Document:

EX-10.1

 Exhibit 10.1 

C4 THERAPEUTICS, INC. 

2015 STOCK OPTION AND GRANT PLAN 
 SECTION
1. GENERAL PURPOSE OF THE PLAN; DEFINITIONS 
 The name of the plan is the C4 Therapeutics, Inc. 2015 Stock Option and Grant Plan (the
“Plan”). The purpose of the Plan is to encourage and enable the officers, employees, directors, Consultants and other key persons of C4 Therapeutics, Inc., a Delaware corporation (including any successor entity, the “Company”)
and its Subsidiaries, upon whose judgment, initiative and efforts the Company largely depends for the successful conduct of its business, to acquire a proprietary interest in the Company. 

The following terms shall be defined as set forth below: 

“Affiliate” of any Person means a Person that directly or indirectly, through one or more intermediaries, controls, is
controlled by or is under common control with the first mentioned Person. A Person shall be deemed to control another Person if such first Person possesses directly or indirectly the power to direct, or cause the direction of, the management and
policies of the second Person, whether through the ownership of voting securities, by contract or otherwise. 
 “Award” or
“Awards,” except where referring to a particular category of grant under the Plan, shall include Incentive Stock Options, Non-Qualified Stock Options, Restricted Stock Awards, Unrestricted
Stock Awards, Restricted Stock Units or any combination of the foregoing. 
 “Award Agreement” means a
written or electronic agreement setting forth the terms and provisions applicable to an Award granted under the Plan. Each Award Agreement may contain terms and conditions in addition to those set forth in the Plan; provided, however,
in the event of any conflict in the terms of the Plan and the Award Agreement, the terms of the Plan shall govern. 

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

“Cause” shall have the meaning as set forth in the Award Agreement(s). In the case that any Award Agreement does not contain
a definition of “Cause,” it shall mean (i) the grantee’s dishonest statements or acts with respect to the Company or any Affiliate of the Company, or any current or prospective customers, suppliers vendors or other third parties
with which such entity does business; (ii) the grantee’s commission of (A) a felony or (B) any misdemeanor involving moral turpitude, deceit, dishonesty or fraud; (iii) the grantee’s failure to perform his assigned
duties and responsibilities to the reasonable satisfaction of the Company which failure continues, in the reasonable judgment of the Company, after written notice given to the grantee by the Company; (iv) the grantee’s gross negligence,
willful misconduct or insubordination with respect to the Company or any Affiliate of the Company; or (v) the grantee’s material violation of any provision of any agreement(s) between the grantee and the Company relating to noncompetition,
nonsolicitation, nondisclosure and/or assignment of inventions. 
 “Chief Executive Officer” means the Chief Executive
Officer of the Company or, if there is no Chief Executive Officer, then the President of the Company. 

 “Code” means the Internal Revenue Code of 1986, as amended, and any
successor Code, and related rules, regulations and interpretations. 
 “Committee” means the Committee of the Board
referred to in Section 2. 
 “Consultant” means any natural person that provides bona fide services to the Company
(including a Subsidiary), and such services are not in connection with the offer or sale of securities in a capital-raising transaction and do not directly or indirectly promote or maintain a market for the Company’s securities. 

“Disability” means “disability” as defined in Section 422(c) of the Code. 

“Effective Date” means the date on which the Plan is adopted as set forth on the final page of the Plan. 

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

“Fair Market Value” of the Stock on any given date means the fair market value of the Stock determined in good faith by the
Committee based on the reasonable application of a reasonable valuation method not inconsistent with Section 409A of the Code. If the Stock is admitted to trade on a national securities exchange, the determination shall be made by reference to
the closing price reported on such exchange. If there is no closing price for such date, the determination shall be made by reference to the last date preceding such date for which there is a closing price. If the date for which Fair Market Value is
determined is the first day when trading prices for the Stock are reported on a national securities exchange, the Fair Market Value shall be the “Price to the Public” (or equivalent) set forth on the cover page for the final prospectus
relating to the Company’s Initial Public Offering. 
 “Good Reason” shall have the meaning as set forth in the Award
Agreement(s). In the case that any Award Agreement does not contain a definition of “Good Reason,” it shall mean (i) a material diminution in the grantee’s base salary except for across-the-board salary reductions similarly affecting all or substantially all similarly situated employees of the Company or (ii) a change of more than 50 miles in the geographic location at which the
grantee provides services to the Company, so long as the grantee provides at least 90 days notice to the Company following the initial occurrence of any such event and the Company fails to cure such event within 30 days thereafter. 

“Grant Date” means the date that the Committee designates in its approval of an Award in accordance with applicable law as
the date on which the Award is granted, which date may not precede the date of such Committee approval. 
 “Holder” means,
with respect to an Award or any Shares, the Person holding such Award or Shares, including the initial recipient of the Award or any Permitted Transferee. 

“Incentive Stock Option” means any Stock Option designated and qualified as an “incentive stock option” as defined
in Section 422 of the Code. 

 “Initial Public Offering” means the consummation of the first firm
commitment underwritten public offering pursuant to an effective registration statement under the Securities Act covering the offer and sale by the Company of its equity securities, as a result of or following which the Stock shall be publicly held.

 “Non-Qualified Stock Option” means any Stock Option that is not an Incentive
Stock Option. 
 “Option” or “Stock Option” means any option to purchase shares of Stock granted pursuant
to Section 5. 
 “Permitted Transferees” shall mean any of the following to whom a Holder may transfer Shares
hereunder (as set forth in Section 9(a)(ii)(A)): the Holder’s child, stepchild, grandchild, parent, stepparent, grandparent, spouse, former spouse, sibling, niece, nephew,
mother-in-law, father-in-law, son-in-law, daughter-in-law, brother-in-law, or sister-in-law, including adoptive relationships, any person sharing the Holder’s household (other than a tenant or employee), a trust in which these persons have more
than fifty percent of the beneficial interest, a foundation in which these persons control the management of assets, and any other entity in which these persons own more than fifty percent of the voting interests; provided, however, that any
such trust does not require or permit distribution of any Shares during the term of the Award Agreement unless subject to its terms. Upon the death of the Holder, the term Permitted Transferees shall also include such deceased Holder’s estate,
executors, administrators, personal representatives, heirs, legatees and distributees, as the case may be. 
 “Person”
shall mean any individual, corporation, partnership (limited or general), limited liability company, limited liability partnership, association, trust, joint venture, unincorporated organization or any similar entity. 

“Restricted Stock Award” means Awards granted pursuant to Section 6 and “Restricted Stock” means Shares
issued pursuant to such Awards. 
 “Restricted Stock Unit” means an Award of phantom stock units to a grantee, which may be
settled in cash or Shares as determined by the Committee, pursuant to Section 8. 
 “Sale Event” means the
consummation of (i) the dissolution or liquidation of the Company, (ii) the sale of all or substantially all of the assets of the Company on a consolidated basis to an unrelated person or entity, (iii) a merger, reorganization or
consolidation pursuant to which the holders of the Company’s outstanding voting power immediately prior to such transaction do not own a majority of the outstanding voting power of the surviving or resulting entity (or its ultimate parent, if
applicable), (iv) the acquisition of all or a majority of the outstanding voting stock of the Company in a single transaction or a series of related transactions by a Person or group of Persons, or (v) any other acquisition of the business of
the Company, as determined by the Board; provided, however, that the Company’s Initial Public Offering, any subsequent public offering or another capital raising event, or a merger effected solely to change the Company’s domicile
shall not constitute a “Sale Event.” 
 “Section 409A” means Section 409A of the Code and
the regulations and other guidance promulgated thereunder. 

 “Securities Act” means the Securities Act of 1933, as amended, and the
rules and regulations thereunder. 
 “Service Relationship” means, except as otherwise set forth in an Award Agreement, any
relationship as a full-time employee, part-time employee, director or other key person (including Consultants) of the Company or any Subsidiary or any successor entity (e.g., a Service Relationship shall be deemed to continue without interruption in
the event an individual’s status changes from full-time employee to part-time employee or Consultant). 
 “Shares”
means shares of Stock. 
 “Stock” means the Common Stock, par value $0.0001 per share, of the Company. 

“Subsidiary” means any corporation or other entity (other than the Company) in which the Company has more than a
50 percent interest, either directly or indirectly. 
 “Ten Percent Owner” means an employee who owns or is deemed to
own (by reason of the attribution rules of Section 424(d) of the Code) more than 10 percent of the combined voting power of all classes of stock of the Company or any parent of the Company or any Subsidiary. 

“Termination Event” means the termination of the Award recipient’s Service Relationship with the Company and its
Subsidiaries for any reason whatsoever, regardless of the circumstances thereof, and including, without limitation, upon death, disability, retirement, discharge or resignation for any reason, whether voluntarily or involuntarily. The following
shall not constitute a Termination Event (unless specifically set forth in an Award Agreement): (i) a transfer to the service of the Company from a Subsidiary or from the Company to a Subsidiary, or from one Subsidiary to another Subsidiary or
(ii) an approved leave of absence for military service or sickness, or for any other purpose approved by the Committee, if the individual’s right to re-employment is guaranteed either by a statute or
by contract or under the policy pursuant to which the leave of absence was granted or if the Committee otherwise so provides in writing. 

“Unrestricted Stock Award” means any Award granted pursuant to Section 7 and “Unrestricted Stock” means
Shares issued pursuant to such Awards. 
  

	SECTION	 2. ADMINISTRATION OF PLAN; COMMITTEE AUTHORITY TO SELECT GRANTEES AND DETERMINE AWARDS

 (a) Administration of Plan. The Plan shall be administered by the Board, or at the discretion of the Board, by a
committee of the Board, comprised of not less than two directors. All references herein to the “Committee” shall be deemed to refer to the group then responsible for administration of the Plan at the relevant time (i.e., either the Board
of Directors or a committee or committees of the Board, as applicable). 
 (b) Powers of Committee. The Committee shall have the power
and authority to grant Awards consistent with the terms of the Plan, including the power and authority: 
 (i) to select the individuals to
whom Awards may from time to time be granted; 
 (ii) to determine the time or times of grant, and the amount, if any, of Incentive Stock
Options, Non-Qualified Stock Options, Restricted Stock Awards, Unrestricted Stock Awards, Restricted Stock Units, or any combination of the foregoing, granted to any one or more grantees; 

 (iii) to determine the number of Shares to be covered by any Award and, subject to the
provisions of the Plan, the price, exercise price, conversion ratio or other price relating thereto; 
 (iv) to determine and, subject to
Section 12, to modify from time to time the terms and conditions, including restrictions, not inconsistent with the terms of the Plan, of any Award, which terms and conditions may differ among individual Awards and grantees, and to approve the
form of Award Agreements; 
 (v) to accelerate at any time the exercisability or vesting of all or any portion of any Award; 

(vi) to impose any limitations on Awards, including limitations on transfers, repurchase provisions and the like, and to exercise repurchase
rights or obligations; 
 (vii) subject to Section 5(a)(ii) and any restrictions imposed by Section 409A, to extend at any time the
period in which Stock Options may be exercised; and 
 (viii) at any time to adopt, alter and repeal such rules, guidelines and practices for
administration of the Plan and for its own acts and proceedings as it shall deem advisable; to interpret the terms and provisions of the Plan and any Award (including Award Agreements); to make all determinations it deems advisable for the
administration of the Plan; to decide all disputes arising in connection with the Plan; and to otherwise supervise the administration of the Plan. 
 All
decisions and interpretations of the Committee shall be binding on all persons, including the Company and all Holders. 
 (c) Award
Agreement. Awards under the Plan shall be evidenced by Award Agreements that set forth the terms, conditions and limitations for each Award. 

(d) Indemnification. Neither the Board nor the Committee, nor any member of either or any delegate thereof, shall be liable for any act,
omission, interpretation, construction or determination made in good faith in connection with the Plan, and the members of the Board and the Committee (and any delegate thereof) shall be entitled in all cases to indemnification and reimbursement by
the Company in respect of any claim, loss, damage or expense (including, without limitation, reasonable attorneys’ fees) arising or resulting therefrom to the fullest extent permitted by law and/or under the Company’s governing documents,
including its certificate of incorporation or bylaws, or any directors’ and officers’ liability insurance coverage which may be in effect from time to time and/or any indemnification agreement between such individual and the Company. 

(e) Foreign Award Recipients. Notwithstanding any provision of the Plan to the contrary, in order to comply with the laws in other
countries in which the Company and any Subsidiary operate or have employees or other individuals eligible for Awards, the Committee, in its sole discretion, shall have the power and authority to: (i) determine which Subsidiaries, if any, shall
be covered by the Plan; (ii) determine which individuals, if any, outside the United States are 

 
eligible to participate in the Plan; (iii) modify the terms and conditions of any Award granted to individuals outside the United States to comply with applicable foreign laws;
(iv) establish subplans and modify exercise procedures and other terms and procedures, to the extent the Committee determines such actions to be necessary or advisable (and such subplans and/or modifications shall be attached to the Plan as
appendices); provided, however, that no such subplans and/or modifications shall increase the share limitation contained in Section 3(a) hereof; and (v) take any action, before or after an Award is made, that the
Committee determines to be necessary or advisable to obtain approval or comply with any local governmental regulatory exemptions or approvals. 
 SECTION 3.
STOCK ISSUABLE UNDER THE PLAN; MERGERS AND OTHER TRANSACTIONS; SUBSTITUTION 
 (a) Stock Issuable. The maximum number of Shares
reserved and available for issuance under the Plan shall be 21,297,353 Shares, subject to adjustment as provided in Section 3(b). For purposes of this limitation, the Shares underlying any Awards that are forfeited, canceled, reacquired
by the Company prior to vesting, satisfied without the issuance of Stock or otherwise terminated (other than by exercise) and Shares that are withheld upon exercise of an Option or settlement of an Award to cover the exercise price or tax
withholding shall be added back to the Shares available for issuance under the Plan. Subject to such overall limitations, Shares may be issued up to such maximum number pursuant to any type or types of Award, and no more than 212,973,530 Shares may
be issued pursuant to Incentive Stock Options. The Shares available for issuance under the Plan may be authorized but unissued Shares or Shares reacquired by the Company. Beginning on the date that the Company becomes subject to Section 162(m)
of the Code, Options with respect to no more than 21,297,353 Shares shall be granted to any one individual in any calendar year period. 

(b) Changes in Stock. Subject to Section 3(c) hereof, if, as a result of any reorganization, recapitalization, reclassification,
stock dividend, stock split, reverse stock split or other similar change in the Company’s capital stock, the outstanding Shares are increased or decreased or are exchanged for a different number or kind of shares or other securities of the
Company, or additional Shares or new or different shares or other securities of the Company or other non-cash assets are distributed with respect to such Shares or other securities, in each case, without the
receipt of consideration by the Company, or, if, as a result of any merger or consolidation, or sale of all or substantially all of the assets of the Company, the outstanding Shares are converted into or exchanged for other securities of the Company
or any successor entity (or a parent or subsidiary thereof), the Committee shall make an appropriate and proportionate adjustment in (i) the maximum number of Shares reserved for issuance under the Plan, (ii) the number and kind of Shares
or other securities subject to any then outstanding Awards under the Plan, (iii) the repurchase price, if any, per Share subject to each outstanding Award, and (iv) the exercise price for each Share subject to any then outstanding Stock
Options under the Plan, without changing the aggregate exercise price (i.e., the exercise price multiplied by the number of Stock Options) as to which such Stock Options remain exercisable. The Committee shall in any event make such adjustments as
may be required by Section 25102(o) of the California Corporation Code and the rules and regulations promulgated thereunder. The adjustment by the Committee shall be final, binding and conclusive. No fractional Shares shall be issued under the
Plan resulting from any such adjustment, but the Committee in its discretion may make a cash payment in lieu of fractional shares. 

 (c) Sale Events. 

(i) Options. 

(A) In the case of and subject to the consummation of a Sale Event, the Plan and all outstanding Options issued hereunder shall
terminate upon the effective time of any such Sale Event unless assumed or continued by the successor entity, or new stock options or other awards of the successor entity or parent thereof are substituted therefor, with an equitable or proportionate adjustment as to the number and kind of shares and, if appropriate, the per share exercise prices, as such parties shall agree (after taking into account any
acceleration hereunder and/or pursuant to the terms of any Award Agreement). 
 (B) In the event of the termination of the
Plan and all outstanding Options issued hereunder pursuant to Section 3(c), each Holder of Options shall be permitted, within a period of time prior to the consummation of the Sale Event as specified by the Committee, to exercise all such
Options which are then exercisable or will become exercisable as of the effective time of the Sale Event; provided, however, that the exercise of Options not exercisable prior to the Sale Event shall be subject to the consummation of the Sale
Event. 
 (C) Notwithstanding anything to the contrary in Section 3(c)(i)(A), in the event of a Sale Event, the Company
shall have the right, but not the obligation, to make or provide for a cash payment to the Holders of Options, without any consent of the Holders, in exchange for the cancellation thereof, in an amount equal to the difference between (A) the
value as determined by the Committee of the consideration payable per share of Stock pursuant to the Sale Event (the “Sale Price”) times the number of Shares subject to outstanding Options being cancelled (to the extent then vested and
exercisable, including by reason of acceleration in connection with such Sale Event, at prices not in excess of the Sale Price) and (B) the aggregate exercise price of all such outstanding vested and exercisable Options. 

(ii) Restricted Stock and Restricted Stock Unit Awards. 

(A) In the case of and subject to the consummation of a Sale Event, all unvested Restricted Stock and unvested Restricted Stock
Unit Awards (other than those becoming vested as a result of the Sale Event) issued hereunder shall be forfeited immediately prior to the effective time of any such Sale Event unless assumed or continued by the successor entity, or awards of the
successor entity or parent thereof are substituted therefor, with an equitable or proportionate adjustment as to the number and kind of shares subject to such awards as such parties shall agree (after taking into account any acceleration hereunder
and/or pursuant to the terms of any Award Agreement). 
 (B) In the event of the forfeiture of Restricted Stock pursuant to
Section 3(c)(ii)(A), such Restricted Stock shall be repurchased from the Holder thereof at a price per share equal to the original per share purchase price paid by the Holder (subject to adjustment as provided in Section 3(b)) for such
Shares. 

 (C) Notwithstanding anything to the contrary in Section 3(c)(ii)(A), in
the event of a Sale Event, the Company shall have the right, but not the obligation, to make or provide for a cash payment to the Holders of Restricted Stock or Restricted Stock Unit Awards, without consent of the Holders, in exchange for the
cancellation thereof, in an amount equal to the Sale Price times the number of Shares subject to such Awards, to be paid at the time of such Sale Event or upon the later vesting of such Awards. 

SECTION 4. ELIGIBILITY 
 Grantees under
the Plan will be such full or part-time officers and other employees, directors, Consultants and key persons of the Company and any Subsidiary who are selected from time to time by the Committee in its sole discretion; provided,
however, that Awards shall be granted only to those individuals described in Rule 701(c) of the Securities Act. 
 SECTION 5. STOCK OPTIONS

 Upon the grant of a Stock Option, the Company and the grantee shall enter into an Award Agreement. The terms and conditions of each such
Award Agreement shall be determined by the Committee, and such terms and conditions may differ among individual Awards and grantees. 

Stock Options granted under the Plan may be either Incentive Stock Options or Non-Qualified Stock
Options. Incentive Stock Options may be granted only to employees of the Company or any Subsidiary that is a “subsidiary corporation” within the meaning of Section 424(f) of the Code. To the extent that any Option does not qualify as
an Incentive Stock Option, it shall be deemed a Non-Qualified Stock Option. 
 (a) Terms of Stock
Options. The Committee in its discretion may grant Stock Options to those individuals who meet the eligibility requirements of Section 4. Stock Options shall be subject to the following terms and conditions and shall contain such additional
terms and conditions, not inconsistent with the terms of the Plan, as the Committee shall deem desirable. 
 (i) Exercise Price. The
exercise price per share for the Shares covered by a Stock Option shall be determined by the Committee at the time of grant but shall not be less than 100 percent of the Fair Market Value on the Grant Date. In the case of an Incentive Stock
Option that is granted to a Ten Percent Owner, the exercise price per share for the Shares covered by such Incentive Stock Option shall not be less than 110 percent of the Fair Market Value on the Grant Date. 

(ii) Option Term. The term of each Stock Option shall be fixed by the Committee, but no Stock Option shall be exercisable more than ten
years from the Grant Date. In the case of an Incentive Stock Option that is granted to a Ten Percent Owner, the term of such Stock Option shall be no more than five years from the Grant Date. 

(iii) Exercisability; Rights of a Stockholder. Stock Options shall become exercisable and/or vested at such time or times, whether or
not in installments, as shall be determined by the Committee at or after the Grant Date. The Award Agreement may permit a grantee to exercise all or a portion of a Stock Option immediately at grant; provided that the Shares issued upon such exercise
shall be subject to restrictions and a vesting schedule identical to the vesting schedule of the related Stock Option, such Shares shall be deemed to be Restricted Stock for purposes of the Plan, and the optionee may be required to enter into an
additional or new Award Agreement as a condition to exercise of such Stock Option. An optionee shall have the rights of a 

 
stockholder only as to Shares acquired upon the exercise of a Stock Option and not as to unexercised Stock Options. An optionee shall not be deemed to have acquired any Shares unless and until a
Stock Option shall have been exercised pursuant to the terms of the Award Agreement and this Plan and the optionee’s name has been entered on the books of the Company as a stockholder. 

(iv) Method of Exercise. Stock Options may be exercised by an optionee in whole or in part, by the optionee giving written or electronic
notice of exercise to the Company, specifying the number of Shares to be purchased. Payment of the purchase price may be made by one or more of the following methods (or any combination thereof) to the extent provided in the Award Agreement: 

(A) In cash, by certified or bank check, by wire transfer of immediately available funds, or other instrument acceptable to the
Committee; 
 (B) If permitted by the Committee, by the optionee delivering to the Company a promissory note, if the Board
has expressly authorized the loan of funds to the optionee for the purpose of enabling or assisting the optionee to effect the exercise of his or her Stock Option; provided, that at least so much of the exercise price as represents the par
value of the Stock shall be paid in cash if required by state law; 
 (C) If permitted by the Committee and the Initial
Public Offering has occurred (or the Stock otherwise becomes publicly-traded), through the delivery (or attestation to the ownership) of Shares that have been purchased by the optionee on the open market or that are beneficially owned by the
optionee and are not then subject to restrictions under any Company plan. To the extent required to avoid variable accounting treatment under ASC 718 or other applicable accounting rules, such surrendered Shares if originally purchased from the
Company shall have been owned by the optionee for at least six months. Such surrendered Shares shall be valued at Fair Market Value on the exercise date; 

(D) If permitted by the Committee and the Initial Public Offering has occurred (or the Stock otherwise becomes
publicly-traded), by the optionee delivering to the Company a properly executed exercise notice together with irrevocable instructions to a broker to promptly deliver to the Company cash or a check payable and acceptable to the Company for the
purchase price; provided that in the event the optionee chooses to pay the purchase price as so provided, the optionee and the broker shall comply with such procedures and enter into such agreements of indemnity and other agreements as the
Committee shall prescribe as a condition of such payment procedure; or 
 (E) If permitted by the Committee, and only with
respect to Stock Options that are not Incentive Stock Options, by a “net exercise” arrangement pursuant to which the Company will reduce the number of Shares issuable upon exercise by the largest whole number of Shares with a Fair Market
Value that does not exceed the aggregate exercise price. 

 Payment instruments will be received subject to collection. No certificates for Shares so
purchased will be issued to the optionee or, with respect to uncertificated Stock, no transfer to the optionee on the records of the Company will take place, until the Company has completed all steps it has deemed necessary to satisfy legal
requirements relating to the issuance and sale of the Shares, which steps may include, without limitation, (i) receipt of a representation from the optionee at the time of exercise of the Option that the optionee is purchasing the Shares for
the optionee’s own account and not with a view to any sale or distribution of the Shares or other representations relating to compliance with applicable law governing the issuance of securities, (ii) the legending of the certificate (or
notation on any book entry) representing the Shares to evidence the foregoing restrictions, and (iii) obtaining from optionee payment or provision for all withholding taxes due as a result of the exercise of the Option. The delivery of
certificates representing the shares of Stock (or the transfer to the optionee on the records of the Company with respect to uncertificated Stock) to be purchased pursuant to the exercise of a Stock Option will be contingent upon (A) receipt
from the optionee (or a purchaser acting in his or her stead in accordance with the provisions of the Stock Option) by the Company of the full purchase price for such Shares and the fulfillment of any other requirements contained in the Award
Agreement or applicable provisions of laws and (B) if required by the Company, the optionee shall have entered into any stockholders agreements or other agreements with the Company and/or certain other of the Company’s stockholders
relating to the Stock. In the event an optionee chooses to pay the purchase price by previously-owned Shares through the attestation method, the number of Shares transferred to the optionee upon the exercise of the Stock Option shall be net of the
number of Shares attested to. 
 (b) Annual Limit on Incentive Stock Options. To the extent required for “incentive stock
option” treatment under Section 422 of the Code, the aggregate Fair Market Value (determined as of the Grant Date) of the Shares with respect to which Incentive Stock Options granted under the Plan and any other plan of the Company or its
parent and any Subsidiary that become exercisable for the first time by an optionee during any calendar year shall not exceed $100,000 or such other limit as may be in effect from time to time under Section 422 of the Code. To the extent that
any Stock Option exceeds this limit, it shall constitute a Non-Qualified Stock Option. 
 (c)
Termination. Any portion of a Stock Option that is not vested and exercisable on the date of termination of an optionee’s Service Relationship shall immediately expire and be null and void. Once any portion of the Stock Option becomes
vested and exercisable, the optionee’s right to exercise such portion of the Stock Option (or the optionee’s representatives and legatees as applicable) in the event of a termination of the optionee’s Service Relationship shall
continue until the earliest of: (i) the date which is: (A) 12 months following the date on which the optionee’s Service Relationship terminates due to death or Disability (or such longer period of time as determined by the Committee and
set forth in the applicable Award Agreement), or (B) three months following the date on which the optionee’s Service Relationship terminates if the termination is due to any reason other than death or Disability (or such longer period of
time as determined by the Committee and set forth in the applicable Award Agreement), or (ii) the Expiration Date set forth in the Award Agreement; provided that notwithstanding the foregoing, an Award Agreement may provide that if the
optionee’s Service Relationship is terminated for Cause, the Stock Option shall terminate immediately and be null and void upon the date of the optionee’s termination and shall not thereafter be exercisable. 

 SECTION 6. RESTRICTED STOCK AWARDS 

(a) Nature of Restricted Stock Awards. The Committee may, in its sole discretion, grant (or sell at par value or such other purchase
price determined by the Committee) to an eligible individual under Section 4 hereof a Restricted Stock Award under the Plan. The Committee shall determine the restrictions and conditions applicable to each Restricted Stock Award at the time of
grant. Conditions may be based on continuing employment (or other Service Relationship), achievement of pre-established performance goals and objectives and/or such other criteria as the Committee may
determine. Upon the grant of a Restricted Stock Award, the Company and the grantee shall enter into an Award Agreement. The terms and conditions of each such Award Agreement shall be determined by the Committee, and such terms and conditions may
differ among individual Awards and grantees. 
 (b) Rights as a Stockholder. Upon the grant of the Restricted Stock Award and payment
of any applicable purchase price, a grantee of Restricted Stock shall be considered the record owner of and shall be entitled to vote the Restricted Stock if, and to the extent, such Shares are entitled to voting rights, subject to such conditions
contained in the Award Agreement. The grantee shall be entitled to receive all dividends and any other distributions declared on the Shares; provided, however, that the Company is under no duty to declare any such dividends or to make
any such distribution. Unless the Committee shall otherwise determine, certificates evidencing the Restricted Stock shall remain in the possession of the Company until such Restricted Stock is vested as provided in subsection (d) below of this
Section, and the grantee shall be required, as a condition of the grant, to deliver to the Company a stock power endorsed in blank and such other instruments of transfer as the Committee may prescribe. 

