Document:

AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT

 Exhibit 10.54 
 AMENDED AND RESTATED 
 INVESTOR RIGHTS AGREEMENT 

This AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT (“Agreement”) is made as of the 22nd day of October, 2007, by and
among Allozyne, Inc., a Delaware corporation (the “Company”), and each of the investors listed on Schedule A hereto, each of which is referred to in this Agreement as an “Investor” and collectively referred
to as the “Investors” and each of the stockholders listed on Schedule B hereto, each of whom is referred to herein as a “Key Holder” and collectively referred to as the “Key Holders.”

 RECITAL 
 WHEREAS, certain of the Investors (the “Existing Investors”) hold shares of the Company’s Series A Preferred Stock and/or shares of Common Stock issued upon conversion thereof
and possess registration rights, information rights, rights of first offer, and other rights pursuant to an Investor Rights Agreement dated as of October 19, 2005 among the Company and the Existing Investors (the “Prior
Agreement”); 
 WHEREAS, the Existing Investors are holders of a majority of the Registrable Securities (as
defined in the Prior Agreement) held by all Existing Investors, and 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, certain of the Investors are parties to that certain Series B Preferred Stock Purchase
Agreement of even date herewith between the Company and such Investors (the “Purchase Agreement”), under which certain of the Company’s and such Investors’ obligations are conditioned upon the execution and delivery of
this Agreement by such Investors, Existing Investors holding at least a majority of the Registrable Securities then held by the Existing Investors, and the Company. 
 NOW, THEREFORE, the parties hereto hereby agree that the Prior Agreement shall be amended and restated to read as follows: 
 1. Definitions. For purposes of this Agreement: 
 1.1.
“Affiliate” means, with respect to any specified Person, any other Person who or which, directly or indirectly, controls, is controlled by, or is under common control with such specified Person, including without limitation any
general partner, officer, director, or manager of such Person and any venture capital fund now or hereafter existing that is controlled by or under common control with one or more general partners or managing members of, or shares the same
management company with, such Person. 
 1.2. “Common Stock” means shares of the Company’s
common stock, par value $0.001 per share. 
 1.3. “Damages” means any loss, damage, 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, 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 

  
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any registration statement of the Company, including any Prospectus; (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. 
 1.4. “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. 

1.5. “Exchange Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations
promulgated thereunder. 
 1.6. “Excluded Registration” means (i) a registration relating
to the sale of securities to employees of the Company or a Subsidiary pursuant to a stock option, stock purchase, or similar plan; (ii) a registration relating to an SEC Rule 145 transaction; and (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. 
 1.7. “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
incorporation of substantial information by reference to other documents filed by the Company with the SEC. 

1.8. “GAAP” means generally accepted accounting principles in the United States. 

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

1.10. “Immediate Family Member” means a child, stepchild, grandchild, parent, stepparent, grandparent,
spouse, 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. 

1.11. “Initiating Holders” means, collectively, Investors who properly initiate a registration request
under this Agreement. 
 1.12. “IPO” means the Company’s first underwritten public offering
of its Common Stock under the Securities Act. 
 1.13. “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). 
 1.14. “Key Holder Registrable Securities” means the shares of Common Stock held
by the Key Holders from time to time. 
 1.15. “Major Investor” means any Investor that,
individually or together with such Investor’s Affiliates, holds at least five percent (5%) of either the shares of Series A Preferred Stock or Series B Preferred Stock (as adjusted for any stock split, stock dividend, combination, or other
recapitalization or reclassification effected after the date hereof). 

  
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 1.16. “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. 
 1.17. “Person” means any individual, corporation, partnership,
trust, limited liability company, association or other entity. 
 1.18. “Preferred Director
Approval” means the affirmative vote or consent, as the case may be, of one (1) Series A Director and one (1) Series B Director. 
 1.19. “Preferred Stock” means, collectively, shares of Series A Preferred Stock and Series B Preferred Stock. 

1.20. “Prospectus” means (i) any prospectus contained in any registration statement filed under the
Securities Act, as amended or supplemented by any prospectus supplement, relating to all or any portion of the Registrable Securities held by any Investor and/or such Investor’s permitted assigns, and all other amendments and supplements to
such prospectus, including all post-effective amendments and all material incorporated by reference in such prospectus; and (ii) any “free writing prospectus” (as defined under Rule 163 under the Securities Act) used in connection
therewith. 
 1.21. “Register,” “registered,” and
“registration” refer to a registration effected by preparing and filing a registration statement or similar document in compliance with the Securities Act, and the declaration or ordering of effectiveness of such registration
statement or document. 
 1.22. “Registrable Securities” means (i) the Common Stock
issuable or issued upon conversion of the Preferred Stock; (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
and the Key Holders 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. 

1.23. “Registrable Securities then outstanding” means the number of shares at a point in time determined
by adding the number of shares of outstanding Common Stock that are Registrable Securities at such time and the number of shares of Common Stock issuable (directly or indirectly) at such time pursuant to then exercisable and/or convertible
securities that are Registrable Securities. 
 1.24. “Restricted Securities” means the
securities of the Company required to bear the legend set forth in Section 2.12(b) hereof. 
 1.25.
“SEC” means the Securities and Exchange Commission. 
 1.26. “SEC Rule 144”
means Rule 144 promulgated by the SEC under the Securities Act, or any successor provisions. 

  
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 1.27. “SEC Rule 144(k)” means Rule 144(k) promulgated by
the SEC under the Securities Act, or any successor provisions. 
 1.28. “SEC Rule 145” means
Rule 145 promulgated by the SEC under the Securities Act, or any successor provisions. 
 1.29. “SEC Rule
172” means Rule 172 promulgated by the SEC under the Securities Act. 
 1.30. “Securities
Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder. 
 1.31. “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 as otherwise provided in Section 2.7. 
 1.32. “Series A
Director” means any director of the Company that has been solely designated by the holders of record of the Series A Preferred Stock pursuant to the Company’s certificate of incorporation, the Stockholders Agreement or otherwise.

 1.33. “Series B Director” means any director of the Company that has been solely designated
by the holders of record of the Series B Preferred Stock pursuant to the Company’s certificate of incorporation, the Stockholders Agreement or otherwise. 
 1.34. “Series A Preferred Stock” means shares of the Company’s Series A Convertible Preferred Stock, par value $0.001 per share. 

1.35. “Series B Preferred Stock” means shares of the Company’s Series B-1 Convertible Preferred
Stock, par value $0.001 per share, and shares of the Company’s Series B-2 Convertible Preferred Stock, par value $0.001 per share. 
 1.36. “Stockholders Agreement” means the Amended and Restated Stockholders Agreement dated as of the date hereof by and among the Company, the Investors and the other parties thereto.

 1.37. “Subsidiary” means any Person of which securities or other ownership interests having
ordinary voting power to elect a majority of the board of directors or other persons performing similar functions are owned directly or indirectly by another Person. 
 2. Registration Rights. The Company covenants and agrees as follows: 
 2.1. Demand Registration. 
 Beginning upon the earlier of
(i) three (3) years after the date of this Agreement or (ii) 180 days after the effective date of the registration statement for the IPO, the Company receives a request from Investors holding at least 75% of the Registrable Securities
then held by all Investors that the Company effect a registration of at least 75% of the Registrable Securities then outstanding (or a lesser percent if the anticipated aggregate offering price, net of Selling Expenses, would exceed $3 million),
then the Company shall (i) within 20 days after the date such request is given, give notice thereof (the “Demand Notice”) to all Holders other than the Initiating Holders; and (ii) as soon as practicable, and in any event
within 60 days after the date such request is given by the Initiating Holders, file a Form S-1 registration 

  
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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 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.

 (a) If at any time when it is eligible to use a Form S-3 registration statement and the Company receives a
request from Investors of at least 30% of the Registrable Securities then outstanding and held by all Investors that the Company file a Form S-3 registration statement with respect to outstanding Registrable Securities of such Holders having an
anticipated aggregate offering price, net of Selling Expenses, of at least $1 million, then the Company shall (i) within 20 days after the date such request is given, give written notice of the proposed registration to all Holders other than
the Initiating Holders (the “S-3 Notice”); and (ii) as soon as practicable, and in any event within 30 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 10 days of the date the S-3 Notice is given, and in each
case, subject to the limitations of Sections 2.1(c) and 2.3. 
 (b) 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 Company’s
Board of Directors (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 180 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 12-month period. 
 (c) 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 60 days before the
Company’s good faith estimate of the date of filing of, and ending on a date that is 180 days after the effective date of, a Company-initiated registration, provided, that the Company is actively employing its good faith
commercially reasonable efforts to cause such registration statement to become effective; (ii) after the Company has effected two (2) 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) (x) during the period that is 30 days before the Company’s good faith estimate of the date of filing of, and ending on a date that is 90 days after the effective date of, a
Company-initiated registration relating to shares to be sold by the 

  
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Company, provided, that the Company is actively employing its good faith commercially reasonable efforts to cause such registration statement to become effective; or (y) if the
Company has effected two (2) 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 (other than as a result of a material
adverse change to the Company), elect not to pay the registration expenses therefor, and forfeit their right to one demand registration statement pursuant to Section 2.61 in which case such withdrawn registration statement shall 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 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 or the S-3 Notice, as the case may be. The underwriters 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 underwriters selected for such underwriting. Notwithstanding any other provision of this Section 2.3, if the managing underwriter advises the Initiating Holders in writing that
marketing factors require a limitation on the number of shares to be 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 

  
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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 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 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 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 25% 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 or (iii) notwithstanding clause (ii) above, any Registrable Securities which are not Key Holder Registrable Securities be excluded from such underwriting unless all Key Holder Registrable
Securities are first excluded from 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. 
 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

  
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period of up to 120 days or, if earlier, until the distribution contemplated in the registration statement has been completed; provided, however, that such 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; 

(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) comply with SEC Rule 172 and (1) advise the selling Holders promptly of any failure by the Company to satisfy the
conditions of SEC Rule 172 and (2) promptly furnish to the selling Holders such numbers of copies of the Prospectus relating to such sale 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) subject to the Company’s obligations under Regulation FD promulgated under the Securities Act, which shall be
reasonably determined by the Company in consultation with Company counsel, promptly make available for inspection by the selling Holders, any managing underwriter 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

  
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accuracy of the information in such registration statement and to conduct appropriate due diligence in connection therewith; 

(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. 

