Document:

EX-4.1

 Exhibit 4.1 

Execution Version 

AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT 

THIS AMENDED AND RESTATED INVESTORS’ RIGHTS AGREEMENT (this “Agreement”), is made as of December 29,
2020, by and among Sensei Biotherapeutics, Inc., a Delaware corporation (the “Company”), each of the investors listed on Schedule A hereto, each of which is referred to in this Agreement as an
“Investor” and any Additional Purchaser (as defined in the Purchase Agreement) that becomes a party to this Agreement in accordance with Section 6.9 hereof. 

RECITALS: 
 A.
Certain of the Investors (the “Existing Investors”) hold shares of the Company’s Series AA Preferred Stock and/or shares of Common Stock issued upon conversion thereof and possess registration rights, information rights,
rights of first offer, and other rights pursuant to that certain Investors’ Rights Agreement dated as of January 10, 2020, by and among the Company and such Existing Investors (the “Prior Agreement”). 

B. The Existing Investors are holders of at least two-thirds of the Registrable Securities of
the Company (as defined in the Prior Agreement), and desire to amend and restate the Prior Agreement in its entirety and to accept the rights created pursuant to this Agreement in lieu of the rights granted to them under the Prior Agreement. 

C. Certain of the Investors are parties to that certain Series BB Preferred Stock Purchase Agreement of even date herewith by and among
the Company and such Investors (the “Purchase Agreement”), under which certain of the Company’s and such Investors’ obligations are conditioned upon the execution and delivery of this Agreement. 

The Existing Investors agree that the Prior Agreement shall be amended and restated in its entirety by this Agreement and the parties to this
Agreement further 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, officer, director or trustee of such Person, or any venture capital fund or registered investment company now
or hereafter existing that is controlled by one or more general partners, managing members or investment advisers of, or shares the same management company or investment adviser with, such Person. 

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

1.3 “Certificate of Incorporation” means the Company’s Amended and Restated Certificate of Incorporation,
as amended and/or restated from time to time. 
 1.4 “Common Stock” means shares of the Company’s common
stock, par value $0.0001 per share. 
 1.5 “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 the business of the Company, but shall not include any financial investment firm or
collective investment vehicle that, together with its Affiliates, holds less than 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. For the avoidance of doubt,
none of the Specified Investors shall be considered a Competitor for purposes of this Agreement. 
 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 or
grant of securities to employees of the Company or a subsidiary pursuant to a stock option, stock purchase, equity incentive or similar plan; (ii) a registration relating to an SEC Rule 145 transaction; (iii) a registration on any form
that does not include substantially the same information as would be required to be included in a registration statement covering the sale of the Registrable Securities; or (iv) a registration in which the only Common Stock being registered is
Common Stock issuable upon conversion of debt securities that are also being registered. 
 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 forward 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 as in effect from time to time.

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

  
 2 

 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 c- and
executive vice president-level executive officers. 
 1.19 “Major Investor” means any Investor that,
individually or together with such Investor’s Affiliates, holds at least 10,000,000 shares of Registrable Securities (as adjusted for any stock split, stock dividend, combination, or other recapitalization or reclassification effected after the
date hereof). 
 1.20 “New Securities” means, collectively, equity securities of the Company, whether or not
currently authorized, as well as rights, options, or warrants to purchase such equity securities, or securities of any type whatsoever that are, or may become, convertible or exchangeable into or exercisable for such equity securities. 

1.21 “Person” means any individual, corporation, partnership, trust, limited liability company, association or
other entity. 
 1.22 “Preferred Director” means any director of the Company that the holders of record of
the Preferred Stock are entitled to elect, exclusively and as a separate class, pursuant to the Certificate of Incorporation. 
 1.23
“Preferred Stock” means, collectively, shares of Series AA Preferred Stock and Series BB Preferred Stock. 

1.24 “Registrable Securities” means (i) the Common Stock issuable or issued upon conversion of the
Preferred Stock; and (ii) 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
Section 6.1, and excluding for purposes of Section 2 any shares for which registration rights have terminated pursuant to Section 2.13 of this Agreement. 

1.25 “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. 

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

  
 3 

 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
Section 2.6. 
 1.32 “Series AA Preferred Stock” means shares of the Company’s
Series AA Preferred Stock, par value $0.0001 per share. 
 1.33 “Series BB Preferred Stock” means shares of
the Company’s Series BB Preferred Stock, par value $0.0001 per share. 
 1.34 “Specified Investors”
means Cambrian BioPharma, Inc. (“Cambrian”), Apeiron Investment Group (“Apeiron”), H&S Ventures, LLC (“H&S”), Catalio Nexus Fund II, LP
(“Catalio”) and Pura Vida Investments, LLC (“Pura Vida”), in each case together with their respective Affiliates, along with any other Investor determined by majority vote of the Board to be a
Specified Investor as defined in this Agreement. 
 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) 180 days after the effective date of the registration statement for an IPO resulting in proceeds to the Company of at least $50 million, the Company receives a request from Holders of at least two-thirds of the Registrable Securities then outstanding that the Company file a Form S-1 registration statement covering the registration of Registrable Securities, then the
Company shall (x) within 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 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 20 days of the date the Demand Notice is
given, and in each case, subject to the limitations of Sections 2.1(c) and 2.3. 
 (b) Form S-3 Demand. If at any time when it is eligible to use a Form S-3 registration statement, the Company receives a request from Holders of at least 30% 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 $5 million, then the Company shall (i) within 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 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 20 days of the date the Demand Notice is given, and in each case, subject to the limitations of Sections 2.1(c) and
2.3. 

  
 4 

 (c) Notwithstanding the foregoing obligations, if the Company furnishes to Holders
requesting a registration pursuant to this Section 2.1 a certificate signed by the Company’s chief executive officer stating that in the good faith judgment of the Board of Directors it would be materially detrimental
to the Company and its stockholders for such registration statement to either become effective or remain effective for as long as such registration statement otherwise would be required to remain effective, because it would be materially detrimental
to the Company and its stockholders for such registration statement to be filed and it is therefore necessary to defer the filing of such registration statement, 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 120 days after the request of the Initiating Holders is given; provided, however, that the Company may
not invoke this right more than once in any 12 month period; and provided further that the Company shall not register any securities for its own account or that of any other stockholder during such 120 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
Section 2.1(a) (i) during the period that is 60 days before the Company’s good faith estimate of the date of filing of, and ending on a date that is 180 days after the effective date of, a Company-initiated
registration, provided that the Company is actively employing in good faith commercially reasonable efforts to cause such registration statement to become effective; (ii) after the Company has effected one registration pursuant to
Section 2.1(a); or (iii) if the Initiating Holders propose to dispose of shares of Registrable Securities that may be immediately registered on Form S-3 pursuant to a request
made pursuant to Section 2.1(b). The Company shall not be obligated to effect, or to take any action to effect, any registration pursuant to Section 2.1(b) (i) during the period that is 30
days before the Company’s good faith estimate of the date of filing of, and ending on a date that is 90 days after the effective date of, a Company-initiated registration, provided that the Company is actively employing in good faith
commercially reasonable efforts to cause such registration statement to become effective; or (ii) if the Company has effected two registrations pursuant to Section 2.1(b) within the 12 month period immediately
preceding the date of such request. A registration shall not be counted as “effected” for purposes of this Section 2.1(d) until such time as the applicable registration statement has been declared effective by the
SEC, unless the Initiating Holders withdraw their request for such registration, elect not to pay the registration expenses therefor, and forfeit their right to one demand registration statement pursuant to Section 2.6, in
which case such withdrawn registration statement shall be counted as “effected” for purposes of this Section 2.1(d); provided, that if such withdrawal is during a period the Company has deferred taking
action pursuant to Section 2.1(c), then the Initiating Holders may withdraw their request for registration and such registration will not be counted as “effected” for purposes of this
Section 2.1(d). 
 2.2 Company Registration. If the Company proposes to register (including, for
this purpose, a registration effected by the Company for stockholders other than the Holders) any of its securities under the Securities Act in connection with the public offering of such securities solely for cash (other than in an Excluded
Registration), the Company shall, at such time, promptly give each Holder notice of such registration. Upon the request of each Holder given within 20 days after such notice is given by the Company, the Company shall, subject to the provisions of
Section 2.3, cause to be registered all of the Registrable Securities that each such Holder has requested to be included in such registration. The Company shall have the right to terminate or withdraw any registration
initiated by it under this Section 2.2 before the effective date of such registration, whether or not any Holder has elected to include Registrable Securities in such registration. The expenses (other than Selling Expenses)
of such withdrawn registration shall be borne by the Company in accordance with Section 2.6. 

