EX-4.2



 Exhibit 4.2 

SURFACE ONCOLOGY, INC. 

INVESTORS’ RIGHTS AGREEMENT 

THIS INVESTORS’ RIGHTS AGREEMENT (this “Agreement”), is made as of the 6th day of November, 2014, by and among SURFACE
ONCOLOGY, 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”. 

RECITALS 

WHEREAS, the Company and the Investors are parties to the Series A Preferred Stock Purchase Agreement of even date herewith (the
“Purchase Agreement”); and 
 WHEREAS, in order to induce the Company to enter into the Purchase Agreement and to
induce the Investors to invest funds in the Company pursuant to the Purchase Agreement, the Investors and the Company hereby agree that this Agreement shall govern the rights of the Investors to cause the Company to register shares of Common Stock
issuable to the Investors, to receive certain information from the Company, and to participate in future equity offerings by the Company, and shall govern certain other matters as set forth in this Agreement. 

NOW, THEREFORE, the parties hereby agree as follows: 

1. Definitions. For purposes of this Agreement: 

1.1 “Affiliate” means, with respect to any specified Person, any other Person who, directly or indirectly, controls, is
controlled by, or is under common control with such Person, including, without limitation, any general partner, managing member, limited partner, member, employee, officer or director of such Person or any venture capital fund now or hereafter
existing that is controlled by one or more general partners or managing members of, or shares the same management company with, such Person. For purposes of this definition, the term “control” when used with respect to any Person means the
power to direct the management or policies of such Person, directly or indirectly, whether through ownership of voting securities, by contract or otherwise, and the terms “controlling” and “controlled” shall have meanings
correlative to the foregoing. 
 1.2 “Amgen” means Amgen Investments Ltd. 

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

1.4 “Competitor” means a Person engaged, directly or indirectly (including through any partnership, limited liability company,
corporation, joint venture or similar arrangement (whether now existing or formed hereafter)), in (i) developing or commercializing one or more products or product candidates, or (ii) conducting or supervising a drug discovery program
against a target, which in either case (i) or (ii) is the subject of a discovery or development program conducted or supervised by the Company in the field of oncology, but shall not include any financial investment firm or collective
investment vehicle that, together with its Affiliates, holds less than twenty percent (20%) of the outstanding equity of any Competitor and does not, nor do any of its Affiliates, have a right to designate any members of the Board of Directors
of any Competitor. The Company and each of the Investors acknowledge that none of the Investors shall be deemed to be a Competitor by virtue of its (or any of its Affiliates’) status as an Investor in, or collaboration or licensing partner
with, the Company, and that Novartis shall not be deemed to be a Competitor solely by virtue of the actions or investments of Novartis Venture Fund. 







 1.5 “Current Investor” means each Investor holding (i) Registrable
Securities or (ii) shares of Common Stock issued or issuable (directly or indirectly) upon conversion of the Series A Preferred Stock, regardless of whether such shares of Common Stock are Registrable Securities. 

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

1.7 “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. 
 1.8 “Exchange Act” means the Securities
Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder. 
 1.9 “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; (iii) a
registration on any form that does not include substantially the same information as would be required to be included in a registration statement covering the sale of the Registrable Securities; or (iv) a registration in which the only Common
Stock being registered is Common Stock issuable upon conversion of debt securities that are also being registered. 
 1.10 “FOIA
Party” means a Person that, in the reasonable determination of the Board of Directors, may be subject to, and thereby required to disclose non-public information furnished by or relating to the Company under, the Freedom of Information Act,
5 U.S.C. 552 (“FOIA”), any state public records access law, any state or other jurisdiction’s laws similar in intent or effect to FOIA, or any other similar statutory or regulatory requirement. 

1.11 “Form S-1” means such form under the Securities Act as in effect on the date hereof or any successor registration form
under the Securities Act subsequently adopted by the SEC. 
 1.12 “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. 

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

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

  
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 1.15 “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. 

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

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

1.18 “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). 

1.19 “Major Investor” means any Investor that, individually or together with such Investor’s Affiliates, holds at least
the number of shares of Registrable Securities (as adjusted for any stock split, stock dividend, combination, or other recapitalization or reclassification effected after the date hereof) at and following each Closing, as described below. For the
avoidance of doubt, any Investor that no longer holds shares of Series A Preferred Stock as a result of a Special Mandatory Conversion pursuant to Article Fourth Section B, Subsection 5A of the Restated Certificate shall not be considered to be a
Major Investor. 
  

			
	Closing	  	Number of shares of Registrable
Securities required to be a Major
Investor
	 Initial Closing*
	  	500,000
	 First Milestone Closing*
	  	1,000,000
	 Second Milestone Closing*
	  	2,000,000

  

	*	as defined in the Purchase Agreement 

 1.20 “NEA” means New Enterprise
Associates 14, L.P. 
 1.21 “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; other than shares of
Series A Preferred Stock to be purchased by the Investors pursuant to the Purchase Agreement, including at the Milestone Closings (as defined therein). 

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

 1.23 “Registrable Securities” means (i) the Common Stock issuable or issued upon conversion of the Series A
Preferred Stock (other than any Common Stock so issued pursuant to Article Fourth Section B, Subsection 5A of the Restated Certificate); (ii) any Common Stock, or any Common Stock issued or issuable (directly or indirectly) upon conversion
and/or exercise of any other securities of 

  
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the Company, acquired by the Investors after the date hereof (other than any Common Stock issued pursuant to any “special mandatory conversion” or “pay-to-play” provision
similar to Article Fourth Section B, Subsection 5A of the Restated Certificate); 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 clause (i) 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 Subsection 6.1, and excluding for purposes of Section 2 any shares for which registration rights have terminated pursuant to Subsection 2.13 of this Agreement. Notwithstanding the
parentheticals in clauses (i) and (ii) above, and solely for the purposes of Section 2, Subsection 3.1 (including the definition of “Current Investor” as used in Subsection 3.1), Subsection 3.7,
and Subsection 6.1 of this Agreement, any Common Stock issued pursuant to Article Fourth Section B, Subsection 5A of the Restated Certificate in connection with a Milestone Closing Election (as defined in the Purchase Agreement) shall be
considered Registrable Securities. 
 1.24 “Registrable Securities then outstanding” means the number of shares determined
by adding the number of shares of outstanding Common Stock that are Registrable Securities and the number of shares of Common Stock issuable (directly or indirectly) pursuant to then exercisable and/or convertible securities that are Registrable
Securities. 
 1.25 “Restated Certificate” means the Company’s Amended and Restated Certificate of Incorporation, as
may be further amended or restated from time to time. 
 1.26 “Restricted Securities” means the securities of the Company
required to be notated with the legend set forth in Subsection 2.12(b) hereof. 
 1.27 “SEC” means the Securities and
Exchange Commission. 
 1.28 “SEC Rule 144” means Rule 144 promulgated by the SEC under the Securities Act. 

1.29 “SEC Rule 145” means Rule 145 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 for the fees and disbursements of the Selling Holder Counsel borne and paid by the Company as provided in Subsection 2.6. 

1.32 “Series A Director” means any director of the Company that the holders of record of the Series A Preferred Stock are
entitled to elect pursuant to the Restated Certificate. 
 1.33 “Series A Preferred Stock” means, shares of the
Company’s Series A Preferred Stock, par value $0.0001 per share. 

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

2.1 Demand Registration. 

(a) Form S-1 Demand. If at any time after the earlier of (i) five (5) years after the date of this Agreement or (ii) one
hundred eighty (180) days after the effective date of the registration statement for the IPO, the Company receives a request from Holders of, if the NEA Purchase (as defined in the Purchase Agreement) has occurred, at least sixty-one percent
(61%) of the Registrable Securities then outstanding, or if the NEA Purchase has not occurred, at least fifty-one percent (51%) of the Registrable Securities then outstanding, that the Company file a Form S-1 registration statement with
respect to at least thirty-three and one-third percent (33 1/3%) of the Registrable Securities then outstanding (or a lesser percent if the anticipated aggregate offering price, net of Selling Expenses, would exceed $10 million), then the Company
shall (x) within ten (10) days after the date such request is given, give notice thereof (the “Demand Notice”) to all Holders other than the Initiating Holders; and (y) as soon as practicable, and in any event within
sixty (60) days after the date such request is given by the Initiating Holders, file a Form S-1 registration statement under the Securities Act covering all Registrable Securities that the Initiating Holders requested to be registered and any
additional Registrable Securities requested to be included in such registration by any other Holders, as specified by notice given by each such Holder to the Company within twenty (20) days of the date the Demand Notice is given, and in each
case, subject to the limitations of Subsections 2.1(c) and 2.3. 
 (b) Form S-3 Demand. If at any time when it is
eligible to use a Form S-3 registration statement, the Company receives a request from Holders of at least 25 percent (25%) of the Registrable Securities then outstanding that the Company file a Form S-3 registration statement with respect to
outstanding Registrable Securities of such Holders having an anticipated aggregate offering price, net of Selling Expenses, of at least $3 million, then the Company shall (i) within ten (10) days after the date such request is given, give
a Demand Notice to all Holders other than the Initiating Holders; and (ii) as soon as practicable, and in any event within forty-five (45) days after the date such request is given by the Initiating Holders, file a Form S-3 registration
statement under the Securities Act covering all Registrable Securities requested to be included in such registration by any other Holders, as specified by notice given by each such Holder to the Company within twenty (20) days of the date the
Demand Notice is given, and in each case, subject to the limitations of Subsections 2.1(c) and 2.3. 
 (c) Notwithstanding the
foregoing obligations, if the Company furnishes to Holders requesting a registration pursuant to this Subsection 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 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 ninety (90) days after the request of the Initiating Holders is
given; provided, however, that the Company may not invoke this right more than twice in any twelve (12) month period; and provided further that the Company shall not register any securities for its own account or that of
any other stockholder during such ninety (90) day period other than an Excluded Registration. 
 (d) The Company shall not be obligated
to effect, or to take any action to effect, any registration pursuant to Subsection 2.1(a)(i) during the period that is sixty (60) days before the Company’s good faith estimate of the date of filing of, and ending on a date that is
one hundred eighty (180) days after the effective date of, a Company-initiated registration, provided that the Company is actively employing in good faith commercially reasonable efforts to cause such registration statement to 