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 $20,000, of one (1) counsel for the selling Holders
(“Selling Holder Counsel”) selected by the Holders of a majority of the Registrable Securities, 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 Section 2.1(a) or Section 2.1(b), as the case may be. 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 

  
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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 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 any indemnity under this 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 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. 

  
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 (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 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(e), 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:

  
 11 

 (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 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). 
 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 Investors holding 75% of the
Registrable Securities then outstanding and held by all Investors, enter into any agreement with any holder or prospective holder of any securities of the Company that would allow such holder or prospective holder (i) to include such securities
in any registration unless, under the terms of such agreement, such holder or prospective holder may include such securities in any such registration only to the extent that the inclusion of such securities will not reduce the number of the
Registrable Securities of the Holders that are included or (ii) to demand registration of any securities held by such holder or prospective holder. 
 2.11. “Market Stand-off” Agreement. Each Holder hereby agrees that, if required by the managing underwriter(s), it will not, during the period commencing on the date of the final
prospectus relating to the IPO and ending on the date specified by the Company and the managing underwriter (such period not to exceed 180 days), (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 (whether such shares or any such securities are then owned by the Holder or are thereafter acquired); 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 clauses (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 apply only to the IPO, shall not apply to the sale of any shares to an underwriter pursuant to an underwriting agreement, and 

  
 12 

 
shall be applicable to the Holders only if all officers, directors, and stockholders individually owning more than 1% of the Company’s outstanding Common Stock (after giving effect to
conversion into Common Stock of all outstanding Preferred Stock are subject to the same restrictions). 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. Any discretionary waiver or termination of the restrictions of any or all of such agreements by the Company or the underwriters shall apply
pro rata to all Holders subject to such agreements, based on the number of shares subject to such agreements. The Company may impose stop-transfer provisions with respect to any shares of capital stock held by a Holder to enforce the
provisions of this Section 2.11. 
 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 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 or instrument 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, recapitalization, merger, consolidation, or similar event, shall (unless
otherwise permitted by the provisions of Section 2.12(c)) be stamped or otherwise imprinted 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. 

  
 13 

 (c) The holder of each certificate representing Restricted Securities, by
acceptance 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 or instrument evidencing the Restricted Securities transferred as above provided shall bear, 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 shall not bear 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. 
 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 closing of a Deemed Liquidation Event, as such term is defined in the Company’s certificate of
incorporation or the later to occur of: 
 (a) such time when all of such Holder’s Registrable Securities
could be sold without restriction under SEC Rule 144(k) within any 90 day period; or 
 (b)
the 10th anniversary of the date of this Agreement.

 3. Information and Observer 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 of the Company: 
 (a) as soon
as practicable, but in any event within 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 

  
 14 

 
public accountants of nationally recognized standing selected by the Company and approved by the Board of Directors; 

(b) as soon as practicable, but in any event within 90 days after the end of each quarter of each fiscal year, an
unaudited income statement and statement of cash flow for such quarter and an unaudited balance sheet and statement of stockholders equity as of the end of such quarter, all prepared in accordance with GAAP (except that such financial statement may
(i) be subject to normal year-end audit adjustments and (ii) not contain all of the notes thereto that may be required in accordance with GAAP); 
 (c) as soon as practicable, but in any event within 60 days after 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); 
 (d) as soon as practicable, but in any event 45 days before the
end of each fiscal year, a budget and business plan for the next fiscal year (collectively, the “Budget”), approved by the Board of Directors 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 Sections 3.1(a)-(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 Sections 3.1(b) and 3.1(c)) and fairly present the financial condition of the
Company and its results of operation for the periods specified therein; and 
 (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 form and substance
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 45 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 

  
 15 

 
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 of the Company), 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 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. The covenants set forth in Sections 3.1 and Section 3.2 shall terminate and be
of no further force or effect (i) immediately before but subject to the consummation of the IPO, or (ii) when the Company first becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act,
(iii) upon a Deemed Liquidation Event as such term is defined in the Company’s certificate of incorporation, or (iv) a transaction or a series of related transactions in which a Person, or a group of related Persons, acquires from
stockholders of the Company shares representing more than 50% of the outstanding voting power of the Company (a “Stock Sale”), whichever event occurs first. 

3.4. Confidentiality. Each Investor agrees 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 (including notice of the Company’s intention to file a
registration statement), unless such confidential information (i) 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), (ii) is or has been independently
developed or conceived by the Investor without use of the Company’s confidential information, or (iii) 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 (1) 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; (2) 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;
(3) to any Affiliate, partner, member, stockholder, or wholly-owned Subsidiary of such Investor in the ordinary course of business, provided that such Investor informs such Person that such information is confidential and directs
such Person to maintain the confidentiality of such information; or (4) as may otherwise be required by law, provided that the Investor promptly notifies the Company of such disclosure and takes reasonable steps to minimize the
extent of any such required disclosure. 
 4. Rights to Future Stock Issuances. 

  
 16 

 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 among itself and its Affiliates in such proportions as it deems appropriate. Notwithstanding the foregoing, if a Major Investor holding Series B-1 Preferred Stock fails to purchase such Major Investor’s
allocated portion of Series B-2 Preferred Stock at the Second Closing (as defined in the Purchase Agreement), if applicable, and is not a Major Investor by way of such Major Investor’s holdings of Series A Preferred Stock, then such Major
Investor shall no longer be entitled to the rights conferred by this Section 4. 
 (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 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 portion of such New Securities which equals the proportion that
the Common Stock issued and held, or 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 Company then outstanding (assuming full conversion and/or exercise, as applicable, of all Preferred Stock and other Derivative Securities). At the expiration of such 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 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 which is equal to the proportion that the Common Stock issued and held, or issuable upon conversion and/or exercise, as applicable, of Preferred Stock and any other Derivative
Securities then held, by such Fully Exercising Investor bears to the Common Stock issued and held, or issuable (directly or indirectly) upon conversion and/or exercise, as applicable, of the Preferred Stock and any other Derivative Securities then
held, by all Fully Exercising Investors who wish to purchase such unsubscribed shares. The closing of any sale pursuant to this Section 4.1(b) shall occur within 60 days of the date that the Offer Notice is given. 

(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 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 30 days of the execution thereof, the right provided hereunder shall be deemed to be revived and such New Securities 

  
 17 

 
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 Company’s certificate of incorporation); (ii) shares of Common Stock issued in the IPO; (iii) securities issued in connection with acquisitions made by the Company and (iv) the sale of the Series B-2 Convertible
Preferred Stock, par value $0.001 per share of the Company as contemplated by and pursuant to 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 but subject to 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, (iii) upon a Deemed Liquidation Event, as such term is defined in the Company’s certificate of
incorporation, or (iv) upon a Stock Sale, whichever event occurs first. 
 5. Additional Covenants. 

5.1. Insurance. The Company shall use its commercially reasonable efforts to obtain, within 90 days after the date
hereof, from financially sound and reputable insurers (i) Directors and Officers Errors and Omissions insurance and (ii) term “key-person” insurance on Meenu Chhabra and Ken Grabstein each in an amount approved by the Board of
Directors, and will use commercially reasonable efforts to cause such insurance policies to be maintained until such time as the Board of Directors determines that such insurance should be discontinued. The key-person policy shall name the Company
as loss payee, and neither policy shall be cancelable by the Company without prior approval of the Board of Directors. 
 5.2. Employee Agreements. The Company will cause (i) 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 and (ii) each Key Employee to enter into a one (1) year noncompetition and nonsolicitation
agreement, substantially in the form approved by the Board of Directors. 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 or approval of the Board of Directors. 

5.3. Employee Vesting. 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 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 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, the Company shall retain a “right of first
refusal” on employee transfers until the Company’s 

  
 18 

 
IPO and shall have the right to repurchase unvested shares at cost upon termination of employment of a holder of restricted stock. 

5.4. Matters Requiring Investor Director Approval. So long as the holders of Preferred Stock are entitled to elect
Directors pursuant to the Company’s certificate of incorporation, the Company hereby covenants and agrees with each of the Investors that it shall not, nor shall it permit any Subsidiary to, without approval of the Board of Directors (which
such approval must include the Preferred Director Approval): 
 (a) 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; 

(b) 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; 

(c) 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; 
 (d)
incur, or permit any Subsidiary to incur, any aggregate indebtedness in excess of $100,000 in the aggregate that is not already included in a budget approved by the Board of Directors, other than trade credit incurred in the ordinary course of
business; 
 (e) otherwise enter into or be a party to any transaction with any director, officer, or employee of
the Company or any Subsidiary thereof 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; 

(f) hire, terminate, or change the compensation of the executive officers of the Company or any Subsidiary thereof,
including approving any option grants or stock awards to any such executive officers; 
 (g) change the principal
business of the Company, enter new lines of business, or exit the current line of business; 
 (h) sell, assign,
license, pledge, or encumber material technology or intellectual property of the Company or any Subsidiary thereof, other than licenses granted in the ordinary course of business; 

(i) make any investment other than investments in prime commercial paper money market funds, certificates of deposit in
any United States bank having a net worth in excess of $100,000,000 or obligations issued or guaranteed by the United States of America, in each case having a maturity not in excess of two years; or 

  
 19 

 (j) amend the Company’s existing option plan to increase the number of
shares issuable thereunder to be greater than 7,237,292. 
 5.5. Meetings of the Board of Directors; Board
Committees. Unless otherwise determined by the vote of a majority of the directors then in office, the Board of Directors shall meet at least quarterly in accordance with an agreed-upon schedule. Each Committee of the Board of Directors shall
include one Series A Director and one Series B Director. 
 5.6. 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. 
 5.7. Board
Expenses. The Company shall reimburse the nonemployee directors for all reasonable out-of-pocket travel expenses incurred (consistent with the Company’s travel policy) in connection with attending meetings of the Board of Directors.