(c) Restrictions. Restricted Stock may not be sold, assigned, transferred, pledged or otherwise encumbered or disposed of except as
specifically provided herein or in the Award Agreement. Except as may otherwise be provided by the Committee either in the Award Agreement or, subject to Section 12 below, in writing after the Award Agreement is issued, if a grantee’s
Service Relationship with the Company and any Subsidiary terminates, the Company or its assigns shall have the right, as may be specified in the relevant instrument, to repurchase some or all of the Shares subject to the Award at such purchase price
as is set forth in the Award Agreement. 
 (d) Vesting of Restricted Stock. The Committee at the time of grant shall specify in the
Award Agreement the date or dates and/or the attainment of pre-established performance goals, objectives and other conditions on which the substantial risk of forfeiture imposed shall lapse and the Restricted
Stock shall become vested, subject to such further rights of the Company or its assigns as may be specified in the Award Agreement. 
 SECTION 7.
UNRESTRICTED STOCK AWARDS 
 The Committee may, in its sole discretion, grant (or sell at par value or such other purchase price
determined by the Committee) to an eligible person under Section 4 hereof an Unrestricted Stock Award under the Plan. Unrestricted Stock Awards may be granted in respect of past services or other valid consideration, or in lieu of cash
compensation due to such grantee. 
 SECTION 8. RESTRICTED STOCK UNITS 

(a) Nature of Restricted Stock Units. The Committee may, in its sole discretion, grant to an eligible person under Section 4 hereof
Restricted Stock Units under the Plan. The Committee shall determine the restrictions and conditions applicable to each Restricted Stock Unit at the time of grant. Vesting conditions may be based on continuing employment (or other Service
Relationship), achievement of pre-established performance goals and objectives and/or other such 

 
criteria as the Committee may determine. Upon the grant of Restricted Stock Units, the grantee and the Company shall enter into an Award Agreement. The terms and conditions of each such Award
Agreement shall be determined by the Committee and may differ among individual Awards and grantees. On or promptly following the vesting date or dates applicable to any Restricted Stock Unit, but in no event later than March 15 of the year
following the year in which such vesting occurs, such Restricted Stock Unit(s) shall be settled in the form of cash or shares of Stock, as specified in the Award Agreement. Restricted Stock Units may not be sold, assigned, transferred, pledged, or
otherwise encumbered or disposed of. 
 (b) Rights as a Stockholder. A grantee shall have the rights of a stockholder only as to
Shares, if any, acquired upon settlement of Restricted Stock Units. A grantee shall not be deemed to have acquired any such Shares unless and until the Restricted Stock Units shall have been settled in Shares pursuant to the terms of the Plan and
the Award Agreement, the Company shall have issued and delivered a certificate representing the Shares to the grantee (or transferred on the records of the Company with respect to uncertificated stock), and the grantee’s name has been entered
in the books of the Company as a stockholder. 
 (c) Termination. Except as may otherwise be provided by the Committee either in the
Award Agreement or in writing after the Award Agreement is issued, a grantee’s right in all Restricted Stock Units that have not vested shall automatically terminate upon the grantee’s cessation of Service Relationship with the Company and
any Subsidiary for any reason. 
 SECTION 9. TRANSFER RESTRICTIONS; COMPANY RIGHT OF FIRST REFUSAL; COMPANY REPURCHASE RIGHTS 

(a) Restrictions on Transfer. 

(i) Non-Transferability of Stock Options. Stock Options and, prior to exercise, the Shares
issuable upon exercise of such Stock Option, shall not be transferable by the optionee otherwise than by will, or by the laws of descent and distribution, and all Stock Options shall be exercisable, during the optionee’s lifetime, only by the
optionee, or by the optionee’s legal representative or guardian in the event of the optionee’s incapacity. Notwithstanding the foregoing, the Committee, in its sole discretion, may provide in the Award Agreement regarding a given Stock
Option that the optionee may transfer by gift, without consideration for the transfer, his or her Non-Qualified Stock Options to his or her family members (as defined in Rule 701 of the Securities Act), to
trusts for the benefit of such family members, or to partnerships in which such family members are the only partners (to the extent such trusts or partnerships are considered “family members” for purposes of Rule 701 of the Securities
Act), provided that the transferee agrees in writing with the Company to be bound by all of the terms and conditions of this Plan and the applicable Award Agreement, including the execution of a stock power upon the issuance of Shares. Stock
Options, and the Shares issuable upon exercise of such Stock Options, shall be restricted as to any pledge, hypothecation, or other transfer, including any short position, any “put equivalent position” (as defined in the Exchange Act) or
any “call equivalent position” (as defined in the Exchange Act) prior to exercise. 
 (ii) Shares. No Shares shall be sold,
assigned, transferred, pledged, hypothecated, given away or in any other manner disposed of or encumbered, whether voluntarily or by operation of law, unless (i) the transfer is in compliance with the terms of the applicable Award Agreement,
all applicable securities laws (including, without limitation, the Securities Act), 

 
and with the terms and conditions of this Section 9, (ii) the transfer does not cause the Company to become subject to the reporting requirements of the Exchange Act, and (iii) the
transferee consents in writing to be bound by the provisions of the Plan and the Award Agreement, including this Section 9. In connection with any proposed transfer, the Committee may require the transferor to provide at the transferor’s
own expense an opinion of counsel to the transferor, satisfactory to the Committee, that such transfer is in compliance with all foreign, federal and state securities laws (including, without limitation, the Securities Act). Any attempted transfer
of Shares not in accordance with the terms and conditions of this Section 9 shall be null and void, and the Company shall not reflect on its records any change in record ownership of any Shares as a result of any such transfer, shall otherwise
refuse to recognize any such transfer and shall not in any way give effect to any such transfer of Shares. The Company shall be entitled to seek protective orders, injunctive relief and other remedies available at law or in equity including, without
limitation, seeking specific performance or the rescission of any transfer not made in strict compliance with the provisions of this Section 9. Subject to the foregoing general provisions, and unless otherwise provided in the applicable Award
Agreement, Shares may be transferred pursuant to the following specific terms and conditions (provided that with respect to any transfer of Restricted Stock, all vesting and forfeiture provisions shall continue to apply with respect to the original
recipient): 
 (A) Transfers to Permitted Transferees. The Holder may transfer any or all of the Shares to one or more
Permitted Transferees; provided, however, that following such transfer, such Shares shall continue to be subject to the terms of this Plan (including this Section 9) and such Permitted Transferee(s) shall, as a condition to any such
transfer, deliver a written acknowledgment to that effect to the Company and shall deliver a stock power to the Company with respect to the Shares. Notwithstanding the foregoing, the Holder may not transfer any of the Shares to a Person whom the
Company reasonably determines is a direct competitor or a potential competitor of the Company or any of its Subsidiaries. 

(B) Transfers Upon Death. Upon the death of the Holder, any Shares then held by the Holder at the time of such death and
any Shares acquired after the Holder’s death by the Holder’s legal representative shall be subject to the provisions of this Plan, and the Holder’s estate, executors, administrators, personal representatives, heirs, legatees and
distributees shall be obligated to convey such Shares to the Company or its assigns under the terms contemplated by the Plan and the Award Agreement. 

(b) Right of First Refusal. In the event that a Holder at any time after but not prior to the expiration of the Repurchase Period (as
defined below) desires to sell or otherwise transfer all or any part of his or her Shares (other than shares of Restricted Stock which by their terms are not transferrable), the Holder first shall give written notice to the Company of the
Holder’s intention to make such transfer. Such notice shall state the number of Shares that the Holder proposes to sell (the “Offered Shares”), the price and the terms at which the proposed sale is to be made and the name and address
of the proposed transferee. At any time within 30 days after the receipt of such notice by the Company, the Company or its assigns may elect to purchase all or any portion of the Offered Shares at Fair Market Value and on the terms offered by the
proposed transferee and specified in the notice. The Company or its assigns shall exercise this right by mailing or delivering written notice to the Holder within the foregoing 30-day period. If the Company or
its assigns elect to exercise its purchase rights under this Section 9(b), the closing for such purchase shall, in any event, take place within 45 days after the receipt by the Company of the initial notice

 
from the Holder. In the event that the Company or its assigns do not elect to exercise such purchase right, or in the event that the Company or its assigns do not pay the full purchase price
within such 45-day period, the Holder shall be required to pay a transaction processing fee of $10,000 to the Company (unless waived by the Committee) and then may, within 60 days thereafter, sell the Offered
Shares to the proposed transferee and at the same price and on the same terms as specified in the Holder’s notice. Any Shares not sold to the proposed transferee shall remain subject to the Plan. If the Holder is a party to any stockholders
agreements or other agreements with the Company and/or certain other of the Company’s stockholders relating to the Shares, (i) the transferring Holder shall comply with the requirements of such stockholders agreements or other agreements
relating to any proposed transfer of the Offered Shares, and (ii) any proposed transferee that purchases Offered Shares shall enter into such stockholders agreements or other agreements with the Company and/or certain of the Company’s
stockholders relating to the Offered Shares on the same terms and in the same capacity as the transferring Holder. 
 (c) Company’s
Right of Repurchase. 
 (i) Right of Repurchase for Shares Issued Under the Plan. Upon a Termination Event, the Company or its
assigns shall have the right and option to repurchase from a Holder any Shares acquired under the Plan. Such repurchase rights may be exercised by the Company within 18 months following the date of such Termination Event (or, if later, six months
and one day following the acquisition of Shares upon exercise of a Stock Option) (the “Repurchase Period”). 
 (ii) Repurchase
Price. The Repurchase Price shall be equal to (a) in the case of Shares which are vested as of the date of the Termination Event giving rise to the repurchase, (x) in the case of a repurchase following a termination of the
Holder’s Service Relationship for Cause, the lesser of the per share price paid by the Holder, subject to adjustment as provided in Section 3(b) of the Plan, and the Fair Market Value of such Shares as of the date the Company elects to
exercise its repurchase rights or (y) in the case of any other Termination Event, the Fair Market Value of such Shares as of the date the Company elects to exercise its repurchase rights and (b) in the case of Shares which are unvested as
of the date of the Termination Event giving rise to the repurchase, the lesser of the per share price paid by the Holder, subject to adjustment as provided in Section 3(b) of the Plan, and the Fair Market Value of such Shares as of the date the
Company elects to exercise its repurchase rights. 
 (iii) Procedure. Any repurchase right of the Company shall be exercised by the
Company or its assigns by giving the Holder written notice on or before the last day of the repurchase period of its intention to exercise such repurchase right. Upon such notification, the Holder shall promptly surrender to the Company, free and
clear of any liens or encumbrances, any certificates representing the Shares being purchased, together with a duly executed stock power for the transfer of such Shares to the Company or the Company’s assignee or assignees. Upon the
Company’s or its assignee’s receipt of the certificates from the Holder, the Company or its assignee or assignees shall deliver to him, her or them a check for the applicable repurchase price; provided, however, that the Company may
pay the repurchase price by offsetting and canceling any indebtedness then owed by the Holder to the Company. 

 (d) Drag Along Right. In the event the holders of a majority of the Company’s
equity securities then outstanding (the “Majority Shareholders”) determine to enter into a Sale Event in a bona fide negotiated transaction (a “Sale”), with any non-Affiliate of the Company
or any majority shareholder (in each case, the “Buyer”), a Holder of Shares, including any Permitted Transferee, shall be obligated to and shall upon the written request of the Majority Shareholders: (a) sell, transfer and deliver, or
cause to be sold, transferred and delivered, to the Buyer, his or her Shares (including for this purpose all of such Holder’s Shares that presently or as a result of any such transaction may be acquired upon the exercise of an Option (following
the payment of the exercise price therefor)) on substantially the same terms applicable to the Majority Shareholders (with appropriate adjustments to reflect the conversion of convertible securities, the redemption of redeemable securities and the
exercise of exercisable securities as well as the relative preferences and priorities of preferred stock); and (b) execute and deliver such instruments of conveyance and transfer and take such other action, including voting such Shares in favor
of any Sale proposed by the Majority Shareholders and executing any purchase agreements, merger agreements, indemnity agreements, escrow agreements or related documents as the Majority Shareholders or the Buyer may reasonably require in order to
carry out the terms and provisions of this Section 9(d). 
 (e) Escrow Arrangement. 

(i) Escrow. In order to carry out the provisions of this Section 9 of this Plan more effectively, the Company shall hold any Shares
issued pursuant to Awards granted under the Plan in escrow together with separate stock powers executed by the Holder in blank for transfer. The Company shall not dispose of the Shares except as otherwise provided in this Plan. In the event of any
repurchase by the Company (or any of its assigns), the Company is hereby authorized by the Holder, as the Holder’s attorney-in-fact, to date and complete the stock
powers necessary for the transfer of the Shares being purchased and to transfer such Shares in accordance with the terms hereof. At such time as any Shares are no longer subject to the Company’s repurchase and first refusal rights, the Company
shall, at the written request of the Holder, deliver to the Holder a certificate representing such Shares with the balance of the Shares to be held in escrow pursuant to this Section. 

(ii) Remedy. Without limitation of any other provision of this Plan or other rights, in the event that a Holder or any other Person is
required to sell a Holder’s Shares pursuant to the provisions of Sections 9(b), (c) or (d) hereof and in the further event that he or she refuses or for any reason fails to deliver to the Company or its designated purchaser of such Shares
the certificate or certificates evidencing such Shares together with a related stock power, the Company or such designated purchaser may deposit the applicable purchase price for such Shares with a bank designated by the Company, or with the
Company’s independent public accounting firm, as agent or trustee, or in escrow, for such Holder or other Person, to be held by such bank or accounting firm for the benefit of and for delivery to him, her, them or it, and/or, in its discretion,
pay such purchase price by offsetting any indebtedness then owed by such Holder as provided above. Upon any such deposit and/or offset by the Company or its designated purchaser of such amount and upon notice to the Person who was required to sell
the Shares to be sold pursuant to the provisions of Sections 9(b), (c) or (d), such Shares shall at such time be deemed to have been sold, assigned, transferred and conveyed to such purchaser, such Holder shall have no further rights thereto (other
than the right to withdraw the payment thereof held in escrow, if applicable), and the Company shall record such transfer in its stock transfer book or in any appropriate manner. 

(f) Lockup Provision. If requested by the Company, a Holder shall not sell or otherwise transfer or dispose of any Shares (including,
without limitation, pursuant to Rule 144 under the Securities Act) held by him or her for such period following the effective date of a public offering by the Company of Shares as the Company shall specify reasonably and in good faith. If requested
by the underwriter engaged by the Company, each Holder shall execute a separate letter confirming his or her agreement to comply with this Section. 

 (g) Adjustments for Changes in Capital Structure. If, as a result of any
reorganization, recapitalization, reclassification, stock dividend, stock split, reverse stock split or other similar change in the Common Stock, the outstanding Shares are increased or decreased or are exchanged for a different number or kind of
securities of the Company, the restrictions contained in this Section 9 shall apply with equal force to additional and/or substitute securities, if any, received by Holder in exchange for, or by virtue of his or her ownership of, Shares. 

(h) Termination. The terms and provisions of Section 9(b), Section 9(c) (except for the Company’s right to repurchase
Shares still subject to a risk of forfeiture upon a Termination Event) and Section 9(d) shall terminate upon the closing of the Company’s Initial Public Offering or upon consummation of any Sale Event, in either case as a result of which
Shares are registered under Section 12 of the Exchange Act and publicly-traded on any national security exchange. 
 SECTION 10. TAX WITHHOLDING

 (a) Payment by Grantee. Each grantee shall, no later than the date as of which the value of an Award or of any Shares or other
amounts received thereunder first becomes includable in the gross income of the grantee for income tax purposes, pay to the Company, or make arrangements satisfactory to the Committee regarding payment of, any Federal, state, or local taxes of any
kind required by law to be withheld by the Company with respect to such income. The Company and any Subsidiary shall, to the extent permitted by law, have the right to deduct any such taxes from any payment of any kind otherwise due to the grantee.
The Company’s obligation to deliver stock certificates (or evidence of book entry) to any grantee is subject to and conditioned on any such tax withholding obligations being satisfied by the grantee. 

(b) Payment in Stock. If permitted by the Committee, the Company’s minimum required tax withholding obligation may be satisfied, in
whole or in part, by the Company withholding from Shares to be issued pursuant to an Award a number of Shares having an aggregate Fair Market Value (as of the date the withholding is effected) that would satisfy the minimum withholding amount due.

 SECTION 11. SECTION 409A AWARDS.  

To the extent that any Award is determined to constitute “nonqualified deferred compensation” within the meaning of Section 409A
(a “409A Award”), the Award shall be subject to such additional rules and requirements as may be specified by the Committee from time to time. In this regard, if any amount under a 409A Award is payable upon a “separation from
service” (within the meaning of Section 409A) to a grantee who is considered a “specified employee” (within the meaning of Section 409A), then no such payment shall be made prior to the date that is the earlier of
(i) six months and one day after the grantee’s separation from service, or (ii) the grantee’s death, but only to the extent such delay is necessary to prevent such payment from being subject to interest, penalties and/or
additional tax imposed pursuant to Section 409A. The Company makes no representation or warranty and shall have no liability to any grantee under the Plan or any other Person with respect to any penalties or taxes under Section 409A that
are, or may be, imposed with respect to any Award. 

 SECTION 12. AMENDMENTS AND TERMINATION 

The Board may, at any time, amend or discontinue the Plan and the Committee may, at any time, amend or cancel any outstanding Award for the
purpose of satisfying changes in law or for any other lawful purpose, but no such action shall adversely affect rights under any outstanding Award without the consent of the holder of the Award. The Committee may exercise its discretion to reduce
the exercise price of outstanding Stock Options or effect repricing through cancellation of outstanding Stock Options and by granting such holders new Awards in replacement of the cancelled Stock Options. To the extent determined by the Committee to
be required either by the Code to ensure that Incentive Stock Options granted under the Plan are qualified under Section 422 of the Code or otherwise, Plan amendments shall be subject to approval by the Company stockholders entitled to vote at
a meeting of stockholders. Nothing in this Section 12 shall limit the Board’s or Committee’s authority to take any action permitted pursuant to Section 3(c). The Board reserves the right to amend the Plan and/or the terms of any
outstanding Stock Options to the extent reasonably necessary to comply with the requirements of the exemption pursuant to paragraph (f)(4) of Rule 12h-1 of the Exchange Act. 

SECTION 13. STATUS OF PLAN 
 With respect
to the portion of any Award that has not been exercised and any payments in cash, Stock or other consideration not received by a grantee, a grantee shall have no rights greater than those of a general creditor of the Company unless the Committee
shall otherwise expressly so determine in connection with any Award. 
 SECTION 14. GENERAL PROVISIONS 

(a) No Distribution; Compliance with Legal Requirements. The Committee may require each person acquiring Shares pursuant to an Award to
represent to and agree with the Company in writing that such person is acquiring the Shares without a view to distribution thereof. No Shares shall be issued pursuant to an Award until all applicable securities law and other legal and stock exchange
or similar requirements have been satisfied. The Committee may require the placing of such stop-orders and restrictive legends on certificates for Stock and Awards as it deems appropriate. 

(b) Delivery of Stock Certificates. Stock certificates to grantees under the Plan shall be deemed delivered for all purposes when the
Company or a stock transfer agent of the Company shall have mailed such certificates in the United States mail, addressed to the grantee, at the grantee’s last known address on file with the Company; provided that stock certificates to be held
in escrow pursuant to Section 9 of the Plan shall be deemed delivered when the Company shall have recorded the issuance in its records. Uncertificated Stock shall be deemed delivered for all purposes when the Company or a stock transfer agent
of the Company shall have given to the grantee by electronic mail (with proof of receipt) or by United States mail, addressed to the grantee, at the grantee’s last known address on file with the Company, notice of issuance and recorded the
issuance in its records (which may include electronic “book entry” records). 
 (c) No Employment Rights. The
adoption of the Plan and the grant of Awards do not confer upon any Person any right to continued employment or Service Relationship with the Company or any Subsidiary. 

 (d) Trading Policy Restrictions. Option exercises and other Awards under the Plan
shall be subject to the Company’s insider trading policy-related restrictions, terms and conditions as may be established by the Committee, or in accordance with policies set by the Committee, from time to time. 

(e) Designation of Beneficiary. Each grantee to whom an Award has been made under the Plan may designate a beneficiary or beneficiaries
to exercise any Award on or after the grantee’s death or receive any payment under any Award payable on or after the grantee’s death. Any such designation shall be on a form provided for that purpose by the Committee and shall not be
effective until received by the Committee. If no beneficiary has been designated by a deceased grantee, or if the designated beneficiaries have predeceased the grantee, the beneficiary shall be the grantee’s estate. 

(f) Legend. Any certificate(s) representing the Shares shall carry substantially the following legend (and with respect to
uncertificated Stock, the book entries evidencing such shares shall contain the following notation): 
 The transferability of this
certificate and the shares of stock represented hereby are subject to the restrictions, terms and conditions (including repurchase and restrictions against transfers) contained in the C4 Therapeutics, Inc. 2015 Stock Option and Grant
Plan and any agreements entered into thereunder by and between the company and the holder of this certificate (a copy of which is available at the offices of the company for examination). 

(g) Information to Holders of Options. In the event the Company is relying on the exemption from the registration requirements of
Section 12(g) of the Exchange Act contained in paragraph (f)(1) of Rule 12h-1 of the Exchange Act, the Company shall provide the information described in Rule 701(e)(3), (4) and (5) of the Securities
Act to all holders of Options in accordance with the requirements thereunder. The foregoing notwithstanding, the Company shall not be required to provide such information unless the optionholder has agreed in writing, on a form prescribed by the
Company, to keep such information confidential. 
 SECTION 15. EFFECTIVE DATE OF PLAN 

The Plan shall become effective upon adoption by the Board and shall be approved by stockholders in accordance with applicable state law and
the Company’s articles of incorporation and bylaws within 12 months thereafter. If the stockholders fail to approve the Plan within 12 months after its adoption by the Board of Directors, then any Awards granted or sold under the Plan shall be
rescinded and no additional grants or sales shall thereafter be made under the Plan. Subject to such approval by stockholders and to the requirement that no Shares may be issued hereunder prior to such approval, Stock Options and other Awards may be
granted hereunder on and after adoption of the Plan by the Board. No grants of Stock Options and other Awards may be made hereunder after the tenth anniversary of the date the Plan is adopted by the Board or the date the Plan is approved by the
Company’s stockholders, whichever is earlier. 

 SECTION 16. GOVERNING LAW 

This Plan, all Awards and any controversy arising out of or relating to this Plan and all Awards shall be governed by and construed in
accordance with the General Corporation Law of the State of Delaware as to matters within the scope thereof, and as to all other matters shall be governed by and construed in accordance with the internal laws of the Commonwealth of
Massachusetts, without regard to conflict of law principles that would result in the application of any law other than the law of the Commonwealth of Massachusetts. 
  

			
	DATE ADOPTED BY THE BOARD OF DIRECTORS:	  	December 29, 2015
		
	DATE APPROVED BY THE STOCKHOLDERS:	  	December 29, 2015

 AMENDMENT NO. 1 TO THE 

2015 STOCK OPTION AND GRANT PLAN 

The 2015 Stock Option and Grant Plan (the “Plan”) of C4 Therapeutics, Inc., a Delaware corporation (the
“Company”), is hereby amended by the Board of Directors of the Company as follows: 
 The first sentence of
Section 3(a) of the Plan is hereby amended by deleting it and replacing it with the following: 
 “The maximum number of Shares
reserved and available for issuance under the Plan shall be 21,152,951 Shares, subject to adjustment as provided in Section 3(b).” 
  

			
	ADOPTED BY BOARD OF DIRECTORS:	  	October 24, 2016

 AMENDMENT NO. 2 TO THE 

2015 STOCK OPTION AND GRANT PLAN 
 The C4
Therapeutics, Inc. 2015 Stock Option and Grant Plan (the “Plan”) is hereby amended by the Board of Directors of C4 Therapeutics, Inc., a Delaware corporation, as follows: 

The first sentence of Section 3(a) of the Plan is hereby amended and restated as follows: 

“The maximum number of Shares reserved and available for issuance under the Plan shall be 30,485,022 Shares, subject to adjustment as
provided in Section 3(b).” 
  

			
	ADOPTED BY BOARD OF DIRECTORS:	  	April 9, 2019

 AMENDMENT NO. 3 TO THE 

2015 STOCK OPTION AND GRANT PLAN 
 The C4
Therapeutics, Inc. 2015 Stock Option and Grant Plan (the “Plan”) is hereby amended by the Board of Directors of C4 Therapeutics, Inc., a Delaware corporation, as follows: 

The second sentence of Section 3(a) of the Plan is hereby amended and restated as follows: 

“For purposes of this limitation, the Shares underlying any Awards that are forfeited, canceled, reacquired by the Company, satisfied
without the issuance of Stock or otherwise terminated (other than by exercise) and Shares that are withheld upon exercise of an Option or settlement of an Award to cover the exercise price or tax withholding shall be added back to the Shares
available for issuance under the Plan.” 
  

			
	ADOPTED BY BOARD OF DIRECTORS:	  	July 17, 2019

  
 22 

 AMENDMENT NO. 4 TO THE 

2015 STOCK OPTION AND GRANT PLAN 
 The C4
Therapeutics, Inc. 2015 Stock Option and Grant Plan (the “Plan”) is hereby amended by the Board of Directors of C4 Therapeutics, Inc., a Delaware corporation, as follows: 

Section 3(a) of the Plan is hereby amended and restated in its entirety as follows: 

(a) Stock Issuable. The maximum number of Shares reserved and available for issuance under the Plan shall be 42,658,355 Shares, subject
to adjustment as provided in Section 3(b). For purposes of this limitation, the Shares underlying any Awards that are forfeited, canceled, reacquired by the Company, satisfied without the issuance of Stock or otherwise terminated (other than by
exercise) and Shares that are withheld upon exercise of an Option or settlement of an Award to cover the exercise price or tax withholding shall be added back to the Shares available for issuance under the Plan. Subject to such overall limitations,
Shares may be issued up to such maximum number pursuant to any type or types of Award, and no more than 212,973,530 Shares may be issued pursuant to Incentive Stock Options. The Shares available for issuance under the Plan may be authorized but
unissued Shares or Shares reacquired by the Company. 
  

			
	ADOPTED BY BOARD OF DIRECTORS:	  	May 19, 2020
		
	ADOPTED BY STOCKHOLDERS:	  	June 3, 2020

  
 23EX-10.5

 Exhibit 10.5 

[***] Certain information in this document has been omitted from this exhibit because it is both (i) not material and (ii) would be
competitively harmful if publicly disclosed. 
 CONFIDENTIAL 

Execution Version 

COLLABORATIVE RESEARCH AND LICENSE AGREEMENT 

BETWEEN 

BIOGEN MA INC. 

