been sent by registered or certified mail, return receipt requested, postage prepaid; or (iv) one (1) business day after the business day of deposit with a nationally recognized overnight courier, freight prepaid, specifying next-day delivery, with written verification of receipt. All communications shall be sent to the respective parties at their addresses as set forth on Schedule A hereto, or to the principal office of the Company and to the attention of the Chief Executive Officer, in the case of the Company, or to such email address or address as subsequently modified by written notice given in accordance with this Section 6.5. If notice is given to the Company, a copy shall also be sent to (which copy shall not constitute notice): ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇, P.C., ▇▇▇▇▇ ▇▇ ▇▇▇▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, Attn: ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇, email: ▇▇▇▇▇▇▇▇@▇▇▇▇.▇▇▇, and if notice is given to the Investors, a copy shall also be sent to (which copy shall not constitute notice): ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇ and ▇▇▇▇ LLP, ▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, Attn: ▇▇▇▇▇ ▇. ▇▇▇▇▇, email: ▇▇▇▇▇.▇▇▇▇▇@▇▇▇▇▇▇▇▇▇▇.▇▇▇.

Subject to the limitations set forth in Delaware General Corporation Law §232(e), each Investor consents to the delivery of any notice to stockholders given by the Company under the Delaware General Corporation Law or the Company’s certificate of incorporation or bylaws by electronic mail to the electronic mail address set forth on Schedule A (or to any other electronic mail address for the Investor in the Company’s records), in each case with confirmation of receipt. This consent may be revoked by an Investor by written notice to the Company and may be deemed revoked in the circumstances specified in Delaware General Corporation Law §232.

6.6 Amendments and Waivers. Any term of this Agreement may be amended and the observance of any term of this Agreement may be waived (either generally or in a particular instance, and either retroactively or prospectively) only with the written consent of the Company and the holders of at least two-thirds of the Registrable Securities then outstanding; provided that the Company may in its sole discretion waive compliance with Section 2.12(c) (and the Company’s failure to object promptly in writing after notification of a proposed assignment allegedly in violation of Section 2.12(c) shall be deemed to be a waiver); provided further that any provision hereof may be waived by any waiving party on such party’s own behalf, without the consent of any other party; provided further that any amendment, termination or waiver of the definition of “Major Investor,” Section 2.8(b), 2.8(d), 2.11, 5.6, 5.7, 5.12, or 6.14 or this clause of Section 6.6 shall require the written consent of each of Samsara, LSP, NEA, Novo, SR One, RA Capital and Deerfield; provided further that any amendment, termination or waiver of Section 5.15 or this clause of Section 6.6 shall require the written consent of each of LSP and Novo; provided further that any amendment, termination or waiver of Section 5.16 or this clause of Section 6.6 shall require the written consent of each of Samsara and LSP; and provided further that any amendment, termination or waiver of Section 3.4 or this clause of Section 6.6 shall require the written consent of each of Deerfield and RA Capital. Notwithstanding the foregoing, (a) this Agreement may not be amended or terminated and the observance of any term hereof may not be waived with respect to any Investor without the written consent of such Investor, unless such amendment, termination, or waiver applies to all Investors in the same fashion and (b) Sections 3.1 and 3.2, Section 4 and any other section of this Agreement applicable to the Major Investors (including this clause (b) of this Section 6.6) may not be amended, terminated or waived without the written consent of the holders of at least two-thirds of the Registrable Securities then outstanding and held by the Major Investors. In the event of any waiver of Section 4.1 with respect to an issuance of New Securities and the subsequent purchase by any Major Investor (a “Participating Major Investor”) of any portion of such New Securities, then all other Major Investors shall have the right to purchase a portion of the New Securities equal to the product obtained by (A) such Major Investor’s pro rata share calculated in accordance with Section 4.1 by (B) the quotient obtained by (x) the number of shares purchased by the Participating Major Investor divided by (y) the maximum number of shares that could have been purchased by such Participating Major Investor pursuant to its pro rata share calculated in