 5.8. Termination of Covenants. The covenants set forth in this Section 5, except for
Section 5.6, shall terminate and be of no further force or effect (i) immediately before but subject to the consummation of the IPO, or (ii) when the Company first becomes subject to the periodic reporting requirements of
Section 12(g) or 15(d) of the Exchange Act, (iii) upon a Deemed Liquidation Event, as such term is defined in the Company’s certificate of incorporation; or (iv) upon a Stock Sale, 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, member, limited partner, retired partner, retired member, 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 that number of shares of Registrable Securities (subject to appropriate adjustment for stock splits, stock dividends, combinations, and other recapitalizations) such that the
transferee would qualify to be a Major Investor hereunder; 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, limited partner, retired partner, member,
retired member, 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 

  
 20 

 
further that all transferees who would not qualify individually for assignment of rights shall 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. Any
transferee permitted by the foregoing may become a party to this Agreement by executing and delivering a joinder to this Agreement pursuant to which such transferee agrees in writing to be bound by all of the obligations as an “Investor”
hereunder, and thereafter shall be deemed an “Investor” for all purposes hereunder. No action or consent by the Investors shall be required for such joinder. 

6.2. Governing Law. This Agreement and any controversy arising out of or relating to this Agreement shall be
governed by and construed in accordance with the General Corporation Law of the State of Delaware as to matters within the scope thereof, and as to all other matters shall be governed by and construed in accordance with the internal laws of the
State of New York, without regard to conflict of law principles that would result in the application of any law other than the law of the State of New York. 
 6.3. Counterparts; Facsimile. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same
instrument. This Agreement may also be executed and delivered by facsimile signature and in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. 

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. 
 6.5. Notices. All notices, requests, and
other communications given or made pursuant to this Agreement shall be in writing and shall be deemed effectively given, delivered and received (i) upon personal delivery to the party to be notified; (ii) when sent by facsimile (with
written confirmation of transmission) if sent during normal business hours of the recipient, and if not so confirmed, then on the next business day; (iii) three (3) 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, 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 or Schedule B (as applicable) 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, facsimile number, 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 (which shall not constitute notice) shall
also be sent to James R. Kasinger, Esq., Goodwin Procter LLP, Exchange Place, Boston, Massachusetts 02109, (fax) 617-523-1231; email: jkasinger@goodwinprocter.com. 

6.6. Amendments and Waivers. Any term of this Agreement, including without limitation Section 4.1, may
be amended and the observance of any term of this 

  
 21 

 
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 Investors holding a majority
of the Registrable Securities then outstanding and held by all Investors; 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); and 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. Notwithstanding the foregoing, 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 (it being agreed that a waiver of the provisions of Section 4 with respect to a particular transaction shall be deemed to apply to all
Investors in the same fashion if such waiver does so by its terms, notwithstanding the fact that certain Investors may nonetheless, by agreement with the Company, purchase securities in such transaction). 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. In connection with entering into this Agreement, the undersigned, representing a majority of the outstanding shares of Series A Preferred Stock hereby waive
Section 2.12 (Third Party Registration Rights) of the Prior Agreement with respect to the Company’s issuance of a Warrant to Purchase Shares of Common Stock to Alexandria Equities, LLC on each of February 12, 2007 and
August 9, 2007. 
 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. 
 6.9. Entire Agreement. This Agreement (including any schedules 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. 

6.10. 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

  
 22 

 
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. 
 6.11. Effect on Prior Agreement. The undersigned hereby acknowledge and agree that (i) the Prior Agreement is hereby amended in its entirety and restated as provided herein; and (ii) all
provisions of, rights granted and covenants made in the Prior Agreement are hereby waived, released and superseded in their entirety and shall have no further force or effect. 
 [Remainder of Page Intentionally Left Blank] 

  
 23 

 SCHEDULE A 
 Investors 
  

			
	 Name and Address, Phone Number
 Fax and Email of Purchaser

	
	 ARCH Venture Fund V, L.P.
 8725 W. Higgins Road
 Suite 290
 Chicago, IL 60631

	Fax:	  	(773) 380-6606
	Attn:	  	Steve Gillis
	Email:	  	sgillis@archventure.com
	
	 ARCH V Entrepreneurs Fund, L.P.
 8725 W. Higgins Road
 Suite 290
 Chicago, IL 60631

	Fax:	  	(773) 380-6606
	Attn:	  	Steve Gillis
	Email:	  	sgillis@archventure.com
	
	 ARCH Venture Fund VI, L.P.
 8725 W. Higgins Road
 Suite 290
 Chicago, IL 60631

	Fax:	  	(773) 380-6606
	Attn:	  	Steve Gillis
	Email:	  	sgillis@archventure.com
	
	 Alexandria Equities, LLC
 385 East Colorado Boulevard
 Suite 299
 Pasadena, CA 91101

	Fax:	  	(626) 578-0770
	Attn:	  	Joel Marcus
	Email:	  	jmarcus@labspace.com

			
	 Name and Address, Phone Number
 Fax and Email of Purchaser
  

	 Alexandria Accelerator LLC
 385 East Colorado Boulevard
 Suite 299
 Pasadena, CA 91101

	Fax:	  	(626) 578-0770
	Attn:	  	Joel Marcus
	Email:	  	jmarcus@labspace.com

 Amgen Ventures LLC 
 4445 Eastgate Mall 
 Suite 230 
 San Diego, California 92121 

			
	Attention:	  	Joseph “Jay” Hagan
		  	Managing Director

 Email: jhagan@amgen.com 
 Facsimile: (858) 626-2709 
 MPM BioVentures III, L.P. 

The John Hancock Tower 
 200 Clarendon Street,
54th Floor 
 Boston, MA 02116 

			
	Fax:	  	(617) 425-9201
	Attn:	  	 Lauren Fiore
 Michael
Steinmetz

	Email:	  	 lfiore@mpmcapital.com

msteinmetz@clarusventures.com

 MPM BioVentures III-QP, L.P. 
 The John Hancock Tower 
 200 Clarendon Street, 54th Floor 

Boston, MA 02116 

			
	Fax:	  	(617) 425-9201
	Attn:	  	 Lauren Fiore
 Michael
Steinmetz

	Email:	  	 lfiore@mpmcapital.com

msteinmetz@clarusventures.com

 Name and Address, Phone Number 
 Fax and Email of Purchaser 
 MPM BioVentures III GmbH & Co. 

Beteiligungs KG 
 The John Hancock Tower

 200 Clarendon Street, 54th Floor 

Boston, MA 02116 

			
	Fax:	  	(617) 425-9201
	Attn:	  	 Lauren Fiore
 Michael
Steinmetz

	Email:	  	 lfiore@mpmcapital.com

msteinmetz@clarusventures.com

 MPM BioVentures III Parallel Fund, L.P. 
 The John Hancock Tower 
 200 Clarendon Street, 54th Floor 

Boston, MA 02116 

			
	Fax:	  	(617) 425-9201
	Attn:	  	 Lauren Fiore
 Michael
Steinmetz

	Email:	  	 lfiore@mpmcapital.com

msteinmetz@clarusventures.com

 MPM Asset Management Investors 2003 
 BVIII LLC 
 The John Hancock Tower 
 200 Clarendon Street, 54th Floor 
 Boston, MA 02116 

			
	Fax:	  	(617) 425-9201
	Attn:	  	 Lauren Fiore
 Michael
Steinmetz

	Email:	  	 lfiore@mpmcapital.com

msteinmetz@clarusventures.com

 OVP Venture Partners VI, L.P. 
 c/o OVP Venture Partners 
 1010 Market Street 

Kirkland, WA 98033 

			
	Attn:	  	Bill Funcannon
	Fax:	  	(425) 889-0152
	Email:	  	 funcannon@ovp.com

waite@ovp.com

 Name and Address, Phone Number 
 Fax and Email of Purchaser 
 OVP VI Entrepreneurs Fund, L.P. 

c/o OVP Venture Partners 
 1010 Market Street

 Kirkland, WA 98033 

			
	 Attn:
	  	Bill Funcannon
	 Fax:
	  	(425) 889-0152
	 Email:
	  	 funcannon@ovp.com

waite@ovp.com

 SCHEDULE B 
 Key Holders 
 Institute for Systems Biology 

1441 North 34th Street 

Seattle, WA 98103 

			
	 Attn:
	  	Lee Hood, Gary Raisl
	 Fax:
	  	(206) 732-1260
	 Email:
	  	 lhood@systemsbiology.org

graisl@systemsbiology.org

 ISB Accelerator Corporation 
 1616 Eastlake Avenue E. 
 Seattle, WA 98102 

			
	 Attn:
	  	Carl Weissman, Lindsay Rayle
	 Fax:
	  	(206) 957-7399
	 Email:
	  	 cweissman@acceleratorcorp.com

lrayle@acceleratorcorp.com

 Meenu Chhabra 

c/o Allozyne, Inc. 
 1616 Eastlake Avenue E.

 Seattle, WA 98102 

			
	 Fax:
	  	
	 Email:
	  	mchhabra@allozyne.com

 Ken Grabstein 

c/o Allozyne, Inc. 
 1616 Eastlake Avenue E.