  
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become effective; (ii) after the Company has effected one registration pursuant to Subsection 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 Subsection 2.1(b). The Company shall not be obligated to effect, or to take any action to effect, any registration pursuant to Subsection
2.1(b) (i) during the period that is thirty (30) days before the Company’s good faith estimate of the date of filing of, and ending on a date that is ninety (90) days after the effective date of, a Company-initiated
registration, provided that the Company is actively employing in good faith commercially reasonable efforts to cause such registration statement to become effective; or (ii) if the Company has effected two registrations pursuant to
Subsection 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 Subsection 2.1(d) until such time as the
applicable registration statement has been declared effective by the SEC, unless the Initiating Holders withdraw their request for such registration, elect not to pay the registration expenses therefor, and forfeit their right to one demand
registration statement pursuant to Subsection 2.6, in which case such withdrawn registration statement shall be counted as “effected” for purposes of this Subsection 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 Common Stock under the Securities Act in connection with the public offering of such securities solely for cash (other than in an Excluded Registration), the Company shall, at such time, promptly give
each Holder notice of such registration. Upon the request of each Holder given within twenty (20) days after such notice is given by the Company, the Company shall, subject to the provisions of Subsection 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 Subsection 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
Subsection 2.6. 
 2.3 Underwriting Requirements. 

(a) If, pursuant to Subsection 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 Subsection 2.1, and the Company shall include such information in the Demand Notice. The underwriter(s) will be selected by the Company and
shall be reasonably acceptable to a majority in interest of the Initiating Holders. In such event, the right of any Holder to include such Holder’s Registrable Securities in such registration shall be conditioned upon such Holder’s
participation in such underwriting and the inclusion of such Holder’s Registrable Securities in the underwriting to the extent provided herein. All Holders proposing to distribute their securities through such underwriting shall (together with
the Company as provided in Subsection 2.4(e)) enter into an underwriting agreement in customary form with the underwriter(s) selected for such underwriting. Notwithstanding any other provision of this Subsection 2.3, if the managing
underwriter(s) advise(s) the Initiating Holders in writing that marketing factors require a limitation on the number of shares to be underwritten, then the Initiating Holders shall so advise all Holders of Registrable Securities that otherwise would
be underwritten pursuant hereto, and the number of Registrable Securities that may be included in the underwriting shall be allocated among such Holders of Registrable Securities, including the Initiating Holders, in proportion (as nearly as
practicable) to the number of Registrable Securities owned by each Holder or in such other proportion as shall mutually be agreed to by all such selling Holders; provided, however, that the number of Registrable Securities held by the
Holders to be included in such underwriting shall not be reduced unless all other securities are first entirely excluded from the underwriting. To facilitate the allocation of shares in accordance with the above provisions, the Company or the
underwriters may round the number of shares allocated to any Holder to the nearest one hundred (100) shares. 

  
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 (b) In connection with any offering involving an underwriting of shares of the Company’s
capital stock pursuant to Subsection 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 one hundred (100) shares. Notwithstanding the foregoing, in no event shall (i) the number of
Registrable Securities included in the offering be reduced unless all other securities (other than securities to be sold by the Company) are first entirely excluded from the offering, or (ii) the number of Registrable Securities included in the
offering be reduced below thirty percent (30%) of the total number of securities included in such offering, unless such offering is the IPO, in which case the selling Holders may be excluded further if the underwriters make the determination
described above and no other stockholder’s securities are included in such offering. For purposes of the provision in this Subsection 2.3(b) concerning apportionment, for any selling Holder that is a partnership, limited liability
company, or corporation, the partners, members, retired partners, retired members, stockholders, and Affiliates of such Holder, or the estates and Immediate Family Members of any such partners, retired partners, members, and retired members and any
trusts for the benefit of any of the foregoing Persons, shall be deemed to be a single “selling Holder,” and any pro rata reduction with respect to such “selling Holder” shall be based upon the aggregate number of Registrable
Securities owned by all Persons included in such “selling Holder,” as defined in this sentence. 
 (c) For purposes of
Subsection 2.1, a registration shall not be counted as “effected” if, as a result of an exercise of the underwriters’ cutback provisions in Subsection 2.3(a), fewer than fifty percent (50%) of the total number of
Registrable Securities that Holders have requested to be included in such registration statement are actually included. 
 2.4 Obligations
of the Company. Whenever required under this Section 2 to effect the registration of any Registrable Securities, the Company shall, as expeditiously as reasonably possible: 

(a) prepare and file with the SEC a registration statement with respect to such Registrable Securities and use its commercially reasonable
efforts to cause such registration statement to become effective and, upon the request of the Holders of a majority of the Registrable Securities registered thereunder, keep such registration statement effective for a period of up to one hundred
twenty (120) days or, if earlier, until the distribution contemplated in the registration statement has been completed; provided, however, that (i) such one hundred twenty (120) day period shall be extended for a period
of time equal to the period the Holder refrains, at the request of an underwriter of Common Stock (or other securities) of the Company, from selling any securities included in such 

  
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registration, and (ii) in the case of any registration of Registrable Securities on Form S-3 that are intended to be offered on a continuous or delayed basis, subject to compliance with
applicable SEC rules, such one hundred twenty (120) day period shall be extended for up to sixty (60) days, if necessary, to keep the registration statement effective until all such Registrable Securities are sold; 

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

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

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

(e) in the event of any underwritten public offering, enter into and perform its obligations under an underwriting agreement, in usual and
customary form, with the underwriter(s) of such offering; 
 (f) use its commercially reasonable efforts to cause all such Registrable
Securities covered by such registration statement to be listed on a national securities exchange or trading system and each securities exchange and trading system (if any) on which similar securities issued by the Company are then listed; 

(g) provide a transfer agent and registrar for all Registrable Securities registered pursuant to this Agreement and provide a CUSIP number for
all such Registrable Securities, in each case not later than the effective date of such registration; 
 (h) promptly make available for
inspection by the selling Holders, any managing underwriter(s) participating in any disposition pursuant to such registration statement, and any attorney or accountant or other agent retained by any such underwriter or selected by the selling
Holders, all financial and other records, pertinent corporate documents, and properties of the Company, and cause the Company’s officers, directors, employees, and independent accountants to supply all information reasonably requested by any
such seller, underwriter, attorney, accountant, or agent, in each case, as necessary or advisable to verify the accuracy of the information in such registration statement and to conduct appropriate due diligence in connection therewith; 

(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. 

  
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 In addition, the Company shall ensure that, at all times after any registration statement
covering a public offering of securities of the Company under the Securities Act shall have become effective, its insider trading policy shall provide that the Company’s directors may implement a trading program under Rule 10b5-1 of the
Exchange Act. 
 2.5 Furnish Information. It shall be a condition precedent to the obligations of the Company to take any action
pursuant to this Section 2 with respect to the Registrable Securities of any selling Holder that such Holder shall furnish to the Company such information regarding itself, the Registrable Securities held by it, and the intended method
of disposition of such securities as is reasonably required to effect the registration of such Holder’s Registrable Securities. 
 2.6
Expenses of Registration. All expenses (other than Selling Expenses) incurred in connection with registrations, filings, or qualifications pursuant to Section 2, including all registration, filing, and qualification fees;
printers’ and accounting fees; fees and disbursements of counsel for the Company; and the reasonable fees and disbursements, not to exceed $30,000, of one counsel for the selling Holders (“Selling Holder Counsel”), shall be
borne and paid by the Company; provided, however, that the Company shall not be required to pay for any expenses of any registration proceeding begun pursuant to Subsection 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 Subsections 2.1(a) or 2.1(b), as the case may be; provided further that if, at the
time of such withdrawal, the Holders shall have learned of a material adverse change in the condition, business, or prospects of the Company from that known to the Holders at the time of their request and have withdrawn the request with reasonable
promptness after learning of such information, then the Holders shall not be required to pay any of such expenses and shall not forfeit their right to one registration pursuant to Subsections 2.1(a) or 2.1(b). All Selling Expenses
relating to Registrable Securities registered pursuant to this Section 2 shall be borne and paid by the Holders pro rata on the basis of the number of Registrable Securities registered on their behalf. 