AND 
 C4
THERAPEUTICS, INC. 
 Dated December 28, 2018 

 

 TABLE OF CONTENTS 

 

							
	 	 	 	  	Page	 
			
	 ARTICLE 1
	 	DEFINITIONS	  	 	1	 
			
	 ARTICLE 2
	 	LICENSE GRANTS	  	 	17	 
			
	 2.1
	 	Licenses and Assignment to Biogen	  	 	17	 
	 2.2
	 	Licenses to C4	  	 	18	 
	 2.3
	 	No Implied Licenses	  	 	18	 
			
	 ARTICLE 3
	 	COLLABORATION	  	 	18	 
			
	 3.1
	 	Candidate Development Programs	  	 	18	 
	 3.2
	 	Sandbox Program	  	 	25	 
	 3.3
	 	Records	  	 	28	 
	 3.4
	 	Copies and Inspection of Records	  	 	28	 
	 3.5
	 	Collaboration Term	  	 	28	 
	 3.6
	 	Exclusivity	  	 	29	 
	 3.7
	 	Effect of Acquisition of C4	  	 	29	 
			
	 ARTICLE 4
	 	GOVERNANCE	  	 	30	 
			
	 4.1
	 	Alliance Management	  	 	30	 
	 4.2
	 	Joint Steering Committee	  	 	30	 
	 4.3
	 	Disbandment of the JSC	  	 	33	 
			
	 ARTICLE 5
	 	DEVELOPMENT, REGULATORY MATTERS, AND COMMERCIALIZATION	  	 	33	 
			
	 5.1
	 	Technology Transfer	  	 	33	 
	 5.2
	 	Development and Medical Affairs	  	 	33	 
	 5.3
	 	Regulatory Activities	  	 	34	 
	 5.4
	 	Commercialization	  	 	34	 
	 5.5
	 	Diligence Obligations	  	 	34	 
	 5.6
	 	C4 Support	  	 	34	 
			
	 ARTICLE 6
	 	MANUFACTURING	  	 	35	 
			
	 6.1
	 	General Responsibilities	  	 	35	 
	 6.2
	 	Observation by Biogen	  	 	35	 
	 6.3
	 	Manufacturing Technology Transfer	  	 	35	 
	 6.4
	 	C4 Manufacturing Support	  	 	35	 
			
	 ARTICLE 7
	 	PAYMENTS AND ROYALTIES	  	 	36	 
			
	 7.1
	 	One-Time R&D Prepayments	  	 	36	 
	 7.2
	 	Hit Fee	  	 	36	 
	 7.3
	 	Lead Fee	  	 	36	 
	 7.4
	 	IND-Enabling Study Commencement Fee	  	 	36	 
	 7.5
	 	Milestone Payments	  	 	37	 
	 7.6
	 	Royalties	  	 	39	 
	 7.7
	 	Payment Method	  	 	41	 
	 7.8
	 	Currency Exchange	  	 	41	 
	 7.9
	 	Late Payments	  	 	41	 
	 7.10
	 	Taxes	  	 	42	 
	 7.11
	 	Financial Audits	  	 	42	 

  
 i 

							
	 ARTICLE 8
	 	REPRESENTATIONS, WARRANTIES, AND COVENANTS	  	 	43	 
			
	 8.1
	 	Mutual Representations and Warranties of the Parties	  	 	43	 
	 8.2
	 	Additional Representations and Warranties of C4	  	 	44	 
	 8.3
	 	Covenants of C4	  	 	46	 
	 8.4
	 	DISCLAIMER OF WARRANTIES	  	 	46	 
	 8.5
	 	LIMITATION OF LIABILITY	  	 	46	 
			
	 ARTICLE 9
	 	CONFIDENTIALITY	  	 	47	 
			
	 9.1
	 	Confidential Information	  	 	47	 
	 9.2
	 	Non-Disclosure and Non-Use Obligation	  	 	47	 
	 9.3
	 	Return of Confidential Information	  	 	47	 
	 9.4
	 	Exemptions	  	 	47	 
	 9.5
	 	Permitted Disclosures	  	 	48	 
	 9.6
	 	Confidential Treatment	  	 	49	 
	 9.7
	 	Use of Name and Logo	  	 	49	 
	 9.8
	 	Residual Knowledge	  	 	49	 
	 9.9
	 	Publications	  	 	49	 
			
	 ARTICLE 10
	 	INTELLECTUAL PROPERTY	  	 	50	 
			
	 10.1
	 	Ownership	  	 	50	 
	 10.2
	 	Assignments	  	 	51	 
	 10.3
	 	Joint Technology	  	 	53	 
	 10.4
	 	Patent Prosecution and Maintenance	  	 	53	 
	 10.5
	 	Patent Enforcement	  	 	55	 
	 10.6
	 	Defense of Claims	  	 	56	 
	 10.8
	 	Patent Term Extensions	  	 	57	 
	 10.9
	 	Summary of Activities	  	 	57	 
			
	 ARTICLE 11
	 	INDEMNIFICATION	  	 	57	 
			
	 11.1
	 	Indemnification by C4	  	 	57	 
	 11.2
	 	Indemnification by Biogen	  	 	57	 
	 11.3
	 	Procedure	  	 	57	 
			
	 ARTICLE 12
	 	TERM AND TERMINATION	  	 	58	 
			
	 12.1
	 	Term	  	 	58	 
	 12.2
	 	Termination for Cause	  	 	58	 
	 12.3
	 	Termination for Insolvency	  	 	59	 
	 12.4
	 	Termination for Convenience	  	 	60	 
	 12.5
	 	Effects of Termination	  	 	60	 
	 12.6
	 	Alternative Remedy in Lieu of Termination	  	 	61	 
	 12.7
	 	Rights Accruing Prior to Expiration or Termination	  	 	61	 
	 12.8
	 	Survival	  	 	61	 
			
	 ARTICLE 13
	 	MISCELLANEOUS	  	 	61	 
			
	 13.1
	 	Assignment	  	 	61	 
	 13.2
	 	Entire Agreement; Amendments	  	 	62	 
	 13.3
	 	Force Majeure	  	 	62	 
	 13.4
	 	Waiver	  	 	62	 
	 13.5
	 	Severability	  	 	62	 
	 13.6
	 	Notices	  	 	62	 
	 13.7
	 	Governing Law	  	 	63	 

  
 ii 

							
	 13.8
	 	Dispute Resolution	  	 	63	 
	 13.9
	 	Jurisdiction; Venue	  	 	63	 
	 13.10
	 	Relationship of the Parties	  	 	64	 
	 13.11
	 	Performance by Affiliates	  	 	64	 
	 13.12
	 	Interpretation	  	 	64	 
	 13.13
	 	Further Assurances	  	 	65	 
	 13.14
	 	Counterparts	  	 	65	 

 Schedules: 
 Schedule
1.37: C4 Hit Criteria 
 Schedule 1.42: C4 Licensed Patent Rights 

Schedule 3.1.3(a): Candidate Development Plan for [***] 

Schedule 3.1.3(b): Candidate Development Plan for [***] 

Schedule 3.1.3(c): Candidate Development Plan for [***] 

Schedule 3.1.9: Form of Candidate Development Financial Report 

Schedule 4.1.1: Contact List 
 Schedule 9.9.2: Press Release 

  
 iii 

 COLLABORATIVE RESEARCH AND
LICENSE AGREEMENT 
 This COLLABORATIVE RESEARCH AND
LICENSE AGREEMENT (this “Agreement”) is entered into as of December 28, 2018 (the “Effective Date”) by and among Biogen MA Inc., a corporation organized and existing under the laws
of Massachusetts and having a principal place of business at 225 Binney Street, Cambridge, MA 02142 (“Biogen”) and C4 Therapeutics, Inc., a corporation organized and existing under the laws of Delaware with a principle place of
business at 490 Arsenal Way, Watertown, MA 02472 (“C4”). Biogen and C4 are sometimes referred to herein individually as a “Party” and collectively as the “Parties.” 

RECITALS 
 WHEREAS,
Biogen is engaged in, among other things, Development, Manufacturing, and Commercialization of biopharmaceutical products; 

WHEREAS, C4 has certain expertise and proprietary protein degradation technology that uses Degronimid compounds to activate the
ubiquitin proteasome system in target proteins; 
 WHEREAS, the Parties are interested in entering into a collaboration to utilize
Biogen’s and C4’s expertise and C4 Degrader Platform to perform research services and other activities, including (a) Candidate Development Activities, with the goal of identifying Development Candidates directed to each Collaboration
Target, and (b) Sandbox Activities to, among other things, inform the selection of the Additional Targets and identification of potentially useful ligands, each in accordance with the terms and conditions set forth in this Agreement; 

WHEREAS, Biogen is making upfront payments to C4 as prepayment of the costs and expenses to be incurred by C4 in the performance of
research services under this Agreement; and 
 WHEREAS, C4 desires to (a) grant to Biogen, and Biogen desires to receive from
C4, an exclusive, worldwide license under the C4 Licensed Technology to exploit Development Candidates and Products in the Field in the Territory, and (b) assign to Biogen, and Biogen desires to accept such assignment from C4, all of C4’s
rights, title, and interests in and to the Target-Specific Technology and Product-Specific Technology. 
 NOW, THEREFORE, the Parties
hereto agree as follows: 
 ARTICLE 1 DEFINITIONS 
  

	1.1	 [***] 

  

	1.2	 “Acquiror” has the meaning set forth in Section 3.7 (Effect of Acquisition of C4).

  

	1.3	 “Acquisition Party” has the meaning set forth in Section 3.7 (Effect of Acquisition of
C4). 

  

	1.4	 “Additional Cure Period” has the meaning set forth in Section 12.2.3 (Disputes Regarding
Material Breach). 

  

	1.5	 “Additional Target” means any target that will be the subject of a Candidate Development
Program, which targets will be selected in accordance with Section 3.1.1(b)(i) (Selection of Additional Targets) and any alternative splice variants, mutants, polymorphisms, and fragments thereof. 

  
 1 

	1.6	 “Additional Target Notice” has the meaning set forth in Section 3.1.1(b)(i) (Selection of
Additional Targets). 

  

	1.7	 “Additional Target Selection Period” has the meaning set forth in Section 3.1.1(b)(i)
(Selection of Additional Targets). 

  

	1.8	 “Affiliates” of a Person means any other Person that (directly or indirectly) is controlled
by, controls or is under common control with such Person. For the purposes of this definition, the term “control” (including, with correlative meanings, the terms “controlled by” and “under common control with”) as used
with respect to a Person, will mean the possession, directly or indirectly, of the power to direct, or cause the direction of, the management or policies of such Person, whether through the ownership of voting securities, by contract or otherwise,
and “control” will be presumed to exist if either of the following conditions is met: (a) in the case of a corporate entity, direct or indirect ownership of voting securities entitled to cast at least 50% of the votes in the election
of directors or (b) in the case of a non-corporate entity, direct or indirect ownership of at least 50% of the equity interests with the power to direct the management and policies of such entity.

  

	1.9	 “Alliance Manager” has the meaning set forth in Section 4.1.1 (Alliance Managers).

  

	1.10	 “Applicable Law” means applicable laws, statutes, rules, regulations, and other pronouncements
having the effect of law of any Governmental Authority that may be in effect from time to time, including for clarity any applicable rules, regulations, guidances, and other requirements of any Regulatory Authority that may be in effect from time to
time. 

  

	1.11	 “Assigned Platform Know-How” means any Collaboration
Platform Know-How that is developed or invented during the Collaboration Term by Biogen or its Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent
contractors, or any Person contractually required to assign or license such Know-How (or Patent Rights Covering such Know-How) to Biogen or any Affiliate of Biogen,
whether solely or jointly with others, in the course of performance of Collaboration Activities undertaken pursuant to this Agreement. Notwithstanding any provision of this Agreement to the contrary, Assigned Platform
Know-How expressly excludes any Product-Specific Know-How or Target-Specific Know-How. 

 

	1.12	 “Assigned Platform Patent Rights” means any Collaboration Platform Patent Rights that Cover
Assigned Platform Know-How. Notwithstanding any provision of this Agreement to the contrary, Assigned Platform Patent Rights expressly excludes any Product-Specific Patent Rights or Target-Specific Patent
Rights. 

  

	1.13	 “Assigned Platform Technology” means Assigned Platform Patent Rights and Assigned Platform Know-How. 

  

	1.14	 “Audited Party” has the meaning set forth in Section 7.11 (Financial Audits).

  

	1.15	 “Auditing Party” has the meaning set forth in Section 7.11 (Financial Audits).

  

	1.16	 “Biogen Candidate Development Activities” has the meaning set forth in Section 3.1.2(b)
(Biogen Candidate Development Activities). 

  
 2 

	1.17	 “Biogen Collaboration Know-How” means Collaboration Know-How, other than Assigned Platform Know-How, developed or invented solely by Biogen’s or its Affiliates’, licensees’, Sublicensees’, or
Subcontractors’ employees, agents, or independent contractors, or any Persons contractually required to assign or license such Collaboration Know-How to Biogen or any Affiliate of Biogen, in each case, in
the performance of Collaboration Activities under this Agreement during the Term. 

  

	1.18	 “Biogen Collaboration Patent Rights” means all Collaboration Patent Rights that Cover Biogen
Collaboration Know-How. 

  

	1.19	 “Biogen First Right Patent Rights” has the meaning set forth in Section 10.4.1(a)
(Biogen’s Rights). 

  

	1.20	 “Biogen Grantback Claim” means any claim (a) of a Collaboration Patent Right
solely owned by Biogen (including those assigned to Biogen pursuant to this Agreement) that solely and specifically Covers a discovery, improvement, modification, enhancement, or creation to (i) an E3 Ligase Binding Moiety, (ii) a Linker,
or (iii) a combination of (i) and (ii), in each case ((i) – (iii)), to the extent that such E3 Ligase Binding Moiety or Linker is delivered by C4 to Biogen pursuant to a Candidate Development Plan, or (b) included in a C4
Licensed Patent Right that exists as of the Effective Date. Notwithstanding anything to the contrary set forth in this Agreement, “Biogen Grantback Claims” does not include any claim of a Product-Specific Patent Right or Target-Specific
Patent Right. 

  

	1.21	 “Biogen Identified Rights” has the meaning set forth in Section 7.6.5 (C4 Third Party
Agreements). 

  

	1.22	 “Biogen Indemnified Party” has the meaning set forth in Section 11.1 (Indemnification by
C4). 

  

	1.23	 “Biogen Know-How” means any Know-How Controlled by Biogen or any of its Affiliates, whether or not developed or acquired by Biogen or any of its Affiliates before or after the Effective Date, including all Biogen Collaboration Know-How, Product-Specific Know-How, and Target-Specific Know-How. 

 

	1.24	 “Biogen Licensed Know-How” means any Biogen Know-How that is (a) necessary or useful for C4 to conduct any C4 Candidate Development Activities under any Candidate Development Plan or the Sandbox Activities allocated to C4 under the Sandbox Plan and
(b) actually provided by Biogen to C4 for use in such C4 Candidate Development Activities or Sandbox Activities. 

  

	1.25	 “Biogen Licensed Patent Rights” means any Patent Rights Controlled by Biogen or any of its
Affiliates that Cover any Biogen Licensed Know-How, including all Biogen Collaboration Patent Rights, Product-Specific Patent Rights, and Target-Specific Patent Rights. 

 

	1.26	 “Biogen Licensed Technology” means Biogen Licensed Know-How and Biogen Licensed Patent Rights. 

  

	1.27	 “Biogen Patent Rights” means any Patent Rights Controlled by Biogen or any of its Affiliates
that Cover Biogen Know-How. 

  

	1.28	 “Biogen-Prosecuted Patent Rights” has the meaning set forth in Section 10.4.1(a)
(Biogen’s Rights). 

  

	1.29	 “Biogen Records” has the meaning set forth in Section 7.11 (Financial Audits).

  
 3 

	1.30	 “Biogen Technology” means Biogen Know-How and
Biogen Patent Rights. 

  

	1.31	 “Business Day” means any day other than a Saturday, Sunday, or bank or other public holiday in
Boston, Massachusetts. 

  

	1.32	 “C4 Candidate Development Activities” has the meaning set forth in Section 3.1.2(a) (C4
Candidate Development Activities). 

  

	1.33	 “C4 Collaboration Know-How” means Collaboration Know-How, other than Target-Specific Know-How and Product-Specific Know-How, developed or invented solely by C4’s or its
Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any Persons contractually required to assign or license such Collaboration
Know-How to C4 or any Affiliate of C4, in each case, in the performance of Collaboration Activities under this Agreement during the Term. 

 

	1.34	 “C4 Collaboration Patent Rights” means all Collaboration Patent Rights that Cover C4
Collaboration Know-How, but expressly excluding Target-Specific Patent Rights and Product-Specific Patent Rights. 

  

	1.35	 “C4 Degrader Platform” means the C4 degradation platform comprised of its proprietary Degrader
Components and assays relevant to the discovery or development of Degraders. 

  

	1.36	 “C4 First Right Patent Rights” has the meaning set forth in Section 10.4.1(b) (C4’s
Rights). 

  

	1.37	 “C4 Hit Criteria” means, with respect to a target that Biogen proposes to select as an
Additional Target, C4’s success criteria for degraders directed to such target set forth on Schedule 1.37 (C4 Hit Criteria), which success criteria are intended to identify such degraders and associated ligands as capable of binding to or
having activity with respect to such target, including appropriate screening assays and parameters, binding potency, and cross-assays to confirm selectivity for such target. 

 

	1.38	 “C4 Indemnified Party” has the meaning set forth in Section 11.2 (Indemnification by
Biogen). 

  

	1.39	 “C4 Internal Program” means, with respect to a target that Biogen proposes to select as an
Additional Target, a bona fide Development or Commercialization program (a) with a detailed written plan and an associated budget with respect to which C4 is performing such Development and Commercialization, and (b) under which C4
or its Affiliates have synthesized at least one degrader directed to such proposed target that meets the C4 Hit Criteria for such proposed target. 

  

	1.40	 “C4 Know-How” means any
Know-How Controlled by C4 or any of its Affiliates, including all C4 Collaboration Know-How and Assigned Platform Know-How,
whether or not developed or acquired by C4 or any of its Affiliates before or after the Effective Date. 

  

	1.41	 “C4 Licensed Know-How” means any and all C4 Know-How, other than any Joint Know-How, that is necessary or useful to (a) perform any Candidate Development Activities or the Sandbox Activities, or (b) Exploit
any Degrader or Product, in each case, including all Assigned Platform Know-How and C4 Collaboration Know-How. 

 

	1.42	 “C4 Licensed Patent Rights” means any and all C4 Patent Rights, other than any Joint
Patent Rights, that are necessary or useful to (a) perform any Candidate Development Activities or the Sandbox Activities, or (b) Exploit any Degrader or Product, including all Assigned Platform Patent Rights and C4 Collaboration Patent
Rights. The C4 Licensed Patent Rights existing as of the Effective Date are set forth on Schedule 1.42 (C4 Licensed Patent Rights). 

  
 4 

	1.43	 “C4 Licensed Technology” means all C4 Licensed
Know-How and C4 Licensed Patent Rights and C4’s interest in the Joint Technology. 

  

	1.44	 “C4 Patent Rights” means any Patent Rights Controlled by C4 or any of its Affiliates that
Cover C4 Know-How. 

  

	1.45	 “C4-Prosecuted Patent Rights” has the meaning set
forth in Section 10.4.1(b) (C4’s Rights). 

  

	1.46	 “C4 Records” has the meaning set forth in Section 7.11 (Financial Audits).

  

	1.47	 “C4 Technology” means C4 Know-How and C4 Patent
Rights. 

  

	1.48	 “C4’s Knowledge” means the actual knowledge, after reasonable investigation
(including consultation with C4’s outside intellectual property counsel), of the following: [***] 

  

	1.49	 “Calendar Quarter” means the respective periods of three consecutive calendar months ending on
March 31st, June 30th, September 30th, or December 31st in any Calendar Year. 

  

	1.50	 “Calendar Year” means any calendar year beginning on January 1st and ending on December 31st.

  

	1.51	 “Candidate Development Activities” has the meaning set forth in Section 3.1.2(b) (Biogen
Candidate Development Activities). 

  

	1.52	 “Candidate Development Budget” has the meaning set forth in Section 3.1.3 (Candidate
Development Plans and Candidate Development Budgets). 

  

	1.53	 “Candidate Development Plan” has the meaning set forth in Section 3.1.3 (Candidate
Development Plans and Candidate Development Budgets). 

  

	1.54	 “Candidate Development Program” means, on a Collaboration Target-by-Collaboration Target basis, the program of Candidate Development Activities undertaken for a Collaboration Target as set forth in Section 3.1 (Candidate Development Programs) and under the
applicable Candidate Development Plan for such Collaboration Target. 

  

	1.55	 “Change of Control” means, with respect to a Party, that: (a) any Third Party acquires
directly or indirectly the beneficial ownership of any voting security of such Party, or if the percentage ownership of such Third Party in the voting securities of such Party is increased through stock redemption, cancellation, or other
recapitalization, and immediately after such acquisition or increase such Third Party is, directly or indirectly, the beneficial owner of voting securities representing at least 50% of the total voting power of all of the then outstanding voting
securities of such Party; (b) a merger, consolidation, recapitalization, or reorganization of such Party is consummated that would result in shareholders or equity holders of such Party immediately prior to such transaction, owning at least 50%
of the outstanding voting securities of the surviving entity (or its parent entity) immediately following such transaction; or (c) there is a sale or transfer to a Third Party of all or substantially all of such Party’s consolidated assets
taken as a whole, through one or more related transactions. 

  
 5 

	1.56	 “Clinical Trial” means any clinical trial in humans that is designed to generate data in
support or maintenance of an IND or MAA, or other similar marketing application, including any Phase I Clinical Trial, Phase II Clinical Trial, Phase III Clinical Trial, or any post-approval clinical trial in humans. 

 

	1.57	 “CMO” has the meaning set forth in Section 6.2 (Observation by Biogen).

  

	1.58	 “Collaboration Activities” means (a) the Candidate Development Activities for each
Collaboration Target and (b) the Sandbox Activities. 

  

	1.59	 “Collaboration Know-How” means any Know-How developed or invented during the Term by a Party’s or its Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any persons
contractually required to assign or license such Know-How to a Party or any Affiliate of a Party, either alone or jointly with the other Party’s or its Affiliates’, licensees’,
Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any persons contractually required to assign or license such Know-How to the other Party or any Affiliate of the
other Party, in each case, in the performance of Collaboration Activities under this Agreement. 

  

	1.60	 “Collaboration Patent Rights” means any Patent Rights that (a) have a priority date after
the Effective Date and (b) Cover any Collaboration Know-How. 

  

	1.61	 “Collaboration Platform Know-How” means any
Collaboration Know-How that constitutes a discovery, improvement, modification, enhancement, or creation of an E3 Ligase Binding Moiety, or the combination of an E3 Ligase Binding Moiety and a Linker wherein
the E3 Ligase Binding Moiety and the Linker are covalently connected. For clarity, Collaboration Platform Know-How does not include Know-How that does not specifically
relate to an E3 Ligase Binding Moiety, or the combination of an E3 Ligase Binding Moiety and a Linker wherein the E3 Ligase Binding Moiety and the Linker are covalently connected. 

 

	1.62	 “Collaboration Platform Patent Rights” means any Collaboration Patent Rights that Cover
any Collaboration Platform Know-How. Notwithstanding any provision of this Agreement to the contrary, (a) any Patent Rights that Cover both Collaboration Platform
Know-How and Target-Specific Know-How will be Target-Specific Patent Rights for the purposes of this Agreement, and (b) any Patent Rights that Cover both
Collaboration Platform Know-How and Product-Specific Know-How will be Product-Specific Patent Rights for the purposes of this Agreement. 

 

	1.63	 “Collaboration Targets” means the Initial Targets and the Additional Targets (including the
Initial Term Targets and the Extended Term Targets). 

  

	1.64	 “Collaboration Term” has the meaning set forth in Section 3.5.2 (Extension of
Collaboration Term). 

  

	1.65	 “Combination Product” means a Product that is (a) sold in the form of a combination that
contains or comprises a Development Candidate together with one or more other therapeutically active pharmaceutical agents (whether coformulated or copackaged or otherwise sold for a single price), (b) sold for a single invoice price together with
any (i) delivery device or component therefor, (ii) companion diagnostic related to any Product, process, service, or therapy, or (iii) product, process, service, or therapy other than the Product (such additional therapeutically
active pharmaceutical agent and each of (i) – (iii), an “Other Component”); or (c) defined as a “combination product” by the FDA pursuant to 21 C.F.R. §3.2(e) or its foreign equivalent.

  
 6 

	1.66	 “Commercialization,” “Commercializing,” or “Commercialize”
means any and all activities directed to the marketing, promotion, distribution, offering for sale, sale, having sold, importing, having imported, exporting, having exported or other commercialization of a pharmaceutical or biologic product, but
excluding activities directed to Manufacturing, Development, or Medical Affairs. “Commercialize,” “Commercializing,” and “Commercialized” will be construed accordingly. 

 

	1.67	 “Commercially Reasonable Efforts” means, [***]. 

 

	1.68	 “Competing Infringement” has the meaning set forth in Section 10.5.2 (Infringement
Actions). 

  

	1.69	 “Competitive Product” has the meaning set forth in Section 3.6 (Exclusivity).

  

	1.70	 “Confidential Information” means, with respect to each Party, all Know-How or other information, including proprietary information and materials (whether or not patentable) regarding or embodying such Party’s technology, products, business information or objectives, that is
communicated by or on behalf of the Disclosing Party to the Receiving Party or its permitted recipients, including information disclosed prior to the Effective Date pursuant to the Confidentiality Agreement. 

 

	1.71	 “Confidentiality Agreement” means that certain Mutual
Non-Disclosure Agreement dated December 11, 2017 by and between the Parties. 

  

	1.72	 “Control” or “Controlled” means the possession by a Party (whether by
ownership, license, or otherwise other than pursuant to this Agreement) of, (a) with respect to any tangible Know-How, the legal authority or right to physical possession of such tangible Know-How, with the right to provide such tangible Know-How to the other Party on the terms set forth herein, or (b) with respect to Patent Rights, Regulatory Approvals,
Regulatory Submissions, intangible Know-How, or other Intellectual Property, the legal authority or right to grant a license, sublicense, access, or right to use (as applicable) to the other Party under such
Patent Rights, Regulatory Approvals, Regulatory Submissions, intangible Know-How, or other Intellectual Property on the terms set forth herein, in each case ((a) and (b)), without breaching or otherwise
violating the terms of any arrangement or agreement with a Third Party in existence as of the time such Party or its Affiliates would first be required hereunder to grant the other Party such access, right to use, licenses, or sublicense.

  

	1.73	 “Cover,” “Covering” or “Covered” means, with respect to a
product, technology, process, method, or mode of administration that, in the absence of ownership of or a license granted under a particular Valid Claim, the manufacture, use, offer for sale, sale, or importation of such product or the practice of
such technology, process, method, or mode of administration would infringe such Valid Claim or, in the case of a claim that has not yet issued, would infringe such claim if it were to issue and become a Valid Claim. 

 

	1.74	 “CPI” means the Consumer Price Index for the US City Average (all times).

  

	1.75	 “Debarred” means, with respect to an individual or entity, that such individual or entity has
been debarred or suspended under 21 U.S.C. §335(a) or (b), the subject of a conviction described in Section 306 of the FD&C Act, excluded from a federal or governmental health care program, debarred from federal contracting, convicted
of or pled nolo contendere to any felony, or to any federal or state legal violation (including misdemeanors) relating to prescription drug products or fraud, the subject to OFAC sanctions or on the OFAC list of specially designated
nationals, or the subject of any similar sanction of any Governmental Authority in the Territory. 

  
 7 

	1.76	 “Defaulting Party” has the meaning set forth in Section 12.2.3 (Disputes regarding
Material Breach). 

  

	1.77	 “Degrader” means with respect to a Collaboration Target, a compound comprising (a) a
Target Binding Moiety, (b) optionally, a Linker, and (c) an E3 Ligase Binding Moiety that degrades such Collaboration Target. 

  

	1.78	 “Degrader Component” means any Target Binding Moiety, Linker, or E3 Ligase Binding Moiety.

  

	1.79	 “Deliverables” means any and all deliverables to be generated or provided by C4 in connection
with the performance of (i) C4 Candidate Development Activities with respect to each Collaboration Target, as specified in the applicable Candidate Development Plan, or (ii) Sandbox Activities, as specified in the applicable Sandbox
Workstream or under the Sandbox Plan. 