  
 5 

 2.3 Underwriting Requirements. 

(a) If, pursuant to Section 2.1, the Initiating Holders intend to distribute the Registrable Securities
covered by their request by means of an underwriting, they shall so advise the Company as a part of their request made pursuant to Section 2.1, and the Company shall include such information in the Demand Notice. The
underwriter(s) will be selected by the Company and shall be reasonably acceptable to a majority in interest of the Initiating Holders. In such event, the right of any Holder to include such Holder’s Registrable Securities in such registration
shall be conditioned upon such Holder’s participation in such underwriting and the inclusion of such Holder’s Registrable Securities in the underwriting to the extent provided herein. All Holders proposing to distribute their securities
through such underwriting shall (together with the Company as provided in Section 2.4(e)) enter into an underwriting agreement in customary form with the underwriter(s) selected for such underwriting. Notwithstanding any
other provision of this Section 2.3, if the managing underwriter(s) advise(s) the Initiating Holders in writing that marketing factors require a limitation on the number of shares to be 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 100 shares. 

(b) In connection with any offering involving an underwriting of shares of the Company’s capital stock pursuant to
Section 2.2, the Company shall not be required to include any of the Holders’ Registrable Securities in such underwriting unless the Holders accept the terms of the underwriting as agreed upon between the Company and
its underwriters, and then only in such quantity as the underwriters in their sole discretion determine will not jeopardize the success of the offering by the Company. If the total number of securities, including Registrable Securities, requested by
stockholders to be included in such offering exceeds the number of securities to be sold (other than by the Company) that the underwriters in their reasonable discretion determine is compatible with the success of the offering, then the Company
shall be required to include in the offering only that number of such securities, including Registrable Securities, which the underwriters and the Company in their sole discretion determine will not jeopardize the success of the offering. If the
underwriters determine that less than all of the Registrable Securities requested to be registered can be included in such offering, then the Registrable Securities that are included in such offering shall be allocated among the selling Holders in
proportion (as nearly as practicable to) the number of Registrable Securities owned by each selling Holder or in such other proportions as shall mutually be agreed to by all such selling Holders. To facilitate the allocation of shares in accordance
with the above provisions, the Company or the underwriters may round the number of shares allocated to any Holder to the nearest 100 shares. Notwithstanding the foregoing, in no event shall (i) the number of Registrable Securities included in
the offering be reduced unless all other securities (other than securities to be sold by the Company) are first entirely excluded from the offering, or (ii) the number of Registrable Securities included in the offering be reduced below 20% of
the total number of securities included in such offering, unless such offering is the IPO, in which case the selling Holders may be excluded further if the underwriters make the determination described above and no other stockholder’s
securities are included in such offering. For purposes of the provision in this Section 2.3(b) concerning apportionment, for any selling Holder that is a partnership, limited liability company, or corporation, the partners,
members, retired partners, retired members, stockholders, and Affiliates of such Holder, or the estates and Immediate Family Members of any such partners, retired partners, members, and retired members and any trusts for the benefit of any of the
foregoing Persons, shall be deemed to be a single “selling Holder,” and any pro rata reduction with respect to such “selling Holder” shall be based upon the aggregate number of Registrable Securities owned by all Persons included
in such “selling Holder,” as defined in this sentence. 

  
 6 

 (c) For purposes of Section 2.1, a registration shall not be
counted as “effected” if, as a result of an exercise of the underwriter’s cutback provisions in Section 2.3(a), fewer than 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 120
days or, if earlier, until the distribution contemplated in the registration statement has been completed; provided, however, that (i) such 120 day period shall be extended for a period of time equal to the period the Holder refrains, at
the request of an underwriter of Common Stock (or other securities) of the Company, from selling any securities included in such registration, 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 120 day period shall be extended for up to 180 days, if necessary, to keep the registration
statement effective until all such Registrable Securities are sold; 
 (b) prepare and file with the SEC such amendments and
supplements to such registration statement, and the prospectus used in connection with such registration statement, as may be necessary to comply with the Securities Act in order to enable the disposition of all securities covered by such
registration statement; 
 (c) furnish to the selling Holders such numbers of copies of a prospectus, including a preliminary
prospectus, as required by the Securities Act, and such other documents as the Holders may reasonably request in order to facilitate their disposition of their Registrable Securities; 

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

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

  
 7 

 (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. 

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 $50,000, of one counsel for the selling Holders (“Selling Holder Counsel”), shall be borne and paid by the Company; provided, however, that the Company shall not be required to pay for any
expenses of any registration proceeding begun pursuant to Section 2.1 if the registration request is subsequently withdrawn at the request of the Holders of a majority of the Registrable Securities to be registered (in
which case all selling Holders shall bear such expenses pro rata based upon the number of Registrable Securities that were to be included in the withdrawn registration), unless the Holders of a majority of the Registrable Securities agree to forfeit
their right to one registration pursuant to Sections 2.1(a) or 2.1(b), as the case may be then the Holders shall not be required to pay any of such expenses and shall not forfeit their right to one registration pursuant to Sections
2.1(a) or 2.1(b). All Selling Expenses relating to Registrable Securities registered pursuant to this Section 2 shall be borne and paid by the Holders pro rata on the basis of the number of Registrable Securities
registered on their behalf. 
 2.7 Delay of Registration. No Holder shall have any right to obtain or seek an injunction
restraining or otherwise delaying any registration pursuant to this Agreement as the result of any controversy that might arise with respect to the interpretation or implementation of this Section 2. 

  
 8 

 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 Section 2.8(a) shall not apply to amounts paid in settlement of any such claim or proceeding if such settlement is effected without the consent of the Company, which consent shall not be unreasonably
withheld, nor shall the Company be liable for any Damages to the extent that they arise out of or are based upon actions or omissions made in reliance upon and in conformity with written information furnished by or on behalf of any such Holder,
underwriter, controlling Person, or other aforementioned Person expressly for use in connection with such registration. 
 (b) To
the extent permitted by law, each selling Holder, severally and not jointly, will indemnify and hold harmless the Company, and each of its directors, each of its officers who has signed the registration statement, each Person (if any), who controls
the Company within the meaning of the Securities Act, legal counsel and accountants for the Company, any underwriter (as defined in the Securities Act), any other Holder selling securities in such registration statement, and any controlling Person
of any such underwriter or other Holder, against any Damages, in each case only to the extent that such Damages arise out of or are based upon actions or omissions made in reliance upon and in conformity with written information furnished by or on
behalf of such selling Holder expressly for use in connection with such registration; and each such selling Holder will pay to the Company and each other aforementioned Person any legal or other expenses reasonably incurred thereby in connection
with investigating or defending any claim or proceeding from which Damages may result, as such expenses are incurred; provided, however, that the indemnity agreement contained in this Section 2.8(b) shall not apply
to amounts paid in settlement of any such claim or proceeding if such settlement is effected without the consent of the Holder, which consent shall not be unreasonably withheld; and provided further that in no event shall the aggregate
amounts payable by any Holder by way of indemnity or contribution under Section 2.8(b) and 2.8(d) exceed the proceeds from the offering received by such Holder (net of any Selling Expenses paid by such Holder),
except in the case of fraud or willful misconduct by such Holder. 
 (c) Promptly after receipt by an indemnified party under this
Section 2.8 of notice of the commencement of any action (including any governmental action) for which a party may be entitled to indemnification hereunder, such indemnified party will, if a claim in respect thereof is to be
made against any indemnifying party under this Section 2.8, give the indemnifying party notice of the commencement thereof. The indemnifying party shall have the right to participate in such action and, to the extent the
indemnifying party so desires, participate jointly with any other indemnifying party to which notice has been given, and to assume the defense thereof with counsel mutually satisfactory to the parties; provided, however, that an indemnified
party (together with all other indemnified parties that may be represented without conflict by one counsel) shall have the right to retain one separate counsel, with the fees and expenses to be paid by the indemnifying party, if representation of
such indemnified party by the counsel retained by the indemnifying party would be inappropriate due to actual or potential differing interests between such indemnified party and any other party represented by such counsel in such action. The failure
to give notice to the indemnifying party within a reasonable time of the commencement of any such action shall relieve such indemnifying party of any liability to the indemnified party under this Section 2.8, to the extent
that such failure materially prejudices the indemnifying party’s ability to defend such action. The failure to give notice to the indemnifying party will not relieve it of any liability that it may have to any indemnified party otherwise than
under this Section 2.8. 

  
 9 

 (d) To provide for just and equitable contribution to joint liability under the
Securities Act in any case in which either: (i) any party otherwise entitled to indemnification hereunder makes a claim for indemnification pursuant to this Section 2.8 but it is judicially determined (by the entry of
a final judgment or decree by a court of competent jurisdiction and the expiration of time to appeal or the denial of the last right of appeal) that such indemnification may not be enforced in such case, notwithstanding the fact that this
Section 2.8 provides for indemnification in such case, or (ii) contribution under the Securities Act may be required on the part of any party hereto for which indemnification is provided under this
Section 2.8, then, and in each such case, such parties will contribute to the aggregate losses, claims, damages, liabilities, or expenses to which they may be subject (after contribution from others) in such proportion as
is appropriate to reflect the relative fault of each of the indemnifying party and the indemnified party in connection with the statements, omissions, or other actions that resulted in such loss, claim, damage, liability, or expense, as well as to
reflect any other relevant equitable considerations. The relative fault of the indemnifying party and of the indemnified party shall be determined by reference to, among other things, whether the untrue or allegedly untrue statement of a material
fact, or the omission or alleged omission of a material fact, relates to information supplied by the indemnifying party or by the indemnified party and the parties’ relative intent, knowledge, access to information, and opportunity to correct
or prevent such statement or omission; provided, however, that, in any such case (x) no Holder will be required to contribute any amount in excess of the public offering price of all such Registrable Securities offered and sold by such
Holder pursuant to such registration statement, and (y) no Person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) will be entitled to contribution from any Person who was not guilty of
such fraudulent misrepresentation; and provided further that in no event shall a Holder’s liability pursuant to this Section 2.8(d), when combined with the amounts paid or payable by such Holder pursuant to
Section 2.8(b), exceed the proceeds from the offering received by such Holder (net of any Selling Expenses paid by such Holder), except in the case of willful misconduct or fraud by such Holder. 