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

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

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

  
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 (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 Subsection 2.8(b) shall not apply to amounts paid in settlement of any such claim or proceeding if such settlement is
effected without the consent of the Holder, which consent shall not be unreasonably withheld; and provided further that in no event shall the aggregate amounts payable by any Holder by way of indemnity or contribution under
Subsections 2.8(b) and 2.8(d) exceed the proceeds from the offering received by such Holder (net of any Selling Expenses paid by such Holder), except in the case of fraud or willful misconduct by such Holder. 

(c) Promptly after receipt by an indemnified party under this Subsection 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 Subsection 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. 

(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 Subsection 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 Subsection 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 Subsection 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 

  
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 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 Subsection 2.8(d), when combined with the amounts paid or payable by such Holder pursuant to
Subsection 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 Subsection 2.8 shall survive the completion of any offering of Registrable Securities in a registration under this Section 2, and otherwise shall survive the termination of this Agreement.

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

(a) use commercially reasonable efforts to make and keep available adequate current public information, as those terms are understood and
defined in SEC Rule 144, at all times after the effective date of the registration statement filed by the Company for the IPO; 
 (b) use
commercially reasonable efforts to file with the SEC in a timely manner all reports and other documents required of the Company under the Securities Act and the Exchange Act (at any time after the Company has become subject to such reporting
requirements); and 
 (c) furnish to any Holder, so long as the Holder owns any Registrable Securities, forthwith upon request (i) to
the extent accurate, a written statement by the Company that it has complied with the reporting requirements of SEC Rule 144 (at any time after ninety (90) days after the effective date of the registration statement filed by the Company for the
IPO), the Securities Act, and the Exchange Act (at any time after the Company has become subject to such reporting requirements), or that it qualifies as a registrant whose securities may be resold pursuant to Form S-3 (at any time after the Company
so qualifies); (ii) a copy of the most recent annual or quarterly report of the Company and such other reports and documents so filed by the Company; and (iii) such other information as may be reasonably requested in availing any Holder of
any rule or regulation of the SEC that permits the selling of any such securities without registration (at any time after the Company has become subject to the reporting requirements under the Exchange Act) or pursuant to Form S-3 (at any time after
the Company so qualifies to use such form). 
 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, if the NEA Purchase has occurred, the Holders of at least sixty-one percent (61%) of the Registrable Securities then outstanding, or if the NEA Purchase has not occurred,
at least fifty-one percent (51%) of the Registrable Securities then outstanding, enter into any agreement with any holder or prospective holder of any securities of the Company that (i) would provide to such holder the right to include
securities in any registration on other than either a pro rata basis with respect to the Registrable Securities or on a subordinate basis after all Holders have had the opportunity to include in the registration and offering all shares of
Registrable 

  
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 Securities that they wish to so include or (ii) allow such holder or prospective holder to initiate a demand
for registration of any securities held by such holder or prospective holder; provided that this limitation shall not apply to any additional Investor who becomes a party to this Agreement in accordance with Subsection 6.9. 

2.11 “Market Stand-off” Agreement. Each Holder hereby agrees that it will not, without the prior written consent of the
managing underwriter, during the period commencing on the date of the final prospectus relating to the registration by the Company of shares of its Common Stock or any other equity securities under the Securities Act on a registration statement on
Form S-1 or Form S-3, and ending on the date specified by the Company and the managing underwriter (such period not to exceed one hundred eighty (180) days in the case of the IPO, or such other period as may be requested by the Company or an
underwriter to accommodate regulatory restrictions on (1) the publication or other distribution of research reports, and (2) analyst recommendations and opinions, including, but not limited to, the restrictions contained in FINRA Rule
2711(f)(4) or NYSE Rule 472(f)(4), or any successor provisions or amendments thereto), or ninety (90) days in the case of any registration other than the IPO, or such other period as may be requested by the Company or an underwriter to
accommodate regulatory restrictions on (1) the publication or other distribution of research reports and (2) analyst recommendations and opinions, including, but not limited to, the restrictions contained in FINRA Rule 2711(f)(4) or NYSE
Rule 472(f)(4), or any successor provisions or amendments thereto), (i) lend; offer; pledge; sell; contract to sell; sell any option or contract to purchase; purchase any option or contract to sell; grant any option, right, or warrant to
purchase; or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable (directly or indirectly) for Common Stock (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 clause (i) or (ii) above is to be settled by delivery of Common Stock or other securities, in cash, or otherwise. The foregoing provisions of this Subsection 2.11 shall not apply to the sale of any shares to
an underwriter pursuant to an underwriting agreement, or the transfer of any shares to any trust for the direct or indirect benefit of the Holder or the immediate family of the Holder, provided that the trustee of the trust agrees to be bound
in writing by the restrictions set forth herein, and provided further that any such transfer shall not involve a disposition for value, and shall be applicable to the Holders only if all officers and directors are subject to the same
restrictions and the Company uses commercially reasonable efforts to obtain a similar agreement from all stockholders individually owning more than one percent (1%) of the Company’s outstanding Common Stock (after giving effect to
conversion into Common Stock of all outstanding Series A Preferred Stock). The underwriters in connection with such registration are intended third-party beneficiaries of this Subsection 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
Subsection 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, except that, notwithstanding the foregoing, the Company and the underwriters may, in their sole discretion, waive or terminate these restrictions with respect to up to
100,000 shares of the Common Stock (as adjusted for any stock split, stock dividend, combination, or other recapitalization or reclassification effected after the date hereof), without application of such waiver or termination to all Holders subject
to such agreements. 

  
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 2.12 Restrictions on Transfer. 

(a) The Series A Preferred Stock and the Registrable Securities shall not be sold, pledged, or otherwise transferred, and the Company shall
not recognize and shall issue stop-transfer instructions to its transfer agent with respect to any such sale, pledge, or transfer, except upon the conditions specified in this Agreement, which conditions are intended to ensure compliance with the
provisions of the Securities Act. A transferring Holder will cause any proposed purchaser, pledgee, or transferee of the Series A Preferred Stock and the Registrable Securities held by such Holder to agree to take and hold such securities subject to
the provisions and upon the conditions specified in this Agreement. 
 (b) Each certificate, instrument, or book entry representing
(i) the Series A 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 Subsection 2.12(c)) be notated with a legend substantially in the following form: 

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

THE SECURITIES REPRESENTED HEREBY MAY BE TRANSFERRED ONLY IN ACCORDANCE WITH THE TERMS OF AN AGREEMENT BETWEEN THE COMPANY AND THE STOCKHOLDER,
A COPY OF WHICH IS ON FILE WITH THE SECRETARY OF THE COMPANY. 
 The Holders consent to the Company making a notation in its records and
giving instructions to any transfer agent of the Restricted Securities in order to implement the restrictions on transfer set forth in this Subsection 2.12. 

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

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

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

(b) such time as Rule 144 or another similar exemption under the Securities Act is available for the sale of all of such Holder’s shares
without limitation during a three-month period without registration; and 
 (c) the fifth anniversary of the IPO. 

3. Information and Observer Rights. 

3.1 Delivery of Financial Statements. For so long as any shares of Preferred Stock shall remain outstanding, the Company shall deliver
to each Current Investor: 
 (a) as soon as practicable, but in any event within one hundred fifty (150) 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 a comparison between (x) the actual amounts as of and for such fiscal year and (y) the
comparable amounts for the prior year and as included in the Budget (as defined in Subsection 3.1(e)) for such year, with an explanation of any material differences between such amounts and a schedule as to the sources and applications of
funds for such year, and (iii) a statement of stockholders’ equity as of the end of such year, prepared in accordance with GAAP, and, beginning for the 2017 fiscal year, audited and certified by an independent public accounting firm of
nationally or regionally recognized standing selected by the Board of Directors. 
 (b) as soon as practicable, but in any event within
forty-five (45) days after the end of each quarter of each fiscal year of the Company, unaudited statements of income and cash flows for such fiscal quarter, and an unaudited balance sheet and a statement of stockholders’ equity as of the
end of such fiscal quarter, all prepared in accordance with GAAP (except that such financial statements may (i) be subject to normal year-end audit adjustments; and (ii) not contain all notes thereto that may be required in accordance with
GAAP); 
 (c) as soon as practicable, but in any event within forty-five (45) days after the end of each quarter of each fiscal year of
the Company, a statement showing the number of shares of each class and series of capital stock and securities convertible into or exercisable for shares of capital stock outstanding at the end of the period, the Common Stock issuable upon
conversion or exercise of any outstanding securities convertible or exercisable for Common Stock and the exchange ratio or exercise price applicable thereto, and the number of shares of issued stock options and stock options not yet issued but
reserved for issuance, if any, all in sufficient detail as to permit the Current Investors to calculate their respective percentage equity ownership in the Company, and certified by the chief financial officer or chief executive officer of the
Company as being true, complete, and correct; and 

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

In addition, the Company shall deliver to each Major Investor, unless the Board of Directors, including each of the Series A Directors, determines otherwise:

 (e) as soon as practicable, but in any event thirty (30) 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; 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 Subsection 3.1 to provide
information (i) that the Company reasonably determines in good faith to be a trade secret or confidential information (unless covered by an enforceable confidentiality agreement, in a form acceptable to the Company); or (ii) the disclosure
of which would adversely affect the attorney-client privilege between the Company and its counsel. 
 If, for any period, the Company has
any subsidiary whose accounts are consolidated with those of the Company, then in respect of such period the financial statements delivered pursuant to the foregoing sections shall be the consolidated and consolidating financial statements of the
Company and all such consolidated subsidiaries. 
 Notwithstanding anything else in this Subsection 3.1 to the contrary, the Company
may cease providing the information set forth in this Subsection 3.1 during the period starting with the date sixty (60) days before the Company’s good-faith estimate of the date of filing of a registration statement if it
reasonably concludes it must do so to comply with the SEC rules applicable to such registration statement and related offering; provided that the Company’s covenants under this Subsection 3.1 shall be reinstated at such time as
the Company is no longer actively employing its commercially reasonable efforts to cause such registration statement to become effective. 