  

	1.80	 “Develop” or “Development” means all internal and external research,
development, and regulatory activities related to pharmaceutical or biologic products, including (a) research, non-clinical testing, toxicology, testing and studies,
non-clinical and preclinical activities, and Clinical Trials, and (b) preparation, submission, review, and development of data or information for the purpose of submission to a Regulatory Authority to
obtain authorization to conduct Clinical Trials and to obtain, support, or maintain Regulatory Approval of a pharmaceutical or biologic product and interacting with Regulatory Authorities following receipt of Regulatory Approval in the applicable
country or region for such pharmaceutical or biologic product regarding the foregoing, but excluding activities directed to Manufacturing, Medical Affairs, or Commercialization. Development will include development and regulatory activities for
additional forms, formulations, or indications for a pharmaceutical or biologic product after receipt of Regulatory Approval of such product (including label expansion), including Clinical Trials initiated following receipt of Regulatory Approval or
any Clinical Trial to be conducted after receipt of Regulatory Approval that was mandated by the applicable Regulatory Authority as a condition of such Regulatory Approval with respect to an approved formulation or indication (such as post-marketing
studies, observational studies, implementation and management of registries and analysis thereof, in each case, if required by any Regulatory Authority in any region in the Territory to support or maintain Regulatory Approval for a pharmaceutical or
biologic product in such region). “Develop,” “Developing,” and “Developed” will be construed accordingly. 

  

	1.81	 “Development Candidate” means on a Collaboration Target-by-Collaboration Target basis, each Degrader directed to a Collaboration Target that (a) is suitable for the commencement of IND-Enabling Studies and
otherwise meets the Development Candidate Criteria set forth in the Candidate Development Plan for such Collaboration Target, or (b) with respect to which Biogen otherwise elects to commence IND-Enabling
Studies (regardless of whether or not such Degrader meets the applicable Development Candidate Criteria). 

  

	1.82	 “Development Candidate Criteria” means, with respect to a Collaboration Target, (a) the
criteria for Degraders directed to such Collaboration Target set forth in the Candidate Development Plan as “Development Candidate Criteria” for such Collaboration Target, which criteria are intended to indicate that such Degraders are
suitable for testing in IND-Enabling Studies, and (b) the IP Criteria for Degraders directed to such Collaboration Target (to the extent not set forth in the Candidate Development Plan).

  

	1.83	 “Development Candidate Report” has the meaning set forth in Section 3.1.8(a) (Delivery of
Development Candidates; Development Candidate Report). 

  
 8 

	1.84	 “Development Milestone Event” has the meaning set forth in Section 7.5.1 (Development
Milestones). 

  

	1.85	 “Development Milestone Payment” has the meaning set forth in Section 7.5.1 (Development
Milestones). 

  

	1.86	 “Directed To” means, with regard to a Degrader, that such Degrader is designed to bind to a
Collaboration Target. 

  

	1.87	 “Disclosing Party” has the meaning set forth in Section 9.1.2 (Confidential Information).

  

	1.88	 “Dollar” means the U.S. dollar, and “$” will be interpreted accordingly.

  

	1.89	 “E3 Ligase Binding Moiety” means a moiety that binds to an E3 ligase that is Controlled by C4
or its Affiliates. 

  

	1.90	 “Effective Date” has the meaning set forth in the preamble. 

 

	1.91	 “Executive Officers” has the meaning set forth in Section 13.8 (Dispute Resolution).

  

	1.92	 “Exploit” means Develop, have Developed, make, have made, use, have used, perform Medical
Affairs, have performed Medical Affairs, offer for sale, have offered for sale, sell, have sold, export, have exported, import, have imported, Manufacture, have Manufactured, Commercialize, have Commercialized or otherwise exploit.
“Exploitation” and “Exploiting” will be construed accordingly. 

  

	1.93	 “Extended Term Targets” means those targets selected pursuant to Section 3.1.1(b)
(Additional Targets) and Section 3.5.3 (Effect of Extension of Initial Collaboration Term) as a result of Biogen’s extension of the Collaboration Term pursuant to Section 3.5.2 (Extension of Collaboration Term). 

 

	1.94	 “FD&C Act” means the Federal Food, Drug and Cosmetic Act, as the same may be amended or
supplemented from time to time. 

  

	1.95	 “FDA” means the U.S. Food and Drug Administration, or any successor agency thereto.

  

	1.96	 “Field” means any and all uses. 

 

	1.97	 “First Commercial Sale” means, with respect to any Product in any country or region, the first
sale of such Product to a Third Party (other than a Sublicensee) for distribution, use, or consumption in such country or region after receipt of Regulatory Approval for such Product in such country or region. First Commercial Sale excludes any
transfers of Product to Third Parties for Clinical Trial purposes, any expanded access program, any compassionate sales or use program (including named patient program or single patient program), or any indigent program. 

 

	1.98	 “FTE” means a qualified full time person, or more than one person working the equivalent of a
full-time person, where “full time” is based upon a total of [***]working hours per Calendar Year of scientific or technical work carried out by one or more duly qualified employees of C4. Overtime, and work on weekends, holidays,
and the like will not be counted with any multiplier (e.g. time-and-a-half or double time) toward the number of hours that
are used to calculate the FTE contribution. 

  
 9 

	1.99	 “FTE Rate” means $[***] per FTE for the Calendar Years 2018 and 2019, subject to annual
increases beginning on January 1, 2020 to reflect any year to year percentage increase in the CPI for 2019 and each subsequent Calendar Year. 

  

	1.100	 “GAAP” means United States generally accepted accounting principles, which principles are
currently used at the relevant time and consistently applied by the applicable Party. 

  

	1.101	 “Generic Product” means with respect to a given Product in a given country in the Territory, a
product that (a) (i) contains the same active pharmaceutical ingredient as such Product and is approved in reliance, in whole or in part, on a prior Regulatory Approval of such Product or (ii) is otherwise approved in reliance, in whole or
in part, on a prior Regulatory Approval of such Product, and (b) is sold or marketed for sale in such country by a Third Party that has not obtained the rights to market or sell such product as a Sublicensee, Subcontractor, or Third Party
Distributor of Biogen or any of its Affiliates, Sublicensees, or Subcontractors with respect to such Product. 

  

	1.102	 “GLP” means all applicable good laboratory practice standards, including, as applicable, as
set forth in the then-current good laboratory practice standards promulgated or endorsed by the U.S. Food and Drug Administration, as defined in 21 C.F.R. Part 58, and the equivalent Applicable Law in the region in the Territory, each as may be
amended and applicable from time to time. 

  

	1.103	 “Governmental Authority” means any court, tribunal, arbitrator, agency, commission,
department, ministry, official, authority or other instrumentality of any national, state, county, city or other political subdivision. 

  

	1.104	 “Grandfathered Products” has the meaning set forth in Section 3.7 (Effect of Acquisition
of C4). 

  

	1.105	 “Hit Criteria” means, with respect to a Collaboration Target, the success criteria for
Degraders directed to such Collaboration Target set forth in the Candidate Development Plan as “Hit Criteria” for such Collaboration Target, which success criteria are intended to identify such Degraders and associated ligands as capable
of binding to or having activity with respect to such Collaboration Target, including appropriate screening assays and parameters, binding potency, and cross-assays to confirm selectivity for such Collaboration Target. 

 

	1.106	 “Hit Fee” has the meaning set forth in Section 7.2 (Hit Fee). 

 

	1.107	 [***] 

  

	1.108	 “IND” means an Investigational New Drug application required pursuant to 21 C.F.R. Part 312 or
any comparable filings outside of the United States required to commence human clinical trials in such country or region, and all supplements or amendments that may be filed with respect to the foregoing. 

 

	1.109	 “IND-Enabling Study” means a toxicology study
(a) that is conducted using applicable GLP, (b) that is conducted in a species that satisfies applicable regulatory requirements, and (c) the data and results from which are intended to meet the standard necessary for submission
thereof as part of an IND with the applicable Regulatory Authority. 

  

	1.110	 “IND-Enabling Study Commencement Fee” has the meaning
set forth in Section 7.4 (IND-Enabling Study Commencement Fee). 

  

	1.111	 “Indemnified Party” has the meaning set forth in Section 11.3 (Procedure).

  
 10 

	1.112	 “Indemnifying Party” has the meaning set forth in Section 11.3 (Procedure).

  

	1.113	 “Infringement” has the meaning set forth in Section 10.5.2 (Infringement Actions).

  

	1.114	 “Infringement Action” has the meaning set forth in Section 10.5.2(a)(i) (Infringement
Actions for Competing Infringements). 

  

	1.115	 “Initial Collaboration Term” has the meaning set forth in Section 3.5.1 (Initial Term).

  

	1.116	 “Initial Targets” has the meaning set forth in Section 3.1.1(a) (Initial Targets).

  

	1.117	 “Initial Term Targets” means the Initial Targets and the [***] Additional Targets
selected pursuant to Section 3.1.1(b)(i) (Selection of Additional Targets) (excluding, for clarity, any Extended Term Targets). 

  

	1.118	 “Initiating Party” has the meaning set forth in Section 10.5.2(c) (Procedures).

  

	1.119	 “Initiation” means the fifth dosing of a human subject in a Clinical Trial.

  

	1.120	 “Intellectual Property” means all Patent Rights, rights to Inventions, copyrights, design
rights, trademarks, trade secrets, Know-How, and all other intellectual property rights (whether registered or unregistered) and all applications and rights to apply for any of the foregoing, anywhere in the
world. 

  

	1.121	 “Invention” means any process, method, utility, formulation, composition of matter, Article of
manufacture, material, creation, discovery or finding, or any improvement thereof, that is made, conceived, discovered, or otherwise generated, whether patentable or not. 

 

	1.122	 “IP Counsels” has the meaning set forth in Section 7.6.6 (Biogen Identified Rights
Dispute). 

  

	1.123	 “IP Criteria” means, with respect to a Collaboration Target, the criteria for Degraders
directed to such Collaboration Target that are agreed to by the Parties, which criteria are intended to reflect any intellectual property considerations in determining whether such Degraders are suitable for testing in
IND-Enabling Studies. 

  

	1.124	 “Joint Collaboration Know-How” means any Collaboration
Know-How developed or invented jointly by a Party’s or its Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any Persons
contractually required to assign or license such Collaboration Know-How to such Party or any Affiliate of such Party, on the one hand, and the other Party’s or its Affiliates’, licensees’,
Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any Persons contractually required to assign or license such Collaboration Know-How to such Party or any Affiliate
of such Party, on the other hand, in the performance of Collaboration Activities under this Agreement during the Term, but excluding any Assigned Platform Know-How, Target-Specific Know-How, or Product-Specific Know-How. 

  

	1.125	 “Joint Collaboration Patent Rights” means those Collaboration Patent Rights that Cover Joint
Collaboration Know-How. 

  

	1.126	 “Joint Know-How” means all Joint Collaboration Know-How and Sandbox Know-How. 

  

	1.127	 “Joint Patent Rights” means all Joint Collaboration Patent Rights and Sandbox Patent Rights.

  
 11 

	1.128	 “Joint Technology” means all Joint Know-How and Joint
Patent Rights. 

  

	1.129	 “JSC” has the meaning set forth in Section 4.2.1 (Joint Steering Committee).

  

	1.130	 “Know-How” means any (a) proprietary information
or materials, including records, improvements, modifications, techniques, assays, chemical or biological materials, designs, protocols, formulas, data (including physical data, chemical data, toxicology data, animal data, raw data, clinical data,
and analytical and quality control data), dosage regimens, control assays, product specifications, marketing, pricing and distribution costs, Inventions, algorithms, technology, forecasts, profiles, strategies, plans, results in any form whatsoever,
know-how, and trade secrets (in each case, whether or not patentable, copyrightable, or otherwise protectable), and (b) any physical embodiments of any of the foregoing. 

 

	1.131	 “Lead Criteria” means, with respect to a Collaboration Target, the success criteria for
Degraders directed to such Collaboration Target set forth in the Candidate Development Plan as “Lead Criteria” for such Collaboration Target, which success criteria are intended to indicate that such Degraders are suitable for further
optimization as a potential Development Candidate directed to such Collaboration Target. 

  

	1.132	 “Lead Fee” has the meaning set forth in Section 7.3 (Lead Fee). 

 

	1.133	 “Liability” has the meaning set forth in Section 11.2 (Indemnification by Biogen).

  

	1.134	 “Linker” means a moiety that is Controlled by C4 or its Affiliates and connects the Target
Binding Moiety and the E3 Ligase Binding Moiety. 

  

	1.135	 “MAA” means any new drug application, biologics license application, or other marketing
authorization application, in each case, filed with the applicable Regulatory Authority in a country or other regulatory jurisdiction, which application is required to commercially market or sell a pharmaceutical or biologic product in such country
or jurisdiction (and any amendments thereto), including all New Drug Applications submitted to the FDA in the United States in accordance with the FD&C Act with respect to a biologic or pharmaceutical product or any analogous application or
submission with any Regulatory Authority outside of the United States. 

  

	1.136	 “Major European Market” means any of France, Germany, Italy, Spain, or the United Kingdom.

  

	1.137	 “Manufacture” means activities directed to manufacturing, processing, packaging, labeling,
filling, finishing, assembly, quality assurance, quality control, testing, and release, shipping, or storage of any pharmaceutical or biologic product (or any components or process steps involving any product or any companion diagnostic), placebo,
or comparator agent, as the case may be, including process development, qualification, and validation, scale-up, pre-clinical, clinical, and commercial manufacture and
analytic development, product characterization, and stability testing, but excluding activities directed to Development, Commercialization, or Medical Affairs. “Manufacturing” will be construed accordingly. 

 

	1.138	 “Medical Affairs” means activities conducted by a Party’s medical affairs departments
(or, if a Party does not have a medical affairs department, the equivalent function thereof), including communications with key opinion leaders, medical education, symposia, advisory boards (to the extent related to medical affairs or clinical
guidance), activities performed in connection with patient registries, and other medical programs and communications, including educational grants, research grants (including conducting investigator-initiated studies), and charitable donations to
the extent related to medical affairs and not to other activities that do not involve the promotion, marketing, sale, or other Commercialization of the Products and are not conducted by a Party’s medical affairs (or equivalent) departments.

  
 12 

	1.139	 “Milestone Payments” has the meaning set forth in Section 7.5.2 (Sales Milestones).

  

	1.140	 “Net Sales” means [***]. 

 

	1.141	 “Non-Defaulting Party” has the meaning set forth in
Section 12.2.3 (Disputes Regarding Material Breach). 

  

	1.142	 “Occupied Target” has the meaning set forth in Section 3.1.1(b)(iv) (Occupied Targets).

  

	1.143	 “One-Time R&D Prepayment” means each of the
payments to C4 described in Section 7.1.1 (Initial Collaboration Term) and Section 7.1.2 (Extended Collaboration Term). 

  

	1.144	 “Other Component(s)” has the meaning set forth in Section 1.140 (Net Sales).

  

	1.145	 “Patent Rights” means any and all (a) patents, (b) patent applications, including all
provisional and non-provisional applications, patent cooperation treaty (PCT) applications, substitutions, continuations,
continuations-in-part, divisions and renewals, and all patent rights granted thereon, (c) all
patents-of-addition, reissues, re-examinations and extensions or restorations by existing or future extension or restoration
mechanisms, including supplementary protection certificates and equivalents thereof, (d) inventor’s certificates, letters patent, or (e) any other substantially equivalent form of government issued right substantially similar to any
of the foregoing described in subsections (a) through (e) above, anywhere in the world. 

  

	1.146	 “Patent Term Extension” has the meaning set forth in Section 10.8 (Patent Term
Extensions). 

  

	1.147	 “Per Product Annual Net Sales” has the meaning set forth in Section 7.6 (Royalties).

  

	1.148	 “Person” means any individual, firm, corporation, partnership, limited liability company,
trust, business trust, joint venture, Governmental Authority, association or other entity. 

  

	1.149	 “Phase I Clinical Trial” means a clinical trial in humans that generally provides for the
first introduction into humans of a pharmaceutical or biologic product with the primary purpose of determining safety, metabolism, and pharmacokinetic properties and clinical pharmacology of such product, in a manner that meets the requirements of
21 C.F.R. § 312.21(a), as amended (or its successor regulation), or, with respect to any other country or region, the equivalent of such a clinical trial in such other country or region. 

 

	1.150	 “Phase II Clinical Trial” mean a clinical trial in humans that is intended to explore the
feasibility, safety, dose ranging, or efficacy of a pharmaceutical or biologic product that is prospectively designed to generate sufficient data (if successful) to commence a Phase III Clinical Trial for such product, in a manner that meets the
requirements of 21 C.F.R. § 312.21(b), as amended (or its successor regulation), or, with respect to any other country or region, the equivalent of such a clinical trial in such other country or region. 

  
 13 

	1.151	 “Phase III Clinical Trial” means a clinical trial in humans of a pharmaceutical or biologic
product that the FDA permits to be conducted under an open IND and that is performed to gain evidence with statistical significance of the efficacy of such product in a target population, and to obtain expanded evidence of safety for such product
that is needed to evaluate the overall benefit-risk relationship of such product, to form the basis for approval of an MAA by a Regulatory Authority and to provide an adequate basis for physician labeling, in a manner that meets the requirements of
21 C.F.R. § 312.21(c), as amended (or its successor regulation), or, with respect to any other country or region, the equivalent of such a clinical trial in such other country or region. Notwithstanding anything to the contrary set forth in
this Agreement, treatment of patients as part of an expanded access program, compassionate sales or use program (including named patient program or single patient program), or an indigent program, in each case, will not be included in
determining whether or not a clinical trial is a Phase III Clinical Trial or whether a patient has been dosed thereunder. 

  

	1.152	 “Pre-Existing Restriction” has the meaning set forth
in Section 3.1.1(b)(iv) (Occupied Targets). 

  

	1.153	 “Product” means any product incorporating a Development Candidate (or derivative thereof).

  

	1.154	 “Product-Specific Know-How” any (a) Collaboration
Know-How that is developed or invented during the Collaboration Term by C4 or its Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent contractors,
or any Person contractually required to assign or license such Know-How (or Patent Rights Covering such Know-How) to C4 or any Affiliate of C4, whether solely or jointly
with others, in the course of performance of Collaboration Activities undertaken pursuant to this Agreement, or (b) C4 Licensed Know-How or Sandbox Know-How, in
each case, ((a) and (b)), related to (i) any Degrader or any Product incorporating or derived from any such Degrader, (ii) any use or a method of using any such Degrader or Product incorporating or derived from any such Degrader, or
(iii) any method for Manufacturing any such Degrader or Product incorporating or derived from any such Degrader. 

  

	1.155	 “Product-Specific Patent Rights” means any C4 Licensed Patent Rights or Collaboration Patent
Rights that Cover any Product-Specific Know-How. Notwithstanding any provision of this Agreement to the contrary, any Patent Rights that Cover both Assigned Platform
Know-How and Product-Specific Know-How will be Product-Specific Patent Rights for the purposes of this Agreement. 

 

	1.156	 “Product-Specific Technology” means Product-Specific
Know-How and Product-Specific Patent Rights. 

  

	1.157	 “Prosecuting Party” means, with respect to any Patent Right, the Party that is responsible for
the preparation, filing, prosecution, and maintenance of such Patent Right pursuant to Section 10.4.1 (Right to Prosecute) or Section 10.4.2 (Step-In Right), as applicable. 

 

	1.158	 “Receiving Party” has the meaning set forth in Section 9.1 (Confidential Information).

  

	1.159	 “Regulatory Approval” means, with respect to a particular country or other regulatory
jurisdiction, any approval of an MAA or other approval, product, or establishment license, registration, or authorization of any Regulatory Authority necessary for the commercial marketing or sale of a pharmaceutical or biologic product in such
country or other regulatory jurisdiction, including, in each case, Reimbursement Approval in those countries and jurisdictions where required. 

  

	1.160	 “Regulatory Authority” means any applicable Governmental Authority with jurisdiction or
authority over the Development, Manufacture, Commercialization, or other Exploitation (including Regulatory Approval or Reimbursement Approval) of pharmaceutical or biologic products in a particular country or other regulatory jurisdiction, and any
corresponding national or regional regulatory authorities. 

  
 14 

	1.161	 “Regulatory Submissions” means any filing, application, or submission with any Regulatory
Authority in support of the Development, Manufacture, Commercialization, or other Exploitation of a pharmaceutical or biologic product (including to obtain, support, or maintain Regulatory Approval from that Regulatory Authority), and all
correspondence or communication with or from the relevant Regulatory Authority, as well as minutes of any material meetings, telephone conferences, or discussions with the relevant Regulatory Authority. Regulatory Submissions include all INDs, MAAs,
and other applications for Regulatory Approval and their equivalents. 

  

	1.162	 “Reimbursement Approval” means an approval, agreement, determination, or other decision by the
applicable Governmental Authority that establishes prices charged to end-users for pharmaceutical or biologic products at which a particular pharmaceutical or biologic product will be reimbursed by the
Regulatory Authorities or other applicable Governmental Authorities in the Territory. 

  

	1.163	 “Replacement Target Notice” has the meaning set forth in Section 3.1.1(b)(ii)
(Replacement Target Notice). 

  

	1.164	 “Results” means any and all (a) results, information, data, presentations, summaries, and
analyses that are generated pursuant to or prepared as a result of, or in connection with the performance of (i) the Candidate Development Activities under the Candidate Development Plan with respect to each Collaboration Target or
(ii) the Sandbox Activities under any Sandbox Workstream or under the Sandbox Plan, including, in each case, information related to the composition, production, and purification of Development Candidates, and (b) Intellectual Property that
claims or otherwise covers any of the foregoing. 

  

	1.165	 “Royalty Term” has the meaning set forth in Section 7.6.2 (Royalty Term).

  

	1.166	 “Sales Milestone Event” has the meaning set forth in Section 7.5.2 (Sales Milestones).

  

	1.167	 “Sales Milestone Payment” has the meaning set forth in Section 7.5.2 (Sales Milestones).

  

	1.168	 “Sandbox Activities” has the meaning set forth in Section 3.2.1 (Sandbox Activities).

  

	1.169	 “Sandbox Budget” has the meaning set forth in Section 3.2.2 (Sandbox Plan).

  

	1.170	 “Sandbox High Interest Target” has the meaning set forth in Section 3.2.7 (Sandbox High
Interest Targets). 

  

	1.171	 “Sandbox High Interest Target List” has the meaning set forth in Section 3.2.7 (Sandbox
High Interest Targets). 

  

	1.172	 “Sandbox Know-How” means any Know-How developed or invented during the Term by a Party’s or its Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any persons
contractually required to assign or license such Know-How to a Party or any Affiliate of a Party, either alone or jointly with the other Party’s or its Affiliates’, licensees’,
Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any persons contractually required to assign or license such Know-How to the other Party or any Affiliate of the
other Party, in each case, in the performance of Sandbox Activities. For clarity, Sandbox Know-How does not include Patent Rights or Know-How owned or Controlled by a
Party prior to the Effective Date, or that are developed or invented by a Party outside of this Agreement. 

  
 15 

	1.173	 “Sandbox Patent Rights” means any Patent Rights that (a) have a priority date after the
Effective Date, and (b) Cover any Sandbox Know-How. 

  

	1.174	 “Sandbox Plan” has the meaning set forth in Section 3.2.2 (Sandbox Plan).

  

	1.175	 “Sandbox Program” means the program of Sandbox Activities undertaken as set forth in
Section 3.2 (Sandbox Program) and under the applicable Sandbox Workstream and the Sandbox Plan. 

  

	1.176	 “Sandbox Target” means a target that is identified, discovered, or otherwise the subject of
any Sandbox Activities set forth in the Sandbox Plan, including under any Sandbox Workstream. 

  

	1.177	 “Sandbox Technology” means Sandbox Patent Rights and Sandbox
Know-How. 

  

	1.178	 “Sandbox Workstream” has the meaning set forth in Section 3.2.1 (Sandbox
Activities). 

  

	1.179	 “Selling Party” has the meaning set forth in Section 1.140 (Net Sales).

  

	1.180	 “Subcontractor” means a Third Party contractor engaged by a Party to perform certain
obligations or exercise certain rights of such Party under this Agreement on a fee-for-service basis (including contract research organizations or contract manufacturing
organizations), excluding all Sublicensees and Third Party Distributors. 

  

	1.181	 “Sublicensees” means any Third Party to whom a Party or any of its Affiliates grants a
sublicense of its rights hereunder to Exploit Products, excluding all Subcontractors and Third Party Distributors. 

  

	1.182	 “Target Binding Moiety” means a moiety that is directed to and binds to a particular
Collaboration Target that is Controlled by C4 or its Affiliates. 

  

	1.183	 “Target Selection Period” has the meaning set forth in Section 3.1.1(b)(v) (Expiration of
Pre-Existing Restrictions). 

  

	1.184	 “Target-Specific Know-How” means any
(a) Collaboration Know-How that is developed or invented during the Collaboration Term by C4 or its Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or
independent contractors, or any Person contractually required to assign or license such Know-How (or Patent Rights Covering such Know-How) to C4 or any Affiliate of C4,
whether solely or jointly with others, in the course of performance of Collaboration Activities undertaken pursuant to this Agreement, or (b) C4 Licensed Know-How or Sandbox
Know-How, in each case, ((a) and (b)), that constitutes a discovery, improvement, modification, enhancement, or creation to any Target Binding Moiety(ies) or Collaboration Target. 

 

	1.185	 “Target-Specific Patent Rights” means any C4 Licensed Patent Rights or Collaboration Patent
Rights that Cover Target-Specific Know-How. Notwithstanding any provision of this Agreement to the contrary, any Patent Rights that Cover both Assigned Platform Know-How
and Target-Specific Know-How will be Target-Specific Patent Rights for the purposes of this Agreement. 

  
 16 

	1.186	 “Target-Specific Technology” means Target-Specific
Know-How and Target-Specific Patent Rights. 

  

	1.187	 [***] 

  

	1.188	 “Term” has the meaning set forth in Section 12.1 (Term). 

 

	1.189	 “Territory” means all of the countries of the world, and their territories and possessions.

  

	1.190	 “Third Party” means any Person other than Biogen or C4 or their respective Affiliates.

  

	1.191	 “Third Party Distributor” means, with respect to a country, any Third Party that purchases its
requirements for Products in such country from Biogen or its Affiliates or Sublicensees and is appointed as a distributor to distribute, market, and resell such Product in such country, even if such Third Party is granted ancillary rights to
Develop, package, or obtain Regulatory Approval of such Product in order to distribute, market, or sell such Product in such country. 

  

	1.192	 “Valid Claim” means a claim of (a) an issued, unexpired, and in-force patent, which claim has not been held invalid or unenforceable by a court or other government agency of competent jurisdiction from which no appeal can be or has been taken and has not been held or admitted
to be invalid or unenforceable through re-examination, inter partes review, post grant review or disclaimer, opposition procedure, nullity suit, or otherwise, or (b) a pending patent
application that has not been finally abandoned, finally rejected, or expired; provided, however, that if a claim of a pending patent application will not have issued within [***] after the earliest filing date from which such claim
takes priority, then such claim will not constitute a Valid Claim for the purposes of this Agreement unless and until a patent issues with such claim. 

ARTICLE 2 LICENSE GRANTS 
  

	2.1	 Licenses and Assignment to Biogen. 

 

	 	2.1.1	 Collaboration License. C4 hereby grants to Biogen and its Affiliates, during the Collaboration Term, a
royalty-free, worldwide, exclusive (even as to C4, except to the extent necessary for C4 to perform any Collaboration Activities under any Candidate Development Plan or expressly allocated to C4 under the Sandbox Plan) license, with the right to
sublicense through multiple tiers (subject to the provisions of Section 2.1.4 (Sublicensing by Biogen)), under the C4 Licensed Technology solely for the purpose of performing (or having performed) Candidate Development Activities (except to the
extent required for C4 to perform the Candidate Development Activities assigned to C4 under the Candidate Development Plans) under each Candidate Development Plan and Sandbox Activities under the Sandbox Plan. 