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

(f) Unless otherwise superseded by an underwriting agreement entered into in connection with the underwritten public offering, the
obligations of the Company and Holders under this Section 2.8 shall survive the completion of any offering of Registrable Securities in a registration under this Section 2, and otherwise shall
survive the termination of this Agreement. 
 2.9 Reports Under Exchange Act. With a view to making available to
the Holders the benefits of SEC Rule 144 and any other rule or regulation of the SEC that may at any time permit a Holder to sell securities of the Company to the public without registration or pursuant to a registration on Form S-3, the Company shall: 
 (a) make and keep available adequate current public information, as
those terms are understood and defined in SEC Rule 144, at all times after the effective date of the registration statement filed by the Company for the IPO; 

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

  
 10 

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

2.10 Limitations on Subsequent Registration Rights. From and after the date of this Agreement, the Company shall not, without
the prior written consent of the Holders of a majority of the Registrable Securities then outstanding, enter into any agreement with any holder or prospective holder of any securities of the Company that would (i) provide to such holder
or prospective holder the right to include securities in any registration on other than either a pro rata basis with respect to the Registrable Securities or on a subordinate basis after all Holders have had the opportunity to include in the
registration and offering all shares of Registrable Securities that they wish to so include or (ii) allow such holder or prospective holder to include such securities in any registration unless, under the terms of such agreement,
such holder or prospective holder may include such securities in any such registration only to the extent that the inclusion of such securities will not reduce the number of the Registrable Securities of the Holders that are included;
provided that this limitation shall not apply to Registrable Securities acquired by any additional Investor that becomes a party to this Agreement in accordance with Section 6.9. 

2.11 “Market Stand-off” Agreement.
Each Holder hereby agrees that it will not, without the prior written consent of the managing underwriter, during the period commencing on the date of the final prospectus relating to the registration by the Company of shares of its Common Stock or
any other equity securities under the Securities Act 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 180 days in the case of the IPO), (i) lend; offer; pledge; sell; contract to sell; sell any option or contract to purchase; purchase any option or contract to sell; grant any option, right, or warrant
to purchase; or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable (directly or indirectly) for Common Stock held immediately before the effective
date of the registration statement for such offering or (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of such securities, whether any such transaction
described in clause (i) or (ii) above is to be settled by delivery of Common Stock or other securities, in cash, or otherwise. The foregoing provisions of this Section 2.11 shall apply only to the IPO, 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 1% of the Company’s outstanding Common Stock (after giving effect to
conversion into Common Stock of all outstanding Preferred Stock). The underwriters in connection with such registration are intended third-party beneficiaries of this Section 2.11 and
shall have the right, power and authority to enforce the provisions hereof as though they were a party hereto. Each Holder further agrees to execute such agreements as may be reasonably requested by the underwriters in connection with such
registration that are consistent with this Section 2.11 or that are necessary to give further effect thereto. 

  
 11 

 2.12 Restrictions on Transfer. 

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

THE SECURITIES REPRESENTED HEREBY HAVE BEEN ACQUIRED FOR INVESTMENT AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.
SUCH SHARES MAY NOT BE SOLD, PLEDGED, OR TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR A VALID EXEMPTION FROM THE REGISTRATION AND PROSPECTUS DELIVERY REQUIREMENTS OF SAID ACT. THE SECURITIES REPRESENTED HEREBY MAY BE TRANSFERRED ONLY IN
ACCORDANCE WITH THE TERMS OF AN AGREEMENT BETWEEN THE COMPANY AND THE STOCKHOLDER, A COPY OF WHICH IS ON FILE WITH THE SECRETARY OF THE COMPANY. 

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

  
 12 

 
set forth in Section 2.12(b), except that such certificate instrument, or book entry shall not be notated with such restrictive legend if, in the opinion of counsel for
such Holder and the Company, such legend is not required in order to establish compliance with any provisions of the Securities Act. 

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

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

(b) such time after consummation of 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. 
 3. Information
Rights. 
 3.1 Delivery of Financial Statements. The Company shall deliver to each Major Investor, provided that
the Board of Directors has not reasonably determined that such Major Investor is a Competitor of the Company: 
 (a) as soon as
practicable, but in any event within 90 days after the end of each fiscal year of the Company (which may be extended to up to 9 months from the end of the fiscal year of the Company upon approval of the Board of Directors, including the approval of
the majority of the Preferred Directors) (i) a balance sheet as of the end of such year, (ii) statements of income and of cash flows for such year, and (iii) a statement of stockholders’ equity as of the end of such year, all
such financial statements audited and certified by independent public accountants of regionally recognized standing selected by the Company; 

(b) as soon as practicable, but in any event within 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 45 days after the end of each of the first three (3) quarters 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 Major 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; 
 (d) as soon as practicable, but in any event 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 (including the majority of the Preferred Directors) 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 

  
 13 

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

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

Notwithstanding anything else in this Section 3.1 to the contrary, the Company may cease providing the information
set forth in this Section 3.1 during the period starting with the date 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 Section 3.1 shall be reinstated at such time as the Company is no longer
actively employing its commercially reasonable efforts to cause such registration statement to become effective. 
 3.2
Inspection. The Company shall permit each Major Investor, provided that the Board of Directors has not reasonably determined that such Major Investor is a Competitor of the Company, at such Major Investor’s expense, to visit and
inspect the Company’s properties; examine its books of account and records; and discuss the Company’s affairs, finances, and accounts with its officers, during normal business hours of the Company as may be reasonably requested by the
Major Investor; provided, however, that the Company shall not be obligated pursuant to this Section 3.2 to provide access to any information that it reasonably and in good faith considers to be a trade secret or
confidential information (unless covered by an enforceable confidentiality agreement, in form acceptable to the Company) or the disclosure of which would adversely affect the attorney-client privilege between the Company and its counsel. 

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

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

  
 14 

 
informs such Person that such information is confidential and directs such Person to maintain the confidentiality of such information; or (iv) as may otherwise be required by law,
regulation, rule, court order or subpoena, provided that such Investor promptly notifies the Company of such disclosure and takes reasonable steps to minimize the extent of any such required disclosure. 

4. Rights to Future Stock Issuances. 

4.1 Right of First Offer. Subject to the terms and conditions of this Section 4.1 and applicable
securities laws, if the Company proposes to offer or sell any New Securities, the Company shall first offer such New Securities to each 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 shall not be entitled to any rights as a Major Investor under Sections 3.1 and 3.2 or as an Investor under Section 4.1 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 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 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 all shares of Common Stock then issuable
(directly or indirectly) upon conversion and/or exercise, as applicable, of the Preferred Stock and any other Derivative Securities then held by such Investor) bears to the total Common Stock of the Company then outstanding (assuming full conversion
and/or exercise, as applicable, of all Preferred Stock and any other Derivative Securities then outstanding). At the expiration of such 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 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 Preferred Stock and any other
Derivative Securities then held, by such Fully Exercising Investor bears to the Common Stock issued and held, or issuable (directly or indirectly) upon conversion and/or exercise, as applicable, of the Preferred Stock and any other Derivative
Securities then held, by all Fully Exercising Investors who wish to purchase such unsubscribed shares. The closing of any sale pursuant to this Section 4.1(b) shall occur within the later of 90 days of the date that the
Offer Notice is given and the date of initial sale of New Securities pursuant to Section 4.1(c). 

  
 15 

 (c) If all New Securities referred to in the Offer Notice are not elected to be
purchased or acquired as provided in Section 4.1(b), the Company may, during the 90 day period following the expiration of the periods provided in Section 4.1(b), offer and sell the remaining
unsubscribed portion of such New Securities to any Person or Persons at a price not less than, and upon terms no more favorable to the offeree than, those specified in the Offer Notice. If the Company does not enter into an agreement for the sale of
the New Securities within such period, or if such agreement is not consummated within 30 days of the execution thereof, the right provided hereunder shall be deemed to be revived and such New Securities shall not be offered unless first reoffered to
the Investors in accordance with this Section 4.1. 
 (d) The right of first offer in this
Section 4.1 shall not be applicable to (i) Exempted Securities (as defined in the Certificate of Incorporation); (ii) shares of Common Stock issued in the IPO; and (iii) the issuance of shares of Series BB
Preferred Stock to Additional Purchasers pursuant to Section 1.2(b) of the Purchase Agreement. 
 (e) Notwithstanding any
provision hereof to the contrary, in lieu of complying with the provisions of this Section 4.1, the Company may elect to give notice to the Investors within 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 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 Section 4.1(b) before giving effect to the issuance of such New Securities. 