 Seattle, WA 98102 

			
	 Fax:
	  	
	 Email:
	  	kgrabstein@allozyne.com

 William Goddard 

139-74 Caltech 
 Pasadena, CA 91125 

			
	 Fax:
	  	
	 Email:
	  	

 David Tirrell 

Division Chair 
 Chemistry and Chemical
Engineering 
 California Institute of Technology 
 Pasadena, CA 91125 

			
	 Fax:
	  	
	 Email:AMENDED AND RESTATED STOCKHOLDERS AGREEMENT

 Exhibit 10.55 
 AMENDED AND RESTATED STOCKHOLDERS AGREEMENT 
 This AMENDED AND RESTATED
STOCKHOLDERS AGREEMENT (the “Agreement”) is made as of this 22nd day of October, 2007, by and among Allozyne, Inc., a Delaware corporation (the “Company”), the individuals and entities listed on Schedule A
attached hereto under the heading “Investors” (each an “Investor” and collectively referred to as the “Investors”), the Institute for Systems Biology. A Washington non-profit corporation
(“ISB”) and the individuals and entities listed on Schedule A attached hereto under the heading “Holders” and each individual or entity who shall, after the date hereof, acquire shares of Common Stock (as defined
below) and become a party to this Agreement by executing and delivering to the Company an Instrument of Adherence substantially in the form of Schedule B attached hereto (each such individual and entity is a “Holder” and
collectively such individuals and entities are referred to as the “Holders”; and the Investors, ISB and the Holders are each referred to as a “Stockholder” and are collectively referred to as the
“Stockholders”). 
 RECITALS 
 WHEREAS, the Holders hold shares of the Company’s Common Stock, par value $0.001 per share (the “Common Stock”), and certain of the Investors (the “Existing
Investors”) hold shares of the Company’s Series A Convertible Preferred Stock, par value $0.001 per share (the “Series A Preferred Stock”), and/or shares of Common Stock issued upon conversion thereof, and have
outlined the means for providing for the efficient management, control and operation of the business of the Company and for the right of first refusal and co-sale in favor of the Existing Investors in connection with certain transfers of securities
of the Company pursuant to that certain Stockholders Agreement dated as of October 19, 2005 between the Company, the Existing Investors and the Holders (as originally executed, and as the same may be amended, modified, supplemented or restated
from time to time in accordance with its terms, the “Prior Agreement”); 
 WHEREAS, the Existing
Investors and the Holders (collectively referred to as the “Existing Stockholders”) are holders of a majority of the outstanding shares of Common Stock and Series A Preferred Stock (on an as-converted basis) held by the Existing
Stockholders, and the Existing Stockholders 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; 

WHEREAS, certain of the Investors are parties to that certain Series B Convertible Preferred Stock Purchase Agreement of even date
herewith between the Company and such Investors (the “Purchase Agreement”), under which certain of the Company’s and such Investors’ obligations are conditioned upon the execution and delivery of this Agreement by such
Investors; and 
 WHEREAS, the Second Amended and Restated Certificate of Incorporation of the Company (as originally
adopted, and as the same may be amended, modified, supplemented or restated from time to time in accordance with its terms, the “Charter”) provides that (a) the holders of record of the shares of the Series A Preferred Stock,
exclusively and as a separate 

 
class, shall be entitled to elect two (2) directors of the Company and the holders of record of the shares of Series B Convertible Preferred Stock, par value $0.001 (the “Series B
Preferred Stock,” which includes both Series B-1 Preferred Stock and Series B-2 Preferred Stock, as both are defined in the Charter, and the Series B Preferred Stock together with the Series A Preferred Stock, referred to collectively
herein as the “Preferred Stock”) shall be entitled to elect two (2) directors of the Company; (b) the holders of record of the shares of Common Stock, voting a separate class, shall be entitled to elect one
(1) director of the Company, provided that such choice is approved by the Investors holding a majority of the Preferred Stock then held by all Investors. 
 NOW, THEREFORE, the Existing Investors, the Holders and the Company hereby agree that the Prior Agreement shall be amended and restated as follows: 

1. Voting Provisions Regarding Board of Directors. 

1.1 Size of the Board. Each Stockholder agrees to vote, or cause to be voted, all Shares (as defined below) owned
by such Stockholder, or over which such Stockholder has voting control, from time to time and at all times, in whatever manner as shall be necessary to ensure that the size of the Board of Directors of the Company (the “Board”)
shall be set and remain at six (6) directors. For purposes of this Agreement, the term “Shares” shall mean and include any securities of the Company the holders of which are entitled to vote for members of the Board, including
without limitation, all shares of Common Stock, Series A Preferred Stock and Series B Preferred Stock, by whatever name called, now owned or subsequently acquired by a Stockholder, however acquired whether through stock splits, stock dividends,
reclassifications, recapitalizations, similar events or otherwise. 
 1.2 Board Composition. Each
Stockholder agrees to vote, or cause to be voted, all Shares owned by such Stockholder, or over which such Stockholder has voting control, from time to time and at all times, in whatever manner as shall be necessary to ensure that at each annual or
special meeting of stockholders at which an election of directors is held or pursuant to any written consent of the stockholders, the following persons shall be elected to the Board: 

(a) At each election of directors in which the holders of the Series A Preferred Stock, voting as a separate class, are
entitled to elect two (2) directors of the Company (the “Series A Directors”), (i) one individual designated by MPM Bioventures Fund III-QP, L.P. (“MPM”), which individual shall initially be Michael Steinmetz,
and (ii) one individual designated by ARCH Venture Fund V, L.P. (“ARCH”), which individual shall initially be Steve Gillis; provided, however, that, notwithstanding the foregoing, if either MPM or ARCH fails to
purchase the number of shares of the Company’s Series B-2 Convertible Preferred Stock, par value $0.001 per share (the “Series B-2 Preferred Stock”), required to be purchased by such Investor at the Milestone Closing (as
defined in the Purchase Agreement), then such Investor shall no longer be entitled to designate a representative to the Board and such Board seat shall be filled in accordance with the provisions of the Charter; 

(b) At each election of directors in which the holders of the Series B Preferred Stock, voting as a separate class, are
entitled to elect two (2) directors of the Company 

  
 2 

 
(the “Series B Directors”), (i) one individual designated by OVP Venture Partners VI, L.P. (“OVP”), which individual shall initially be Carl Weissman, and
(ii) one individual designated by Amgen Ventures LLC (“Amgen”), which individual shall initially be Jay Hagan; provided, however, that, notwithstanding the foregoing, if either OVP or Amgen fails to purchase the
number of shares of Series B-2 Preferred Stock required to be purchased by such Investor at the Milestone Closing, then such Investor shall no longer be entitled to designate a representative to the Board and such Board seat shall be filled in
accordance with the provisions of the Charter; 
 (c) The person serving as the Company’s Chief Executive
Officer (the “CEO Director”), who shall initially be Meenu Chhabra; provided that if for any reason the person serving as the CEO Director ceases to serve as the Chief Executive Officer of the Company for any reason,
each of the Stockholders shall promptly vote their respective Shares (i) to remove the former Chief Executive Officer from the Board if such person has not resigned as a member of the Board and (ii) to elect such person’s replacement
as Chief Executive Officer of the Company as the new CEO Director; and 
 (d) One (1) individual that is
(i) designated by a majority of the holders of the Common Stock, voting as a separate class, and (ii) approved by Investors holding a majority of the outstanding Preferred Stock held by all Investors (the “Common
Director”), which individual shall initially be David Tirrell. 
 For purposes of this Agreement, an individual, firm,
corporation, partnership, association, limited liability company, trust or any other entity (collectively, a “Person”) shall be deemed an “Affiliate” of another Person who, directly or indirectly, controls, is controlled
by or is under common control with such Person, including, without limitation, any general partner, officer, director, or manager of such Person and any venture capital fund now or hereafter existing that is controlled by one or more general
partners of or shares the same management company with such Person. 
 1.3 Failure to Designate a Board
Member. In the absence of any designation from the persons or groups with the right to designate a director as specified in Section 1.2, the director previously designated by them and then serving shall be reelected if still eligible
and willing to serve as provided herein. Until such designee is chosen, the remaining members of the Board shall continue to operate as a fully functioning Board. 

1.4 Removal of Board Members. Each Stockholder also agrees to vote, or cause to be voted, all Shares owned by such
Stockholder, or over which such Stockholder has voting control, from time to time and at all times, in whatever manner as shall be necessary to ensure that: 
 (a) no director elected pursuant to Sections 1.2 or 1.3 of this Agreement may be removed from office unless (i) such removal is directed or approved by the affirmative vote of the
Person(s), or by the holders of a majority of the shares of stock, entitled under Section 1.2 to designate that director (ii) the Person(s) originally entitled to designate or approve such director pursuant to
Section 1.2 is no longer so entitled to designate or approve such director, and 

  
 3 

 (b) any vacancies created by the resignation, removal or death of a director
elected pursuant to Sections 1.2 or 1.3 shall be filled pursuant to the provisions of this Section 1. 
 All
Stockholders agree to execute any written consents required to perform the obligations of this Agreement, and the Company agrees at the request of any party entitled to designate directors to call a special meeting of stockholders for the purpose of
electing directors. 
 1.5 No Liability for Election of Recommended Directors. No party, nor any Affiliate
of any such party, shall have any liability as a result of designating a person for election as a director for any act or omission by such designated person in his or her capacity as a director of the Company, nor shall any party have any liability
as a result of voting for any such designee in accordance with the provisions of this Agreement. 
 1.6
Chairman of the Board. The Board shall have an Executive Chairman to oversee Board meetings. Michael Steinmetz shall initially serve as the Executive Chairman of the Board. 