 

	 	2.1.2	 Commercial License. C4 hereby grants to Biogen and its Affiliates a worldwide, royalty-bearing,
exclusive (even as to C4, except to the extent necessary for C4 to perform any Collaboration Activities under any Candidate Development Plan or expressly allocated to C4 under the Sandbox Plan) license, with the right to sublicense through multiple
tiers (subject to the provisions of Section 2.1.4 (Sublicensing by Biogen)), under the C4 Licensed Technology to Exploit all Degraders and Products in the Field in the Territory. 

  
 17 

	 	2.1.3	 C4 Collaboration Technology License. C4 hereby grants to Biogen and its Affiliates a worldwide,
royalty-free, irrevocable, perpetual, non-exclusive license, with the right to sublicense through multiple tiers, under all C4 Collaboration Patent Rights and C4 Collaboration
Know-How, to modify, improve, and enhance Degraders or Products (including any Degrader Component included therein). 

  

	 	2.1.4	 Sublicensing by Biogen. Biogen and its Affiliates may grant sublicenses under Section 2.1.1
(Collaboration License) and Section 2.1.2 (Commercial License) to any Affiliate or Third Party. Any such sublicense will be consistent with the terms of this Agreement and will include confidentiality,
non-disclosure, and non-use provisions at least as restrictive or protective of the Parties as those set forth in this Agreement. 

 

	2.2	 Licenses to C4. 

 

	 	2.2.1	 Collaboration License. Biogen hereby grants to C4, during the Collaboration Term, a royalty-free, non-exclusive, worldwide license, with the right to sublicense through multiple tiers (subject to the provisions of Section 2.2.3 (Sublicensing by C4)), under the Biogen Licensed Technology solely for the
purpose of performing the C4 Candidate Development Activities under the applicable Candidate Development Plan, and to the extent allocated to C4 under the Sandbox Plan, the Sandbox Activities. 

 

	 	2.2.2	 Grantback License. Biogen hereby grants to C4 an irrevocable, royalty-free, fully-paid, non-exclusive, perpetual, worldwide license, with the right to sublicense through multiple tiers, under any Biogen Grantback Claims to practice any method and to make, use, sell, offer for sale or import any product
other than (a) Degraders or Products or (b) any compounds or products Directed To any Collaboration Target. 

  

	 	2.2.3	 Sublicensing by C4. C4 may not grant any sublicense to use the Biogen Licensed Technology under
Section 2.2.1 (Collaboration License), except with the prior written consent of Biogen. Any such sublicense will be consistent with the terms of this Agreement and will include confidentiality,
non-disclosure, and non-use provisions at least as restrictive or protective of the Parties as those set forth in this Agreement. 

 

	2.3	 No Implied Licenses. Except as expressly provided in this Agreement, neither Party will be deemed to
have granted the other Party any license or other right with respect to any Intellectual Property of such Party. 

ARTICLE 3 COLLABORATION 
  

	3.1	 Candidate Development Programs. 

 

	 	3.1.1	 Collaboration Targets. 

 

	 	(a)	 Initial Targets. As of the Effective Date, the initial targets that will be the subject of Candidate
Development Programs are [***] (such targets, the “Initial Targets”). 

  

	 	(b)	 Additional Targets. 

 

	 	(i)	 Selection of Additional Targets. During the period commencing on the Effective Date and ending on the
date that is [***] thereafter (the “Additional Target Selection Period”), Biogen may select [***] additional targets (that are not Initial Targets) as Additional Targets

  
 18 

	 	
hereunder (which such Additional Targets so selected pursuant to this sentence will be Initial Term Targets hereunder). In addition, if Biogen elects to extend the Collaboration Term for an
additional [***] pursuant to Section 3.5.2 (Extension of Collaboration Term), then (A) upon such election, Biogen may select [***] additional targets as Additional Targets hereunder, and (B) during the period commencing
on the date of such election and ending on the date that is [***] thereafter, Biogen may select [***] additional targets as Additional Targets hereunder (all of which such Additional Targets so selected pursuant to the foregoing
clauses ((A) and (B)), will be Extended Term Targets hereunder), as described further in Section 3.5.3 (Effect of Extension of Initial Collaboration Term). Biogen may select each such Additional Target by sending a written notice to C4 during
the Collaboration Term, which notice will identify the applicable proposed target (each, an “Additional Target Notice”). 

  

	 	(ii)	 Replacement Target Notice. On an Initial
Target-by-Initial Target basis, if the JSC determines that the Candidate Development Program for an Initial Target has failed to deliver at least [***] in a
particular series directed to such Initial Target that meet the Hit Criteria set forth in the applicable Candidate Development Plan, then, subject to Section 3.1.1(b)(iv) (Occupied Targets), Biogen may select a replacement target as a
Collaboration Target by sending a written notice to C4 during the Collaboration Term, which notice will identify the applicable proposed target (each, a “Replacement Target Notice”). During the Collaboration Term, Biogen may send no
more than [***] Replacement Target Notice for each Initial Target. 

  

	 	(iii)	 Effects of Notice. Effective immediately upon C4’s receipt of an Additional Target Notice or
Replacement Target Notice (as applicable), subject to Section 3.1.1(b)(iv) (Occupied Targets), the applicable target that is specified in such notice will become an Additional Target for purposes of this Agreement and, following the
Parties’ agreement on a Candidate Development Plan with respect to such Additional Target in accordance with Section 3.1.4 (Additional Candidate Development Plans), C4 will promptly initiate Candidate Development Activities with respect to
such Additional Target in accordance with this Section 3.1 (Candidate Development Programs). 

  

	 	(iv)	 Occupied Targets. If, at the time of C4’s receipt of an Additional Target Notice or
Replacement Target Notice for a proposed target, [***] then Biogen may select another proposed target (and another if such other proposed target is an Occupied Target and so on) until such time that Biogen selects a target that is not an
Occupied Target, at which point such proposed target will be added as an Additional Target under this Agreement. 

  

	 	(v)	 Expiration of Pre-Existing Restrictions. If at any time during
the period in which Biogen is eligible to send C4 an Additional Target Notice under Section 3.1.1(b)(i) (Selection of Additional Targets) or Replacement Target Notice under Section 3.1.1(b)(ii) (Replacement Target Notice) (such period, the
“Target Selection Period”), any Pre-Existing 

  
 19 

	 	
Restriction that precluded Biogen from selecting a proposed target as an Additional Target that Biogen previously proposed to C4 under Section 3.1.1(b)(iv) (Occupied Targets) later expires,
terminates, or is otherwise modified such that such proposed target would no longer be an Occupied Target, then C4 will promptly notify Biogen of such expiration, termination, or modification. 

 

	 	3.1.2	 Candidate Development Activities. 

 

	 	(a)	 C4 Candidate Development Activities. For each Candidate Development Program with respect to a
Collaboration Target, C4 will be responsible for (i) performing all activities assigned to it under the applicable Candidate Development Plan, (ii) applying its C4 Degrader Platform to the discovery and initial optimization of at least
[***] directed to each Collaboration Target that satisfy the applicable Hit Criteria for such Collaboration Target, and (iii) preparing and delivering all Deliverables and Results related to such Collaboration Target in accordance with
this Agreement and the applicable Candidate Development Plan, including the preparation of all reports in accordance with Section 3.1.9 (Reports of Candidate Development Activities) and the Development Candidate Report for each Development
Candidate in accordance with Section 3.1.8(a) (Delivery of Development Candidates; Development Candidate Report) (collectively, together with any other activity expressly set forth under this Agreement to be performed by or on behalf of C4
during the Collaboration Term (other than the Sandbox Activities), the “C4 Candidate Development Activities”). C4 will perform, or have performed, all C4 Candidate Development Activities in accordance with the applicable Candidate
Development Plan and the applicable Candidate Development Budget for such Collaboration Target and otherwise in accordance with this Agreement. C4 will not perform any activities with respect to a Collaboration Target (including the Exploitation of
any Degrader directed to such Collaboration Target) that are not set forth in the applicable Candidate Development Plan for such Collaboration Target (other than the Sandbox Activities, which activities C4 will perform in accordance with
Section 3.2 (Sandbox Program)). 

  

	 	(b)	 Biogen Candidate Development Activities. Biogen (i) will perform all activities assigned to it
under the applicable Candidate Development Plan, and (ii) may elect to lead other neurosciences-related activities with respect to each Collaboration Target, including cellular testing of Degraders, development of target binding assays and
primary and secondary screening assays and testing and validation of the binding of ligands, and Degraders, in each case, to such Collaboration Target using such assays, cellular mechanism of action studies, pharmacokinetic studies, efficacy and
pharmacodynamic models, translational efforts, further optimizing Degraders that satisfy the applicable Hit Criteria and Lead Criteria for such Collaboration Target for potency, selectivity, brain penetrance, and ADME/PK properties to demonstrate
in vivo proof of principle, and other pilot toxicology (together ((i) and (ii)), with any other activities to be performed by or on behalf of Biogen with respect to each Collaboration Target during the Collaboration Term, collectively, the
“Biogen Candidate Development Activities,” and, together with the C4 Candidate Development Activities, the “Candidate Development Activities”). 

  
 20 

	 	3.1.3	 Candidate Development Plans and Candidate Development Budgets. For each Collaboration Target, C4
will perform the C4 Candidate Development Activities for such Collaboration Target and Biogen will perform the Biogen Candidate Development Activities for such Collaboration Target in accordance with a written development plan that sets forth:
(a) the C4 Candidate Development Activities to be performed by or on behalf of C4 during the Collaboration Term, (b) the Biogen Candidate Development Activities to be performed by or on behalf of Biogen during the Collaboration Term,
(c) the Hit Criteria for Degraders directed to the applicable Collaboration Target, (d) the Lead Criteria for Degraders directed to the applicable Collaboration Target, (e) the Development Candidate Criteria for Degraders directed to
the applicable Collaboration Target, (f) the timelines upon which C4 will work to deliver to Biogen Degraders that meet each of the Hit Criteria, Lead Criteria, and Development Candidate Criteria for such Collaboration Target and their
respective satisfaction of the applicable criteria, (g) the Deliverables and other Results required for the JSC to determine whether Degraders directed to such Collaboration Target have satisfied the Hit Criteria, Lead Criteria, and Development
Candidate Criteria for such Collaboration Target, and other Deliverables and Results to be provided by C4 to Biogen with respect to the C4 Candidate Development Activities, (h) a timeline for completion of other C4 Candidate Development
Activities, and (i) the dedicated and planned resources to be provided by C4 in furtherance of performing the C4 Candidate Development Activities (each such plan, a “Candidate Development Plan”). In addition, for each
Collaboration Target, the Candidate Development Plan will include a written budget pursuant to which C4 or its authorized Third Party designees will perform the C4 Candidate Development Activities allocated to C4 under such Candidate Development
Plan, which budget will include a good-faith estimate of (i) the number of FTEs to be dedicated by C4 under such Candidate Development Plan, and (ii) any direct
out-of-pocket expenses expected to be incurred (each such budget, the “Candidate Development Budget”). All internal personnel and resources of C4 under
each Candidate Development Budget will be expressed in terms of FTEs plus any direct out-of-pocket costs to be incurred (e.g., from the use of contract research
organizations) in connection with the performance of Candidate Development Activities as outlined in the applicable Candidate Development Plan and such budgeted cost will be calculated using the relevant FTE Rates. The initial Candidate Development
Plan agreed to by the Parties for each of the Initial Targets is attached hereto as Schedule 3.1.3(a) (Candidate Development Plan for [***]), Schedule 3.1.3(b) (Candidate Development Plan for [***]), and Schedule 3.1.3(c) (Candidate
Development Plan for [***]), respectively. 

  

	 	3.1.4	 Additional Candidate Development Plans and Budgets. No later than [***] after
Biogen’s delivery of an Additional Target Notice for an Additional Target, subject to Section 3.1.1(b)(iv) (Occupied Targets), the Parties will develop, through the JSC, a Candidate Development Plan for such Additional Target and an
associated Candidate Development Budget included in such Candidate Development Plan for the costs and expenses associated with the performance of the Candidate Development Activities set forth under such Candidate Development Plan, in each case, in
accordance with this Section 3.1.4 (Additional Candidate Development Plans and Budgets). The content of the Candidate Development Plan for each Additional Target will be consistent in scale and scope to that set forth in the Candidate
Development Plans for the Initial Targets, including (a) Hit Criteria, Lead Criteria, and Development Candidate for Degraders directed to such Additional Target that are substantially similar to the corresponding criteria set forth under the
Candidate Development Plans for such Initial Targets, and (b) C4 Candidate Development Activities that are consistent in scale and scope with the corresponding activities under the Candidate Development Plans for such Initial Targets and Biogen

  
 21 

	 	
Candidate Development Activities that are at least equivalent in scale and scope as the corresponding activities under the Candidate Development Plans for such Initial Targets. The Candidate
Development Budget for each Additional Target will be substantially similar to the Candidate Development Budgets for the Initial Targets. 

  

	 	3.1.5	 Updates to Candidate Development Plans. The Parties may update and amend each Candidate Development Plan
and the corresponding Candidate Development Budget included in such Candidate Development Plan from time to time through the JSC, each of which updated plan and budget the JSC will have the right to determine whether to approve, subject to
Section 4.2.4 (Decision Making Authority). 

  

	 	3.1.6	 Satisfaction of Hit Criteria. On a Collaboration Target-by-Collaboration Target basis, C4 will use diligent efforts to deliver to Biogen at least [***] directed to each Collaboration Target that meet the Hit Criteria set forth in the applicable
Candidate Development Plan in accordance with the timeframes for such delivery set forth in such Candidate Development Plan. On a Collaboration Target-by-Collaboration
Target basis, C4 will provide written notice to the JSC upon the development of each Degrader directed to each Collaboration Target that satisfies the Hit Criteria for such Collaboration Target, together with all Deliverables to be provided with
respect to Degraders that satisfy such Hit Criteria (as set forth in the applicable Candidate Development Plan) and applicable Deliverables and supporting Results. The JSC will review, discuss, and determine whether each such Degrader satisfies the
applicable Hit Criteria for the applicable Collaboration Target. Upon the JSC’s confirmation that at least [***] directed to a Collaboration Target satisfy the Hit Criteria for such Collaboration Target, Biogen will pay the Hit Fee with
respect to such Collaboration Target in accordance with Section 7.2 (Hit Fee). Biogen will only be obligated to pay the Hit Fee one time with respect to each Collaboration Target, and after Biogen pays the Hit Fee for a Collaboration Target,
without limiting C4’s obligations under this Agreement, Biogen will not be obligated to pay any additional Hit Fee for any additional Degraders directed to such Collaboration Target that satisfy the Hit Criteria. 

 

	 	3.1.7	 Satisfaction of Lead Criteria. On a Collaboration Target-by-Collaboration Target basis, C4 will use diligent efforts to deliver to Biogen at least [***] directed to each Collaboration Target that meet the Lead Criteria set forth in the applicable
Candidate Development Plan in accordance with the timeframes for such delivery set forth in such Candidate Development Plan. On a Collaboration Target-by-Collaboration
Target basis, C4 will provide written notice to the JSC upon the development of each Degrader directed to each Collaboration Target that satisfies the Lead Criteria for such Collaboration Target, together with all Deliverables to be provided with
respect to Degraders that satisfy such Lead Criteria (as set forth in the applicable Candidate Development Plan) and applicable Deliverables and supporting Results. The JSC will review, discuss, and determine whether each such Degrader satisfies the
applicable Lead Criteria for the applicable Collaboration Target. Upon the JSC’s confirmation that at least [***] directed to a Collaboration Target satisfy the Lead Criteria for such Collaboration Target, Biogen will pay the Lead Fee
with respect to such Collaboration Target in accordance with Section 7.3 (Lead Fee). Biogen will only be obligated to pay the Lead Fee one time with respect to each Collaboration Target, and after Biogen pays the Lead Fee for a Collaboration
Target, without limiting C4’s obligations under this Agreement, Biogen will not be obligated to pay any additional Lead Fee for any additional Degraders directed to such Collaboration Target that satisfy the Lead Criteria for such Collaboration
Target. 

  
 22 

	 	3.1.8	 Satisfaction of Development Candidate Criteria. 

 

	 	(a)	 Delivery of Development Candidates; Development Candidate Report. On a Collaboration Target-by-Collaboration Target basis, C4 will use diligent efforts to deliver to Biogen at least [***] directed to each Collaboration Target that meets the Development
Candidate Criteria set forth in the applicable Candidate Development Plan in accordance with the timeframes for such delivery set forth in such Candidate Development Plan. In addition, no later than [***] after completion by C4 of all C4
Candidate Development Activities set forth under the applicable Candidate Development Plan with respect to each Degrader, C4 will deliver to Biogen a report summarizing all Results for each Degrader as a result of the performance by or on behalf of
C4 of the C4 Candidate Development Activities set forth under the applicable Candidate Development Plan with respect to such Degrader (for each Degrader, a “Development Candidate Report”). On a Degrader-by-Degrader basis, following C4’s completion of the C4 Candidate Development Activities set forth under the applicable Candidate Development Plan with respect to such Degrader, Biogen will have
sole control over, will bear all costs and expenses of, and will have sole discretion and decision-making authority with respect to, the performance of further activities with respect to such Degrader and all Products that incorporate such Degrader,
in each case, during the Collaboration Term. 

  

	 	(b)	 IND-Enabling Study Commencement Fee. On a Collaboration Target-by-Collaboration Target basis, with respect to the first Degrader directed to each Collaboration Target for which Biogen commences
IND-Enabling Studies, Biogen will pay to C4 the IND-Enabling Study Commencement Fee for such Collaboration Target pursuant to Section 7.4 (IND-Enabling Study Commencement Fee). Biogen will only be obligated to pay the IND-Enabling Study Commencement Fee one time with respect to each Collaboration Target, and
after Biogen pays the IND-Enabling Study Commencement Fee for the first Degrader directed to a particular Collaboration Target, Biogen may commence IND-Enabling Studies
for any other Degrader directed to such Collaboration Target without paying any additional IND-Enabling Study Commencement Fee. For clarity, Biogen may, at its sole discretion, determine to conduct IND-Enabling Studies (or further Development or Commercialization thereafter) with respect to any Degrader, regardless of whether such Degrader meets the Hit Criteria, Development Candidate Criteria, or Lead
Criteria set forth in the applicable Candidate Development Plan. 

  

	 	3.1.9	 Reports of Candidate Development Activities. Notwithstanding anything to the contrary in this Agreement,
C4 will keep Biogen reasonably informed, through the JSC, regarding the status and progress of C4’s activities with respect to Collaboration Targets and Degraders, including the status of all C4 Candidate Development Activities. Biogen will
keep C4 reasonably informed, through the JSC, regarding the status and progress of Biogen’s activities with respect to Collaboration Targets and Degraders by providing C4 a high-level summary of the status of Biogen Candidate Development
Activities at each meeting of the JSC. During the Collaboration Term on a quarterly basis, C4 will prepare written reports for each Collaboration Target for which C4 is performing (or has performed) any C4 Candidate Development Activities to update
Biogen on the status of all such C4 Candidate Development Activities for such Collaboration Target performed by or on behalf of C4 during the applicable Calendar Quarter. Such reports must be sufficient in

  
 23 

	 	
content to allow Biogen to evaluate the progress of the C4 Candidate Development Activities against the objectives, One-Time R&D Prepayment and
timelines included therefor in the applicable Candidate Development Plan. In addition, for each Calendar Quarter, C4 shall provide to Biogen a summary report in the form attached hereto as Schedule 3.1.9 (Form of Candidate Development Financial
Report). In addition, C4 will include in such reports such other Deliverables, Results, or other information as may be required under any Candidate Development Plan or otherwise required for the performance of the Biogen Candidate Development
Activities with respect to a particular Collaboration Target (or as may be reasonably requested by Biogen). The JSC will review the quarterly update reports for each such Collaboration Target and (i) confer regarding the progress towards
developing Degraders directed to such Collaboration Target that satisfy the Hit Criteria, Lead Criteria, and Development Candidate Criteria (including determining whether or not Degraders directed to each Collaboration Target satisfy the Hit
Criteria, Lead Criteria, and Development Candidate Criteria, in each case, for such Collaboration Target), (ii) review relevant Deliverables provided and Results generated in the performance of such C4 Candidate Development Activities,
(iii) consider and advise on any technical issues that may arise, and (iv) discuss the Biogen Candidate Development Activities performed by or on behalf of Biogen with respect to such Collaboration Target during the same period;
provided that Biogen will not be obligated to discuss the Biogen Candidate Development Activities with the JSC or C4 in the event of a Change of Control of C4 involving a Third Party that is, at such time, Exploiting any Competitive Product.

  

	 	3.1.10	 Costs of Candidate Development Activities. The payments to be made pursuant to Section 7.1 (One-Time R&D Prepayments) will compensate C4 for, and are being made to C4 as a prepayment of costs and expenses to be incurred by or on behalf of C4 in connection with the performance of all C4 Candidate
Development Activities to be performed by or on behalf of C4 under each Candidate Development Plan. C4 will be responsible for all costs and expenses incurred by or on behalf of C4 in the performance of all C4 Candidate Development Activities and
any other activities undertaken by C4 with respect to each Candidate Development Program during the Collaboration Term (including any additional resources that may be required for C4 to perform the C4 Candidate Development Activities under any
Candidate Development Plan in accordance with this Agreement). Biogen will be responsible for all costs and expenses incurred by or on behalf of Biogen in the performance of all Biogen Candidate Development Activities and any other activities
undertaken by Biogen with respect to each Candidate Development Program during the Collaboration Term. 

  

 

	 	3.1.11	 Performance of C4 Candidate Development Activities. C4 will (a) provide all resources necessary for
it to perform all C4 Candidate Development Activities and (b) perform all C4 Candidate Development Activities with reasonable care and skill in accordance with all Applicable Laws and the terms of this Agreement. On a Collaboration Target-by-Collaboration Target basis, as set forth under this Agreement, C4 will use diligent efforts to complete all C4 Candidate Development Activities set forth under each
Candidate Development Plan in accordance with the performance timelines set forth in the applicable Candidate Development Plan, deliver to Biogen [***] that satisfy each of the Hit Criteria, Lead Criteria, and [***] that satisfies the
Development Candidate Criteria set forth under the applicable Candidate Development Plan in accordance with the timeframes set forth in each such Candidate Development Plan, and provide to Biogen all Deliverables and Results set forth in the
applicable Candidate Development Plan within the timeframes included therefor. During the Collaboration Term, C4 will devote the efforts of suitably qualified and trained employees and research assistants capable of carrying out the C4 Candidate
Development Activities set forth under each Candidate Development Plan to a professional workmanlike standard and will provide all necessary materials and facilities therefor. 

  
 24 

	3.2	 Sandbox Program. 

 

	 	3.2.1	 Sandbox Activities. During the Collaboration Term, the Parties will undertake a series of research and
activities to (a) better understand the C4 Degrader Platform and inform Biogen’s selection of the Additional Targets, including understanding the chemical approaches to targeted protein degradation through the modulation of the ubiquitin-
proteasome pathway for the purpose of identifying and discovering ligands and targets (other than the Initial Targets) to be added as Additional Targets hereunder, and (b) with respect to C4, prepare and deliver all Deliverables and Results
related to such activities in accordance with this Agreement, including all reports to be prepared in accordance with Section 3.2.4 (Reports of Sandbox Activities) (the “Sandbox Activities”). For clarity, no target that is an
Occupied Target shall be eligible for any Sandbox Activities. The Parties agree that the Additional Targets derived from the Sandbox Activities shall be intended to address indications in the field of neurology. 

 

	 	3.2.2	 Sandbox Plan and Sandbox Workstreams. 

 

	 	(a)	 Sandbox Plan. Each Party will perform (or have performed) the Sandbox Activities allocated to it in
accordance with a written plan that sets forth: (a) those activities to be performed in order to validate targets that may be selected as Additional Targets and to identify novel ligands, (b) a detailed timeline for the identification of
such targets and ligands and the completion by C4 of all other Sandbox Activities allocated to C4 under such plan, (c) the Deliverables and Results to be provided to Biogen by C4 with respect to the Sandbox Activities to be performed by or on
behalf of C4 under such plan (which Deliverables and Results will be sufficient for Biogen to determine whether or not it wishes to select any such target as an Additional Target), and (d) the FTEs to be dedicated by C4 in furtherance of
performing the activities and achieving the objectives set forth in the foregoing clauses (a) – (d) (the “Sandbox Plan”). Either Party may propose to perform (or have performed, subject to the terms of this Agreement) under the
Sandbox Plan specific Sandbox Activities with respect to a particular Sandbox Target (each, a “Sandbox Workstream”), each of which Sandbox Workstreams will be attached as a separate appendix to the Sandbox Plan and will set
forth in writing (i) those activities to be performed in order to validate a Sandbox Target, (ii) a detailed timeline for the performance of such validation activities and the completion by C4 of all other Sandbox Activities allocated to
C4 under such Sandbox Workstream, (iii) the Deliverables and Results to be provided to Biogen by C4 with respect to the Sandbox Activities to be performed by or on behalf of C4 under such Sandbox Workstream (which Deliverables and Results will
be sufficient for Biogen to determine whether or not it wishes to select any Sandbox Target as an Additional Target), and (iv) the FTEs to be dedicated by C4 in furtherance of performing the activities and achieving the objectives set forth in
the foregoing clauses (i) – (iii). No later than [***] after the Effective Date, the Parties will develop, through the JSC, the Sandbox Plan that sets forth the initial Sandbox Activities (including an individual Sandbox Workstream for
each Sandbox Target that will be the subject of Sandbox Activities as of the date of such initial Sandbox Plan) and the associated detailed, written budget for the costs and expenses of the Sandbox Activities allocated to C4 under the Sandbox Plan

  
 25 

	 	
(including under each such initial Sandbox Workstream), which costs will be based on the number of FTEs to be dedicated by C4 under the Sandbox Plan, charged at the FTE Rate, as well as any
direct out-of-pocket costs incurred by C4 in the course of conducting such Sandbox Activities (for each Sandbox Workstream, a “Sandbox Budget”).

  

	 	(b)	 Additional Sandbox Workstreams. Thereafter, at any point until the earlier of:
(i) the [***] anniversary of the Effective Date, or (ii) the date on which the total costs and expenses incurred by or on behalf of C4 in the performance of all Sandbox Activities under the Sandbox Plan in accordance with the
applicable Sandbox Budget equals [***], either Party may propose a Sandbox Workstream for an additional target to the JSC with respect to which Sandbox Activities are to be conducted under the Sandbox Plan and the associated proposed Sandbox
Budget for the conduct of Sandbox Activities under such Sandbox Workstream. Following the JSC’s approval of each Sandbox Workstream and associated Sandbox Budget with respect to a target, such Sandbox Workstream and Sandbox Budget will be
attached as an appendix to, incorporated into, and made part of the Sandbox Plan. 

  

	 	3.2.3	 Performance of Sandbox Activities. C4 will dedicate the number of FTEs set forth under the Sandbox Plan
(including under each Sandbox Workstream) to perform the Sandbox Activities allocated to C4 under the Sandbox Plan (or applicable Sandbox Workstream) and C4 or its authorized Third Party designees will perform such Sandbox Activities in accordance
with the Sandbox Plan (including as set forth in the applicable Sandbox Workstream) and applicable Sandbox Budget, and otherwise in accordance with this Agreement. The Parties may update and amend the Sandbox Plan or any Sandbox Workstream and
associated Sandbox Budget from time to time through the JSC, each of which updated plan and budget the JSC will have the right to determine whether to approve, subject to Section 4.2.4 (Decision Making Authority); provided that, unless
otherwise agreed to by the Parties (not the JSC) in writing, the total costs and expenses to be incurred by or on behalf of C4 under the Sandbox Budgets in the performance of all Sandbox Activities under the Sandbox Plan (including all Sandbox
Workstreams) may not exceed $[***] in the aggregate. 