4.2 Termination. The covenants set forth in Section 4.1 shall terminate and be of no further force or
effect (i) immediately before the consummation of the IPO, (ii) when the Company first becomes subject to the periodic reporting requirements of Section 12(g) or 15(d) of the Exchange Act, or (iii) upon the closing of a Deemed
Liquidation Event, as such term is defined in the Certificate of Incorporation, whichever event occurs first. 
 5. Additional
Covenants. 
 5.1 Insurance. The Company shall maintain, 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 the majority of the Preferred Directors), and will use commercially reasonable efforts to cause such insurance policies to be
maintained until such time as the Board of Directors determines that such insurance should be discontinued. The policy will not be cancelable by the Company without prior approval by the Board of Directors. 

5.2 Employee Agreements. The Company will cause (i) each Person now or hereafter employed by it or by any subsidiary (or
engaged by the Company or any subsidiary as a consultant/independent contractor) with access to confidential information and/or trade secrets to enter into a confidential information and invention assignment agreement; and (ii) each Key
Employee to enter into a one year non-solicitation agreement, substantially in the form previously provided to the Board of Directors (including the Preferred 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 at least two of the Preferred Directors.

 5.3 Employee Stock. Unless otherwise approved by the Board of Directors, all future employees and consultants of the
Company who purchase, receive options to purchase, or receive awards of shares of the Company’s capital stock after the date hereof shall be required to execute restricted stock or option agreements, as applicable, providing for
(i) vesting of shares over a four year period, with the first 25% of such shares vesting following 12 months of continued employment or service, and the remaining shares vesting in equal monthly installments over the following 36 months, and
(ii) a market stand-off 

  
 16 

 
provision substantially similar to that in Section 2.11. Without the prior approval by the Board of Directors, the Company shall not amend, modify, terminate, waive or
otherwise alter, in whole or in part, any stock purchase, stock restriction or option agreement with any existing employee or service provider if such amendment would cause it to be inconsistent with this Section 5.3. In
addition, unless otherwise approved by the Board of Directors, the Company shall retain (and not waive) a “right of first refusal” on employee transfers until the IPO and shall have the right to repurchase unvested shares at cost upon
termination of employment of a holder of restricted stock. 
 5.4 Matters Requiring Investor Director Approval. So long as the
holders of Preferred Stock are entitled to elect a Preferred Director, 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 Preferred Directors: 
 (a) issue or obligate itself to issue any equity or debt securities other than pursuant
to an equity incentive or similar plan approved by the Board of Directors; 
 (b) create any new shares in an existing or novel
class of stock; 
 (c) incur, or obligate the Company to 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; 
 (d)
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; 

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

(f) 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; 
 (g) make any investment inconsistent
with any investment policy approved by the Board of Directors; 
 (h) otherwise enter into or be a party to any transaction with any
director, officer, or employee of the Company or any “associate” (as defined in Rule 12b-2 promulgated under the Exchange Act) of any such Person, except for transactions contemplated by this
Agreement, 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; 
 (i) hire or change the compensation of the C- and EVP-level executive officers, including approving any option grants or stock awards to executive officers; 

(j) change the principal business of the Company, enter new lines of business, or exit the current line of business; 

  
 17 

 (k) sell, assign, license, pledge, or encumber material technology or intellectual
property, other than licenses granted in the ordinary course of business; or 
 (l) 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 $200,000. 
 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 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, within 180 days after such request, and will maintain, an audit and compensation committee, each of which shall consist solely of non-management directors.
Each non-employee director 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, the Certificate of Incorporation, or elsewhere, as
the case may be. 
 5.7 Indemnification Matters. The Company hereby acknowledges that one (1) or more of the directors
nominated to serve on the Board of Directors by the Investors (each an “Investor Director”) may have certain rights to indemnification, advancement of expenses and/or insurance provided by one or more of the Investors and certain of
their Affiliates (collectively, the “Investor Indemnitors”). The Company hereby agrees (a) that it is the indemnitor of first resort (i.e., its obligations to any such Investor Director are primary and any obligation of the
Investor Indemnitors to advance expenses or to provide indemnification for the same expenses or liabilities incurred by such Investor Director are secondary), (b) that it shall be required to advance the full amount of expenses incurred by such
Investor Director and shall be liable for the full amount of all expenses, judgments, penalties, fines and amounts paid in settlement by or on behalf of any such Investor Director to the extent legally permitted and as required by the Company’s
Certificate of Incorporation or Bylaws of the Company (or any agreement between the Company and such Investor Director), without regard to any rights such Investor Director may have against the Investor Indemnitors, and, (c) that it irrevocably
waives, relinquishes and releases the Investor Indemnitors from any and all claims against the Investor Indemnitors for contribution, subrogation or any other recovery of any kind in respect thereof. The Company further agrees that no advancement or
payment by the Investor Indemnitors on behalf of any such Investor Director with respect to any claim for which such Investor Director has sought indemnification from the Company shall affect the foregoing and the Investor Indemnitors shall have a
right of contribution and/or be subrogated to the extent of such advancement or payment to all of the rights of recovery of such Investor Director against the Company. The Investor Directors and the Investor Indemnitors are intended third party
beneficiaries of this Section 5.9 and shall have the right, power and authority to enforce the provisions of this Section 5.9 as though they were a party to this Agreement. 

5.8 Right to Conduct Activities. The Company hereby agrees and acknowledges that each of the Specified Investors is a
professional investment organization, and as such reviews the business plans and related proprietary information of many enterprises, some of which may compete directly or indirectly with the Company’s business (as currently conducted or as
currently proposed to be conducted). The Company hereby agrees that, to the extent permitted under applicable law, each of the Specified 

  
 18 

 
Investors shall not be liable to the Company for any claim arising out of, or based upon, (i) the investment by such Specified Investor in any entity competitive with the Company, or
(ii) actions taken by any partner, officer, employee or other representative of such Specified Investor to assist any such competitive company, whether or not such action was taken as a member of the board of directors of such competitive
company or otherwise, and whether or not such action has a detrimental effect on the Company; provided, however, that the foregoing shall not relieve (x) any of the Investors from liability associated with the unauthorized disclosure of the
Company’s confidential information obtained pursuant to this Agreement, or (y) any director or officer of the Company from any liability associated with his or her fiduciary duties to the Company. 

5.9 Harassment Policy. The Company shall, within 120 days following the Initial Closing (as defined in the Purchase Agreement),
adopt and thereafter maintain in effect (i) a Code of Conduct governing appropriate workplace behavior and (ii) an Anti-Harassment and Discrimination Policy prohibiting discrimination and harassment at the Company. Such policy shall be
reviewed and approved by the Board of Directors. 
 5.10 Cybersecurity. The Company shall, within 180 days following the
Initial Closing (as defined in the Purchase Agreement), (a) identify its sensitive data and information, and restrict access (through physical and electronic controls) to those individuals who have a need to access it and (b) implement
cybersecurity solution(s) (the “Cybersecurity Solutions”) designed to protect its technology and systems (including servers, laptops, desktops, cloud, containers, virtual environments and data centers) and all data contained in such
systems. The Company shall use commercially reasonable efforts to ensure that the Cybersecurity Solutions (x) are up-to-date and include industry-standard
protections (e.g., antivirus, endpoint detection and response and threat hunting), (y) to the extent determined necessary by the Company or its Board of Directors, are backed by a breach prevention warranty from the vendor certifying the
effectiveness of such solutions, and (z) cause vendors to notify the Company of any security incidents posing a risk to the Company’s information (regardless of whether information was actually compromised). The Company shall evaluate on a
regular basis whether the Cybersecurity Solutions should be updated to ensure continued effectiveness and industry-standard protections. The Company shall also educate its employees about the proper use and storage of sensitive information,
including regular training as determined reasonably necessary by the Company or its Board of Directors. 
 5.11 Termination of
Covenants. The covenants set forth in this Section 5, except for Sections 5.5, 5.6, 5.7 and 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
Certificate of Incorporation, 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 10,000,000 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 Section 2.11. For the purposes of determining the number of
shares of Registrable Securities held by a transferee, the holdings of a transferee 

  
 19 

 
(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, as a condition to the applicable
transfer, establish a single attorney-in-fact for the purpose of exercising any rights, receiving notices, or taking any action under this Agreement. The terms and
conditions of this Agreement inure to the benefit of and are binding upon the respective successors and permitted assignees of the parties. Nothing in this Agreement, express or implied, is intended to confer upon any party other than the parties
hereto or their respective successors and permitted assignees any rights, remedies, obligations or liabilities under or by reason of this Agreement, except as expressly provided herein. 

6.2 Governing Law. This Agreement shall be governed by the internal law of the State of Delaware, without regard to conflict of
law principles that would result in the application of any law other than the law of the State of Delaware. 
 6.3
Counterparts. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Counterparts may be delivered via facsimile,
electronic mail (including pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, the Uniform Electronic Transactions Act or other applicable law, 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. 