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

(a) For so long as Atlas Venture Fund IX, L.P. or its Affiliates (“Atlas”) is a Major Investor, the Company shall invite a
representative of Atlas (the “Atlas Observer”) to attend all meetings of its Board of Directors in a nonvoting observer capacity and, in this respect, shall give such representative copies of all notices, minutes, consents, and
other materials that it provides to its directors at the same time and in the same manner as provided to such directors. 

  
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 (b) For so long as Amgen or its Affiliates is a Major Investor, the Company shall invite a
representative of Amgen (the “Amgen Observer”) to attend all meetings of its Board of Directors in a nonvoting observer capacity and, in this respect, shall give such representative copies of all notices, minutes, consents, and
other materials that it provides to its directors at the same time and in the same manner as provided to such directors. Amgen agrees that any information received by the Amgen Observer will not be shared within Amgen other than (i) with
investment, legal, finance, tax, accounting and audit personnel thereof solely for the purpose of monitoring its investment in the Company, including without limitation consideration of any potential follow-on investment; provided that in each such
case, the recipient shall only receive such information as is pertinent to permit such party to carry out the permitted purposes hereunder, or (ii) as otherwise approved in advance by the Board of Directors. 

(c) For so long as Novartis Institutes for BioMedical Research, Inc. or its Affiliates (“Novartis”) is a Major Investor, the
Company shall invite a representative of Novartis who is acceptable to the Company’s Board of Directors, which acceptance shall not be unreasonably withheld (the “Novartis Observer” and together with the Atlas Observer and
Amgen Observer, the “Board Observers”) to attend all meetings of its Board of Directors in a nonvoting observer capacity and, in this respect, shall give such representative copies of all notices, minutes, consents, and other
materials that it provides to its directors at the same time and in the same manner as provided to such directors. The Novartis Observer shall initially be Martin Seidel or Catherine Thut. Novartis agrees that any information received by the
Novartis Observer will not be shared within Novartis other than (i) with investment, legal, finance, tax, accounting and audit personnel thereof solely for the purpose of monitoring its investment in the Company, including without limitation
consideration of any potential follow-on investment; provided that in each such case, the recipient shall only receive such information as is pertinent to permit such party to carry out the permitted purposes hereunder, or (ii) as otherwise
approved in advance by the Board of Directors. 
 (d) The Board Observers shall agree to hold in confidence and trust and to act in a
fiduciary manner with respect to all information provided to them in accordance with this Subsection 3.3. The Company reserves the right to withhold any information and to exclude a Board Observer from any meeting or portion thereof if, after
consultation with counsel, (1) the Company determines in good faith that access to such information or attendance at such meeting could adversely affect the attorney-client privilege between the Company and its counsel, (2) the Company
determines in good faith that access to such information or attendance at such meeting could result in disclosure of trade secrets or a conflict of interest, or (3) the Board of Directors determines in good faith that a Board Observer or the
Investor represented by such Board Observer is a Competitor. 
 3.4 FIRPTA Compliance. 

(a) For so long as NEA or its Affiliates is a Major Investor, the Company shall provide prompt notice to NEA following any “determination
date” (as defined in Treasury Regulation Section 1.897-2(c)(1)) on which the Company becomes a United States real property holding corporation. In addition, upon a written request by NEA, the Company shall provide NEA with a written
statement informing NEA whether NEA’s interest in the Company constitutes a United States real property interest. The Company’s determination shall comply with the requirements of Treasury Regulation Section 1.897-2(h)(1) or any
successor regulation, and the Company shall provide timely notice to the Internal Revenue Service, in accordance with and to the extent required by Treasury Regulation Section 1.897-2(h)(2) or any successor regulation, that such statement has
been made. The Company’s written statement to NEA shall be delivered to NEA within 10 days of NEA’s written request therefor. The Company’s obligation to furnish such written statement shall continue notwithstanding the fact that a
class of the Company’s stock may be regularly traded on an established securities market or the fact that there is no preferred stock then outstanding. 

  
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 (b) For so long as Amgen or its Affiliates is a Major Investor, the Company shall provide prompt
notice to Amgen following any “determination date” (as defined in Treasury Regulation Section 1.897-2(c)(1)) on which the Company becomes a United States real property holding corporation. In addition, upon a written request by Amgen,
the Company shall provide Amgen with a written statement informing Amgen whether Amgen’s interest in the Company constitutes a United States real property interest. The Company’s determination shall comply with the requirements of Treasury
Regulation Section 1.897-2(h)(1) or any successor regulation, and the Company shall provide timely notice to the Internal Revenue Service, in accordance with and to the extent required by Treasury Regulation Section 1.897-2(h)(2) or any
successor regulation, that such statement has been made. The Company’s written statement to Amgen shall be delivered to Amgen within 10 days of Amgen’s written request therefor. The Company’s obligation to furnish such written
statement shall continue notwithstanding the fact that a class of the Company’s stock may be regularly traded on an established securities market or the fact that there is no preferred stock then outstanding. 

3.5 Qualified Small Business Stock. The Company shall use commercially reasonable efforts to cause the shares of Series A Preferred
Stock issued pursuant to the Purchase Agreement, as well as any shares into which such shares are converted, within the meaning of Section 1202(f) of the Internal Revenue Code of 1986, as amended (the “Code”), to constitute
“qualified small business stock” as defined in Section 1202(c) of the Code; provided, however, that such requirement shall not be applicable if the Board of Directors determines, in its good faith business judgment, that such
qualification is inconsistent with the best interests of the Company. The Company shall submit to its stockholders (including the Investors) and to the Internal Revenue Service any reports that may be required under Section 1202(d)(1)(C) of the
Code and the regulations promulgated thereunder. In addition, within twenty (20) business days after any Investor’s written request therefor, the Company shall, at its option, either (i) deliver to such Investor a written statement
indicating whether (and what portion of) such Investor’s interest in the Company constitutes “qualified small business stock” as defined in Section 1202(c) of the Code or (ii) deliver to such Investor such factual
information in the Company’s possession as is reasonably necessary to enable such Investor to determine whether (and what portion of) such Investor’s interest in the Company constitutes “qualified small business stock” as defined
in Section 1202(c) of the Code. 
 3.6 Termination of Certain Covenants. The covenants set forth in Subsection 3.1,
Subsection 3.2, Subsection 3.3, Subsection 3.4 and Subsection 3.5 shall terminate and be of no further force or effect (i) immediately before the consummation of the IPO, (ii) when the Company first
becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon a Deemed Liquidation Event, as such term is defined in the Restated Certificate, whichever event occurs first. 

3.7 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, including without limitation any potential follow-on investment) 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 (a) is known or becomes known to the public in general (other than as a result of a breach of this Subsection 3.7 by such Investor),
(b) is or has been independently developed or conceived by the Investor without use of the Company’s confidential information, or (c) is or has been made known or disclosed to the Investor by a third party without a breach of any
obligation of confidentiality such third party may have to the Company; provided, 

  
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 however, that an Investor may disclose confidential information (i) to its attorneys, accountants,
consultants, and other professionals to the extent necessary to obtain their services in connection with monitoring its investment in the Company; (ii) to any prospective purchaser of any Registrable Securities from such Investor, if such
prospective purchaser agrees to be bound by the provisions of this Subsection 3.7; (iii) 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 (iv) 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. In the event that an Investor or any of its Affiliates (other than, in the case of Novartis, Novartis Venture Fund) becomes a
Competitor, such Investor shall so inform the Company and, as a condition to the disclosure thereafter of any Confidential Information to such Investor, such Investor and the Company shall negotiate and enter into a supplemental confidentiality and
non-use agreement, reasonably satisfactory to the Company. Alternatively, an Investor may elect at any time to negotiate and enter into such supplemental confidentiality and non-use agreement in advance of such Investor or its Affiliates becoming a
Competitor, and the Company will cooperate therewith. In the event that the Board of Directors determines in good faith that an Investor or any of its Affiliates (other than, in the case of Novartis, Novartis Venture Fund) has become a Competitor,
the Company shall so inform such Investor and, as a condition to the disclosure thereafter of any Confidential Information to such Investor, such Investor and the Company shall negotiate and enter into a supplemental confidentiality and non-use
agreement, reasonably satisfactory to the Company. 
 4. Rights to Future Stock Issuances. 