2. Observer Rights. 
 2.1 Observer Rights Generally. Each of (1) MPM, for so long as MPM owns at least 100,000 shares of Series A Preferred Stock or Series B Preferred Stock (as appropriately adjusted to reflect
any stock split, subdivision or combination of the Series A Preferred Stock or Series B Preferred Stock, as the case may be) and (2) any Investor that (i) owns at least 100,000 shares of Series A Preferred Stock or Series B Preferred Stock
(as appropriately adjusted to reflect any stock split, subdivision or combination of the Series A Preferred Stock or Series B Preferred Stock, as the case may be), and (ii) does not have a representative sitting on the Board, shall have the
right to designate one (1) representative of such Investor to serve as a non-voting observer (each, an “Observer”) of the Board; provided that prior to commencing service as an Observer and from time to time
thereafter promptly upon any change in circumstance or at the request of the Company, each Observer shall disclose to the Company (which disclosure shall be in writing if the Company so requests) any conflicts of interest such Observer may have with
any party engaged in any business activity that is in competition, directly or indirectly, with the products or services being developed, offered, marketed, sold or licensed by the Company. Each such Investor may remove its Observer or appoint an
Observer if a vacancy in such position occurs for any reason by delivery of a written notice to the Secretary of the Company. For purposes of applying the provisions of this Section 2.1, Investors that are Affiliates shall be entitled to
only one (1) Observer as a group. The initial Observer designed by MPM shall be William Greene and the initial Observer designated by Alexandria Accelerator LLC shall be Imran N. Alibhai. 

2.2 Procedures; Limitations. The Company or the applicable members of the Board will give each Observer oral or
written notice of each meeting of the Board (whether annual or special) at the same time and in the same manner as oral or written notice is given to the applicable members of the Board (which notice may be waived by each Observer). Notwithstanding
the foregoing, if an Observer attends (or, in the case of a telephonic meeting, listens by telephone to) any such meeting of the Board, then such Observer shall be deemed to 

  
 4 

 
have had proper notice of such meeting. Notwithstanding anything contained herein to the contrary, the failure of an Observer to be given notice of a meeting of the Board pursuant to the
immediately preceding two sentences or to attend such meeting shall not in any way affect the authority of the Board to have or to adopt resolutions at such meeting or the legitimacy of any actions taken by the Board at such meeting. Subject to the
foregoing, the Company will permit the Observers to attend (or, in the case of a telephonic meeting, to listen by telephone to) each meeting of the Board as non-voting observers. The Company shall provide each Observer all written materials and
other information (including copies of meeting minutes) given to the members of the Board in connection with any such meeting at the same time as such information is delivered to the members of the Board and, if an Observer does not attend (or, in
the case of a telephonic meeting, does not listen by telephone to) a meeting of the Board, such Observer will be entitled, upon request, to receive the written minutes or an oral summary of the meeting from the Secretary of the Company. Prior to
attending or listening to any meeting of the Board or obtaining any documents or summaries of such meetings, each Observer shall agree in writing to be bound by the same duties of confidentiality, good faith and loyalty as if such Observer were a
member of the Board. If the Company takes any action by written consent of the Board in lieu of a meeting of the Board, then the Company shall give prompt written notice of such action to the Observers. In all cases where notice, meeting materials
or minutes would otherwise be required to be delivered to an Observer or where an Observer would be permitted to attend a meeting under this Section 2, the Company reserves the right not to provide notice, meeting materials or minutes
relating to and to exclude Observers from any meeting or portion thereof if the Board determines in good faith that the delivery of such information or attendance at such meeting by such Observer would result in disclosure of trade secrets or other
material confidential information to such Observer, present an actual or potential conflict of interest between such Observer and the Company, would adversely affect the attorney-client privilege between the Company and its counsel or would
otherwise be materially injurious to the Company in such circumstances. Observers shall be solely responsible for maintaining current phone and fax numbers, and mailing and electronic mail instructions on file with the Company. 

3. Transfers. 
 3.1 Prohibited Transfers. No Holder shall sell, assign, transfer, pledge, hypothecate, mortgage, encumber or dispose of, by gift or otherwise (collectively, a “Transfer”) all or
any of his, her or its Shares except as expressly provided in this Agreement. Notwithstanding the foregoing, a Holder may Transfer all or any of his, her or its Shares (i) by way of gift to any family member or to any trust or limited liability
company for the benefit of any such family member of such Holder, in which event each such transferee shall be bound by all of the provisions of this Agreement to the same extent as if such transferee were such Holder; or (ii) by will or the
laws of descent and distribution, in which event each such transferee shall be bound by all of the provisions of this Agreement to the same extent as if such transferee were such Holder (each such transferee as described in Sections 3.l(i)
and 3.l(ii), a “Permitted Transferee”); or (iii) by transfer to an Affiliate or Affiliates by a Transfer of Shares in compliance with this Section 3.1 and Section 3.4. No Transfer of Shares to
a Permitted Transferee shall be effective if the purpose of such Transfer shall have been to circumvent the provisions of this Agreement. Any Transfer of Shares pursuant to this Section 3.1 shall be expressly conditioned upon the
transferee of such Shares becoming a party to this Agreement by executing an Instrument of Adherence substantially in the form attached hereto as Schedule B 

  
 5 

 
(an “Instrument of Adherence”), in which event each such transferee shall be bound by all of the provisions of this Agreement to the same extent as if such transferee were such
Holder, and all Shares transferred shall at all times remain subject to the terms of this Agreement in the hands of the transferee. As used herein, the term “family member” means a person’s parents, spouse, children, and
siblings, in each case, whether by blood, marriage or adoption. Notwithstanding anything to the contrary herein, no Holder may Transfer his, her or its Shares to a third party for any consideration other than cash. 

3.2 Right of First Refusal on Dispositions of Shares. 

(a) If at any time any Holder desires to sell all or any portion of such Holder’s Shares pursuant to a third party (a
“Proposed Transferee”), such selling Holder shall, within five (5) Business Days after the Proposed Transferee has delivered such offer to such selling Holder, submit a written offer (the “Offer”) to sell such
Shares (the “Offered Shares”) to the Investors on terms and conditions, including price, not less favorable to the Investors than those on which the selling Holder proposes to sell such Offered Shares to the Proposed Transferee. The
Offer shall disclose the identity of the Proposed Transferee, the number of Offered Shares proposed to be sold, the total number of Shares owned by the selling Holder, the terms and conditions, including price, of the proposed sale, and any other
material facts relating to the proposed sale, and shall be accompanied by a copy of the written offer to purchase the Offered Shares from the Proposed Transferee. The Offer shall further state that the Investors may acquire, in accordance with the
provisions of this Agreement, all or any portion of the Offered Shares for the price and upon the other terms and conditions, including deferred payment (if applicable), set forth in the Offer. For purposes of this Agreement, “Business
Day” means any day other than Saturday, Sunday, any federal holidays and any state holidays in the State of Washington. 
 (b) Each Investor shall have the absolute right to purchase up to that number of Offered Shares as shall be equal to the aggregate number of Offered Shares multiplied by a fraction, the numerator of which
shall be the number of shares of Common Stock issuable upon conversion of the Preferred Stock then held by such Investor and the denominator of which is the aggregate number of shares of Common Stock issuable upon conversion of the Preferred Stock
then held by all of the Investors. The amount of Offered Shares that each participating Investor is entitled to purchase under this Section 3.2(b) shall be referred to as its “Pro Rata Fraction.” 

(c) The participating Investors shall have a right of oversubscription such that if any other Investor fails to accept the
Offer as to its Pro Rata Fraction, the other participating Investors shall, among them, have the right to purchase up to the balance of the Offered Shares not so purchased. Such right of oversubscription shall be exercised by a participating
Investor accepting the Offer in writing to the Company and the selling Holder for the number of Offered Shares such Investor desires to purchase in excess of its Pro Rata Fraction. If, as a result thereof, such oversubscriptions exceed the total
number of Offered Shares available in respect of such oversubscription privilege, the oversubscribing participating Investors shall be cut back with respect to their oversubscriptions on a pro rata basis in accordance with their
respective Pro Rata Fractions or as they may otherwise agree among themselves. 

  
 6 

 (d) If an Investor desires to purchase all or any part
of the Offered Shares, such Investor shall deliver in person or mail such written communication to the selling Holder at the address set forth in accordance with Section 5.1 below within ten (10) Business Days after the date the
Offer was delivered to the Investors, which communication shall state the number of Offered Shares such Investor desires to purchase. Such written communication by a Investor shall, when taken in conjunction with the Offer, be deemed to constitute a
valid, legally binding and enforceable agreement for the sale and purchase of such Offered Shares by the Investors. Sales of the Offered Shares to be sold to the participating Investors pursuant to this Section 3.2 shall be made at the
offices of the Company on the 20th Business Day after the
date the Offer was delivered to the Investors. Such sales shall be effected by the selling Holder’s delivery to a participating Investor of a certificate or certificates evidencing the Offered Shares to be purchased by it, duly endorsed for
transfer to such participating Investor against payment to the selling Holder of the purchase price therefor by said participating Investor. 
 (e) If the Investors do not purchase all of the Offered Shares within the time frame specified in Section 3.2(d), the remaining Offered Shares shall be subject to a right of first refusal in
favor of the Company (the “Company Right of Refusal”). If the Company desires to exercise all or a portion of the Company Right of Refusal, the Company shall deliver in person or mail such written communication to the selling Holder
at the address set forth in accordance with Section 5.1 below within ten (10) Business Days after the date the Company was notified by the Holder of the Company Right of First Refusal, which communication shall state the number of
Offered Shares the Company desires to purchase. Such written communication by the Company shall, when taken in conjunction with the Offer by the selling Holder, be deemed to constitute a valid, legally binding and enforceable agreement for the sale
and purchase of such Offered Shares by the Company. 
 (f) Notwithstanding the foregoing, if the total number of
Offered Shares that the Investors and the Company have agreed to purchase is less than the total number of Offered Shares, then the Investors and the Company shall be deemed to have forfeited any right to purchase such Offered Shares, and the
selling Holder shall be free to sell all, but not less than all, of the Offered Shares to the Proposed Transferee on terms and conditions substantially similar to (and in no event more favorable than) the terms and conditions set forth in the Offer,
it being understood and agreed that (i) any such sale or transfer shall be subject to the other terms and restrictions of this Agreement, including without limitation the terms and restrictions set forth in Sections 3.3, 4 and
5.2; (ii) any future proposed Holder Transfer shall remain subject to the terms and conditions of this Agreement; and (iii) such sale shall be consummated within forty-five (45) Business Days after receipt of the Offer by the
Investors and, if such sale is not consummated within such forty-five (45) day period, such sale shall again become subject to the right of first refusal in favor of the Investors and the Company Right of Refusal on the terms set forth herein.
If Offered Shares are sold pursuant to this Section 3.2 to a Investor or any Affiliate thereof, in such case only, the Offered Shares so sold to such Investor shall no longer be subject to any of the restrictions imposed by this
Agreement. 
 (g) Except as otherwise provided herein, no Holder shall Transfer any Shares to any person
(including any transfers pursuant to this Section 3.2), other than a Investor, who does not first execute an Instrument of Adherence. If any Transfer of Shares is attempted contrary to the provisions of this Agreement, the Company and
the Investors shall have the right 