6.5 Notices. 

(a) 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 days after having been sent by registered or certified mail, return receipt requested, postage prepaid; or (iv) one 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 Section 6.5. If notice is given to the Company, it shall be sent to 620 Professional Drive, Gaithersburg, MD 20879, Attention: John Celebi; and a copy (which
shall not constitute notice) shall also be sent to Cooley LLP, 3175 Hanover Street, Palo Alto, CA 94304-1130, Attention: Michael E. Tenta. 

(b) Consent to Electronic Notice. Each Investor consents to the delivery of any stockholder notice pursuant to the Delaware
General Corporation Law (the “DGCL”), as amended or superseded from time to time, by electronic transmission pursuant to Section 232 of the DGCL (or any successor thereto) at the electronic mail address or the facsimile
number set forth below such Investor’s name on the Schedules hereto, as updated from time to time by notice to the Company, or as on the books of the Company. To the extent that any notice given by means of electronic transmission is returned
or undeliverable for any reason, the foregoing consent shall be deemed to have been revoked until a new or corrected electronic mail address has been provided, and such attempted electronic notice shall be ineffective and deemed to not have been
given. Each Investor agrees to promptly notify the Company of any change in such stockholder’s electronic mail address, and that failure to do so shall not affect the foregoing. 

  
 20 

 6.6 Amendments and Waivers. Any term of this Agreement may be amended, modified or
terminated and the observance of any term of this Agreement may be waived (either generally or in a particular instance, and either retroactively or prospectively) only with the written consent of the Company, the holders of at least two-thirds of the Registrable Securities then outstanding; provided that the Company may in its sole discretion waive compliance with Section 2.12(c) (and the Company’s failure
to object promptly in writing after notification of a proposed assignment allegedly in violation of Section 2.12(c) shall be deemed to be a waiver); 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, (a) this Agreement may not be amended, modified 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, modification, 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) and (b) an amendment, modification, termination to or waiver of Sections 3.1 and 3.2, and any other section of this Agreement applicable to the Major Investors
(including this clause (b) of this Section 6.6) shall require only the written consent of the Company and the holders of a majority of the Registrable Securities then outstanding and held by the Major Investors.
Notwithstanding the foregoing, Schedule A hereto may be amended by the Company from time to time to add transferees of any Registrable Securities in compliance with the terms of this Agreement without the consent of the other parties; and
Schedule A hereto may also be amended by the Company after the date of this Agreement without the consent of the other parties to add information regarding any additional Investor who becomes a party to this Agreement in accordance with
Section 6.9. The Company shall give prompt notice of any amendment, modification or termination hereof or waiver hereunder to any party hereto that did not consent in writing to such amendment, modification, termination, or
waiver. Any amendment, modification, termination, or waiver effected in accordance with this Section 6.6 shall be binding on all parties hereto, regardless of whether any such party has consented thereto. No waivers of or
exceptions to any term, condition, or provision of this Agreement, in any one or more instances, shall be deemed to be or construed as a further or continuing waiver of any such term, condition, or provision. 

6.7 Severability. In case any one or more of the provisions contained in this Agreement is for any reason held to be invalid,
illegal or unenforceable in any respect, such invalidity, illegality, or unenforceability shall not affect any other provision of this Agreement, and such invalid, illegal, or unenforceable provision shall be reformed and construed so that it will
be valid, legal, and enforceable to the maximum extent permitted by law. 
 6.8 Aggregation of Stock. All shares of
Registrable Securities held or acquired by Affiliates shall be aggregated together for the purpose of determining the availability of any rights under this Agreement and such Affiliates may apportion such rights as among themselves in any manner
they deem appropriate. 
 6.9 Additional Investors. Notwithstanding anything to the contrary contained herein, if the Company
issues additional shares of the Company’s Preferred Stock after the date hereof, whether pursuant to the Purchase Agreement or otherwise, any purchaser of such shares of 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. 

  
 21 

 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 Termination of Prior Agreement. Upon execution of this Agreement by the Company and the undersigned
Investors, the Prior Agreement is hereby deemed amended and restated and superseded and replaced in its entirety by this Agreement, and shall be of no further force or effect. 

6.12 Dispute Resolution. Any unresolved controversy or claim arising out of or relating to this Agreement, except as
(i) otherwise provided in this Agreement, or (ii) any such controversies or claims arising out of either party’s intellectual property rights for which a provisional remedy or equitable relief is sought, shall be submitted to
arbitration by one arbitrator mutually agreed upon by the parties, and if no agreement can be reached within 30 days after names of potential arbitrators have been proposed by the American Arbitration Association (the “AAA”), then
by one arbitrator having reasonable experience in corporate finance transactions of the type provided for in this Agreement and who is chosen by the AAA. The arbitration shall take place in Gaithersburg, Maryland, in accordance with the AAA rules
then in effect, and judgment upon any award rendered in such arbitration will be binding and may be entered in any court having jurisdiction thereof. There shall be limited discovery prior to the arbitration hearing as follows: (a) exchange of
witness lists and copies of documentary evidence and documents relating to or arising out of the issues to be arbitrated, (b) depositions of all party witnesses and (c) such other depositions as may be allowed by the arbitrators upon a
showing of good cause. Depositions shall be conducted in accordance with the Maryland Code of Civil Procedure, the arbitrator shall be required to provide in writing to the parties the basis for the award or order of such arbitrator, and a court
reporter shall record all hearings, with such record constituting the official transcript of such proceedings. 
 Each party will bear its
own costs in respect of any disputes arising under this Agreement. The prevailing party shall be entitled to reasonable attorneys’ fees, costs, and necessary disbursements in addition to any other relief to which such party may be entitled.
Each of the parties to this Agreement consents to personal jurisdiction for any equitable action sought in the U.S. District Court for the District of Maryland or any court of the State of Maryland having subject matter jurisdiction. 

6.13 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. 
 [Remainder of page intentionally left
blank] 

  
 22 

 Execution Version 

The parties have executed this Amended and Restated Investors’ Rights Agreement as of the date first written above. 

 

			
	COMPANY: 
	
	SENSEI BIOTHERAPEUTICS, INC. 
		
	By:	 	/s/ John Celebi
		 	Name:    John Celebi
		 	Title:      Chief Executive Officer

 Signature Page to Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	APEIRON INVESTMENT GROUP LTD.
		
	By:	 	 /s/ Julien Hoefer

	Name:	 	Julien Hoefer
	Title:	 	Director

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	RICKS FAMILY TRUST
		
	By:	 	 /s/ Thomas G. Ricks

	Name:	 	Thomas G. Ricks
	Title:	 	Trustee

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 CAMBRIAN BIOPHARMA, INC.

		
	Signature:	 	 /s/ James Peyer

	Name:	 	James Peyer

 
			
	Title (if applicable):	 	CEO

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 infinitas capital AG

	(print name above, if an entity)
		
	Signature:	 	 /s/ Robin Lauber

	Name:	 	Robin Lauber

 
			
	Title (if applicable):	 	CEO

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 KORIFY CAPITAL AG

	 (print name above, if an entity)
  

	Signature:	 	 /s/ Robin Lauber

	Name:	 	Robin Lauber

 
			
	Title (if applicable):	 	CEO

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  
 (print name above, if an
entity)

		
	Signature:	 	 /s/ Mehdi Hatamian

	Name:	 	Mehdi Hatamian

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	 INVESTOR:
  

	 LIVE REALLY LONG AND PROSPER, LLC

	 (print name above, if an entity)

		
	 Signature:
	 	 /s/ Nathan Laurell

	 Name:
	 	 Nathan Laurell

			
	 Title (if applicable):
	 	 Manager + Member

			
	 Address:
	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	 INVESTOR:

	
	 FUTURE VENTURES, LP

		
	 By:
	 	 /s/ Maryanna Saenko

	 Name:
	 	 Maryanna Saenko

	 Title:
  
	 	 Managing Director

	 FUTURE VENTURES SIDE FUND, LP

 

	 By:
	 	 /s/ Maryanna Saenko

	 Name:
	 	 Maryanna Saenko

	 Title:
	 	 Managing Director

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	 INVESTOR:
  

	 COELI EUROPEAN OPPORTUNITY

(print name above, if an entity)

 
			
		
	Signature:	 	/s/ [ILLEGIBLE]
	Name:	 	[ILLEGIBLE]

 
			
	Title (if applicable):	 	PM

 
			
	Address:	 	              

	              

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

					
	INVESTOR:
	
	H&S Ventures, LLC
		
	By:	 	              

		 	Name:	 	              

		 	Title:	 	              

	
	Cambrian BioPharma, Inc.
		