  

	 	3.2.4	 Reports of Sandbox Activities. Notwithstanding anything to the contrary set forth in this Agreement,
each Party will keep the other Party reasonably informed, through the JSC, regarding the status and progress of the Sandbox Activities performed by or on behalf of such Party. During the Collaboration Term on a [***] basis, C4 will prepare
written reports to update Biogen on the status of such Sandbox Activities performed by or on behalf of C4 during the applicable [***]. Such reports must be sufficient in content to allow the receiving Party to evaluate the progress of the
Sandbox Activities being performed by or on behalf of the other Party against the objectives, Sandbox Budget and timelines included therefor in each Sandbox Plan. In addition, Biogen will prepare a high-level summary to update C4 on the status of
the Sandbox Activities performed by or on behalf of Biogen during the applicable [***]. C4 will (a) record and account the FTE efforts and direct
out-of-pocket expenses (along with reasonable documentation), in each case, incurred by or on behalf of C4 during the applicable [***] in the performance of the
Sandbox Activities by or on behalf of C4 during the applicable [***] under the Sandbox Plan, and (b) provide a reasonable estimate of the FTEs and direct
out-of-pocket expenses, in each case, to be incurred on a [***] basis by or on behalf of C4 in order to complete the Sandbox Activities as set forth under the
then-current Sandbox Plan in accordance with the applicable Sandbox Budget. In addition, each Party will provide to the other Party such other information as 

  
 26 

	 	
may be reasonably required under the Sandbox Plan or otherwise for the performance of the Sandbox Program or reasonably requested by the other Party. The JSC will review the quarterly update
reports of such Sandbox Activities and (i) confer regarding the progress towards identifying and discovering ligands and targets that Biogen may select as Additional Targets, (ii) review relevant Deliverables provided and Results generated
in the performance of such Sandbox Activities, and (iii) consider and advise on any technical issues that may arise. 

  

	 	3.2.5	 Costs of Sandbox Activities. For each applicable Calendar Quarter, Biogen will reimburse C4 for
(a) the FTE hours actually spent by C4 employees at the applicable FTE Rate in the performance of Sandbox Activities under the Sandbox Plan, and (b) the direct
out-of-pocket expenses (provided with reasonable supporting documentation) incurred by or on behalf of C4 in performing such Sandbox Activities, in each case ((a) and
(b)), in accordance with the Sandbox Plan and applicable Sandbox Budget. In each such Calendar Quarter, C4 will invoice Biogen, and Biogen will pay C4 all undisputed amounts due under this Section 3.2.5 (Costs of Sandbox Activities) within
[***] following receipt of the applicable invoice. Notwithstanding anything to the contrary set forth in this Agreement, unless otherwise agreed to in writing by the Parties (not the JSC), the total amount payable by Biogen to C4 pursuant to
this Section 3.2.5 (Costs of Sandbox Activities) or otherwise with respect to the performance of any Sandbox Activities will not exceed $[***]. In addition, Biogen will be responsible for all costs and expenses incurred by or on behalf
of Biogen in the performance of the Sandbox Activities allocated to Biogen in the applicable Sandbox Plan. 

  

	 	3.2.6	 Performance of Sandbox Activities. C4 will dedicate the number of FTEs set forth in the Sandbox Plan to
perform the Sandbox Activities allocated to C4 thereunder and such FTEs will perform such Sandbox Activities with reasonable care and skill in accordance with all Applicable Laws and the terms of this Agreement. In addition, as set forth in this
Agreement, C4 will use diligent efforts to (a) complete all Sandbox Activities allocated to C4 under the Sandbox Plan in accordance with the applicable Sandbox Budget, and (b) deliver to Biogen, through the JSC all Deliverables and Results
set forth in the Sandbox Plan within the timeframes included therefor. During the Collaboration Term, the FTEs of C4 dedicated to performing the Sandbox Activities under the Sandbox Plan will be suitably qualified and trained employees and research
assistants capable of carrying out such Sandbox Activities to a professional workmanlike standard and will provide all necessary materials and facilities therefor. 

 

	 	3.2.7	 Sandbox High Interest Targets. Within [***] following the Additional Target Selection Period,
Biogen will provide C4 with a prioritized list of up to [***] Sandbox Targets that may be potentially selected as a Replacement Target in accordance with Section 3.1.1(b)(i) (Selection of Additional Targets) or as an Extended Term Target
in accordance with Section 3.1.1(b)(ii) (Replacement Target Notice) (each such Sandbox Target, a “Sandbox High Interest Target” and such list, the “Sandbox High Interest Target List”). Biogen may add or remove
a Sandbox Target to or from the Sandbox High Interest Target List (as applicable) at any time during the Term upon written notice to C4, provided, however, that (a) at no time will the Sandbox High Interest Target List include more than
[***] Sandbox High Interest Targets and (b) if Biogen designates a Sandbox High Interest Target as a Replacement Target in accordance with Section 3.1.1(b)(i) (Selection of Additional Targets) or as an Extended Term Target in
accordance with Section 3.1.1(b)(ii) (Replacement Target Notice), then, in each case, such Sandbox High Interest Target will be automatically removed from the Sandbox High Interest Target List and such Sandbox

  
 27 

	 	
High Interest Target will no longer be deemed a Sandbox High Interest Target for the purposes of this Agreement. During the Collaboration Term, each Sandbox High Interest Target will be subject
to the restrictions set forth in Section 3.6 (Exclusivity) and C4 will, and will cause its Affiliates to, comply with such restrictions with respect thereto. 

 

	3.3	 Records. During the Collaboration Term and for [***] thereafter, C4 will maintain records of all
Collaboration Activities in sufficient detail and in good scientific manner, appropriate for scientific, patent, and regulatory purposes, which records will be complete and properly reflect all work done and results achieved in the performance of
Collaboration Activities by or on behalf of C4. In addition, C4 will calculate and maintain records of FTE effort and direct out-of-pocket expenses, in each case,
incurred by it in the same manner as used for other products developed by C4. 

  

	3.4	 Copies and Inspection of Records. [***], during normal business hours and upon reasonable notice
not less than [***], Biogen will have the right to inspect all records of C4 or its authorized Third Party designees that relate to the performance of Collaboration Activities by or on behalf of C4. Notwithstanding anything to the contrary
set forth in this Agreement, Biogen will have the right to inspect such records more than [***] if it in good faith believes performance of Collaboration Activities by or on behalf of C4 are not in compliance with the terms and conditions of
this Agreement. Biogen will have the right to arrange for its employees or independent consultants and (sub)contractors involved in the performance of activities under this Agreement to (a) visit the offices and laboratories of C4 [***]
during normal business hours and upon reasonable notice not less than [***], and (b) discuss with C4’s technical personnel and consultants the performance and progress of the Collaboration Activities and applicable Deliverables and
associated Results in detail. After preparing or receiving the report for such visit or inspection, Biogen will provide C4 with a written summary of Biogen’s findings of any deficiencies or other areas of remediation that Biogen identifies
during any such visit or inspection. C4 will use diligent efforts to remediate any such deficiencies within [***] after C4’s receipt of such report, at C4’s cost and expense. 

 

	3.5	 Collaboration Term. 

 

	 	3.5.1	 Initial Term. The Collaboration Activities will be performed by or on behalf of the Parties during the
period commencing on the Effective Date and expiring on the date that is [***] thereafter unless (a) extended by Biogen pursuant to Section 3.5.2 (Extension of Collaboration Term), or (b) earlier terminated as provided in
Article 12 (Term and Termination) (the “Initial Collaboration Term”). 

  

	 	3.5.2	 Extension of Collaboration Term. Biogen may elect to extend the Initial Collaboration Term for an
additional [***] (for a total period of [***] after the Effective Date) by delivering to C4 written notice of its desire to so extend the Initial Collaboration Term no later than the fourth anniversary of the Effective Date (the
Initial Collaboration Term, together with such additional [***] period if Biogen so delivers such notice pursuant to this Section 3.5.2 (Extension of Collaboration Term), unless this Agreement is earlier terminated as provided in Article
12 (Term and Termination), collectively, the “Collaboration Term”). Notwithstanding anything to the contrary set forth in this Agreement, each Party will use commercially reasonable efforts to complete within [***] following
the end of the Collaboration Term (whether the Initial Collaboration Term or as extended for an additional [***] period pursuant to this Section 3.5.2 (Extension of Collaboration Term)), all Candidate Development Activities assigned to
such Party under, and in accordance with, each Candidate Development Plan that are ongoing or incomplete at the end of the Collaboration Term (unless technically or scientifically infeasible, as determined by the JSC). 

  
 28 

	 	3.5.3	 Effect of Extension of Initial Collaboration Term. If Biogen elects to extend the Initial Collaboration
Term pursuant to Section 3.5.2 (Extension of Collaboration Term), then: (a) Biogen will have the right to select five more Additional Targets with respect to which the Parties will perform Candidate Development Activities in accordance
with this Agreement, which targets will be selected in accordance with Section 3.1.1(b)(i) (Selection of Additional Targets), and upon selection thereof, such Additional Targets will be Extended Term Targets for purposes of this Agreement and
(b) Biogen will pay to C4 the payment to so extend the Initial Collaboration Term in accordance with Section 7.1.2 (Extended Collaboration Term). 

  

	3.6	 Exclusivity. On a Candidate Development
Program-by-Candidate Development Program and Sandbox Program-by-Sandbox Program Basis,
other than in the performance of activities under this Agreement and subject to Section 3.7 (Exception for Acquisition of C4), C4 will not (and will not permit its Affiliates to), either alone or directly or indirectly with any Third Party,
Exploit : (a) solely with respect to C4 and its Affiliates (other than any Acquiror or any Affiliate of such Acquiror prior to the consummation of the applicable Change of Control) any protein antibody, small molecule compound, or other biological
molecule, chemical compound, or other molecule, and (b) with respect to any Acquiror (including any Affiliate of such Acquiror prior to the consummation of the applicable Change of Control), any protein degrader, in each case ((a) and (b)),
that is Directed To (i) during the Term, any Collaboration Target, (ii) during the Additional Target Selection Period, any Sandbox Target or (iii) during the Collaboration Term, any Sandbox High Interest Target (any such protein,
antibody, small molecule, compound, or other biological molecule, chemical compound, other molecule, or protein degrader, as applicable. described in the foregoing clauses (a) or (b), a “Competitive Product”). For the avoidance
of doubt, the foregoing obligations of exclusivity shall cease immediately with respect to a Candidate Development Program upon termination of this Agreement with respect to such Candidate Development Program and will cease with respect to a
Collaboration Target upon replacement of such Collaboration Target in accordance with Section 3.1.1(b)(ii) (Replacement Target Notice). 

  

	3.7	 Effect of Acquisition of C4. C4 will not be in breach of the restrictions set forth in Section 3.6
(Exclusivity) if C4 undergoes a Change of Control with a Third Party (such Third Party, an “Acquiror,” and, together with its pre-Change of Control Affiliates, the “Acquisition
Party”) that is (either directly or through any Third Party) Exploiting one or more Competitive Products prior to such Change of Control. Competitive Products being Exploited by the Acquisition Party prior to the Change of Control are
referred to herein as “Grandfathered Products.” The Acquisition Party may continue to Exploit such Grandfathered Products following the Change of Control; provided that (a) no C4 Licensed Technology or Biogen Technology is used
by or on behalf of the Acquisition Party or its Affiliates in connection with the Exploitation of such Competitive Products, and (b) C4 and the Acquisition Party institutes commercially reasonable technical and administrative safeguards to
ensure the requirements set forth in the foregoing clause (a) are met, including by creating “firewalls” between the personnel working on such Grandfathered Products and the personnel teams charged with working on any Product or
having access to data from activities performed under this Agreement or Confidential Information of the Parties. 

  
 29 

 ARTICLE 4 GOVERNANCE 

 

	4.1	 Alliance Management. 

 

	 	4.1.1	 Alliance Managers. Each Party will appoint a single individual who possesses sufficient alliance
management experience and is otherwise suitably qualified and that has the requisite decision-making authority, in each case, to act as its alliance manager under this Agreement to support the Collaboration Activities, the Sandbox Program, and the
Candidate Development Programs (the “Alliance Manager”). The initial Alliance Managers will be set forth on Schedule 4.1.1 (Contact List). Each Party may change the person designated as its Alliance Manager upon
written notice (including via email notification) to the other Party, provided that such new Alliance Manager possesses sufficient alliance management experience and otherwise meets the requirements set forth in this Section 4.1.1
(Alliance Managers). 

  

	 	4.1.2	 Roles and Responsibilities. The Alliance Managers will be responsible for (a) facilitating the flow
of information and otherwise promoting communication of the day-to-day work for the Sandbox Program and each Candidate Development Program, (b) coordinating the
Collaboration Activities, (c) providing a single point of communication for seeking consensus both internally within the respective Party’s organization and between the Parties regarding key strategy and planning issues, (d) assisting
the integration of teams across functional areas, (e) preparing and disseminating agendas and presentations for the JSC meetings, (f) conducting the meetings of the JSC, and (g) performing such other functions as requested by the JSC.

  

	4.2	 Joint Steering Committee. 

 

	 	4.2.1	 Formation. As soon as practicable, but no later than [***] after the Effective Date, the Parties
will establish a joint steering committee (the “JSC”) to oversee the Collaboration Activities. The JSC will be comprised of [***] representatives of Biogen and [***] representatives of C4, each of whom will have the
appropriate experience and expertise to perform its responsibilities on the JSC. Each Party will provide notice to the other Party of its initial representatives to the JSC. Either Party may replace its representatives with similarly qualified
individuals at any time upon prior written notice to the other Party. If agreed by the JSC on a case-by-case basis, the JSC may invite other nonmembers to participate in
the discussions and meetings of the JSC, provided that such participants will have no voting authority at the JSC and that any such non-employee participants are bound by written obligations of non-use and confidentiality no less stringent than those set forth in Article 9 (Confidentiality). The Alliance Managers will be responsible, on behalf of the JSC, for setting the agenda for meetings of the JSC with
input from the other members and for conducting the meetings of the JSC. Neither Alliance Manager will be a member of the JSC, but the Alliance Managers or suitable designees will attend all meetings of the JSC. 

 

	 	4.2.2	 Meetings. The JSC will meet in person (alternating between a site designated by each of C4 and Biogen)
or by teleconference at least [***], or with such other frequency as the Parties may agree. Specific meeting dates will be determined by agreement of the Parties. Either Party may also call a special meeting of the JSC (by videoconference or
teleconference) upon at least [***] prior written notice to the other Party if such Party reasonably believes that a significant matter must be addressed before the next regularly scheduled JSC meeting, and such Party will provide the JSC
materials reasonably adequate to enable an informed discussion by its members no later than [***] before the special 

  
 30 

	 	
meeting. Biogen will host the first meeting of the JSC at a mutually agreeable time and place no later than [***] after the Effective Date. Each Party will be responsible for its own
expenses relating to attendance at or participation in JSC meetings. The Alliance Managers will prepare and disseminate agendas and presentations no later than [***] in advance of each JSC meeting unless otherwise agreed to by the Parties in
writing. The Alliance Managers will jointly prepare and circulate minutes for each JSC meeting within [***] after each such meeting and will ensure that such minutes are reviewed and approved by their respective companies within [***]
thereafter. 

  

	 	4.2.3	 Responsibilities. The JSC will oversee and monitor the progress of the Collaboration Activities. Within
such scope the JSC will, subject to Section 4.2.4 (Decision Making Authority) and Section 4.2.5 (Limits of JSC Decision Making Authority): 

  

	 	(a)	 discuss and determine whether a Replacement Target Notice is warranted, as described in
Section 3.1.1(b)(ii) (Replacement Target Notice); 

  

	 	(b)	 prepare the Candidate Development Plan (and the Candidate Development Budget included in such Candidate
Development Plan) for each Additional Target, as described in Section 3.1.4 (Additional Candidate Development Plans and Budgets); 

  

	 	(c)	 review and amend each Candidate Development Plan and the corresponding Candidate Development Budget included in
such Candidate Development Plan, as described in Section 3.1.5 (Updates to Candidate Development Plans and Budgets); 

  

	 	(d)	 review and determine whether Degraders directed to a given Collaboration Target satisfy the Hit Criteria set
forth in the applicable Candidate Development Plan for such Collaboration Target, as described in Section 3.1.6 (Satisfaction of Hit Criteria); 

  

	 	(e)	 review and determine whether Degraders directed to a given Collaboration Target satisfy the Lead Criteria set
forth in the applicable Candidate Development Plan for such Collaboration Target, as described in Section 3.1.7 (Satisfaction of Lead Criteria); 

  

	 	(f)	 review C4’s quarterly update reports to Biogen on the status of all C4 Candidate Development Activities
and discuss the C4 Candidate Development Activities performed since the previous JSC meeting, as described in Section 3.1.9 (Reports of Candidate Development Activities); 

 

	 	(g)	 review Biogen’s quarterly high-level summary to C4 on the status of Biogen Candidate Development
Activities and discuss the Biogen Candidate Development Activities performed since the previous JRC meeting, as described in Section 3.1.9 (Reports of Candidate Development Activities); 

 

	 	(h)	 prepare the initial Sandbox Plan and initial Sandbox Workstreams and the associated Sandbox Budgets, and make
amendments thereto, in each case, as described in Section 3.2.2(a) (Sandbox Plan); 

  
 31 

	 	(i)	 review and determine whether to approve each additional Sandbox Workstream and the associated Sandbox Budget,
as described in Section 3.2.2(b) (Additional Sandbox Workstreams); 

  

	 	(j)	 review C4’s quarterly update reports to Biogen on the status of all Sandbox Activities performed by or on
behalf of C4 and discuss the Sandbox Activities performed since the previous JSC meeting, as described in Section 3.2.4 (Reports of Sandbox Activities); 

  

	 	(k)	 review Biogen’s high-level summary to C4 on the status of all Sandbox Activities performed by or on behalf
of Biogen and discuss the Sandbox Activities performed since the previous JSC meeting, as described in Section 3.2.4 (Reports of Sandbox Activities); 

  

	 	(l)	 review, discuss, and determine whether any Candidate Development Activities assigned to a Party that are
ongoing or complete at the end of the Collaboration Term are technically or scientifically infeasible to complete within [***] following the end of the Collaboration Term, as described in Section 3.5.2 (Extension of Collaboration Term);

  

	 	(m)	 consider and advise on any technical issues that arise under the Collaboration Activities;

  

	 	(n)	 discuss, plan, and coordinate the transition of Manufacturing activities and transfer of Know-How from C4 to Biogen that is necessary or useful for the Manufacture of Degraders and Products, such discussion, planning and coordination to begin, on a Candidate Development Program-by- Candidate Development Program basis, prior to the satisfaction of the Lead Criteria with respect to a Candidate Development Program; 

 

	 	(o)	 discuss and coordinate the transfer of (i) all Know-How Controlled
by C4 that is necessary or useful to enable the Manufacture of a Development Candidate and (ii) any materials (as well as any intermediates and impurities of such materials) used by C4 or its Affiliates or Subcontractors in the Manufacture of
such Development Candidate, in each case ((i) and (ii)), in accordance with the applicable technology transfer plan with respect to such Development Candidate, as described in Section 6.3 (Manufacturing Technology Transfer);

  

	 	(p)	 form such other committees as the JSC may deem appropriate, including individual committees to oversee
Collaboration Activities related to particular Collaboration Targets; 

  

	 	(q)	 attempt to resolve any disputes on an informal basis; and 

 

	 	(r)	 perform such other functions as expressly set forth in this Agreement or allocated to the JSC by the written
agreement of the Parties. 

  

	 	4.2.4	 Decision Making Authority. A quorum for a meeting of the JSC will require the presence of at least
[***] from each Party. The JSC will endeavor to reach decisions by consensus, with each Party, through its representative members of the JSC, having [***], provided that a quorum must be present for any decision to be made by
the JSC. Subject to the terms 

  
 32 

	 	
of this Agreement, including Section 4.2.5 (Limits on JSC Decision Making Authority), [***] will have final decision making authority with respect to such decision, including any
Candidate Development Plan or Candidate Development Budget or the Sandbox Plan (including any Sandbox Workstream) or any Sandbox Budget, or any update to any of the foregoing. 

 

	 	4.2.5	 Limits on JSC Decision Making Authority. Notwithstanding anything to the contrary set forth in this
Agreement, without C4’s prior written consent, no decision of the JSC or [***] (in the exercise of its final decision-making authority on any such matters as set forth in Section 4.2.4
(Decision Making Authority)), in each case, may (a) result in a material increase in the scope of activities required to be performed by C4 under this Agreement, including under any Candidate Development Plan or require C4 to dedicate FTEs in
excess of the Sandbox Budget, (b) take or decline to take any action that would be reasonably likely to result in a violation of any Applicable Law, the requirements of any Regulatory Authority, or any agreement between C4 and any Third Party
or that would be reasonably likely to result in the infringement, misappropriation, or other violation of any Intellectual Property of any Third Party, (c) impose any obligation on either Party that would be in violation of such Party’s
written standard operating procedures, written business policies, or written compliance policies or procedures, or (d) conflict with this Agreement. 

  

	4.3	 Disbandment of the JSC. The JSC will terminate upon the earlier of (a) the expiration (or earlier
termination) of the Collaboration Term or (b) the date on which Biogen has, for each Collaboration Target, commenced IND-Enabling Studies for a Development Candidate directed to such Collaboration Target.
Upon the termination of the JSC, the JSC will have a final meeting thereafter to review the results of the all Collaboration Activities and will thereafter have no further authority with respect to the activities hereunder. 

ARTICLE 5 DEVELOPMENT, REGULATORY MATTERS, AND COMMERCIALIZATION 

 

	5.1	 Technology Transfer. C4 will provide to Biogen copies of all C4 Licensed
Know-How that is necessary or useful for the performance of all Biogen Candidate Development Activities no later than [***] after the Effective Date. Thereafter, C4 will provide to Biogen copies of all
C4 Licensed Know-How that is made, conceived, discovered, or otherwise generated following such initial transfer of C4 Licensed Know-How that is (a) necessary or
useful to continue to enable Biogen to perform such Biogen Candidate Development Activities and Sandbox Activities, or (b) necessary or useful to allow Biogen to continue to Exploit any Degrader and Products that incorporate such Degrader, in
each case (a) and (b), as determined by the JSC. In addition to providing copies of the C4 Licensed Know-How in accordance with this Section 5.1 (Technology Transfer), C4 will make its personnel
reasonably available to Biogen so as to enable Biogen to practice under the C4 Licensed Technology in connection with its performance of the Biogen Candidate Development Activities and the Sandbox Activities and the Exploitation of the Degraders and
Products that include such Degraders. 

  

	5.2	 Development and Medical Affairs. On a Development Candidate-by-Development Candidate basis, following completion of the Candidate Development Activities with respect to such Development Candidate, Biogen will have sole control over, will bear all costs and
expenses of, and will have sole discretion and decision-making authority with respect to, the further Development of, and the performance of all Medical Affairs with respect to, such Development Candidate and all Products that incorporate such
Development Candidate. 

  
 33 

	5.3	 Regulatory Activities. Biogen will have sole control over the preparation and submission of all
Regulatory Submissions for all Products at its own cost and expense, including all MAAs and applications for obtaining, supporting, and maintaining Reimbursement Approvals for all Products. Biogen may file all such applications in its own name (or
in the name of its designee) and will own and control all such applications. Without limiting the generality of Section 5.6 (C4 Support), C4 will use commercially reasonable efforts to assist Biogen in its efforts to prepare and submit any
Regulatory Submissions to obtain, support, or maintain Regulatory Approvals for all Products, including by providing to Biogen, upon Biogen’s reasonable request, all data, written reports, and other documentation related to such Product
Controlled by C4 or its Affiliates (which assistance and data generation must be in accordance with Applicable Law and requirements and standards by applicable Regulatory Authorities) as well as any necessary samples and materials. C4 may invoice
Biogen for the internal costs (at the FTE Rate) and documented expenses incurred in connection with providing such assistance and cooperation, and Biogen will pay the undisputed invoiced amounts within [***] after the date of such invoice.

  

	5.4	 Commercialization. Biogen will have sole control over, will bear all costs and expenses of, and will
have sole discretion and decision-making authority with respect to, the Commercialization of all Products. 

  

	5.5	 Diligence Obligations. 

 

	 	5.5.1	 Development Diligence Obligations. If Biogen has commenced an
IND-Enabling Study for a Development Candidate directed to a Collaboration Target in the United States or one Major European Market, then Biogen, itself or through its Affiliates, Sublicensees, or
Subcontractors, will use Commercially Reasonable Efforts to Develop and seek Regulatory Approval for at least [***] directed to such Collaboration Target in the United States or [***] Major European Market. Biogen will have no other
diligence obligations under this Agreement with respect to the Development or Regulatory Approval of any Development Candidates or Products. 

  

	 	5.5.2	 Commercialization Diligence Obligations. Following receipt by or on behalf of Biogen of Regulatory
Approval for a Product in the United States or a Major European Market, Biogen will use Commercially Reasonable Efforts to Commercialize such Product in the United States or such Major European Market (as applicable). Biogen will have no other
diligence obligations under this Agreement with respect to the Commercialization of any Products. 

  

	5.6	 C4 Support. The Parties understand and agree that following completion of the Sandbox Activities and C4
Candidate Development Activities, in addition to the cooperation and assistance to be expressly provided under Section 5.1 (Technology Transfer), Section 5.3 (Regulatory Activities), and Section 6.4 (C4 Manufacturing Support), from
time to time it may be necessary for Biogen to seek assistance and cooperation from C4 in connection with the performance of the Biogen Candidate Development Activities or further Exploitation of Development Candidates and Products. C4 hereby agrees
to use commercially reasonable efforts to provide any such assistance and cooperation reasonably requested by Biogen within [***] following completion of such Sandbox Activities or C4 Candidate Development Activities (as applicable), as a
consultant. C4 may invoice Biogen for the internal costs (at the FTE Rate) and documented expenses incurred in connection with providing such assistance and cooperation, and Biogen will pay the undisputed invoiced amounts within [***] after
the date of such invoice. 

  
 34 

 ARTICLE 6 MANUFACTURING 

 

	6.1	 General Responsibilities. On a Development Candidate-by-Development Candidate basis, following successful manufacturing technology transfer as set forth in Section 6.3 (Manufacturing Technology Transfer) for each Development Candidate and all
Products that incorporate such Development Candidate, Biogen will have sole responsibility for, and sole decision-making authority with respect to, all Manufacturing activities and associated costs and expenses for the Manufacture of such
Development Candidate and all such Products. 

  

	6.2	 Observation by Biogen. Following C4’s delivery to Biogen of a Development Candidate Report for a
Degrader, C4 will provide Biogen with the opportunity, upon Biogen’s reasonable request during normal business hours, to observe the Manufacturing processes and procedures for such Degrader (e.g., review assays, batch records, and
release processes and procedures) for the purpose of enabling Biogen (or a Third Party contract manufacturer (“CMO”) designated by Biogen) to Manufacture such Degrader and Products that incorporate such Degrader pursuant to
Section 6.3 (Manufacturing Technology Transfer). If C4 utilizes a CMO for the Manufacture of any Degrader, then C4 will take all reasonable actions, including entering into a three party agreement with Biogen and such CMO, to enable Biogen to
exercise its rights under Section 6.1 (General Responsibilities) and this Section 6.2 (Observation by Biogen). 