  
 7 

 
to (i) purchase such Shares from the transferring Holder or his or her purported transferee; (ii) obtain a temporary and/or permanent injunction restraining such transfer (no bond or
other security shall be required in connection with such action); or (iii) refuse to recognize any purported transferee as a Holder and may continue to treat the transferor as a Holder for all purposes, including, without limitation, for
purposes of dividend and voting rights, until all applicable provisions of this Agreement have been complied with. The remedies provided herein are cumulative and not exclusive of any other remedies provided by law. 

3.3 Co-Sale Right. 
 (a) If at any time a Holder proposes to Transfer or sell any Shares (the “Co-Sale Shares”) to any person other than the Company (a “Buyer”), each of the Investors shall
have the right to sell to the Buyer, as a condition to such sale by such Holder, at the same price per share and on the same terms and conditions as involved in such sale by such Holder (as stated in the Offer provided under
Section 3.2(a)), such number of shares equal to the Co-Sale Shares multiplied by a fraction, the numerator of which is the aggregate number of shares of capital stock of the Company (calculated on a fully-diluted basis) owned by the
particular Investor desiring to sell shares to a Buyer, and the denominator of which is the sum of all shares of capital stock of the Company (calculated on a fully­diluted basis) owned by all Investors desiring to participate in a sale to a
Buyer under this Section 3.3. 
 (b) Each Investor wishing to participate in any sale under this
Section 3.3 shall notify in writing the Holder selling hereunder of such intention as soon as practicable after such Investor’s receipt of the Offer made pursuant to Section 3.2(a), and in any event within ten
(10) Business Days after the date such Offer was delivered to the Investors. 
 (c) The Holder selling
hereunder and each participating Investor shall sell to the Buyer all, or at the option of the Buyer, any part of the shares proposed to be sold by them at not less than the price and upon such other terms and conditions, if any, not more favorable
to the Buyer than those in the Offer provided by such Holder under Section 3.2(a); provided, however, that any purchase of less than all of such shares by the Buyer shall be deducted from the number of shares offered to be
sold by such Holder and each participating Investor pro rata based upon the applicable number of Co-Sale Shares desired to be sold by the Holder and the number of shares that each participating Investor is entitled to sell pursuant to
Section 3.3(a). 
 (d) Any sale of securities pursuant to this Section 3.3 shall be
expressly conditioned upon the Buyer of such securities becoming a party to this Agreement by executing an Instrument of Adherence, in which event such Buyer shall be bound by all of the provisions of this Agreement to the same extent as if such
Buyer were the Holder selling such securities, and all securities sold shall at all times remain subject to the terms of this Agreement in the hands of such Buyer. 

3.4 Prohibition on Transfers of Shares to Competitors. Without the prior approval of the Board, no Stockholder may
at any time Transfer any Shares to any individual, company, partnership or other entity that engages in any business activity that is in competition, directly or indirectly, with the products or services being developed, offered, marketed, sold or

  
 8 

 
licensed by the Company. The determination of whether any proposed transferee engages in any business activity that is in competition with those of the Company shall be made by the Board in good
faith. This prohibition shall be applicable in addition to and separately from the other provisions hereof. 

3.5 Failure to Deliver Shares. 

(a) If any Holder (or such Holder’s legal representative) who has become obligated to sell Shares hereunder shall
fail to deliver such Shares in accordance with the terms of this Agreement, the Company may, at its option, in addition to all other remedies it may have, send to such Holder by registered mail, return receipt requested, or express overnight courier
service the purchase price for such Shares as is herein specified. Thereupon, the Company: (i) shall cancel on its books the certificate or certificates representing such Shares to be sold; and (ii) shall issue, in lieu thereof, a new
certificate or certificates in the name of the Company representing such Shares, and thereupon all of such Holder’s rights in and to such Shares shall terminate. 

(b) In the event of any sale, transfer, assignment or other disposition of any capital stock of the Company by a Holder in
violation of any provision of Section 3.3, each Investor shall have the right to elect to cause such Holder to purchase, and such Holder shall be obligated to purchase from such Investor, at the same price per share and on the same terms
and conditions as involved in such sale by the Holder, such number of shares of capital stock (calculated on a fully-diluted basis) equal to the number of shares sold by such Holder multiplied by a fraction, the numerator of which is the aggregate
number of shares of capital stock owned by any particular Investor desiring to sell shares to such Holder under this Section 3.5 (calculated on a fully-diluted basis) and the denominator of which is the sum of all shares of capital stock
owned by all Investors desiring to sell shares to such Holder under this Section 3.5 (calculated on a fully-diluted basis). 
 4. Drag-Along Right. 
 4.1 Definitions. A
“Sale of the Company” shall mean either: (a) a transaction or series of related transactions in which a Person, or a group of related Persons, acquires from stockholders of the Company shares representing more than fifty
percent (50%) of the outstanding voting power of the Company (a “Stock Sale”); or (b) a transaction that qualifies as a “Deemed Liquidation Event” as defined in the Charter. 

4.2 Actions to be Taken. In the event that the holders of 75% of the outstanding shares of Common Stock issued or
issuable upon conversion of the shares of Preferred Stock (the “Selling Investors”) approve a Sale of the Company in writing, specifying that this Section 4 shall apply to such transaction, then each Stockholder hereby
agrees: 
 (a) if such transaction requires stockholder approval, with respect to all Shares that such
Stockholder owns or over which such Stockholder otherwise exercises voting power, to vote (in person, by proxy or by action by written consent, as applicable) all Shares in favor of, and adopt, such Sale of the Company (together with any related
amendment to the Charter required in order to implement such Sale of the Company) and to vote in 

  
 9 

 
opposition to any and all other proposals that could delay or impair the ability of the Company to consummate such Sale of the Company; 

(b) if such transaction is a Stock Sale, to sell the same proportion of shares of capital stock of the Company
beneficially held by such Stockholder as is being sold by the Selling Investors to the Person to whom the Selling Investors propose to sell their Shares, and, except as permitted in Section 4.3 below, on the same terms and conditions as
the Selling Investors; 
 (c) to execute and deliver all related documentation and take such other action in
support of the Sale of the Company as shall reasonably be requested by the Company or the Selling Investors in order to carry out the terms and provision of this Section 4, including without limitation executing and delivering
instruments of conveyance and transfer, and any purchase agreement, merger agreement, indemnity agreement, escrow agreement, consent, waiver, governmental filing, share certificates duly endorsed for transfer (free and clear of impermissible liens,
claims and encumbrances) and any similar or related documents; 
 (d) not to deposit, and to cause their
Affiliates not to deposit, except as provided in this Agreement, any Shares of the Company owned by such party or Affiliate in a voting trust or subject any Shares to any arrangement or agreement with respect to the voting of such Shares, unless
specifically requested to do so by the acquirer in connection with the Sale of the Company; 
 (e) to refrain
from exercising any dissenters’ rights or rights of appraisal under applicable law at any time with respect to such Sale of the Company; and 
 (f) if the consideration to be paid in exchange for the Shares pursuant to this Section 4 includes any securities and due receipt thereof by any Stockholder would require under applicable law
(x) the registration or qualification of such securities or of any person as a broker or dealer or agent with respect to such securities or (y) the provision to any Stockholder of any information other than such information as a prudent
issuer would generally furnish in an offering made solely to “accredited investors” as defined in Regulation D promulgated under the Securities Act of 1933, as amended, the Company may cause to be paid to any such Stockholder in lieu
thereof, against surrender of the Shares which would have otherwise been sold by such Stockholder, an amount in cash equal to the fair value (as determined in good faith by the Company) of the securities which such Stockholder would otherwise
receive as of the date of the issuance of such securities in exchange for the Shares. 
 4.3 Exceptions.
Notwithstanding the forgoing, a Stockholder will not be required to comply with Section 4.2 above in connection with any proposed Sale of the Company (the “Proposed Sale”) unless: 

(a) any representations and warranties to be made by such Stockholder in connection with the Proposed Sale are limited to
representations and warranties related to authority, ownership and the ability to convey title to such Shares, including but not limited to representations and warranties that (i) the Stockholder holds all right, title and interest in and to
the Shares such Stockholder purports to hold, free and clear of all liens and encumbrances, 

  
 10 

 
(ii) the obligations of the Stockholder in connection with the transaction have been duly authorized, if applicable, (iii) the documents to be entered into by the Stockholder have been
duly executed by the Stockholder and delivered to the acquirer and are enforceable against the Stockholder in accordance with their respective terms and (iv) neither the execution and delivery of documents to be entered into in connection with
the transaction, nor the performance of the Stockholder’s obligations thereunder, will cause a breach or violation of the terms of any agreement, law or judgment, order or decree of any court or governmental agency; 