25

accordance with Section 4.1; provided, for clarity, that if there is more than one Participating Major Investor, then the larger fraction obtained pursuant to (B) above shall apply. Notwithstanding the foregoing, Schedule A hereto may be amended by the Company from time to time to add transferees of any Registrable Securities in compliance with the terms of this Agreement without the consent of the other parties; and Schedule A hereto may also be amended by the Company after the date of this Agreement without the consent of the other parties to add information regarding any additional Investor who becomes a party to this Agreement in accordance with Section 6.9. The Company shall give prompt notice of any amendment or termination hereof or waiver hereunder to any party hereto that did not consent in writing to such amendment, termination, or waiver. Any amendment, termination, or waiver effected in accordance with this Section 6.6 shall be binding on all parties hereto, regardless of whether any such party has consented thereto. No waivers of or exceptions to any term, condition, or provision of this Agreement, in any one or more instances, shall be deemed to be or construed as a further or continuing waiver of any such term, condition, or provision.

6.7 Severability. In case any one or more of the provisions contained in this Agreement is for any reason held to be invalid, illegal or unenforceable in any respect, such invalidity, illegality, or unenforceability shall not affect any other provision of this Agreement, and such invalid, illegal, or unenforceable provision shall be reformed and construed so that it will be valid, legal, and enforceable to the maximum extent permitted by law.

6.8 Aggregation of Stock. All shares of Registrable Securities held or acquired by Affiliates shall be aggregated together for the purpose of determining the availability of any rights under this Agreement and such Affiliated persons may apportion such rights as among themselves in any manner they deem appropriate.

6.9 Additional Investors. Notwithstanding anything to the contrary contained herein, if the Company issues additional shares of the Company’s Series B Preferred Stock after the date hereof, whether pursuant to the Purchase Agreement or otherwise, any purchaser of such shares of Series B Preferred Stock may become a party to this Agreement by executing and delivering an additional counterpart signature page to this Agreement, and thereafter shall be deemed an “Investor” for all purposes hereunder. No action or consent by the Investors shall be required for such joinder to this Agreement by such additional Investor, so long as such additional Investor has agreed in writing to be bound by all of the obligations as an “Investor” hereunder.

6.10 Entire Agreement. This Agreement (including any Schedules and Exhibits hereto) constitutes the full and entire understanding and agreement among the parties with respect to the subject matter hereof, and any other written or oral agreement relating to the subject matter hereof existing between the parties is expressly canceled. Upon the effectiveness of this Agreement, the Prior Agreement shall be deemed amended and restated and superseded and replaced in its entirety by this Agreement, and shall be of no further force or effect.

6.11 Dispute Resolution. The parties (a) hereby irrevocably and unconditionally submit to the jurisdiction of the state courts of Delaware and to the jurisdiction of the United States District Court for the District of Delaware for the purpose of any suit, action or other proceeding arising out of or based upon this Agreement, (b) agree not to commence any suit, action or other proceeding arising out of or based upon this Agreement except in the state courts of Delaware or the United States District Court for the District of Delaware, and (c) hereby waive, and agree not to assert, by way of motion, as a defense, or otherwise, in any such suit, action or proceeding, any claim that it is not subject personally to the jurisdiction of the above-named courts, that its property is exempt or immune from attachment or execution, that the suit, action or proceeding is brought in an inconvenient forum, that the venue of the suit, action or proceeding is improper or that this Agreement or the subject matter hereof may not be enforced in or by such court.