4.1 Right of First Offer. Subject to the terms and conditions of this Subsection 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 Investor. An Investor shall be entitled to apportion the right of first offer hereby granted to it in such proportions as it deems
appropriate, among (i) itself, (ii) its Affiliates and (iii) its beneficial interest holders, such as limited partners, members or any other Person having “beneficial ownership,” as such term is defined in Rule 13d-3
promulgated under the Exchange Act, of such Investor (“Investor Beneficial Owners”); provided that each such Affiliate or Investor Beneficial Owner (x) is not a Competitor or FOIA Party, unless such party’s purchase
of New Securities is otherwise consented to by the Board of Directors, (y) agrees to enter into this Agreement and each of the Voting Agreement and Right of First Refusal and Co-Sale Agreement of even date herewith among the Company, the
Investors and the other parties named therein, as an “Investor” under each such agreement (provided that any Competitor or FOIA Party to whom the foregoing right of first offer is apportioned shall not be entitled to any
rights as a Current Investor, Major Investor or Investor, as applicable, under Subsections 3.1, 3.2 and 4.1 hereof but the Investor that so apportioned the right of first offer shall retain all rights hereunder to which it would
otherwise be entitled in accordance with the terms hereof), and (z) agrees to purchase at least such number of New Securities as are allocable hereunder to the Investor holding the fewest number of Series A Preferred Stock and any other
Derivative Securities. 
 (a) The Company shall give notice (the “Offer Notice”) to each Investor, stating (i) its
bona fide intention to offer such New Securities, (ii) the number of such New Securities to be offered, and (iii) the price and terms, if any, upon which it proposes to offer such New Securities. 

(b) By notification to the Company within twenty (20) days after the Offer Notice is given, each 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 then held by such Investor (including the shares of Common Stock then
issuable (directly or indirectly) upon conversion and/or exercise, as applicable, of the Series A Preferred Stock and 

  
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 any other Derivative Securities then held by such Investor, but not including any shares of Common Stock then
held by such Investor that were acquired other than upon the exercise or conversion of Derivative Securities) bears to the total number of shares of Common Stock of the Company then held by all the Investors (including the shares of Common Stock
then issuable (directly or indirectly) upon conversion and/or exercise, as applicable, of the Series A Preferred Stock and any other Derivative Securities then held by the Investors, but not including any shares of Common Stock then held by the
Investors that were acquired other than upon the exercise or conversion of Derivative Securities) (with such portion being referred to as the “Pro Rata Percentage”). At the expiration of such twenty (20) day period, the Company
shall promptly notify each Investor that elects to purchase or acquire all the shares available to it (each, a “Fully Exercising Investor”) of any other Investor’s failure to do likewise. During the ten (10) day period
commencing after the Company has given such notice, each Fully Exercising Investor may, by giving notice to the Company, elect to purchase or acquire, in addition to the number of shares specified above, up to that portion of the New Securities for
which Investors were entitled to subscribe but that were not subscribed for by the Investors which is equal to the proportion that the Common Stock issued and held, or issuable (directly or indirectly) upon conversion and/or exercise, as applicable,
of Series A 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
Series A 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 Subsection 4.1(b) shall occur within the later of
ninety (90) days of the date that the Offer Notice is given and the date of initial sale of New Securities pursuant to Subsection 4.1(c). 

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

 (d) The right of first offer in this Subsection 4.1 shall not be applicable to (i) Exempted Securities (as defined in the
Restated Certificate); (ii) shares of Common Stock issued in the IPO, or (iii) shares of Series A Preferred Stock sold pursuant to the Purchase Agreement. 

(e) If an Investor fails to purchase, directly or through opportunities permitted by Subsection 4.1, in any transaction subject to this
Subsection 4.1, at least its Pro Rata Percentage of the New Securities allocated (or, if less than such Investor’s pro rata amount is offered by the Company, such lesser amount so offered), at an issuance of New Securities subject to
this Subsection 4.1, such Investor’s Pro Rata Percentage applicable to the next issuance of New Securities shall be reduced to the amount obtained by multiplying: (x) the Investor’s Pro Rata Percentage (obtained in accordance
with Subsection 4.1(b)) by (y) the Participation Percentage (as defined below). For the purposes of this section, the “Participation Percentage” shall be the amount obtained by dividing: (x) the number or amount of
New Securities purchased by such Investor at the immediately preceding issuance of New Securities by (y) the number or amount of New Securities that such Investor was entitled to purchase, as determined in accordance with Subsection
4.1(b). For the purposes of clarity, nothing in this Subsection 4.1(e) shall entitle an Investor to purchase more than its Pro Rata Percentage in any offering of New Securities. 

  
 19 








 (f) Notwithstanding any provision hereof to the contrary, in lieu of complying with the
provisions of this Subsection 4.1, the Company may elect to give notice to the Investors within thirty (30) days after the issuance of New Securities. Such notice shall describe the type, price, and terms of the New Securities. Each
Investor shall have twenty (20) days from the date notice is given to elect to purchase up to the number of New Securities that would, if purchased by such Investor, maintain such Investor’s percentage-ownership position, calculated as set
forth in Subsection 4.1(b) before giving effect to the issuance of such New Securities. The closing of such sale shall occur within sixty (60) days of the date notice is given to the Investors. 

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

5.1 Insurance. The Company shall use its commercially reasonable efforts to obtain, within ninety (90) days of the date hereof,
from financially sound and reputable insurers Directors and Officers liability insurance in an amount and on terms and conditions satisfactory to the Board of Directors (including all of the Series A Directors), and will use commercially reasonable
efforts to cause such insurance policy to be maintained until such time as the Board of Directors (including all of the Series A Directors) determines that such insurance should be discontinued. Such policy shall not be cancelable by the Company
without prior approval by the Board of Directors including (i) all of the Series A Directors and (ii) if the NEA Purchase has occurred, holders of at least sixty-one percent (61%) of the Series A Preferred Stock, or if the NEA
Purchase has not occurred, holders of at least fifty-one percent (51%) of the Series A Preferred Stock. Notwithstanding any other provision of this Section 5.1 to the contrary, for so long as any Series A Director (as defined in the
Restated Certificate) is serving on the Board of Directors, the Company shall not cease to maintain a Directors and Officers liability insurance policy in an amount of at least two million dollars ($2,000,000) unless approved by all Series A
Directors, and the Company shall annually, within one hundred twenty (120) days after the end of each fiscal year of the Company, deliver to each Investor that is then entitled to designate a Series A Director a certification that such a
Directors and Officers liability insurance policy remains in effect. 
 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 of a majority of the Series A Directors.

 5.3 Employee Stock. Unless otherwise approved by the Board of Directors, including a majority of the Series A Directors, all future
employees and consultants of the Company who purchase, receive options to purchase, or receive awards of shares of the Company’s capital stock after the date hereof shall be required to execute restricted stock or option agreements, as
applicable, providing for (i) vesting of shares over a four (4) year period, with the first twenty-five percent (25%) of such shares vesting following twelve (12) months of continued employment or service, and the remaining
shares vesting in equal monthly installments over the following thirty-six (36) months, and (ii) a market stand-off provision substantially similar to that in Subsection 2.11. In addition, unless otherwise approved by


  
 20 








 
the Board of Directors, including the Series A Directors, the Company shall retain a “right of first refusal” on employee transfers until the Company’s 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 Series A Preferred Stock are entitled to elect Series A Directors, the Company hereby covenants and agrees with each of the Investors that it shall not, without approval of the Board of Directors,
which approval must include the affirmative vote of a majority of the Series A Directors: 
 (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 in excess of $10,000 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) make any investment inconsistent with any
investment policy approved by the Board of Directors; 
 (e) incur any aggregate indebtedness in excess of $100,000 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; 
 (f)
otherwise enter into or be a party to any transaction with any director, officer, or employee of the Company or any “associate” (as defined in Rule 12b-2 promulgated under the Exchange Act) of any such Person, including without limitation
any “management bonus” or similar plan providing payments to employees in connection with a Deemed Liquidation Event, as such term is defined in the Company’s Certificate of Incorporation, except for transactions contemplated by this
Agreement and the Purchase Agreement, or transactions made in the ordinary course of business and pursuant to reasonable requirements of the Company’s business and upon fair and reasonable terms that are approved by a majority of the Board of
Directors; 
 (g) hire, terminate, or change the compensation of the executive officers, including approving any option grants or stock
awards to executive officers; 
 (h) change the principal business of the Company, enter new lines of business, or exit the current line of
business; 
 (i) sell, assign, license, pledge, or encumber material technology or intellectual property, other than licenses granted in the
ordinary course of business; or 
 (j) enter into any corporate strategic relationship involving the payment, contribution, or assignment by
the Company or to the Company of money or assets greater than $100,000. 

  
 21 








 5.5 Board Matters. 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. 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. The Company shall cause to be established, as soon as practicable after such request, and will maintain, an audit and compensation committee, each of
which shall consist solely of non-management directors. Each of the Series A Directors shall be entitled in such person’s discretion to be a member of any committee of the Board of Directors. 

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 Restated Certificate, or elsewhere, as the case may be. 