	By:	 	
                 

		 	Name:	 	              

		 	Title:	 	              

	
	Albert Büll Beteiligungs GmbH
		
	By:	 	 /s/ Albert Büll

		 	Name:	 	Albert Büll
		 	Title:	 	Managing Director

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
		
	Signed:	 	 /s/ Mark Lee Ford

	Name:	 	Mark Lee Ford

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
		
	Signed:	 	 /s/ Terry Lem

	Name:	 	Terry Lem

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	H&S INVESTMENTS I, LP
	By: H & S Ventures, LLC, its general partner
		
	By:	 	 /s/ Michael Schulman

	Name:	 	Michael Schulman
	Title:	 	Manager

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Jack Wands

	Name:	 	Jack Wands

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Gilbert Lim

	Name:	 	Gilbert Lim

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Babak Arbabha

	Name:	 	Babak Arbabha

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Hamad T. AlAnjari

	Name:	 	Hamad T. AlAnjari

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	          

	(print name above, if an entity)
		
	Signature:	 	 /s/ Ramin Chirdel

	Name:	 	Ramin Chirdel

 
			
	Title (if applicable):	 	
         

			
	Address:	 	          

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	          

	(print name above, if an entity)
		
	Signature:	 	 /s/ Khaled Al-Otaibi

	Name:	 	Khaled Al-Otaibi

 
			
	Title (if applicable):	 	
         

			
	Address:	 	          

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 THE REVOCABLE LIVING TRUST UAD 02/03/2013 ARYA BEHZAD & MARYAM ESHGHIPOUR
TTEES

	(print name above, if an entity)
		
	Signature:	 	 /s/ Arya Behzad

	Name:	 	Arya Behzad

 
			
	Title (if applicable):	 	Trustee

 
			
	Address:	 	          

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	          

	(print name above, if an entity)
		
	Signature:	 	 /s/ Sasan Arbabha

	Name:	 	Sasan Arbabha

 
			
	Title (if applicable):	 	
         

			
	Address:	 	          

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)

 
			
		
	Signature:	 	 /s/ Bijan Motamedi

	Name:	 	Bijan Motamedi

 
			
	Title (if applicable):	 	
         

			
	Address:	 	          

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Jonathan K. Kishi

	Name:	 	Jonathan K. Kishi

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	Block.one Investments 1, an exempted company incorporated in the Cayman Islands (registered no. PA-326400) with limited liability whose registered office is at Maples
Corporate Services Centre Limited, PO Box 309, Ugland House, Grand Cayman, KY1-1104
		
	Signature:	 	 /s/ Andrew Bliss

	Name:	 	Andrew Bliss

 
			
	Title (if applicable):	 	Director

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Nari Persad

	Name:	 	Nari Persad

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Paul Thomas Wasilewski

	Name:	 	Paul Thomas Wasilewski

 
			
	Title (if applicable):	 	
         

			
	Address:	 	              

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 CATALIO NEXUS FUND II, LP

	By: Catalio Nexus GP II, LLC, its General Partner
		
	Signature:	 	 /s/ R. Jacob Vogelstein

	Name:	 	R. Jacob Vogelstein

 
			
	Title (if applicable):	 	Managing Member

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 WildeCo UG

	(print name above, if an entity)
		
	Signature:	 	 /s/ Lars Christian Wilde

	Name:	 	Lars Christian Wilde

 
			
	Title (if applicable):	 	Managing Director

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 Moore Strategic Ventures, LLC

	(print name above, if an entity)
		
	Signature:	 	 /s/ Scott Dinnell

	Name:	 	Scott Dinnell

 
			
	Title (if applicable):	 	Controller

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	 PURA VIDA MASTER FUND, LTD.

	domiciled in the Cayman Islands
		
	Signature:	 	 /s/ Efrem Kamen

	Name:	 	Efrem Kamen

 
			
	Title (if applicable):	 	Managing Member of Pura Vida Investments, LLC, in its capacity as Investment Manager

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Shahraab Ahmad

	Name:	 	Shahraab Ahmad

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	APEIRON SICAV LTD. – PRESIGHT CAPITAL
	FUND ONE
		
	By:	 	 /s/ Heinz Daxl

	Name:	 	Heinz Daxl
	Title:	 	Director
		
	By:	 	 /s/ Jefim Gewiet

	Name:	 	Jefim Gewiet
	Title:	 	Director

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	   

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Emi Yoshizaki

	Name:	 	Emi Yoshizaki

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	  

	(print name above, if an entity)
		
	Signature:	 	 /s/ Shuji Yoshizaki

	Name:	 	Shuji Yoshizaki

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	   

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Rabya Gillani

	Name:	 	Rabya Gillani

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	   

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Michael Harte

	Name:	 	Michael Harte

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

			
	INVESTOR:
	
	PRESIGHT SENSEI CO-INVEST FUND, L.P.
	
	 By: Presight Sensei Co-Invest Management, L.L.C.

Its: General Partner

		
	By:	 	 /s/ Fabian Hansen

	Name:	 	Fabian Hansen
	Title:	 	Authorized Signatory

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	   

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Noreen Valla

	Name:	 	Noreen Valla

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	 EFM Global Growth Master Fund

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Jeffrey Emmanuel

	Name:	 	Jeffrey Emmanuel

 
			
	Title (if applicable):	 	Chairman & CIO

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	   

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Shun Manabe

	Name:	 	Shun Manabe

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	   

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Kenro Tsutsumi

	Name:	 	Kenro Tsutsumi

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:

  

			
	Signed:	 	 /s/ Shinichi Yokote

	Name:	 	Shinichi Yokote

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	Stephen Aftel Eisenberg Family Trust UAD 3/17/17
	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Stephen Eisenberg

	Name:	 	Stephen Eisenberg

 
			
	Title (if applicable):	 	Trustee

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights Agreement 

 The parties have executed this Amended and Restated Investors’ Rights Agreement as of
the date first written above. 
  

	
	INVESTOR:
	
	   

	(print name above, if an entity)

  

			
	Signature:	 	 /s/ Saied Kazemi

	Name:	 	Saied Kazemi

 
			
	Title (if applicable):	 	  

 
			
	Address:	 	  

	  

  
 Signature Page to
Amended and Restated Investors’ Rights AgreementEX-4.2

 Exhibit 4.2 

THIS WARRANT AND THE SECURITIES ISSUABLE UPON THE EXERCISE HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
“ACT”), OR UNDER THE SECURITIES LAWS OF ANY STATES IN THE UNITED STATES. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER THE ACT AND THE
APPLICABLE STATE SECURITIES LAWS, PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER OR RESALE
IS IN COMPLIANCE WITH THE ACT AND ANY APPLICABLE STATE SECURITIES LAWS. 
 SENSEI BIOTHERAPEUTICS, INC. 

[AMENDED AND RESTATED] WARRANT TO PURCHASE COMMON STOCK 

VOID AFTER 

THIS CERTIFIES THAT, for value received,
                , or [its][his][her] assigns (the “Holder”), is entitled to subscribe for and purchase from SENSEI
BIOTHERAPEUTICS, INC., a Delaware corporation (the “Company”), the Exercise Shares at the Exercise Price (each subject to adjustment as provided herein). [This
Warrant is issued pursuant to that certain Convertible Promissory Note issued by the Company to the Holder, dated as of the date hereof][(the “Note”)]. [This Amended and Restated Warrant amends and restates and supersedes
in its entirety that certain Warrant to Purchase Common Stock dated as of April 1, 2019 (the “Prior Warrant”) which was issued to Holder pursuant to that certain Convertible Promissory Note issued by
the Company to the Holder, dated as April 1, 2019 (the “Note”). Upon acceptance of this Warrant by Holder, Holder hereby agrees that the Prior Warrant is terminated in its entirety. ] 

1. DEFINITIONS. As used herein, the following terms shall have the following
respective meanings: 
 (a) “Exercise Price” shall mean $
                 per Exercise Share. 
 (b)
“Exercise Period” shall mean the period commencing on the date hereof and ending ten (10) years later, unless sooner terminated as provided below. 

(c) “Exercise Shares” shall mean shares of the Company’s Common Stock, subject to adjustment pursuant to
the terms hereof, including but not limited to adjustments pursuant to Section 5 below, issuable upon exercise of this Warrant. 

2. EXERCISE OF WARRANT. 

2.1 Exercise. The rights represented by this Warrant may be exercised in whole or in part at any time during the Exercise
Period, by delivery of the following to the Company at its address set forth in Section 11 (or at such other address as it may designate by notice in writing to the Holder): 

(a) An executed Notice of Exercise in the form attached hereto as
EXHIBIT A; 
 (b) Payment of the Exercise Price either (i) in
cash or by check, (ii) by cancellation of indebtedness or (iii) pursuant to Section 2.2; and 

  
 1 

 (c) This Warrant. 

2.2 Net Exercise. Notwithstanding any provisions herein to the contrary, if the fair market value of one Exercise Share is
greater than the Exercise Price (at the date of calculation as set forth below), then, in lieu of exercising this Warrant as provided in Section 2.1, the Holder may, by surrender of this Warrant at the principal office of the Company together
with the properly endorsed Notice of Exercise, elect to receive the number of Exercise Shares computed using the following formula: 
  

	
	X = Y(A-B)
	      A

  

							
	Where	 	X	 	=	 	the number of Exercise Shares to be issued to the Holder;
				
	 	 	Y	 	=	 	the number of Exercise Shares purchasable under the Warrant or, if only a portion of the Warrant is being exercised, that
portion of the Warrant being canceled (at the date of such calculation);
				
	 	 	A	 	=	 	the fair market value of one Exercise Share (at the date of such calculation);
				
	 	 	B	 	=	 	Exercise Price (as adjusted to the date of such calculation);

 For purposes of the above calculation, the
fair market value of one Exercise Share shall be determined by the Company’s Board of Directors in good faith; provided, however, that in the event that this Warrant is exercised pursuant to this Section 2.2 in connection with the
Company’s initial public offering of its Common Stock, the fair market value per share shall be the per share offering price to the public of the Company’s initial public offering. 