(b) The Stockholder shall not be liable for the inaccuracy of any representation or warranty made by any other Person in
connection with the Proposed Sale, other than the Company; 
 (c) the liability for indemnification, if any, of
such Stockholder in the Proposed Sale and for the inaccuracy of any representations and warranties made by the Company in connection with such Proposed Sale, is several and not joint with any other Person, and is pro rata in proportion to the amount
of consideration paid to such Stockholder in connection with such Proposed Sale (in accordance with the provisions of the Charter); 
 (d) liability shall be limited to such Stockholder’s pro rata share (determined in proportion to proceeds received by such Stockholder in connection with such Proposed Sale in
accordance with the provisions of the Charter) of a negotiated aggregate indemnification amount that applies equally to all Stockholders but that in no event exceeds the amount of consideration actually paid to such Stockholder in connection with
such Proposed Sale, except with respect to claims related to fraud by such Stockholder, the liability for which need not be limited as to such Stockholder; 
 (e) upon the consummation of the Proposed Sale, (i) each holder of each series of the Company’s Preferred Stock and each holder of Common Stock will, subject to Section 4.2(f),
receive the same form of consideration for their shares of Common Stock and Preferred Stock, (ii) each holder of a series of Preferred Stock will receive the same amount of consideration per share of such series of Preferred Stock,
(iii) each holder of Common Stock will receive the same amount of consideration per share of Common Stock, and (iv) unless the holders of 75% of the outstanding shares of Common Stock issued or issuable upon conversion of the shares of
Preferred Stock elect otherwise by written notice given to the Company at least five (5) days prior to the effective date of any such Proposed Sale, the aggregate consideration receivable by all holders of the Preferred Stock and Common Stock
shall be allocated among the holders of Preferred Stock and Common Stock on the basis of the relative liquidation preferences to which the holders of each respective series of Preferred Stock and the holders of Common Stock are entitled in a Deemed
Liquidation Event (assuming for this purpose that the Proposed Sale is a Deemed Liquidation Event) in accordance with the Charter in effect immediately prior to the Proposed Sale; and 

(f) subject to Section 4.3(e), requiring the same form of consideration to be received by the holders of the
Common Stock and Preferred Stock, if any holders of any capital stock of the Company are given an option as to the form and amount of consideration to be received as a result of the Proposed Sale, all holders of such capital stock will be given the
same option. 

  
 11 

 4.4 Restrictions on Sales of Control of the Company. No Stockholder
shall be a party to any Stock Sale unless all Stockholders are allowed to participate in such transaction and the consideration received pursuant to such transaction is allocated among the parties thereto in the manner specified in the Charter in
effect immediately prior to the Stock Sale (as if such transaction were a Deemed Liquidation Event), unless the holders of 75% of the outstanding shares of Common Stock issued or issuable upon conversion of the shares of Preferred Stock elect
otherwise by written notice given to the Company at least five (5) days prior to the effective date of any such transaction or series of related transactions. 
 5. Miscellaneous. 
 5.1 Notices. All notices,
requests, consents and other communications to be given or otherwise made to any party to this Agreement shall be deemed to be sufficient if contained in a written instrument, delivered by hand in person, by express overnight courier service, or by
electronic mail or facsimile transmission (with a confirming copy sent by U.S. mail, first class, postage prepaid mail), or by registered or certified mail, return receipt requested, postage prepaid, addressed to such party at the address set forth
in Schedule A or at such other address as may hereafter be designated in writing by the addressee, with a copy to the respective party’s counsel listed therein. All notices shall be considered to be delivered three (3) days after dispatch
in the event of first class or registered mail, and on the next succeeding Business Day in the event of electronic mail or facsimile transmission (with continuation of receipt) or overnight courier service. 

5.2 Benefit. This Agreement shall be binding upon and inure to the benefit of the parties hereto and their
respective heirs, executors, personal representatives, successors and permitted assigns and shall be binding upon any person, firm, company or other entity to whom any shares of Stock are transferred (even if in violation of the provisions of this
Agreement) and the heirs, executors, personal representatives, successors and assigns of such person, firm, company or other entity. No provision of this Agreement shall be construed to provide a benefit to any party hereto who no longer owns any
Stock. 
 5.3 Term. This Agreement shall be effective as of the date hereof and shall continue in effect
until and shall terminate upon the earliest to occur of (a) the consummation of the Company’s first underwritten public offering of its Common Stock (other than a registration statement relating either to the sale of securities to
employees of the Company pursuant to its stock option, stock purchase or similar plan or an SEC Rule 145 transaction); (b) the consummation of a Sale of the Company and distribution of proceeds to or escrow for the benefit of the Stockholders
in accordance with the Charter, provided that the provisions of Section 4 hereof will continue after the closing of any Sale of the Company to the extent necessary to enforce the provisions of Section 4 with respect to such
Sale of the Company. 
 5.4 Legends. 

(a) Each certificate representing Shares owned by a Holder or issued to any person in connection with a transfer pursuant
to Section 3 hereof shall be endorsed with a legend in substantially the following form (the “Transfer Legend”): 

  
 12 

 “THE SALE, PLEDGE, HYPOTHECATION OR TRANSFER OF THE SECURITIES REPRESENTED BY THIS
CERTIFICATE IS SUBJECT TO THE TERMS AND CONDITIONS OF A STOCKHOLDERS AGREEMENT BY AND BETWEEN THE STOCKHOLDER, THE COMPANY AND CERTAIN HOLDERS OF STOCK OF THE COMPANY. A COPY WILL BE FURNISHED TO THE RECORD HOLDER OF THIS CERTIFICATE WITHOUT CHARGE
UPON WRITTEN REQUEST TO THE COMPANY AT ITS PRINCIPAL PLACE OF BUSINESS.” 
 The Holders agree that the Company may instruct its transfer
agent to impose transfer restrictions on the shares represented by certificates bearing the Transfer Legend to enforce the provisions of this Agreement and the Company agrees to promptly do so. The Transfer Legend shall be removed at the request of
any Holder following termination of this Agreement. 
 (b) Each certificate representing Stock now or hereafter
owned by any party hereto or issued shall be endorsed with a legend in substantially the following form (the “Voting Legend”): 
 “THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO THE TERMS AND CONDITIONS OF A STOCKHOLDERS AGREEMENT WHICH PLACES CERTAIN RESTRICTIONS ON THE VOTING OF THE SHARES REPRESENTED HEREBY. ANY
PERSON ACCEPTING ANY INTEREST IN SUCH SHARES SHALL BE DEEMED TO AGREE TO AND SHALL BECOME BOUND BY ALL THE PROVISIONS OF SUCH AGREEMENT. A COPY OF SUCH STOCKHOLDERS 
 AGREEMENT WILL BE FURNISHED TO THE RECORD HOLDER OF THIS CERTIFICATE WITHOUT CHARGE UPON WRITTEN REQUEST TO THE COMPANY AT ITS PRINCIPAL PLACE OF BUSINESS.” 

The Company agrees that, during the term of this Agreement, it will not remove, and will not permit to be removed (upon registration of transfer,
reissuance of otherwise), the Voting Legend from any such certificate and will place or cause to be placed the Voting Legend on any new certificate issued to represent Stock theretofore represented by a certificate carrying the Voting Legend.

 5.5 Entire Agreement. This Agreement, the Purchase Agreement and the other Transaction Documents (as
defined in the Purchase Agreement) together with all exhibits and schedules to the such agreements, constitute the entire agreement among the parties hereto pertaining to the subject matter hereof and, subject to the terms and conditions herein,
supersede all prior and contemporaneous agreements and understandings, whether oral or written, of any of the parties hereto with respect thereto. 

  
 13 

 5.6 Amendment and Waiver. No provision of this Agreement may be
amended, modified or waived except by an instrument in writing executed by the Company and the Stockholders owning 75% of the then outstanding shares of Common Stock and Preferred Stock held by all Stockholders, with such shares voting or
consenting, as the case may be, together as a single class on an as-converted basis; provided, however, notwithstanding the foregoing: 
 (a) this Agreement may not be amended or terminated and the observance of any term of this Agreement may not be waived with respect to any Investor or Holder without the written consent of such Investor
or Holder unless such amendment, termination or waiver applies by its terms to all Investors or Holders, as the case may be, in the same fashion; 
 (b) the consent of the Holders shall not be required for any amendment or waiver if such amendment or waiver either (i) is not directly applicable to rights of the Holders hereunder or (ii) does
not adversely affect the rights of the Holders in a manner that is different than the effect on the rights of the other parties hereto; 
 (c) Schedule A and Schedule B may be amended by the Company from time to time to add information regarding additional Investors without the consent of the other parties hereto; 

(d) any provision hereof may be waived by the waiving party on such party’s own behalf, without the consent of any
other party; and 
 (e) Section 1.2(a)(i) shall not be amended or waived without the written consent
of MPM; Section 1.2(a)(ii) shall not be amended or waived without the written consent of ARCH; Section 1.2(b)(i) shall not be amended or waived without the written consent of OVP; and Section 1.2(b)(ii) shall not
be amended or waived without the written consent of Amgen, in each case, as long as such Investors are entitled to the rights conferred by Sections 1.2(a)(i), 1.2(a)(ii), 1.2(b)(i) and 1.2(b)(ii). 

The Company shall give prompt written notice of any amendment, termination or waiver hereunder to any party that did not consent in writing thereto. Any
amendment, termination or waiver effected in accordance with this Section 5.6 shall be binding on each party and all of such party’s successors and permitted assigns, whether or not any such party, successor or assignee entered into or
approved such amendment, termination or waiver. 
 5.7 Governing Law. This Agreement and any controversy
arising out of or relating to this Agreement shall be governed by and construed in accordance with the General Corporation Law of the State of Delaware as to matters within the scope thereof, and as to all other matters shall be governed by and
construed in accordance with the internal laws of the State of New York, without regard to conflict of law principles that would result in the application of any law other than the law of the State of New York. 