5.7 Option Plan. The Company hereby covenants and agrees to take all actions reasonably necessary, prior to each of the First Milestone
Closing (as defined in the Purchase Agreement) and the Second Milestone Closing (as defined in the Purchase Agreement), to approve an increase in the aggregate number of shares reserved for issuance under the Company’s 2014 Stock
Option & Grant Plan (as amended from time to time) to such number of shares of Common Stock as equals fifteen percent (15%) of the Company’s fully diluted capitalization (including for this purpose all shares of Common Stock
reserved for issuance under the Company’s 2014 Stock Option and Grant Plan and regardless of whether such shares are subject to outstanding options or other awards) as determined immediately following such First Milestone Closing or Second
Milestone Closing, as applicable. 
 5.8 Right to Conduct Activities. The Company hereby agrees and acknowledges that each of Atlas,
Lilly Ventures Fund I, LLC, Beacon Bioventures Fund IV Limited Partnership, NEA, Amgen and Novartis (each, together with its Affiliates) invests in numerous portfolio companies, some of which may be deemed competitive with the Company’s
business (as currently conducted or as currently proposed to be conducted). The parties agree that no Investors or any of their partners, officers or representatives which manage or advise such Investors shall be considered a Competitor of the
Company solely as a result of such investment, management or advisory activities for purposes of this Agreement; provided, however, that notwithstanding any other provision of this Agreement, at any time prior to the occurrence of any of the
termination events described in clauses (i), (ii) and (iii) of Subsection 5.9, if any Investor knowingly invests in any new portfolio company that, at the time of such initial investment, is a Competitor, such Investor may be deemed to be a
Competitor if the Board, after considering the circumstances of such investment, so determines; provided, further, that no Investor may be deemed to be a Competitor solely on the basis of such investment unless such Investor has been provided with a
reasonable opportunity to explain to the Board why it believes it should not be considered a Competitor. To facilitate compliance with the foregoing, prior to the occurrence of any of the termination events described in clauses (i), (ii) and
(iii) of Subsection 5.9, each Investor shall disclose to the Company any such new investment by such Investor in a new portfolio company that the Investor reasonably believes may be deemed competitive with the Company within thirty
(30) days of making such investment, and shall, prior to its purchase of additional shares of Series A Preferred Stock at each Milestone Closing under the Purchase Agreement, certify to the Company that such Investor has complied with its
obligations under this Subsection 5.8. The Company agrees that subject to the foregoing, to the extent permitted under applicable law, none of the Investors shall be liable to the Company for any claim arising out of, or based upon,
(i) the investment by any of the Investors in any entity competitive with the Company, or (ii) actions taken by any partner, officer or other representative of any of the Investors to 

  
 22 








 
assist any such competitive company, whether or not such action was taken as a member of the board of directors of such competitive company or otherwise, and whether or not such action has a
detrimental effect on the Company; provided, however, that the foregoing shall not relieve (x) any of the Investors from liability associated with the unauthorized disclosure of the Company’s confidential information obtained pursuant to
this Agreement, or (y) any director or officer of the Company from any liability associated with his or her fiduciary duties to the Company. 

5.9 Termination of Covenants. The covenants set forth in this Section 5, except Subsections 5.6 and 5.8 (other than
as explicitly as set forth otherwise in Subsection 5.8), shall terminate and be of no further force or effect (i) immediately before the consummation of the IPO, (ii) when the Company first becomes subject to the periodic reporting
requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon a Deemed Liquidation Event, as such term is defined in the Restated Certificate, whichever event occurs first. 

6. Miscellaneous. 
 6.1
Successors and Assigns. The rights under this Agreement may be assigned (but only with all related obligations) by a Holder to a transferee of Registrable Securities that (i) is an Affiliate of a Holder; (ii) is a Holder’s
Immediate Family Member or trust for the benefit of an individual Holder or one or more of such Holder’s Immediate Family Members; or (iii) after such transfer, holds at least 2,000,000 shares of Registrable Securities (subject to
appropriate adjustment for stock splits, stock dividends, combinations, and other recapitalizations); 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 Subsection 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 or
stockholder of a Holder; (2) who is a Holder’s Immediate Family Member; or (3) that is a trust for the benefit of an individual Holder or such Holder’s Immediate Family Member shall be aggregated together and with those of the
transferring Holder; provided further that all transferees who would not qualify individually for assignment of rights shall have a single attorney-in-fact for the purpose of exercising any rights, receiving notices, or taking any
action under this Agreement. The terms and conditions of this Agreement inure to the benefit of and are binding upon the respective successors and permitted assignees of the parties. Nothing in this Agreement, express or implied, is intended to
confer upon any party other than the parties hereto or their respective successors and permitted assignees any rights, remedies, obligations or liabilities under or by reason of this Agreement, except as expressly provided herein. 

6.2 Governing Law. This Agreement and any controversy arising out of or relating to this Agreement shall be governed by and construed in
accordance with the internal law of the State of Delaware. 
 6.3 Counterparts. This Agreement may be executed in two (2) or more
counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Counterparts may be delivered via facsimile, electronic mail (including pdf or any electronic signature complying with
the U.S. federal ESIGN Act of 2000, e.g., www.docusign.com) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes. 

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

  
 23 








 6.5 Notices. All notices and other communications given or made pursuant to this Agreement
shall be in writing and shall be deemed effectively given upon the earlier of actual receipt or (i) personal delivery to the party to be notified; (ii) when sent, if sent by electronic mail or facsimile during the recipient’s normal
business hours, and if not sent during normal business hours, then on the recipient’s next business day; (iii) five (5) days after having been sent by registered or certified mail, return receipt requested, postage prepaid; or
(iv) one (1) business day after the business day of deposit with a nationally recognized overnight courier, freight prepaid, specifying next-day delivery, with written verification of receipt. All communications shall be sent to the
respective parties at their addresses as set forth on Schedule A hereto, or to the principal office of the Company and to the attention of the Chief Executive Officer, in the case of the Company, or to such email address, facsimile number, or
address as subsequently modified by written notice given in accordance with this Subsection 6.5. If notice is given to the Company, a copy shall also be sent to Goodwin Procter LLP, Exchange Place, Boston, MA 02109, Attn: Kingsley L. Taft,
Esq. If notice is given to the Investors, a copy shall also be given to such person or entity listed under the Investor’s name on Schedule A. 

6.6 Amendments and Waivers. Any term of this Agreement may be amended and the observance of any term of this Agreement may be waived
(either generally or in a particular instance, and either retroactively or prospectively) only with the written consent of (i) the Company and (ii) if the NEA Purchase has occurred, the holders of at least sixty-one percent (61%) of
the Registrable Securities then outstanding, or if the NEA Purchase has not occurred, the holders of at least fifty-one percent (51%) of the Registrable Securities then outstanding; provided that the Company may in its sole discretion
waive compliance with Subsection 2.12(c) (and the Company’s failure to object promptly in writing after notification of a proposed assignment allegedly in violation of Subsection 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, (i) 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), (ii) none of the text of Subsection 3.1 before clause (a) thereunder, Subsections 3.1(a)-(d), or Subsection 3.3 shall be amended or
waived with respect to an Investor without the prior written consent of such Investor, (iii) the definitions of “Competitor,” “Registrable Securities,” and “Current Investor” contained herein shall not be amended
or changed in a manner that materially and adversely affects an Investor without the consent of such Investor. 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 Subsection 6.6 shall be binding on all parties hereto, regardless of whether any such party has consented thereto. No
waivers of or exceptions to any term, condition, or provision of this Agreement, in any one or more instances, shall be deemed to be or construed as a further or continuing waiver of any such term, condition, or provision. 

6.7 Severability. In case any one or more of the provisions contained in this Agreement is for any reason held to be invalid, illegal or
unenforceable in any respect, such invalidity, illegality, or unenforceability shall not affect any other provision of this Agreement, and such invalid, illegal, or unenforceable provision shall be reformed and construed so that it will be valid,
legal, and enforceable to the maximum extent permitted by law. 
 6.8 Aggregation of Stock. All shares of Registrable Securities held
or acquired by Affiliates shall be aggregated together for the purpose of determining the availability of any rights under this Agreement and such Affiliated persons may apportion such rights as among themselves in any manner they deem appropriate.


  
 24 








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

6.10 Entire Agreement. This Agreement (including any Schedules and Exhibits hereto) constitutes the full and entire understanding and
agreement among the parties with respect to the subject matter hereof, and any other written or oral agreement relating to the subject matter hereof existing between the parties is expressly canceled. 

6.11 Delays or Omissions. No delay or omission to exercise any right, power, or remedy accruing to any party under this Agreement, upon
any breach or default of any other party under this Agreement, shall impair any such right, power, or remedy of such nonbreaching or nondefaulting party, nor shall it be construed to be a waiver of or acquiescence to any such breach or default, or
to any similar breach or default thereafter occurring, nor shall any waiver of any single breach or default be deemed a waiver of any other breach or default theretofore or thereafter occurring. All remedies, whether under this Agreement or by law
or otherwise afforded to any party, shall be cumulative and not alternative. 
 6.12 Acknowledgment. The Company acknowledges that the
Investors are in the business of venture capital investing and therefore review the business plans and related proprietary information of many enterprises, including enterprises which may have products or services which compete directly or
indirectly with those of the Company. Nothing in this Agreement shall preclude or in any way restrict the Investors from investing or participating in any particular enterprise whether or not such enterprise has products or services which compete
with those of the Company. 
 6.13 Dispute Resolution. The parties (a) hereby irrevocably and unconditionally submit to the
jurisdiction of the state courts of Delaware and to the jurisdiction of the United States District Court for the District of Delaware for the purpose of any suit, action or other proceeding arising out of or based upon this Agreement, (b) agree
not to commence any suit, action or other proceeding arising out of or based upon this Agreement except in the state courts of Delaware or the United States District Court for the District of Delaware, and (c) hereby waive, and agree not to
assert, by way of motion, as a defense, or otherwise, in any such suit, action or proceeding, any claim that it is not subject personally to the jurisdiction of the above-named courts, that its property is exempt or immune from attachment or
execution, that the suit, action or proceeding is brought in an inconvenient forum, that the venue of the suit, action or proceeding is improper or that this Agreement or the subject matter hereof may not be enforced in or by such court. 