2.3 Mechanics of Exercise. Upon the exercise of the rights represented by this Warrant, a certificate or certificates for the
Exercise Shares so purchased, registered in the name of the Holder or persons affiliated with the Holder, if the Holder so designates, shall be issued and delivered to the Holder within a reasonable time after the rights represented by this Warrant
shall have been so exercised. In the event that this Warrant is being exercised for less than all of the then-current number of Exercise Shares purchasable hereunder, then the Company shall, concurrently with the issuance by the Company of the
number of Exercise Shares for which this Warrant is then being exercised, issue a new Warrant exercisable for the remaining number of Exercise Shares purchasable hereunder. The person in whose name any certificate or certificates for Exercise Shares
are to be issued upon exercise of this Warrant shall be deemed to have become the holder of record of such shares on the date on which this Warrant was surrendered and payment of the Exercise Price was made, irrespective of the date of delivery of
such certificate or certificates, except that, if the date of such surrender and payment is a date when the stock transfer books of the Company are closed, such person shall be deemed to have become the holder of such shares at the close of business
on the next succeeding date on which the stock transfer books are open. 
 3. COVENANTS OF
THE COMPANY. The Company covenants and agrees that all Exercise Shares that may be issued upon the exercise of the rights represented by this Warrant will, upon issuance, be validly
issued and outstanding, fully paid and nonassessable, and free from all taxes, liens and charges with respect to the issuance thereof. The Company further covenants and agrees that the Company will at all times during the Exercise Period, have
authorized and reserved a sufficient number of shares of the series of equity securities comprising the Exercise Shares to provide for the exercise of the rights represented by this Warrant. The issuance of the Exercise Shares will not be subject to
any preemptive rights that have not been properly waived or complied with. If at any time during the Exercise Period the number of authorized but unissued shares of such series of the Company’s equity securities shall not be sufficient to
permit exercise of this Warrant, the Company will take such corporate action as may, in the opinion of its counsel, be necessary to increase its authorized but unissued shares of such series of the Company’s equity securities to such number of
shares as shall be sufficient for such purposes. 

  
 2 

 4. REPRESENTATIONS OF
HOLDER. 
 4.1 Acquisition of Warrant for Personal Account. The Holder represents and
warrants that it is acquiring the Warrant and the Exercise Shares solely for its account for investment and not with a view to or for sale or distribution of said Warrant or Exercise Shares or any part thereof. The Holder also represents that the
entire legal and beneficial interests of the Warrant and Exercise Shares the Holder is acquiring is being acquired for, and will be held for, its account only. 

4.2 Securities Are Not Registered. 

(a) The Holder understands that the Warrant and the Exercise Shares have not been registered under the Securities Act of 1933, as
amended (the “Act”) on the basis that no distribution or public offering of the stock of the Company is to be effected. The Holder realizes that the basis for the exemption may not be present if, notwithstanding its
representations, the Holder has a present intention of acquiring the securities for a fixed or determinable period in the future, selling (in connection with a distribution or otherwise), granting any participation in, or otherwise distributing the
securities. The Holder has no such present intention. 
 (b) The Holder recognizes that the Warrant and the Exercise Shares must be
held indefinitely unless they are subsequently registered under the Act or an exemption from such registration is available. The Holder recognizes that the Company has no obligation to register the Warrant or the Exercise Shares of the Company, or
to comply with any exemption from such registration. 
 (c) The Holder is aware that neither the Warrant nor the Exercise Shares may
be sold pursuant to Rule 144 adopted under the Act unless certain conditions are met. These conditions may include, among other things, the existence of a public market for the shares, the availability of certain current public information about the
Company, the resale following the required holding period under Rule 144 and the number of shares being sold during any three month period not exceeding specified limitations. Holder is aware that the conditions for resale set forth in Rule 144 have
not been satisfied and that the Company presently has no plans to satisfy these conditions in the foreseeable future. 
 4.3
Disposition of Warrant and Exercise Shares. 
 (a) The Holder further agrees not to make any disposition of all or any part
of the Warrant or Exercise Shares in any event unless and until: 
 (i) The Company shall have received a letter secured by the
Holder from the Securities and Exchange Commission stating that no action will be recommended to the Commission with respect to the proposed disposition; 

(ii) There is then in effect a registration statement under the Act covering such proposed disposition and such disposition is made in
accordance with said registration statement; or 
 (iii) The Holder shall have notified the Company of the proposed disposition and
shall have furnished the Company with a detailed statement of the circumstances surrounding the proposed disposition, and if reasonably requested by the Company, the Holder shall have furnished the Company with an opinion of counsel, reasonably
satisfactory to the Company, for the Holder to the effect that such disposition will not require registration of such Warrant or Exercise Shares under the Act or any applicable state securities laws. The Company agrees that it will not require an
opinion of counsel with respect to transactions under Rule 144 of the Act except in unusual circumstances. 

  
 3 

 (b) The Holder understands and agrees that all certificates evidencing the shares to
be issued to the Holder may bear the following legend: 
  

			
	 THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
“ACT”). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THE SECURITIES UNDER THE ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH
REGISTRATION IS NOT REQUIRED.
	  	

 4.4 Accredited Investor Status. The Holder is an “accredited investor” as defined in
Regulation D promulgated under the Act. 
 5. ADJUSTMENT OF EXERCISE
PRICE AND NUMBER OF EXERCISE SHARES. 

5.1 Changes in Securities. In the event of changes in the class of equity securities of the Company comprising the Exercise
Shares by reason of stock dividends, splits, recapitalizations, reclassifications, combinations or exchanges of such class of equity securities, then the number and class of Exercise Shares available under the Warrant in the aggregate and the
Exercise Price shall be correspondingly adjusted to give the Holder of the Warrant, on exercise for the same aggregate Exercise Price, the total number, class, and kind of shares as the Holder would have owned had the Warrant been exercised prior to
the event and had the Holder continued to hold such shares until after the event requiring adjustment. For purposes of this Section 5, the “aggregate Exercise Price” shall mean the aggregate Exercise Price payable in
connection with the exercise in full of this Warrant. The form of this Warrant need not be changed because of any adjustment in the number of Exercise Shares subject to this Warrant. 

6. FRACTIONAL SHARES. No fractional shares shall be issued upon the
exercise of this Warrant as a consequence of any adjustment pursuant hereto. All Exercise Shares (including fractions) to be issued upon exercise of this Warrant shall be aggregated for purposes of determining whether the exercise would result in
the issuance of any fractional share. If, after aggregation, the exercise would result in the issuance of a fractional share, the Company shall, in lieu of issuance of any fractional share, pay the Holder otherwise entitled to such fraction a sum in
cash equal to the product resulting from multiplying the then current fair market value of one Exercise Share by such fraction. 
 7.
MARKET STANDOFF. To the extent requested by the Company or an underwriter of securities of the Company, Holder and any permitted transferee thereof shall not, without the prior
written consent of the managing underwriters in the IPO (as hereafter defined), offer, sell, make any short sale of, grant or sell any option for the purchase of, lend, pledge, otherwise transfer or dispose of (directly or indirectly), enter into
any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership (whether any such transaction is described above or is to be settled by delivery of Exercise Shares or other securities, in
cash, or otherwise), any Exercise Shares or other shares of stock of the Company then owned by such Holder or any transferee thereof, or enter into an agreement to do any of the foregoing, for up to 180 days following the effective date of the
registration statement of the initial public offering of the Company (the “IPO”) filed under the Act. For purposes of this paragraph, “Company” includes any wholly owned subsidiary of the Company into
which the Company merges or consolidates. The Company may place restrictive legends on the certificates representing the shares subject to this paragraph and may impose stop transfer instructions with respect to this Warrant and the Exercise Shares
and such other shares of stock of Holder and any transferee thereof (and the shares or securities of every other person subject to the foregoing restriction) until the end of such period. Holder 

  
 4 

 
and any transferee thereof shall enter into any agreement reasonably required by the underwriters to the IPO to implement the foregoing within any reasonable timeframe so requested. The
underwriters for any IPO are intended third party beneficiaries of this paragraph and shall have the right, power and authority to enforce the provisions of this paragraph as though they were parties hereto. 