  

	6.3	 Manufacturing Technology Transfer. In addition to the initial technology transfer set forth in
Section 5.1 (Technology Transfer), on a Development Candidate-by-Development Candidate basis, following selection of such Development Candidate by Biogen, beginning
at the time of selection of a Development Candidate and for a period of [***] thereafter, C4 will work with Biogen to transfer to Biogen (a) all Know-How Controlled by C4 that is necessary or
useful to enable the Manufacture of such Development Candidate, to the extent not previously transferred to Biogen under this Agreement, by providing copies or samples of relevant documentation, materials, and other embodiments of such Know-How, and by making available its qualified technical personnel on a reasonable basis to consult with Biogen with respect to such Know-How, and (b) any materials (as
well as any intermediates and impurities of such materials) used by C4 or its Affiliates or Subcontractors in the Manufacture of such Development Candidate, including any materials, intermediates and impurities used prior to the performance of IND-Enabling Studies for such Development Candidate. Each such Know-How transfer will be conducted pursuant to technology transfer plan developed and agreed by the Parties at
least [***] prior to the anticipated commencement of such transfer, the purpose of which plan will be to ensure the complete and timely transfer of such Know-How and materials in a manner that is
consistent with then-current internal technology transfer corporate standards (or equivalent policy) of Biogen. The JSC will coordinate and ensure that such transfer has been completed under the applicable technology transfer plan.

  

	6.4	 C4 Manufacturing Support. Without limiting the generality of Section 5.6 (C4 Support), the Parties
understand and agree following the technology transfer contemplated by Section 6.3 (Manufacturing Technology Transfer) it may be necessary for Biogen from time to time to seek assistance and cooperation from C4 in connection with the
Manufacture of Development Candidates and Products, including with respect to scale-up activities. C4 hereby agrees to use commercially reasonable efforts to provide any such assistance and cooperation
reasonably requested by Biogen within [***] following such technology transfer, as a consultant. C4 may invoice Biogen for the internal costs (at the FTE Rate) and documented expenses incurred in connection with providing such assistance and
cooperation, and Biogen will pay the undisputed invoiced amounts within[***] after the date of such invoice. 

  
 35 

 ARTICLE 7 PAYMENTS AND ROYALTIES 

 

	7.1	 One-Time R&D Prepayments. 

 

	 	7.1.1	 Initial Collaboration Term. No later than [***] after the Effective Date Biogen will pay to C4 an
upfront payment of $[***] as prepayment for the C4 Candidate Development Activities to be performed hereunder, payable by wire transfer of immediately available funds. 

 

	 	7.1.2	 Extended Collaboration Term. If Biogen elects to extend the Collaboration Term for an additional
[***] period pursuant to Section 3.5.2 (Extension of Collaboration Term), then Biogen will pay to C4 a payment of $[***], payable by wire transfer of immediately available funds. Biogen will pay such amount to C4 no later than
[***] after Biogen’s receipt of an invoice therefor, which invoice C4 may not provide to Biogen until C4’s receipt of written notice from Biogen of Biogen’s desire to so extend the Initial Collaboration Term.

  

	7.2	 Hit Fee. On a Collaboration
Target-by-Collaboration Target basis, Biogen will pay to C4 a one-time payment of $[***] upon receipt of at least
[***] Degraders directed to each Collaboration Target that satisfy the Hit Criteria for such Collaboration Target (as confirmed by the JSC pursuant to Section 4.2.3(d)) (each, a “Hit Fee”). Biogen will pay the Hit Fee to
C4 for each applicable Collaboration Target no later than [***] after Biogen’s receipt of an invoice therefor, which invoice C4 may not provide to Biogen with respect to a Collaboration Target unless and until the JSC confirms that the
applicable Degraders directed to such Collaboration Target satisfy the Hit Criteria for such Collaboration Target. 

  

	7.3	 Lead Fee. On a Collaboration
Target-by-Collaboration Target basis, Biogen will pay to C4 a one-time payment of $[***] in consideration of at least
[***] Degraders directed to each Collaboration Target that satisfy the Lead Criteria for such Collaboration Target (as confirmed by the JSC pursuant to Section 4.2.3(e)) (each, a “Lead Fee”). Biogen will pay the Lead Fee
to C4 for each applicable Collaboration Target no later than [***] after Biogen’s receipt of an invoice therefor, which invoice C4 may not provide to Biogen with respect to a Collaboration Target unless and until the JSC confirms that
the applicable Degraders directed to such Collaboration Target satisfy the Lead Criteria for such Collaboration Target. 

  

	7.4	 IND-Enabling Study Commencement Fee. On a Collaboration Target-by-Collaboration Target basis, Biogen will pay to C4 a one-time payment of $[***] in consideration of the commencement by
or on behalf of Biogen of the [***] IND-Enabling Study for a Development Candidate directed to each Collaboration Target (for each Collaboration Target, a
“IND-Enabling Study Commencement Fee”). Biogen will notify C4 in writing of the commencement (i.e., the first dosing of an animal subject) of an
IND-Enabling Study with respect to the [***] Development Candidate directed to each Collaboration Target. Thereafter, C4 will provide Biogen with an invoice for the
IND-Enabling Study Commencement Fee for the applicable Collaboration Target, and Biogen will pay to C4 such IND-Enabling Study Commencement Fee no later than
[***] after its receipt of invoice therefor. 

  
 36 

	7.5	 Milestone Payments. 

 

	 	7.5.1	 Development Milestones. On a Collaboration Target-by-Collaboration Target basis, Biogen will make one-time milestone payments (each, a “Development Milestone Payment”) to C4 upon the
first achievement by Biogen or its Affiliates or Sublicensees of each of the development milestone events (each, a “Development Milestone Event”) (a) set forth in TABLE 7.5.1(a) below for the first Product directed to each Initial
Term Target that is Covered by a Valid Claim of a C4 Licensed Patent Right (at the time of such achievement) to achieve the applicable Development Milestone Event, and (b) set forth in TABLE 7.5.1(b) below for the first Product directed to each
Extended Term Target that is Covered by a Valid Claim of a C4 Licensed Patent Right (at the time of such achievement) to achieve the applicable Development Milestone Event. For the avoidance of doubt, each Development Milestone Payment hereunder
will be payable only once per Collaboration Target upon the first achievement of the applicable Development Milestone Event by a Product directed to such Collaboration Target. No additional Development Milestone Payments will be made for any
subsequent achievement of such Development Milestone Event by any other Product directed to the same Collaboration Target. If one or more Development Milestone Events are skipped for a Product directed to a particular Collaboration Target, then such
skipped Development Milestone Events will be payable upon the first achievement by a Product that is Covered by a Valid Claim of a C4 Licensed Patent Right (at the time of such achievement) directed to the same Collaboration Target of the subsequent
Development Milestone Event, except that a Development Milestone Event in one territory will not be deemed to be skipped solely because a subsequent Development Milestone Event was achieved in a different territory (e.g., [***]).
Biogen will notify C4 in writing of the achievement of a Development Milestone Event by Biogen or its Affiliates or Sublicensees no later than [***] after Biogen becomes aware of the achievement thereof. Thereafter, C4 will provide Biogen
with an invoice for the corresponding Development Milestone Payment, and Biogen will pay to C4 such Development Milestone Payment no later than [***] after its receipt of invoice for such Development Milestone Payment. If Biogen or its
Affiliates or Sublicensees achieve all Development Milestone Events with respect to Products directed to a particular Collaboration Target (regardless of the number of times such events occur or the number of Products that trigger such event), then
(a) the maximum amount payable by Biogen with respect to a particular Initial Term Target under this Section 7.5.1 (Development Milestones) is $[***], and (b) the maximum amount payable by Biogen with respect to a particular
Extended Term Target under this Section 7.5.1 (Development Milestones) is $[***]. 

  

			
	 TABLE 7.5.1(a) – Development
Milestones
 Products Directed to Initial Term Targets

	 Development Milestone Event
	  	Development Milestone
Payment
	[***]	  	[***]
	[***]	  	[***]
	[***]	  	[***]
	[***]	  	[***]
	[***]	  	[***]

  
 37 

			
	 TABLE 7.5.1(b) – Development
Milestones
 Products Directed to Extended Term Targets

	 Development Milestone Event
	  	Development Milestone
Payment
	[***]	  	[***]
	[***]	  	[***]
	[***]	  	[***]
	[***]	  	[***]
	[***]	  	[***]

  

	 	7.5.2	 Sales Milestones. On a Collaboration
Target-by-Collaboration Target basis, Biogen will make one-time sales milestone payments (each, a “Sales Milestone
Payment” and together with the Development Milestone Payments, the “Milestone Payments”) to C4 upon the achievement by Biogen or its Affiliates or Sublicensees of each of the sales-based milestones events (each, a
“Sales Milestone Event”) (a) set forth in TABLE 7.5.2(a) below with respect to aggregate annual Net Sales of Products directed to each Initial Term Target and Covered by a Valid Claim of a C4 Licensed Patent Right (at the
time of sale in the applicable country), and (b) set forth in TABLE 7.5.2(b) below with respect to aggregate annual Net Sales of Products directed to each Extended Term Target and Covered by a Valid Claim of a C4 Licensed Patent Right (at the
time of sale in the applicable country). Each of the Sales Milestone Payments set forth below will be payable only one time, for the first Calendar Year in which the corresponding Sales Milestone Event is achieved. Biogen will notify C4 in writing
of the achievement of a Sales Milestone Event by Biogen or its Affiliates or Sublicensees no later than [***] after the end of the Calendar Year in which such Sales Milestone Payment is payable pursuant to the preceding sentence. Thereafter,
C4 will provide Biogen with an invoice for the corresponding Sales Milestone Payment, and Biogen will pay to C4 such Sales Milestone Payment no later than [***] after its receipt of invoice for such Sales Milestone Payment. If Biogen or its
Affiliates or Sublicensees achieve all Sales Milestone Events with respect to Products directed to a particular Collaboration Target (regardless of the number of times such events occur or the number of Products that trigger such event), then
(i) the maximum amount payable by Biogen with respect to a particular Initial Term Target under this Section 7.5.2 (Sales Milestones) is $[***], and (ii) the maximum amount payable by Biogen with respect to a particular
Extended Term Target under this Section 7.5.2 (Sales Milestones) is $[***]. 

  

			
	 TABLE 7.5.2(a) – Sales
Milestones
 Products Directed to Initial Term Targets

	 Sales Milestone Event
	  	Sales Milestone
Payment
	[***]	  	[***]
	[***]	  	[***]

  
 38 

			
	 TABLE 7.5.2(b) – Sales
Milestones
 Products Directed to Extended Term Targets

	 Sales Milestone Event
	  	Sales Milestone
Payment
	[***]	  	[***]
	[***]	  	[***]

  

	7.6	 Royalties. 

  

	 	7.6.1	 Royalty Payments. Subject to the provisions of Section 7.6.4 (Royalty Adjustments), on a Product-by-Product and country-by-country basis, Biogen will pay to C4 royalties in the amount
of the marginal royalty rates set forth in TABLE 7.6.1 below of the aggregate Net Sales resulting from the sale of Products in the Territory during each Calendar Year of the applicable Royalty Term for each Product in each country (each, the
“Per Product Annual Net Sales”). 

  

			
	 TABLE 7.6.1 – Marginal Royalty
Rates

	 Per Product Annual Net Sales
	  	Marginal Royalty Rate (% of Per
Product Annual Net Sales)
	[***]	  	[***]
	[***]	  	[***]

 Each marginal royalty rate set forth in TABLE 7.6.1 above will apply only to that portion of the Net Sales of
a given Product in the Territory during a given Calendar Year that falls within the indicated range. For example, [***]. 
  

	 	7.6.2	 Royalty Term. On a
Product-by-Product and country-by-country basis, Biogen’s obligation to pay
royalties will begin upon the First Commercial Sale of a Product in a country and will expire upon the expiration of the last-to-expire Valid Claim of a C4 Licensed
Patent Right, Product-Specific Patent Right, or Target-Specific Patent Right, in each case, Covering the composition of matter or method of use in the approved label of such Product in such country (the “Royalty Term”). Upon
expiration of the Royalty Term for a given Product in a given country (a) no further royalties will be payable in respect of sales of such Product in such country, and (b) the licenses granted to Biogen under Section 2.1.2 (Commercial
License) with respect to the Exploitation of such Product in such country will automatically become fully paid-up, perpetual, irrevocable, and royalty free. For clarity, only a single royalty will be payable
as a result of one or more Valid Claims Covering a Product during the Royalty Term. 

  

	 	7.6.3	 Royalty Reports; Payments. 

 

	 	(a)	 Royalty Reports. No later than [***] after the end of each Calendar Quarter during which any
royalty payments are owed, Biogen will submit to C4 a written report of Net Sales of Products sold, in the currency for which such Products were sold (and, if the currency of sale was not Dollars, also in Dollars), by or on behalf of Biogen and its
Affiliates and Sublicensees during such Calendar Quarter, and the royalty payments payable on such Net Sales in sufficient detail to permit confirmation of the accuracy of royalty payments paid hereunder. 

  
 39 

	 	(b)	 Royalty Payments. Royalties will be payable on a Calendar Quarter basis and Biogen will make any such
payments within [***] after the end of the Calendar Quarter during which the applicable Net Sales of Products occurred. 

  

	 	7.6.4	 Payment Adjustments. 

 

	 	(a)	 Generic Competition. If, in a particular country, a Third Party obtains approval for and sells a Generic
Product with respect to a particular Product, then the royalties payable by Biogen pursuant to Section 7.6 (Royalties) for such Product in such country will be reduced by [***] for the remainder of the Royalty Term for such Product in
such country. 

  

	 	(b)	 Third Party Payments. If Biogen enters into an agreement with a Third Party to obtain rights under a
Patent Right or other Intellectual Property owned or controlled by such Third Party (whether by acquisition or license) that is necessary or useful to Exploit one or more Products, then Biogen may reduce the [***] royalties due to C4 by
[***] of the amounts paid to such Third Party [***]. 

  

	 	(c)	 Maximum Payment Adjustments. In no event will the [***] royalties payable to C4 in a given
Calendar Quarter reduced by more than [***] of the aggregate amount that would otherwise be payable to C4 in respect such [***] royalties in such Calendar Quarter as a result of the reductions permitted pursuant to
Section 7.6.4(a) (Generic Competition) and Section 7.6.4(b) (Third Party Payments). Biogen may carry forward any such reductions permitted under Section 7.6.4(a) (Generic Competition) and Section 7.6.4(b) (Third Party Payments)
that are incurred or accrued in a Calendar Quarter but are not applied against [***] royalties due to C4 in such Calendar Quarter as a result of the foregoing floor and apply such amounts against [***] royalties due to C4 in any
subsequent Calendar Quarter (subject to the minimum floor set forth in this Section 7.6.4(c) (Maximum Royalty Adjustments)) until the amount of such reduction has been fully applied against [***] royalties due to C4.

  

	 	7.6.5	 Third Party Agreements. C4 will be responsible for obtaining and maintaining rights to use any and all
Third Party Intellectual Property (whether through acquisition or license) that would, absent such right, be infringed, misappropriated, or otherwise violated by the practice of the C4 Degrader Platform or the performance of C4’s obligations
under this Agreement. Upon Biogen’s written notice identifying any such Third Party Intellectual Property, or promptly upon C4 otherwise becoming aware of any such Third Party Intellectual Property (“Biogen Identified Rights”),
C4 will, subject to Section 7.6.6 (Biogen Identified Rights Dispute), use diligent efforts to promptly obtain rights to such Biogen Identified Rights. C4 will ensure that any such rights acquired under license are freely sublicenseable to
Biogen to the extent of the licenses and rights granted to Biogen under this Agreement. C4 will be solely responsible for (a) all obligations (including any royalty or other obligations that relate to the C4 Licensed Technology) under any
agreement between C4 and any Third Party that is in effect as of the Effective Date or that C4 enters into during the Term, including any agreements entered into pursuant to this Section 7.6.5 (Third Party Agreements) for Biogen Identified
Rights, and (b) all payments to inventors (other than inventors that are representatives of Biogen) of C4 Licensed Know-How, Results, Deliverables, and Sandbox
Know-How, including payments under inventorship compensation laws. 

  
 40 

	 	7.6.6	 Biogen Identified Rights Dispute. If a Party disputes whether certain Biogen Identified Rights would,
absent obtaining rights to use such Biogen Identified Rights, be infringed, misappropriated, or otherwise violated by the practice of the C4 Degrader Platform or the performance of C4’s obligations under this Agreement, then each Party may
refer the matter to the IP Counsel of Biogen and the outside intellectual property counsel of C4 or their designees (the “IP Counsels”) to determine whether such Biogen Identified Rights would, absent obtaining rights to use such
Biogen Identified Rights, be infringed, misappropriated, or otherwise violated by the practice of the C4 Degrader Platform or the performance of C4’s obligations under this Agreement. The IP Counsels will meet promptly to discuss and resolve
the matter within [***] after referral of such matter to such IP Counsels. If the IP Counsels cannot agree on a resolution to the matter within such [***] period, then either Party may refer such matter for resolution to an independent
Third Party expert agreed upon by the Parties within [***] after the IP Counsels have failed to resolve such matter. Such independent Third Party expert will be an attorney who has practiced United States patent law for at least [***]
(or who has such other similar credentials as agreed by the Parties), and unless otherwise agreed in writing by the Parties, must not be a current or former employee, contractor, agent, or consultant of either Party or its Affiliates. The Party
bringing a dispute pursuant to this Section 7.6.6 (Biogen Identified Rights Dispute) will promptly engage such expert and the Parties will share the out-of-pocket
costs incurred in connection with the engagement of such expert equally (50:50). Within [***] of the engagement of such expert by the disputing Party, such expert will deliver its written decision to the Parties (including a detailed report
as to such expert’s rationale for such decision), and such decision will be binding on the Parties. Notwithstanding anything to the contrary set forth in this Agreement, at any time during the Term (including during the pendency of any such
dispute), Biogen will have the right to obtain rights to such Biogen Identified Rights from the applicable Third Party. If such expert determines that such Biogen Identified Rights would, absent obtaining rights to use such Biogen Identified Rights,
be infringed, misappropriated, or otherwise violated by the practice of the C4 Degrader Platform or the performance of C4’s obligations under this Agreement, then C4 will reimburse Biogen for [***] of the amounts paid to such Third Party
under any agreement between Biogen and such Third Party with respect to such Biogen Identified Rights (including any upfront payments, milestone payments, royalties, and profit-sharing payments). C4 will pay the amounts set forth in any invoice for
such payments within [***] after the date of such invoice. 

  

	7.7	 Payment Method. All payments to be made between the Parties under this Agreement will be made in Dollars
and may be paid by wire transfer in immediately available funds to a bank account designated by C4; provided that in no event will Biogen be obligated to make payments under this Agreement to any Affiliate of C4 that is organized in any
jurisdiction outside of the U.S. without Biogen’s prior written consent. 

  

	7.8	 Currency Exchange. Biogen’s then-current standard exchange rate methodology will be employed for
the translation of foreign currency sales into Dollars. 

  

	7.9	 Late Payments. If a Party does not receive payment of any undisputed sum due to it on or before the due
date set forth under this Agreement, then simple interest will thereafter accrue on the sum due to such Party from the due date until the date of payment at a per-annum rate of [***] percentage point
over the then-current prime rate reported in The Wall Street Journal or the maximum rate allowable under Applicable Law, whichever is lower. 

  
 41 

	7.10	 Taxes. 

  

	 	7.10.1	 Responsibility. Except as expressly set forth in Section 7.10.2 (Withholding Taxes), C4 will pay
any and all taxes levied on account of all payments it receives under this agreement. 

  

	 	7.10.2	 Withholding Taxes. C4 will provide such information and documentation to Biogen as are reasonably
requested by Biogen to determine if any withholding taxes apply to any payments to be made by Biogen to C4 under this Agreement. Solely to the extent that Applicable Law require that taxes be withheld with respect to any such payments to be made by
Biogen to C4 under this Agreement, Biogen will: (a) deduct those taxes from the remittable payment, (b) pay the taxes to the proper taxing authority, and (c) send evidence of the obligation together with proof of tax payment to C4 on
a reasonable and timely basis following such tax payment. Each Party agrees to cooperate with the other Party in claiming refunds or exemptions from such deductions or withholdings under any relevant agreement or treaty that is in effect. The
Parties will discuss applicable mechanisms for minimizing such taxes to the extent possible in compliance with Applicable Law. C4 will pay any and all other taxes levied on account of all payments it receives under this Agreement.

  

	 	7.10.3	 Cooperation. The Parties will cooperate in accordance with Applicable Law to minimize indirect taxes
(such as value added tax, sales tax, consumption tax, and other similar taxes) in connection with payments to be made under this Agreement. 

  

	7.11	 Financial Audits. 

 

	 	7.11.1	 Record Retention; Audits. Each Party will keep (and will cause its Affiliates and Sublicensees to keep)
complete and accurate records pertaining to (a) in the case of Biogen, the sale or other disposition of Products (the “Biogen Records”) and (b) in the case of C4, all costs and expenses incurred with the performance of its
Sandbox Activities (the “C4 Records”), in each case ((a) and (b)), in reasonable detail to permit the other Party to confirm the accuracy of all payments or costs reported, for at least the preceding [***]. Upon reasonable
(but in any case no less than [***]) [***] advance notice by one Party (the “Auditing Party”) to the other Party (the “Audited Party”) and not more than once in each Calendar Year and once per audited
period (in each case, except for cause), the Audited Party and its Affiliates will permit, and will cause their Sublicensees to permit, an independent certified public accounting firm of internationally recognized standing, selected by the Auditing
Party and reasonably acceptable to the Audited Party, to have access during normal business hours to such of the records of the Audited Party and its Affiliates and, if applicable, their Sublicensees, as may be reasonably necessary to verify the
accuracy of (i) in the case of Biogen as the Audited Party, the Biogen Records and (ii) in the case of C4 as the Audited Party, the C4 Records, for any year ending not more than [***] prior to the date of such request. The
accounting firm will enter a confidentiality agreement reasonably acceptable to the Audited Party governing the use and disclosure of the Audited Party’s information disclosed to such firm, and such firm will disclose to the Auditing Party only
whether information provided by the Audited Party to the Auditing Party as described in clauses (a) and (b) above was accurate and the specific details concerning any discrepancies, which information will be Confidential Information of the
Audited Party. 

  
 42 

	 	7.11.2	 Audit Disputes. Any disputes with respect to the findings of such accounting firm may be referred by
either Party to the dispute resolution procedure set forth in Section 13.8 (Dispute Resolution). If either Party is found to have been underpaid any amounts payable to such Party hereunder or to have overpaid to the other Party any amounts
payable hereunder, then such first Party will be entitled to recover any undisputed discrepancy, plus interest as set forth in Section 7.9 (Late Payments), no later than [***] after delivery to the Parties of the final report of such
accounting firm. The fees charged by such accounting firm will be paid by the Auditing Party; provided that if the audit discloses a net underpayment of amounts owed or overreporting of expenses by the Audited Party of more than [***]
of total amounts owed or expenses reported by the Audited Party for any Calendar Year period covered by the audit, then the Audited Party will pay the reasonable fees and expenses charged by such accounting firm. The Auditing Party will treat all
financial information disclosed by its accounting firm pursuant to this Section 7.11 (Financial Audits) as Confidential Information of the Audited Party for purposes of Article 9 (Confidentiality) of this Agreement, and will cause its
accounting firm to do the same. 

 ARTICLE 8 REPRESENTATIONS, WARRANTIES, AND COVENANTS 

 

	8.1	 Mutual Representations and Warranties of the Parties. Each Party represents and warrants to the other
Party as of the Effective Date that: 

  

	 	8.1.1	 it is duly organized, validly existing and in good standing under the Applicable Law of the jurisdiction of its
incorporation and has all requisite corporate power and authority to enter into this Agreement and to perform its obligations, in each case, under this Agreement; 

 

	 	8.1.2	 the execution of this Agreement and the performance by such Party of its obligations hereunder have been duly
authorized; 

  

	 	8.1.3	 this Agreement has been duly executed and delivered on behalf of such Party, and is valid, legally binding, and
enforceable against such Party in accordance with its terms; 

  

	 	8.1.4	 the performance of this Agreement by such Party does not create a breach or default under any other agreement
to which it is a Party; 

  

	 	8.1.5	 the execution, delivery, and performance of this Agreement by such Party does not conflict with any agreement,
instrument, or understanding, oral or written, to which it is a party or by which it is bound, nor violate any Applicable Law or regulation of any Governmental Authority; and 

 

	 	8.1.6	 it has obtained all necessary government authorizations, consents, approvals, licenses, exemptions of, or
filings or registrations with Governmental Authorities, under any Applicable Law currently in effect, that are or will be necessary for the transactions contemplated by this Agreement or any other agreement or instrument executed in connection
herewith, or for the performance by it of its obligations under this Agreement. 

  
 43 

	8.2	 Additional Representations and Warranties of C4. C4 represents and warrants to Biogen as of the
Effective Date that: 

  

	 	8.2.1	 it has and will have the full right, power, and authority to grant all of the licenses and rights granted to
Biogen under this Agreement; 

  

	 	8.2.2	 (a) Schedule 1.42 (C4 Licensed Patent Rights) sets forth a complete and accurate list of all Patent Rights
existing as of the Effective Date that are owned, Controlled, or held by C4 or any of its Affiliates and necessary or useful to (i) perform the Sandbox Activities or the Candidate Development Activities, or (ii) Exploit any Degrader or
Product, (b) C4 owns or otherwise Controls all Patent Rights listed on Schedule 1.42 (C4 Licensed Patent Rights); and (c) except as otherwise noted on Schedule 1.42 (C4 Licensed Patent Rights), C4 exclusively owns all rights,
title, and interests in and to such Patent Rights; 

  

	 	8.2.3	 there is no pending litigation, or litigation that has been threatened in writing, that alleges, or any written
communication alleging, that C4’s practice of the C4 Licensed Technology or the C4 Degrader Platform prior to the Effective Date has infringed, misappropriated, or otherwise violated, or would infringe, misappropriate, or otherwise violate, any
of the Intellectual Property of any Third Party; 

  

	 	8.2.4	 there are no claims, judgments, or settlements against or pending, or amounts with respect thereto, owed by C4
or any of its Affiliates, with respect to the C4 Licensed Technology or the C4 Degrader Platform, and C4 has not received written notice threatening any such claims, judgments, or settlements; 

 

	 	8.2.5	 to C4’s Knowledge, practice by C4 or Biogen under the C4 Licensed Technology or C4 Degrader Platform or
the Exploitation by C4 or Biogen (or their respective Affiliates or Sublicensees) of any Degrader or Product, in each case, as contemplated under this Agreement, does not and will not infringe any issued patent of any Third Party or, if and when
issued, any claim within any published patent application of any Third Party; 

  

	 	8.2.6	 to C4’s Knowledge no Third Party has challenged the ownership, scope, duration, validity, enforceability,
priority, or right to use any C4 Licensed Patent Rights or the Patent Rights Covering the C4 Degrader Platform (including, by way of example, through the institution of or written threat of institution of interference, inter partes review,
reexamination, protest, opposition, nullity, or similar invalidity proceeding before the United States Patent and Trademark Office or any foreign patent authority or court); 

 

	 	8.2.7	 to C4’s Knowledge, no Third Party is infringing, misappropriating, or otherwise violating, or threatening
to infringe, misappropriate, or otherwise violate the C4 Licensed Technology or the C4 Degrader Platform; 

  

	 	8.2.8	 all fees required to be paid by C4 in any jurisdiction in order to maintain the C4 Licensed Patent Rights have
been timely paid and the C4 Licensed Patent Rights and the Patent Rights Covering the C4 Degrader Platform are valid, subsisting, and to C4’s Knowledge, enforceable; 

 

	 	8.2.9	 C4 has not previously assigned, transferred, conveyed, or granted any license or other rights under the C4
Licensed Technology that would conflict with or limit the scope of any of the rights or licenses granted to Biogen hereunder; 

  

	 	8.2.10	 C4’s rights, title, and interests to all the C4 Licensed Technology are free of any lien or security
interest; 

  
 44 

	 	8.2.11	 C4 has obtained, or caused its Affiliates, as applicable, to obtain, assignments from the inventors of all
inventorship rights to the C4 Licensed Patent Rights and the Patent Rights Covering the C4 Degrader Platform, and all such assignments are valid and enforceable; 

 

	 	8.2.12	 the inventorship of the C4 Licensed Patent Rights is properly identified on each issued patent or patent
application in the C4 Licensed Patent Rights; 

  

	 	8.2.13	 there are no Third Party agreements pursuant to which C4 Controls any of the C4 Licensed Technology or C4
Degrader Platform, and no Third Party has any rights, title, or interests in or to, or any license under, any of the C4 Licensed Technology or C4 Degrader Platform that would conflict with the rights and licenses granted to Biogen hereunder.