WAIVER OF JURY TRIAL: EACH PARTY HEREBY WAIVES ITS RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS AGREEMENT, THE
OTHER TRANSACTION DOCUMENTS, THE SECURITIES OR THE SUBJECT MATTER HEREOF OR THEREOF. THE SCOPE OF THIS WAIVER IS INTENDED TO BE ALL-ENCOMPASSING OF ANY AND ALL DISPUTES THAT MAY BE FILED IN ANY COURT AND THAT RELATE TO THE SUBJECT MATTER OF THIS
TRANSACTION, INCLUDING, WITHOUT 

  
 25 








 
LIMITATION, CONTRACT CLAIMS, TORT CLAIMS (INCLUDING NEGLIGENCE), BREACH OF DUTY CLAIMS, AND ALL OTHER COMMON LAW AND STATUTORY CLAIMS. THIS SECTION HAS BEEN FULLY DISCUSSED BY EACH OF THE PARTIES
HERETO AND THESE PROVISIONS WILL NOT BE SUBJECT TO ANY EXCEPTIONS. EACH PARTY HERETO HEREBY FURTHER WARRANTS AND REPRESENTS THAT SUCH PARTY HAS REVIEWED THIS WAIVER WITH ITS LEGAL COUNSEL, AND THAT SUCH PARTY KNOWINGLY AND VOLUNTARILY WAIVES ITS
JURY TRIAL RIGHTS FOLLOWING CONSULTATION WITH LEGAL COUNSEL. 
 [Remainder of Page Intentionally Left Blank] 

  
 26 








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

			
	COMPANY:
	
	SURFACE ONCOLOGY, INC.


 
			
		
	By:	 	 /s/ Joshua Renick

	Name:	 	Joshua Renick
	Title:	 	President


 SIGNATURE PAGE TO INVESTORS’
RIGHTS AGREEMENT 







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

			
	INVESTOR:
	
	ATLAS VENTURE FUND IX, L.P.
	
	By: Atlas Venture Associates IX, L.P.
	Its General Partner
	By: Atlas Venture Associates IX, LLC
	Its General Partner
		
	By:	 	 /s/ Frank Castellucci

	Name:	 	Frank Castellucci
	Title:	 	General Counsel


 SIGNATURE PAGE TO INVESTORS’
RIGHTS AGREEMENT 







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

	
	INVESTOR:
	
	BEACON BIOVENTURES FUND IV LIMITED
	PARTNERSHIP
	
	By: Beacon Bioventures Advisors Fund IV Limited
	Partnership, its General Partner
	
	By: Impresa Holdings LLC, its General Partner
	
	By: Impresa Management LLC, its Managing
	Member


  

			
	By:	 	 /s/ Mary Bevelock Pendergast

	Name: Mary Bevelock Pendergast
	Title: Vice President


 SIGNATURE PAGE TO INVESTORS’
RIGHTS AGREEMENT 







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

			
	INVESTOR:
	
	LILLY VENTURES FUND I, LLC
		
	By:	 	 /s/ S. Edward Torres

	Name: S. Edward Torres
	Title: Managing Director


 SIGNATURE PAGE TO INVESTORS’
RIGHTS AGREEMENT 







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

			
	INVESTOR:
	
	NOVARTIS INSTITUTES FOR BIOMEDICAL RESEARCH, INC.
		
	By:	 	 /s/ H. Martin Seidel

	Name:	 	H. Martin Seidel
	Title:	 	VP, Global Head of Strategic Alliances


 SIGNATURE PAGE TO INVESTORS’
RIGHTS AGREEMENT 







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

			
	INVESTOR:
	
	AMGEN INVESTMENTS LTD.
		
	By:	 	 /s/ Janis C. Naeve

	Name:	 	Janis C. Naeve
	Title:	 	Managing Director, Amgen Ventures


 SIGNATURE PAGE TO INVESTORS’
RIGHTS AGREEMENT 







 SCHEDULE A 

Investors 
  

			
	Name and Address	  	Number of Shares Held
	 Atlas Venture Fund IX, L.P.

c/o Atlas Venture

25 1st Street, Suite 303

Cambridge, MA 02141
	  	2,200,000
		
	 Lilly Ventures Fund I, LLC

115 West Washington Street, Suite 1680S

Indianapolis, IN 46204
	  	2,200,000
		
	 BEACON BIOVENTURES FUND IV LIMITED PARTNERSHIP

One Main Street, 13th Floor

Cambridge, MA 02142
	  	2,200,000
		
	 New Enterprise Associates 14, Limited Partnership
	  	2,190,000
		
	 NEA Ventures 2014, Limited Partnership

c/o NEA

1954 Greenspring Dr. Ste 600

Timonium, MD 21093
	  	10,000
		
	 Novartis Institutes for BioMedical Research

250 Massachusetts Avenue

Cambridge, MA 02139

Attn: General Counsel
	  	1,571,429
		
	 Amgen Investments Ltd.

22 Victoria Street

Hamilton, HM 12

Bermuda
	  	628,571








 AMENDMENT NO. 1 

TO 
 INVESTORS’
RIGHTS AGREEMENT 
 THIS AMENDMENT NO. 1 TO INVESTORS’ AGREEMENT (this “Amendment”) is made and entered into as of
January 9, 2016, by and among Surface Oncology, Inc., a Delaware corporation (the “Company”), and the investors of the Company set forth on the signature pages hereto. Capitalized terms used, but not otherwise defined, herein
shall have the meanings ascribed thereto in the IRA (as defined herein). 
 WITNESSETH 

WHEREAS, the Company previously entered into that certain Investors’ Rights Agreement (as amended or otherwise modified from time
to time, the “IRA”), dated as of November 6, 2014, by and among the Company and the investors set forth on Schedule A thereto (the “Investors”). 

WHEREAS, pursuant to Subsection 6.6 of the IRA, the IRA may be amended by the written consent of (a) the Company; and
(b) the holders of at least sixty-one percent (61%) of the Registrable Securities then outstanding (the “Requisite Holders”). 

WHEREAS, concurrently with this Amendment, the Company and a certain Investor (the “Series
A-1 Investor”) of the Company are entering into the Series A-1 Stock Purchase Agreement (the “Series A-1
Purchase Agreement”) providing for the sale of shares of the Company’s Series A-1 Preferred Stock, par value $0.0001 per share (the “Series A-1
Preferred Stock”), and in connection therewith the Company and the Investors desire to amend certain provisions of the IRA. 

NOW, THEREFORE, in consideration of the mutual promises and covenants contained in this Amendment, the Company and the undersigned
Investors party hereto, representing the Requisite Holders, hereby agree as follows: 
 1. Amendment to the Preamble of the IRA. The
first paragraph of the IRA is hereby amended and restated to read in its entirety as follows: 
 “THIS INVESTORS’ RIGHTS AGREEMENT
(as amended, this “Agreement”), is made as of the 6th day of November, 2014, by and among SURFACE ONCOLOGY, 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.” 
 2. Amendment to Section 1 of the IRA.

 2.1 Each reference to “Series A Preferred Stock” in the definition of each of “Current Investor” and
“Registrable Securities” shall be deleted in its entirety and replaced with “Preferred Stock.” 
  







 2.2 The definition of “Restated Certificate” set forth in Section 1.25 of
the IRA is hereby amended and restated to read in its entirety as follows: 
 “Restated Certificate” means the
Company’s Third Amended and Restated Certificate of Incorporation, as may be further amended or restated from time to time. 
 ”
2.3 The definition of “Series A Director” set forth in Section 1.32 of the IRA is hereby amended and restated to read in its entirety as follows: 

“Preferred Director” means any director of the Company that the holders of record of the Preferred Stock
are entitled to elect pursuant to the Restated Certificate. 
 2.4 The following new definitions are hereby added to Section 1 of the
IRA in proper numerical order: 
 “Preferred Stock” means shares of the Series A Preferred Stock and shares of the Series A-1 Preferred Stock. 
 “Series A-1 Preferred
Stock” means shares of the Company’s Series A-1 Preferred Stock, par value $0.0001 per share. 

3. Amendment to Subsection 2.1(a) of the IRA. Subsection 2.1(a) of the IRA is hereby amended and restated to read in its entirety as
follows: 
 “Form S-1 Demand. If at any time after the earlier of (i) five (5) years
after the date of this Agreement or (ii) one hundred eighty (180) days after the effective date of the registration statement for the IPO, the Company receives a request from Holders of at least
sixty-one percent (61%) of the Registrable Securities then outstanding that the Company file a Form S-1 registration statement with respect to at least thirty-three and one-third percent (33 1/3%) of the Registrable Securities then outstanding (or a lesser percent if the anticipated aggregate offering price, net of Selling Expenses, would exceed $10 million), then the Company shall
(x) within ten (10) days after the date such request is given, give notice thereof (the “Demand Notice”) to all Holders other than the Initiating Holders; and (y) as soon as practicable, and in any event within sixty
(60) days after the date such request is given by the Initiating Holders, file a Form S-1 registration statement under the Securities Act covering all Registrable Securities that the Initiating Holders
requested to be registered and any additional Registrable Securities requested to be included in such registration by any other Holders, as specified by notice given by each such Holder to the Company within twenty (20) days of the date the
Demand Notice is given, and in each case, subject to the limitations of Subsections 2.1(c) and 2.3.” 