26

WAIVER OF JURY TRIAL: EACH PARTY HEREBY WAIVES ITS RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS AGREEMENT, THE OTHER TRANSACTION DOCUMENTS, THE SECURITIES OR THE SUBJECT MATTER HEREOF OR THEREOF. THE SCOPE OF THIS WAIVER IS INTENDED TO BE ALL-ENCOMPASSING OF ANY AND ALL DISPUTES THAT MAY BE FILED IN ANY COURT AND THAT RELATE TO THE SUBJECT MATTER OF THIS TRANSACTION, INCLUDING, WITHOUT LIMITATION, CONTRACT CLAIMS, TORT CLAIMS (INCLUDING NEGLIGENCE), BREACH OF DUTY CLAIMS, AND ALL OTHER COMMON LAW AND STATUTORY CLAIMS. THIS SECTION HAS BEEN FULLY DISCUSSED BY EACH OF THE PARTIES HERETO AND THESE PROVISIONS WILL NOT BE SUBJECT TO ANY EXCEPTIONS. EACH PARTY HERETO HEREBY FURTHER WARRANTS AND REPRESENTS THAT SUCH PARTY HAS REVIEWED THIS WAIVER WITH ITS LEGAL COUNSEL, AND THAT SUCH PARTY KNOWINGLY AND VOLUNTARILY WAIVES ITS JURY TRIAL RIGHTS FOLLOWING CONSULTATION WITH LEGAL COUNSEL.

The prevailing party shall be entitled to reasonable attorney’s fees, costs, and necessary disbursements in addition to any other relief to which such party may be entitled. Each of the parties to this Agreement consents to personal jurisdiction for any equitable action sought in the U.S. District Court for the District of Delaware or any court of the State of Delaware having subject matter jurisdiction.

6.12 Delays or Omissions. No delay or omission to exercise any right, power, or remedy accruing to any party under this Agreement, upon any breach or default of any other party under this Agreement, shall impair any such right, power, or remedy of such nonbreaching or nondefaulting party, nor shall it be construed to be a waiver of or acquiescence to any such breach or default, or to any similar breach or default thereafter occurring, nor shall any waiver of any single breach or default be deemed a waiver of any other breach or default theretofore or thereafter occurring. All remedies, whether under this Agreement or by law or otherwise afforded to any party, shall be cumulative and not alternative.

6.13 Acknowledgment. The Company acknowledges that certain of the Investors and their respective Affiliates are in the business of venture capital investing and therefore review the business plans and related proprietary information of many enterprises, including enterprises which may have products or services which compete directly or indirectly with those of the Company. Nothing in this Agreement shall preclude or in any way restrict the Investors and their respective Affiliates from investing or participating in any particular enterprise whether or not such enterprise has products or services which compete with those of the Company.

6.14 Limitation of Liability; Freedom to Operate Affiliates. The total liability, in the aggregate, of each of the Investors, and its respective Affiliates, officers, directors, employees and agents, for any and all claims, losses, costs or damages, including attorneys’ and accountants’ fees and expenses and costs of any nature whatsoever or claims or expenses resulting from or in any way related to this Agreement from any cause or causes shall be several and not joint with the other Investors and shall not exceed the total purchase price paid to the Company by the Investors, respectively, for the Shares (as defined in the Purchase Agreement) under the Purchase Agreement and the shares of Series A Preferred Stock held by such Purchaser. It is intended that this limitation apply to any and all liability or cause of action however alleged or arising, unless otherwise prohibited by law. Nothing in this Agreement or the Transaction Agreements shall restrict each Investor’s freedom to operate any of its affiliates (including any such affiliate that is a potential competitor of the Company).

27

[Remainder of Page Intentionally Left Blank]

28

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

		INVESTORS:
		AMGEN VENTURES LLC
		By:		/s/ ▇▇▇▇▇ ▇. ▇▇▇▇▇▇
		Name: ▇▇▇▇▇ ▇. ▇▇▇▇▇▇
		Title: EVP & Chief Financial Officer
		Address:
		Amgen Ventures LLC [***]
		Copy to:
		Amgen Inc. [***]

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA, INC.

IN WITNESS WHEREOF, the parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above.

SIGNATURE PAGE TO

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT OF

NKARTA,INC.

Schedule A

INVESTORS

[***]