8. NO STOCKHOLDER RIGHTS. This Warrant in and of
itself shall not entitle the Holder to any voting rights or other rights as a stockholder of the Company. 
 9.
TRANSFER OF WARRANT. Subject to applicable laws and the restriction on transfer set forth on the first page of this Warrant, this Warrant and all rights hereunder are
transferable, by the Holder in person or by duly authorized attorney, upon delivery of this Warrant and the form of assignment attached hereto as EXHIBIT B to any transferee designated by Holder.
The transferee shall sign an investment letter in form and substance reasonably satisfactory to the Company. 
 10.
LOST, STOLEN, MUTILATED OR DESTROYED WARRANT. If this Warrant is lost, stolen, mutilated or destroyed, the Company may, on
such terms as to indemnity or otherwise as it may reasonably impose (which shall, in the case of a mutilated Warrant, include the surrender thereof), issue a new Warrant of like denomination and tenor as the Warrant so lost, stolen, mutilated or
destroyed. Any such new Warrant shall constitute an original contractual obligation of the Company, whether or not the allegedly lost, stolen, mutilated or destroyed Warrant shall be at any time enforceable by anyone. 

11. NOTICES, ETC. [All notices required or permitted hereunder shall be in writing and shall be deemed effectively given:
(a) upon personal delivery to the party to be notified, (b) when sent by electronic transmission or facsimile if sent during normal business hours of the recipient, if not, then on the next business day, (c) five (5) days after having
been sent by registered or certified mail, return receipt requested, postage prepaid, or (d) one (1) day after deposit with a nationally recognized overnight courier, specifying next day delivery, with written verification of receipt. All
communications shall be sent to the Company at 620 Professional Drive, Gaithersburg, Maryland 20879, Attn: Chief Executive Officer, and to Holder at
                    , or at such other address as the Company or Holder may designate by ten (10) days advance written notice to the other
parties hereto.][All notices required or permitted hereunder shall be in writing and shall be deemed effectively given in accordance with the provisions of Section 6(j) of the Note.] 

12. SUCCESSOR AND ASSIGNS. This Warrant and the rights evidenced
hereby shall be binding upon and shall inure to the benefit of the parties hereto and the successors of the Company and the successors and permitted assigns of the Holder. Such successors and/or permitted assigns of the Holder shall be deemed to be
a Holder for all purposes hereunder. 
 13. NO THIRD-PARTY
BENEFICIARIES. This Warrant is for the sole benefit of the Company and the Holder and their respective successors and, in the case of the Holder, permitted assigns and nothing herein, express or implied, is intended
to or shall confer upon any other Person any legal or equitable right, benefit or remedy of any nature whatsoever, under or by reason of this Warrant. 

14. HEADINGS. The headings in this Warrant are for reference only and shall not affect the
interpretation of this Warrant. 
 15. AMENDMENT AND MODIFICATION;
WAIVER. [Except as otherwise provided herein, this Warrant may be amended, modified or supplemented only by an agreement in writing signed by the Holder and the Company. No waiver by the Company or the Holder of any
of the provisions hereof shall be effective unless explicitly set forth in writing and signed by the party so waiving. No waiver by any party shall operate or be construed as a waiver in respect of any failure, breach or default not expressly
identified by such written waiver, whether of a similar or different character, and whether occurring before or after 

  
 5 

 
that waiver. No failure to exercise, or delay in exercising, any rights, remedy, power or privilege arising from this Warrant shall operate or be construed as a waiver thereof; nor shall any
single or partial exercise of any right, remedy, power or privilege hereunder preclude any other or further exercise thereof or the exercise of any other right, remedy, power or privilege.][Except as otherwise provided herein, this Warrant may be
amended, modified or supplemented only by an agreement in writing signed by the Holder or the Majority Holders (as defined in the Note), on the one hand, and the Company, on the other hand. Upon the effectuation of such amendment, modification or
supplement with the consent of the Majority Holders in conformance with this paragraph, such amendment, modification or supplement shall be effective as to, and binding against, the holders of all warrants issued pursuant to the Notes (as defined in
the Note), and the Company shall promptly give written notice thereof to the Holder if the Holder has not previously consented to such amendment, modification or waiver in writing; provided that the failure to give such notice shall not affect the
validity of such amendment, modification or waiver. No waiver by the Company, the Majority Holders, or the Holder of any of the provisions hereof shall be effective unless explicitly set forth in writing and signed by the party or parties so
waiving. No waiver by any party shall operate or be construed as a waiver in respect of any failure, breach or default not expressly identified by such written waiver, whether of a similar or different character, and whether occurring before or
after that waiver. No failure to exercise, or delay in exercising, any rights, remedy, power or privilege arising from this Warrant shall operate or be construed as a waiver thereof; nor shall any single or partial exercise of any right, remedy,
power or privilege hereunder preclude any other or further exercise thereof or the exercise of any other right, remedy, power or privilege.] 

16. SEVERABILITY. If any term or provision of this Warrant is invalid, illegal or unenforceable in
any jurisdiction, such invalidity, illegality or unenforceability shall not affect any other term or provision of this Warrant or invalidate or render unenforceable such term or provision in any other jurisdiction. 

17. ACCEPTANCE. Receipt of this Warrant by the Holder shall constitute acceptance of
and agreement to all of the terms and conditions contained herein. 
 18. GOVERNING
LAW. This Warrant and all rights, obligations and liabilities hereunder shall be governed by and construed under the laws of the State of Delaware as applied to agreements among Delaware residents,
made and to be performed entirely within the State of Delaware without giving effect to conflicts of laws principles. 

[SIGNATURE PAGE FOLLOWS] 

  
 6 

 IN WITNESS WHEREOF, the
Company has caused this Warrant to be executed by its duly authorized officer as of the date first written above. 
  

			
	 SENSEI BIOTHERAPEUTICS,
INC.

 
			
		
	 By:
	 	 
	 Name:
	 	 
	 Title:
	 	 

  

[WARRANT TO PURCHASE COMMON STOCK] 

 EXHIBIT A 

NOTICE OF EXERCISE 
 TO:
SENSEI BIOTHERAPEUTICS, INC. 
 (1) ☐ The undersigned hereby elects to purchase
__________ shares of Common Stock (the “Exercise Shares”) of Sensei Biotherapeutics, Inc. (the “Company”) pursuant to the terms of the attached Warrant, and tenders herewith payment of the exercise
price in full, together with all applicable transfer taxes, if any. 
       ☐ The undersigned hereby
elects to purchase __________ shares of Common Stock (the “Exercise Shares”) of Sensei Biotherapeutics, Inc. (the “Company”) pursuant to the terms of the net exercise provisions set forth in
Section 2.2 of the attached Warrant, and shall tender payment of all applicable transfer taxes, if any. 
 (2) Please issue a
certificate or certificates representing said Exercise Shares in the name of the undersigned or in such other name as is specified below: 
  

					
	 	 	  	 	 
	 	 	(Name)	 	 
	 	 	  	 	 
	 	 	(Address)	 	 

 (3) The undersigned represents that (i) the aforesaid Exercise Shares are being
acquired for the account of the undersigned for investment and not with a view to, or for resale in connection with, the distribution thereof and that the undersigned has no present intention of distributing or reselling such shares; (ii) the
undersigned is aware of the Company’s business affairs and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision regarding its investment in the Company; (iii) the
undersigned is experienced in making investments of this type and has such knowledge and background in financial and business matters that the undersigned is capable of evaluating the merits and risks of this investment and protecting the
undersigned’s own interests; (iv) the undersigned understands that Exercise Shares issuable upon exercise of this Warrant have not been registered under the Act by reason of a specific exemption from the registration provisions of the Act,
which exemption depends upon, among other things, the bona fide nature of the investment intent as expressed herein, and, because such securities have not been registered under the Act, they must be held indefinitely unless subsequently registered
under the Act or an exemption from such registration is available; (v) the undersigned is aware that the aforesaid Exercise Shares may not be sold pursuant to Rule 144 adopted under the Act unless certain conditions are met and until the
undersigned has held the shares for the number of years prescribed by Rule 144, that the conditions for use of the Rule may include the availability of current information to the public about the Company and the Company has not made such information
available and has no present plans to do so; and (vi) the undersigned agrees not to make any disposition of all or any part of the aforesaid shares of Exercise Shares unless and until there is then in effect a registration statement under the
Act covering such proposed disposition and such disposition is made in accordance with said registration statement, or, if reasonably requested by the Company, the undersigned has provided the Company with an opinion of counsel satisfactory to the
Company, stating that such registration is not required. 
  

					
	 	 		 	 
	 (Date)
	 		 	 (Signature)

			
		 		 	 
		 		 	 (Print name)

  
 A-1 

 EXHIBIT B 

ASSIGNMENT FORM 
  

					
		  	(To assign the foregoing Warrant, execute this form and supply required information. Do not use this form to purchase shares.)	  	

 FOR VALUE RECEIVED, the foregoing Warrant
and all rights evidenced thereby are hereby assigned to 
 Name:
______________________________________________________________________________________________________ 
 (Please Print) 

Address: _____________________________________________________________________________________________________ 

(Please Print) 
 Dated: ____________, 20__ 

Holder’s 
 Signature:
_______________________________________________________ 
 Holder’s 

Address: ________________________________________________________ 

NOTE: The signature to this Assignment Form must correspond with the name as it appears on the face of the Warrant, without alteration or enlargement
or any change whatever. Officers of corporations and those acting in a fiduciary or other representative capacity should file proper evidence of authority to assign the foregoing Warrant. 

  
 A-1

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00320-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00320-of-00352.parquet"}]]