  
 -2- 








 4. Amendment to Subsection 2.10 of the IRA. Subsection 2.10 of the IRA is hereby amended
and restated to read in its entirety as follows: 
 “2.10 Limitations on Subsequent Registration Rights. From and after the date
of this Agreement, the Company shall not, without the prior written consent of the Holders of at least sixty-one percent (61%) of the Registrable Securities then outstanding enter into any agreement with any
holder or prospective holder of any securities of the Company that (i) would provide to such holder the right to include securities in any registration on other than either a pro rata basis with respect to the Registrable Securities or on a
subordinate basis after all Holders have had the opportunity to include in the registration and offering all shares of Registrable Securities that they wish to so include or (ii) allow such holder or prospective holder to initiate a demand for
registration of any securities held by such holder or prospective holder; provided that this limitation shall not apply to any additional Investor who becomes a party to this Agreement in accordance with Subsection 6.9.” 

5. Amendment to Subsections 2.12, 4.1, 5.4 and 6.9 of the IRA. Each reference to “Series A Preferred Stock” in
Subsections 2.12, 4.1, 5.4 and 6.9, of the IRA shall be deleted in its entirety and replaced with “Preferred Stock.”  

6. Amendment to Subsection 2.13(b) of the IRA. Subsection 2.13(b) of the IRA is hereby amended and restated to read in its entirety as
follows:“(b) such time following the IPO as Rule 144 or another similar exemption under the Securities Act is available for the sale of all of such Holder’s shares without limitation during a three-month period without registration;
and” 
 7. Amendment to Subsection 3.1 and Section 5 of the IRA. Each reference to “Series A
Director” in Subsection 3.1 and Section 5 of the IRA shall be deleted in its entirety and replaced with “Preferred Director.”  

8. Amendment to Subsection 5.1 of the IRA. The second sentence of Subsection 5.1 of the IRA is hereby amended and restated to read in
its entirety as follows: 
 “Such policy shall not be cancelable by the Company without prior approval by the Board of Directors
including (i) all of the Series A Directors and (ii) holders of at least sixty-one percent (61%) of the Preferred Stock.” 

9. Amendment to Subsection 5.8 of the IRA. Reference to “Beacon Bioventures Fund IV Limited Partnership” in the Subsection
5.8 of the IRA is hereby deleted in its entirety and replaced with “F-Prime Capital Partners Healthcare Fund IV LP.” 

10. Amendment to Subsection 6.6 of the IRA. Clause (ii) of Section 6.6 is hereby amended and restated to read in its entirety
as follows: 

  
 -3- 








 “(ii) the holders of at least sixty-one percent
(61%) of the Registrable Securities then outstanding; provided that the Company may in its sole discretion waive compliance with Subsection 2.12(c) (and the Company’s failure to object promptly in writing after notification of a proposed
assignment allegedly in violation of Subsection 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.”  
 11. Amendment to Schedule A of the IRA. Schedule A of the IRA is hereby deleted in its entirety and
replaced with Schedule A attached hereto as Exhibit A.  
 12. IRA. By execution of this Amendment, the Company
and the Requisite Holders executing the same, holding in the aggregate a sufficient number of shares of stock to amend the IRA in accordance with Subsection 6.6 thereof, hereby agree that the provisions set forth in the IRA are hereby amended
as set forth herein. The IRA, as amended by this Amendment, contains the entire agreement among the parties with respect to the subject matter thereof and hereof and shall be read and construed together as a single agreement. Except to the extent
amended hereby, all of the terms, provisions and conditions of the IRA are hereby ratified and confirmed and shall remain in full force and effect as of the date specified therein. 

13. Counterparts. This Amendment 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. Counterparts may be delivered via facsimile, electronic mail (including .pdf) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly
delivered and be valid and effective for all purposes. 
 14. Titles and Subtitles. The titles and subtitles used in this Amendment
are used for convenience only and are not to be considered in construing or interpreting this Amendment. 
 15. Severability. The
invalidity or unenforceability of any provision hereof shall in no way affect the validity or enforceability of any other provision. 

[Remainder of this page is intentionally left blank.] 

 

  
 -4- 








 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to
Investors’ Rights Agreement as of the date first written above. 
  

			
	THE COMPANY:
	
	SURFACE ONCOLOGY, INC.
		
	By:	 	 /s/ Detlev Biniszkiewicz

	Name:	 	Detlev Biniszkiewicz
	Title:	 	President and CEO


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to Investors’ Rights
Agreement as of the date first written above. 
  

			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 14,
	LIMITED PARTNERSHIP
	
	By: NEA Partners 14, Limited Partnership, its general partner
	By: NEA 14 GP, LTD, its general partner
		
	By:	 	 /s/ Louis S. Citron

	Name: Louis S. Citron
	Title: Chief Legal Officer
	
	NEA VENTURES 2014, LIMITED
	PARTNERSHIP
		
	By:	 	 /s/ Louis S. Citron

	Name: Louis S. Citron
	Title: Vice President


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to
Investors’ Rights Agreement as of the date first written above. 
  

			
	INVESTORS:
	
	F-PRIME CAPITAL PARTNERS HEALTHCARE FUND IV LP
	
	By: F-Prime Capital Partners Healthcare Advisors Fund IV LP, its General Partner
	
	By: Impresa Holdings LLC, its General Partner
	
	By: Impresa Management LLC, its Managing Member
		
	By:	 	 /s/ Mary Bevelock Pendergast

	Name:	 	Mary Bevelock Pendergast
	Title:	 	Vice President


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to Investors’ Rights
Agreement as of the date first written above. 
  

			
	INVESTORS:
	
	SIGAL FAMILY INVESTMENTS, LLC
		
	By:	 	 /s/ Elliot Sigal

	Name:	 	Elliot Sigal
	Title:	 	Manager


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to
Investors’ Rights Agreement as of the date first written above. 
  

			
	INVESTORS:
	
	LILLY VENTURES FUND I, LLC
		
	By:	 	 /s/ S. Edward Torres

		 	Name: S. Edward Torres
		 	Title: Managing Director


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to
Investors’ Rights Agreement as of the date first written above. 
  

			
	INVESTORS:
	
	ATLAS VENTURE FUND IX, L.P.
	
	By: Atlas Venture Associates IX, L.P.
	Its General Partner
	By: Atlas Venture Associates IX, LLC
	Its General Partner
		
	By:	 	 /s/ Frank Castellucci

	Name:	 	Frank Castellucci
	Title:	 	Secretary


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to
Investors’ Rights Agreement as of the date first written above. 
  

					
	INVESTORS:
	
	AMGEN INVESTMENTS LTD.
	By:	 	 /s/ Janis Naeve
	 	




	Name:	 	Janis Naeve	 
	Title:	 	Corporate Development Executive Director


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 IN WITNESS WHEREOF, the parties have executed this Amendment No. 1 to
Investors’ Rights Agreement as of the date first written above. 
  

			
	INVESTORS:
	
	NOVARTIS INSTITUTES FOR BIOMEDICAL RESEARCH, INC.
		
	By:	 	 /s/ H. Martin Seidel

	Name:	 	H. Martin Seidel
	Title:	 	VP, Global Head of Strategic Alliances


 [Amendment No. 1 to IRA – Surface Oncology, Inc.] 







 EXHIBIT A 

SCHEDULE A 

INVESTORS 
  

					
	 Name and Address
	  	Number of Shares Held	 
	 Atlas Venture Fund IX, L.P.
	  	 	4,500,000	 
	 c/o Atlas Venture

25 1st Street, Suite 303
	  			
	 Cambridge, MA 02141
	  			
	 Lilly Ventures Fund I, LLC
	  	 	4,500,000	 
	 115 West Washington Street, Suite 1680S
	  			
	 Indianapolis, IN 46204
	  			
	 F-PRIME CAPITAL PARTNERS
	  	 	4,500,000	 
	 HEALTHCARE FUND IV LP
	  			
	 One Main Street, 13th Floor
	  			
	 Cambridge, MA 02142
	  			
	 New Enterprise Associates 14, Limited Partnership
	  	 	4,495,000	 
	 NEA Ventures 2014, Limited Partnership
	  	 	5,000	 
	 c/o NEA 1954 Greenspring Dr. Ste 600
	  			
	 Timonium, MD 21093
	  			
	 Novartis Institutes for BioMedical Research
	  			
	 250 Massachusetts Avenue
	  	 	5,214,286	 
	 Cambridge, MA 02139
	  			
	 Attn: General Counsel
	  			
	 Amgen Investments Ltd.
	  			
	 22 Victoria Street
	  	 	1,285,714	 
	 Hamilton, HM 12
	  			
	 Bermuda
	  			
	 Sigal Family Investments, LLC
	  			
	 32 Brearly Road
	  	 	64,286	 
	 Princeton, NJ 08540