5.8 Additional Parties. The Company shall take all necessary action to ensure that each person who shall after the
date hereof acquire in excess of one percent (1%) of the issued and outstanding shares of the capital stock of the Company or securities of the Company 

  
 14 

 
exchangeable or exercisable for or convertible into such number of shares of capital stock of the Company shall become a party to this Agreement by executing and delivering to the Company an
Instrument of Adherence, and such additional party shall thereafter be added to Schedule A hereto and be deemed a Holder for all purposes of this Agreement, without the consent of the other parties hereto. The rights and obligations of any
Investor under this Agreement may be assigned or transferred to a third party in connection with any permitted sale or transfer of such Investor’s shares, provided that such assignee or transferee shall agree to be bound by and execute a
counterpart signature to this Agreement and thereafter, such assignee or transferee shall be deemed and “Investor” for the purposes of this Agreement. 
 5.9 Severability. If any provision of this Agreement shall be held to be illegal, invalid or unenforceable, such illegality, invalidity or unenforceability shall attach only to such provision and
shall not in any manner affect or render illegal, invalid or unenforceable any other provision of this Agreement, and this Agreement shall be carried out as if any such illegal, invalid or unenforceable provision were not contained herein.

 5.10 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 any term or provision of this Agreement. 
 5.11
Pronouns. Whenever the context may require, any pronouns used in this Agreement shall including the corresponding masculine, feminine or neuter form, and the singular form of nouns and pronouns shall include the plural, and vice versa.

 5.12 Counterparts. This Agreement may be executed in more than one counterpart, each of which shall be
deemed to be an original and which, together, shall constitute one and the same instrument. This Agreement, to the extent signed and delivered by means of a facsimile machine, will be treated in all manner and respects as an original agreement and
will be considered to have the same binding legal effect as if it were the original signed version thereof delivered in person. 
 5.13 Remedies. Each of the parties to this Agreement will be entitled to enforce its rights under this Agreement specifically, to recover damages by reason of any breach of any provision of this
Agreement and to exercise all other rights existing in its favor. The parties hereto agree and acknowledge that money damages may not be an adequate remedy for any breach of the provisions of this Agreement and that any party may in its sole
discretion apply to any court of law or equity of competent jurisdiction for specific performance or injunctive relief in order to enforce or prevent any violations of the provisions of this Agreement. 

5.14 Lock-up Agreement. In connection with an underwritten public offering of securities of the Company, each
Stockholder agrees not to sell publicly any shares of Stock owned (beneficially or of record) by such Stockholder or any other shares of Common Stock (other than shares of Stock or other shares of Common Stock being registered in such offering),
without the consent of such underwriters, for a period of not more than 180 days following the effective date of the registration statement relating to an initial public offering of the Company’s securities or for such shorter period requested
by the underwriters; provided, however, that (a) all other persons selling shares of Common Stock in such offering, all persons holding in excess of 

  
 15 

 
1% of the capital stock of the Company on a fully­ diluted basis and all executive officers and directors of the Company shall also have agreed not to sell publicly their Common Stock under
the circumstances and pursuant to the terms set forth in this Section 5.14; (b) such agreement only applies to the first such registration statement of the Company including securities to be sold on its behalf to the public in an
underwritten offering; (c) any discretionary waiver or termination of the restrictions of such agreements by the Company or the managing underwriter shall apply to all persons subject to such agreements pro rata based on the
number of shares of Common Stock subject to such agreements; and (d) shares of Common Stock purchased in the open market or from the several underwriters on or after the date of the effectiveness of the registration statement shall not be
restricted from transfer under such agreements. The Company may impose stop-transfer instructions with respect to the Stock owned by each Stockholder to enforce the provisions of this Section 5.14. 

5.15 Aggregation of Stock. For purposes of determining the availability of any rights under this Agreement, all
shares of Shares owned of record by any Affiliate of a Investor shall be deemed to be owned by such Investor. 
 [REMAINDER OF
PAGE INTENTIONALLY LEFT BLANK] 

  
 16 

 SCHEDULE A 

Holders 
 Name and
Address, Phone Number 
 Fax and Email of Investor 
 Deepshikha Datta 
 702 Park Avenue, #202 
 South Pasedena, CA 91030 
 Fax: 
 Email: 
 William Goddard 
 139-74 Caltech 
 Pasadena, CA 91125 
 Fax: 
 Email: 
 David Tirrell 
 Division Chair 
 Chemistry and Chemical Engineering 
 California Institute of Technology 

Pasadena, CA 91125 
 Fax: 

Email: 
 Meenu Chhabra 

c/o Allozyne, Inc. 
 1616 Eastlake Ave. E., Suite
202 
 Seattle, WA 98102 
 Fax:

 Email:   mchhabra@allozyne.com 
 Ken Grabstein 
 c/o Allozyne, Inc. 
 1616 Eastlake Ave. E., Suite 202 
 Seattle, WA 98102 

Fax: 
 Email:   kgrabstein@allozyne.com

  
 17 

 ISB 
 Institute for Systems Biology 
 1441 North 34th Street 
 Seattle, WA 98103 
 Attn: Lee Hood, Gary Raisl 

Fax: (206) 732-1260 
 Email:
lhood@systemsbiology.org 
             graisl@systemsbiology.org 

  
 18 

 Investors 

 

			
	Name and Address, Phone Number
	Fax and Email of lnvestor
	
	ARCH Venture Fund V, L.P.
	8725 W. Higgins Road
	Suite 290
	Chicago, IL 60631
	Fax:	 	(773) 380-6606
	Attn:	 	Steve Gillis
	Email:	 	sgillis@archventure.com
	
	ARCH V Entrepreneurs Fund, L.P.
	8725 W. Higgins Road
	Suite 290
	Chicago, IL 60631
	Fax:	 	(773) 380-6606
	Attn:	 	Steve Gillis
	Email:	 	sgillis@archventure.com
	
	ARCH Venture Fund VI, L.P.
	8725 W. Higgins Road
	Suite 290
	Chicago, IL 60631
	Fax:	 	(773) 380-6606
	Attn:	 	Steve Gillis
	Email:	 	sgillis@archventure.com
	
	Alexandria Equities, LLC
	385 East Colorado Boulevard
	Suite 299
	Pasadena, CA 91101
	Fax:	 	(626) 578-0770
	Attn:	 	Joel Marcus
	Email:	 	jmarcus@labspace.com
	
	Alexandria Accelerator LLC
	385 East Colorado Boulevard
	Suite 299
	Pasadena, CA 91101
	Fax:	 	(626) 578-0770
	Attn:	 	Joel Marcus
	Email: 	 	jmarcus@labspace.com

  
 19 

			
	Name and Address, Phone Number
	Fax and Email of lnvestor
	
	Amgen Ventures LLC
	4445 Eastgate Mall
	 Suite 230
 San
Diego, California 92121

	Attention:	 	Joseph “Jay” Hagan
		 	Managing Director
	Email:	 	jhagan@amgen.com
	Facsimile: 	 	(858) 626-2709
	
	MPM BioVentures III, L.P.
	The John Hancock Tower
	200 Clarendon Street, 54th Floor
	Boston, MA 02116
	Fax:	 	(617) 425-9201
	Attn:	 	 Lauren Fiore
 Michael
Steinmetz

	Email:	 	lfiore@mpmcapital.com
		 	msteinmetz@clarusventures.com
	
	MPM BioVentures III-QP, L.P.
	The John Hancock Tower
	200 Clarendon Street, 54th Floor
	Boston, MA 02116
	Fax:	 	(617) 425-9201
	Attn:	 	Lauren Fiore
		 	Michael Steinmetz
	Email:	 	lfiore@mpmcapital.com
		 	msteinmetz@clarusventures.com
	
	MPM BioVentures III GmbH & Co.
	Beteiligungs KG
	The John Hancock Tower
	200 Clarendon Street, 54th Floor
	Boston, MA 02116
	Fax:	 	(617) 425-9201
	Attn:	 	Lauren Fiore
		 	Michael Steinmetz
	Email:	 	lfiore@mpmcapital.com
		 	msteinmetz@clarusventures.com

  
 20 

			
	Name and Address, Phone Number
	Fax and Email of lnvestor
	
	MPM BioVentures III Parallel Fund, L.P.
	The John Hancock Tower
	200 Clarendon Street, 54th Floor
	Boston, MA 02116
	Fax:	 	(617) 425-9201
	Attn:	 	 Lauren Fiore
 Michael
Steinmetz

	Email: 	 	lfiore@mpmcapital.com
		 	msteinmetz@clarusventures.com
	
	MPM Asset Management Investors 2003
	BVIII LLC
	The John Hancock Tower
	200 Clarendon Street, 54th Floor
	Boston, MA 02116
	Fax:	 	(617) 425-9201
	Attn:	 	Lauren Fiore
		 	Michael Steinmetz
	Email:	 	lfiore@mpmcapital.com
		 	msteinmetz@clarusventures.com
	
	OVP Venture Partners VI, L.P.
	c/o OVP Venture Partners
	1010 Market Street
	Kirkland, WA 98033
	Attn:	 	Bill Funcannon
	Fax:	 	(425) 889-0152
	Email:	 	funcannon@ovp.com
		 	waite@ovp.com
	
	OVP VI Entrepreneurs Fund, L.P.
	c/o OVP Venture Partners
	1010 Market Street
	Kirkland, WA 98033
	Attn:	 	Bill Funcannon
	Fax:	 	(425) 889-0152
	Email:	 	funcannon@ovp.com
		 	waite@ovp.com

  
 21

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00194-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00194-of-00352.parquet"}]]