  

	 	8.2.14	 No written notice of default or termination has been received or given under any agreement pursuant to which C4
Controls any C4 Licensed Technology or Patent Rights Covering or Know-How related to the C4 Degrader Platform, and there is no act or omission by C4 or its Affiliates that would provide a right to terminate
any such agreement; 

  

	 	8.2.15	 C4 and its Affiliates have taken commercially reasonable measures consistent with industry practices to protect
the secrecy, confidentiality, and value of all C4 Licensed Know-How that constitutes trade secrets under Applicable Law (including requiring all employees, consultants, and independent contractors to execute
binding and enforceable agreements requiring all such employees, consultants, and independent contractors to maintain the confidentiality of such C4 Licensed Know-How) and such C4 Licensed Know-How has not been used, disclosed to, or discovered by any Third Party except pursuant to such confidentiality agreements and there has not been a breach by any party to such confidentiality agreements;

  

	 	8.2.16	 the C4 Licensed Technology has not been created pursuant to, and are not subject to, any funding agreement with
any Governmental Authority or any Third Party, and are not subject to the requirements of the Bayh-Dole Act or any similar provision of any Applicable Law; 

  

	 	8.2.17	 to C4’s Knowledge, all information disclosed to Biogen by C4 relating to the C4 Degrader Platform, the C4
Licensed Technology, and the materials and methods to be employed by C4 in the performance by or on behalf of C4 of the C4 Candidate Development Activities under the Candidate Development Plans and the Sandbox Activities under the Sandbox Plans and
otherwise under this Agreement is, at the time of disclosure, accurate in all respects; 

  

	 	8.2.18	 neither C4, nor its Affiliates, nor any of their employees, officers, Subcontractors, or consultants who have
rendered services relating to the C4 Degrader Platform: (a) has ever been Debarred or is subject to debarment or convicted of a crime for which an entity or person could be Debarred; or (b) have ever been under indictment for a crime for
which a person or entity could be so Debarred; and 

  

	 	8.2.19	 C4 has not intentionally failed to furnish Biogen with any information requested by Biogen, or intentionally
concealed from Biogen any information in its possession, including information relating to the C4 Licensed Technology or C4 Degrader Platform, in each case, that C4 reasonably believes would be material to Biogen’s decision to enter into this
Agreement and undertake the commitments and obligations set forth herein. 

  
 45 

	8.3	 Covenants of C4. C4 covenants to Biogen that: 

 

	 	8.3.1	 during the Term, C4 will not assign, transfer, convey, or grant any license or other rights to its rights,
title, and interests in or to the C4 Licensed Technology in any way that would conflict with or limit the scope of any of the rights or licenses granted to Biogen hereunder; 

 

	 	8.3.2	 C4 will not, and will cause its Affiliates not to (a) license, sell, assign, or otherwise transfer to any
Person any Product-Specific Know-How, Product-Specific Patent Rights, Target-Specific Know-How, or Target-Specific Patent Rights (or agree to do any of the foregoing),
or (b) incur or permit to exist, with respect to any Product-Specific Know-How, Product-Specific Patent Rights, Target-Specific Know-How, or Target-Specific Patent
Rights, any lien, encumbrance, charge, security interest, mortgage, liability, grant of license to Third Parties, or other restriction (including in connection with any indebtedness); 

 

	 	8.3.3	 C4 will, and will ensure that its Affiliates, Sublicensees, and Subcontractors obtain written agreements from
any and all Persons involved in or performing any Collaboration Activities by or on behalf of C4 that assign such Persons’ rights, title, and interests in and to any C4 Licensed Technology, Sandbox Technology, or Results to C4 prior to any such
person performing such activities; 

  

	 	8.3.4	 in the performance of activities under this Agreement, C4 will not employ or use any Person who to C4’s
Knowledge: (a) has ever been Debarred or is subject to debarment or convicted of a crime for which an entity or person could be Debarred; or (b) has ever been under indictment for a crime for which a person or entity could be so Debarred;
and 

  

	 	8.3.5	 during the Collaboration Term, C4 will maintain sufficient resources to perform the Collaboration Activities
for which it is responsible under this Agreement in accordance herewith. 

  

	8.4	 DISCLAIMER OF WARRANTIES. EXCEPT AS OTHERWISE EXPRESSLY SET FORTH HEREIN, NEITHER PARTY MAKES ANY
REPRESENTATION OR EXTENDS ANY WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. IN
PARTICULAR, BIOGEN DOES NOT MAKE ANY REPRESENTATION OR EXTEND ANY WARRANTY THAT THE DEVELOPMENT CANDIDATES OR PRODUCTS WILL BE SUCCESSFULLY DEVELOPED OR COMMERCIALIZED HEREUNDER. 

 

	8.5	 LIMITATION OF LIABILITY. EXCEPT FOR DAMAGES RESULTING FROM BREACHES OF SECTION 3.5 (EXCLUSIVITY),
ARTICLE 9 (CONFIDENTIALITY), OR ANY REPRESENTATIONS OR WARRANTIES CONTAINED IN SECTION 8.2.2, OR INDEMNIFIABLE CLAIMS UNDER ARTICLE 11 (INDEMNIFICATION), IN NO EVENT WILL EITHER PARTY HAVE ANY CLAIMS AGAINST OR LIABILITY TO THE OTHER PARTY WITH
RESPECT TO ANY INDIRECT, PUNITIVE, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES (INCLUDING ANY CLAIMS FOR LOST PROFITS OR REVENUES) ARISING UNDER OR IN CONNECTION WITH THIS AGREEMENT UNDER ANY THEORY OF LIABILITY, EVEN IF SUCH PARTY HAS BEEN
INFORMED OR SHOULD HAVE KNOWN OF THE POSSIBILITY OF SUCH DAMAGES. 

  
 46 

 ARTICLE 9 CONFIDENTIALITY 

 

	9.1	 Confidential Information. It is understood and agreed by the Parties that: 

 

	 	9.1.1	 The terms and conditions of this Agreement will be considered Confidential Information of both Parties and kept
confidential by each of the Parties in accordance with this Article 9 (Confidentiality). 

  

	 	9.1.2	 The C4 Licensed Technology, Biogen Technology, Sandbox Technology, all royalty reports provided to C4 pursuant
to Section 7.6.3(a) (Royalty Reports), all Development Candidate Reports, all reports provided to Biogen pursuant to Section 3.1.9 (Reports of Candidate Development Activities) and Section 3.2.4 (Reports of Sandbox Activities), the
identities of the Collaboration Targets, the Degraders, the Products, and all Deliverables and Results will each be considered the Confidential Information of Biogen, with Biogen deemed to be the disclosing Party in respect thereof (the
“Disclosing Party”) and C4 deemed to be the receiving Party (the “Receiving Party”) with respect thereto. 

  

	9.2	 Non-Disclosure and Non-Use
Obligation. Except as otherwise expressly set forth herein, the Receiving Party will, during the Term and for a period of [***] thereafter, keep the Confidential Information of the Disclosing Party confidential using at least the same
degree of care with which the Receiving Party holds its own confidential information (but in no event less than a reasonable degree of care) and will not (a) disclose such Confidential Information to any Person without the prior written
approval of the Disclosing Party, except, solely to the extent necessary to exercise its rights or perform its obligations under this Agreement, to its employees, Affiliates, Sublicensees, and Subcontractors, consultants, or agents who have a need
to know such Confidential Information, all of whom will be similarly bound by confidentiality, non-disclosure, and non-use provisions at least as restrictive or
protective of the Parties as those set forth in this Agreement and for whom the Disclosing Party will be responsible, or (b) use such Confidential Information for any purpose other than for the purposes contemplated by this Agreement. The
Receiving Party will use diligent efforts to cause the foregoing Persons to comply with the restrictions on use and disclosure set forth in this Section 9.2 (Non-Disclosure and Non-Use Obligation), and will be responsible for ensuring that such Persons maintain the Disclosing Party’s Confidential Information in accordance with this Article 9 (Confidentiality). Each Party will promptly
notify the other Party of any misuse or unauthorized disclosure of the other Party’s Confidential Information. 

  

	9.3	 Return of Confidential Information. Upon the expiration or termination of this Agreement, the Receiving
Party will return (or, as directed by the Disclosing Party, destroy) all Confidential Information of the Disclosing Party to the Disclosing Party that is in the Receiving Party’s possession or control (other than any Confidential Information
required to continue to exercise a Party’s rights that survive termination of this Agreement), provided, however, copies may be retained and stored solely for the purpose of determining its obligations under this Agreement, subject to
the non-disclosure and non-use obligation under this Article 9 (Confidentiality). In addition, the Receiving Party will not be required to return or destroy Confidential
Information contained in any computer system back-up records made in the ordinary course of business; provided that such Confidential Information may not be accessed without the Disclosing Party’s
prior written consent or as required by Applicable Law. 

  

	9.4	 Exemptions. Information of a Disclosing Party will not be Confidential Information of such Disclosing
Party to the extent that the Receiving Party can demonstrate through competent evidence that such information: (a) is already in the possession of the Receiving Party at the time of its receipt from the Disclosing Party and not through a prior
disclosure by or on behalf of the 

  
 47 

	 	
Disclosing Party, as evidenced by contemporaneous written records, (b) is generally available to the public before its receipt from the Disclosing Party, (c) became generally available
to the public or otherwise part of the public domain after its disclosure by the Disclosing Party and other than through any act or omission of the Receiving Party or any of its Affiliates or discloses in breach of this Agreement, including pursuant
to Section 9.9.3 (Publication Rights), (d) is subsequently disclosed to the Receiving Party or any of its Affiliates without obligation of confidentiality by a Third Party who may rightfully do so and is not under a conflicting obligation of
confidentiality to the Disclosing Party, or (e) is developed independently by employees, subcontractors, consultants or agents of the Receiving Party or any of its Affiliates without use of or reliance upon the Disclosing Party’s
Confidential Information, as evidenced by contemporaneous written records. No combination of features or disclosures will be deemed to fall within the foregoing exclusions merely because individual features are published or available to the general
public or in the rightful possession of the Receiving Party unless the combination itself and principle of operation are published or available to the general public or in the rightful possession of the Receiving Party. 

 

	9.5	 Permitted Disclosures. In addition to the exceptions contained in Sections 9.2 (Non-Disclosure and Non-Use Obligation) and 9.4 (Exemptions), the Receiving Party may disclose Confidential Information of the Disclosing Party to the extent (and solely to
the extent) that such disclosure is reasonably necessary in the following instances: 

  

	 	9.5.1	 (a) the prosecution and maintenance of C4 Licensed Patent Rights and Joint Patent Rights, in each case, as
contemplated by this Agreement; or (b) Regulatory Submissions and other filings with Governmental Authorities (including Regulatory Authorities), as necessary for the Exploitation of a Degrader or Product; 

 

	 	9.5.2	 disclosure of the existence and applicable terms of this Agreement and the status and results of Exploitation
of one or more Degraders or Products to actual or bona fide potential investors, acquirors, Sublicensees, lenders, and other financial or commercial partners (including in connection with any royalty factoring transaction), and their
respective attorneys, accountants, banks, investors, and advisors, solely for the purpose of evaluating or carrying out an actual or potential investment, acquisition, sublicense, debt transaction, or collaboration; provided that, in each
such case, on the condition that such Persons are bound by obligations of confidentiality, non-disclosure, and non-use provisions at least as restrictive or protective
of the Parties as those set forth in this Agreement or otherwise customary for such type and scope of disclosure any such disclosure is limited to the maximum extent practicable for the particular context in which it is being disclosed;

  

	 	9.5.3	 to comply with Applicable Law (whether generally or in pursuit of an application for listing of securities)
including the United States Securities and Exchange Commission or equivalent foreign agency or regulatory body, or otherwise required by judicial or administrative process, provided that in each such event, as promptly as reasonably
practicable and to the extent not prohibited by Applicable Law or judicial or administrative process, such Party will notify the other Party of such required disclosure and provide a draft of the disclosure to the other Party reasonably in advance
of such filing or disclosure for the other Party’s review and comment. The non-disclosing Party will provide any comments as soon as practicable, and the disclosing Party will consider in good faith any
timely comments provided by the non-disclosing Party; provided that the disclosing Party may or may not accept such comments in its sole discretion. Confidential Information that is disclosed in order
to comply with Applicable Law or by judicial or administrative process pursuant to this Section 9.5.3, in each case, will remain otherwise subject to the confidentiality and non-use provisions of this
Article 9 (Confidentiality) with respect to the 

  
 48 

	 	
Party disclosing such Confidential Information, and such Party will take all steps reasonably necessary, including seeking of confidential treatment or a protective order for a period of at least
[***] (to the extent permitted by Applicable Law or Governmental Authority), to ensure the continued confidential treatment of such Confidential Information, and each Party will be responsible for its own legal and other external costs in
connection with any such filing or disclosure pursuant to this Section 9.5.3; 

  

	 	9.5.4	 to prosecute or defend litigation so long as there is [***] prior written notice given by the Receiving
Party before filing, and to enforce Patent Rights in connection with the Receiving Party’s rights and obligations pursuant to this Agreement; and 

  

	 	9.5.5	 to allow the Receiving Party to exercise its rights and perform its obligations hereunder, provided that
such disclosure is covered by terms of confidentiality and non-use at least as restrictive as those set forth herein. 

  

	9.6	 Confidential Treatment. Notwithstanding anything to the contrary set forth in this Agreement, if a Party
is required or permitted to make a disclosure of the other Party’s Confidential Information pursuant to Section 9.5 (Permitted Circumstances), then it will, to the extent not prohibited by Applicable Law or judicial or administrative
process, except where impracticable, give reasonable advance notice to the other Party of such proposed disclosure and use reasonable efforts to secure confidential treatment of such information and will only disclose that portion of Confidential
Information that is legally required to be disclosed as advised by its legal counsel. In any event, each Party agrees to take all reasonable action to avoid disclosure of Confidential Information of the other Party hereunder. 

 

	9.7	 Use of Name and Logo. Subject to Section 9.9.2 (Announcement), neither C4 nor Biogen will use the
other Party’s or its Affiliates’ name or logo in any label, press release, or product advertising, or for any other promotional purpose, without first obtaining the other Party’s written consent. 

 

	9.8	 Residual Knowledge. Notwithstanding anything to the contrary set forth in this Agreement, Confidential
Information will not include any knowledge, technique, experience, or Know-How that is retained in the unaided memory of any authorized representative of the Receiving Party after having access to such
Confidential Information (“Residual Knowledge”). Any use made by the Receiving Party of any such Residual Knowledge is on an “as is, where is” basis, with all faults and all representations and warranties disclaimed and at
its sole risk. 

  

	9.9	 Publications. 

 

	 	9.9.1	 Coordination. C4 and Biogen will, from time to time and at the request of the other Party, discuss the
general information content relating to this Agreement that may be publicly disclosed; provided, however, that Biogen will have no obligation to consult with C4 with respect to any scientific publication or public announcement
concerning Biogen’s Exploitation of any Development Candidate or Product (except as otherwise expressly set forth in Section 9.9.3 (Publication Rights)). 

 

	 	9.9.2	 Announcements. Except as may be expressly permitted under Section 9.5 (Permitted Disclosures),
neither Party will make any public announcement regarding this Agreement without the prior written approval of the other Party. For clarity, nothing in this Agreement will prevent Biogen from making any scientific publication or public announcement
concerning Biogen’s Exploitation of any Product under this Agreement; provided that, except as permitted under Section 9.5 (Permitted Disclosures), Biogen will not disclose

  
 49 

	 	
any of C4’s Confidential Information in any such publication or announcement without obtaining C4’s prior written consent to do so. The Parties intend to release the joint press release
attached hereto as Schedule 9.9.2 (Press Release) regarding the signing of this Agreement promptly after the Effective Date. After the issuance of such press release or other public disclosure by a Party, the disclosing Party may make subsequent
public disclosures reiterating such information without having to obtain the other Party’s prior consent and approval so long as the information in such press release or other public announcement remains true, correct, and the most current
information with respect to the subject matters set forth therein. 

  

	 	9.9.3	 Publication Rights. Biogen will be the exclusive owner of any publication rights with respect to the
Results, the Degraders, and the Products, and will have the sole and exclusive right to publish on such Results, Degraders, and Products without the prior consent of C4, provided that any portion of such publication or presentation that
contains Results prepared as a result of, or in connection with the performance of (a) the C4 Candidate Development Activities under a Candidate Development Plan or (b) Sandbox Activities performed by or on behalf of C4 under the Sandbox
Plan will, in each case ((a) and (b)), be subject to the prior review of C4 and will be provided by Biogen to C4 at least [***] prior to its submission for publication or presentation. C4 will use reasonable efforts to complete such review at
least [***] prior to Biogen’s intended publication or presentation date Biogen will, as reasonably requested by C4, (i) delete from such publication any of C4’s Confidential Information, or (ii) upon a determination that
(A) such publication includes patentable material and (B) C4 has the right to file a patent application claiming such material in accordance with Section 10.4 (Patent Prosecution and Maintenance), delay the submission of such
publication or presentation for an additional period of up to [***] in order to allow C4 to pursue patent protection. 

ARTICLE 10 INTELLECTUAL PROPERTY 
  

	10.1	 Ownership. 

  

	 	10.1.1	 Inventions. Except as expressly set forth in this Agreement, (a) each Party will own all rights,
title, and interests in and to (i) any and all Know-How made solely by or on behalf of such Party or its Affiliates in connection with the performance of such Party’s activities under this Agreement
and (ii) any and all Patent Rights claiming any such Know-How described in clause (a)(i) of this Section 10.1.1 (Inventions), and (b) the Parties will jointly own any and all (i) Know-How made jointly by or behalf of the Parties or their Affiliates in connection with the performance of the Parties’ activities under this Agreement and (ii) Patent Rights claiming any such Know-How described in clause (b)(i) of this Section 10.1.1 (Inventions). Notwithstanding anything to the contrary set forth in this Agreement, as between the Parties, (A) Biogen will solely own all Biogen
Technology, including all Target-Specific Technology and Product-Specific Technology, but excluding all Joint Technology; (B) C4 will solely own all C4 Technology, including all Assigned Platform Technology, but excluding all Joint Technology,
and (C) both Parties will jointly own all Joint Technology. All determinations of inventorship under this Agreement will be made in accordance with U.S. patent law. 

 

	 	10.1.2	 Disclosure. (a) Biogen will promptly disclose to C4 all Inventions within the Assigned
Platform Know-How, (b) C4 will promptly disclose to Biogen all Inventions within the Target-Specific Know-How or Product-Specific
Know-How, and (c) each Party will promptly disclose to the other Party all Inventions within the Joint Know-How, in each

  
 50 

	 	
case ((a) through (c)), that it develops or invents, whether solely or jointly with others (in any event, prior to the filing of any patent application with respect to such Inventions), including
all invention disclosures or other similar documents submitted to such Party by its or its Affiliates’ employees, agents, or independent contractors relating thereto. Each Party will also promptly respond to reasonable requests from the other
Party for additional information relating thereto. 

  

	10.2	 Assignments. 

  

	 	10.2.1	 Assignment by Biogen. 

 

	 	(a)	 Assignment. Biogen will and hereby does assign to C4 (a) all of Biogen’s rights, title, and
interests in and to Assigned Platform Technology, and (b) a joint and undivided interest in and to (i) any Sandbox Know-How developed or invented solely by Biogen’s or its Affiliates’,
licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any Persons contractually required to assign or license such Sandbox Know-How to Biogen or any
Affiliate of Biogen, and (ii) any Sandbox Patent Rights Covering such Sandbox Know-How, and, in each case ((a) and (b)), C4 hereby accepts such assignment. 

 

	 	(b)	 Covenants in Support of Assignment. Biogen will take (and cause its Affiliates and Sublicensees, and
their respective employees, agents, and contractors to take) such further actions reasonably requested by C4 to evidence such assignment and to assist C4 in obtaining Patent Rights and other Intellectual Property protection for Inventions within the
Assigned Platform Know-How including executing further assignments, consents, releases, and other commercially reasonable documentation and providing good faith testimony by affidavit, declaration, in-person, or other proper means in support of any effort by C4 to establish, perfect, defend, or enforce its rights in any Assigned Platform Technology through prosecution of governmental filings, regulatory
proceedings, litigation, and other means, including through the filing, prosecution, maintenance, and enforcement of the Assigned Platform Technology. Biogen will obligate its Affiliates, Sublicensees, and Subcontractors to assign all Assigned
Platform Technology to Biogen (or directly to C4) so that Biogen can comply with its obligations under this Section 10.2.1 (Assignment by Biogen), and Biogen will promptly obtain such assignment. Without limitation, Biogen will cooperate with
C4 if C4 applies for U.S. or foreign patent protection for Inventions within the Assigned Platform Technology and will obtain the cooperation of the individual inventors of any such Assigned Platform Technology. If Biogen is unable to assign any
Assigned Platform Technology as set forth in Section 10.2.1(a) (Assignment), then Biogen hereby grants and agrees to grant to C4 a royalty-free, fully paid-up, worldwide, exclusive, perpetual, irrevocable
license (with the right to grant sublicenses through multiple tiers) under such Assigned Platform Technology for any and all purposes. 

  
 51 

	 	10.2.2	 Assignment by C4. 

 

	 	(a)	 Assignment. 

  

	 	(i)	 On a Degrader-by-Degrader
basis, effective upon the earlier of (A) C4’s completion of the C4 Candidate Development Activities set forth under the applicable Candidate Development Plan for the Collaboration Target that is degraded by such Degrader, or (B) the
commencement of IND-Enabling Studies for a Degrader in accordance with Section 3.1.8(b) (IND-Enabling Study Commencement Fee), in each case ((A) and (B)), but in no
event later than the expiration (or earlier termination) of the Collaboration Term in accordance with Section 3.5 (Collaboration Term), C4 will and hereby does assign to Biogen all of its rights, title, and interests in and to all
(I) Target-Specific Technology relating to (1) the Collaboration Target that is degraded by such Degrader or (2) any Target Binding Moiety that is directed to such Collaboration Target and (II) Product-Specific Technology
relating to such Degrader, and, in each case ((I) and (II)), Biogen hereby accepts such assignment. 

  

	 	(ii)	 C4 will and hereby does assign to Biogen a joint and undivided interest in and to (A) any Sandbox Know-How developed or invented solely by C4’s or its Affiliates’, licensees’, Sublicensees’, or Subcontractors’ employees, agents, or independent contractors, or any Persons contractually
required to assign or license such Sandbox Know-How to C4 or any Affiliate of C4, and (B) any Sandbox Patent Rights Covering such Sandbox Know-How, and Biogen
hereby accepts such assignment. 

  

	 	(b)	 Covenants in Support of Assignment. C4 will take (and cause its Affiliates and Sublicensees, and their
respective employees, agents, and contractors to take) such further actions reasonably requested by Biogen to evidence such assignment and to assist Biogen in obtaining Patent Rights and other Intellectual Property protection for Inventions within
the Target-Specific Know-How and Product-Specific Know-How including executing further assignments, consents, releases, and other commercially reasonable documentation
and providing good faith testimony by affidavit, declaration, in-person, or other proper means in support of any effort by Biogen to establish, perfect, defend, or enforce its rights in any Target-Specific
Technology and Product-Specific Technology through prosecution of governmental filings, regulatory proceedings, litigation, and other means, including through the filing, prosecution, maintenance, and enforcement of the Target-Specific Technology
and Product-Specific Technology. C4 will obligate its Affiliates, Sublicensees, and Subcontractors to assign all Target-Specific Technology and Product-Specific Technology to C4 (or directly to Biogen) so that C4 can comply with its obligations
under this Section 10.2.2(a) (Assignment), and C4 will promptly obtain such assignment. Without limitation, C4 will cooperate with Biogen if Biogen applies for U.S. or foreign patent protection for Inventions within the Target-Specific
Technology and Product-Specific Technology and will obtain the cooperation of the individual inventors of any such Target-Specific Technology and Product-Specific Technology. If C4 is unable to assign any Target-Specific Technology and
Product-Specific Technology, then C4 hereby grants and agrees to grant to Biogen a royalty-free, fully paid-up, worldwide, exclusive (even as to C4, subject to the terms and conditions of this Agreement,
including the licenses granted to C4 pursuant to Section 2.2 (Licenses to C4)), perpetual, irrevocable license (with the right to grant sublicenses through multiple tiers) under such Target-Specific Technology and Product-Specific Technology
for any and all purposes. 

  
 52 

	10.3	 Joint Technology. Subject to the terms and conditions set forth in this Agreement, including the
licenses granted in Section 2.1 (Licenses and Assignment to Biogen) and Section 2.2 (Licenses to C4), the Parties will jointly own all Joint Technology, and each Party is entitled to practice the Joint Technology for all purposes on a
worldwide basis and to license such Joint Technology through multiple tiers without consent of the other Party (where consent is required by Applicable Law, such consent is deemed hereby granted) and without a duty of accounting to the other Party.
Each Party will grant and hereby does grant to the other Party all further permissions, consents, and waivers with respect to, and all licenses under, the Joint Technology, throughout the world, necessary to provide the other Party with full rights
of use and Exploitation of the Joint Technology. Without limitation, each Party will cooperate with the other Party if the Parties determine to apply for U.S. or foreign patent protection for any Joint Technology and will obtain the cooperation of
the individual inventors of any such Joint Technology. 

  

	10.4	 Patent Prosecution and Maintenance. 

 

	 	10.4.1	 Right to File and Prosecute. 

 

	 	(a)	 Biogen’s Rights. Biogen will have (i) the sole right (but not the obligation) to
prepare, file, prosecute, and maintain all Biogen Patent Rights (other than Biogen Collaboration Patent Rights), and (ii) the first right (but not the obligation) to prepare, file, prosecute, and maintain all Biogen Collaboration Patent Rights
and Joint Patent Rights (the Patent Rights described in the foregoing clause (ii), the “Biogen First Right Patent Rights” and the Patent Rights described in the foregoing clauses (i) and (ii), collectively, the
“Biogen-Prosecuted Patent Rights”). Biogen will be the Prosecuting Party with respect to all Biogen-Prosecuted Patent Rights. Biogen will be responsible for and pay all future costs and expenses incurred in connection with the
preparation, filing, prosecution, and maintenance of the Biogen-Prosecuted Patent Rights and will keep C4 reasonably informed as to material developments with respect to the preparation, filing, prosecution, issuance, and maintenance of the Biogen
First Right Patent Rights, including providing to C4 notice in advance of abandoning any such Biogen First Right Patent Rights. 

  

	 	(b)	 C4’s Rights. C4 will have (i) the sole right (but not the obligation) to
prepare, file in its name, prosecute, and maintain all Collaboration Platform Patent Rights, and (ii) the first right (but not the obligation) to prepare, file, prosecute, and maintain all other C4 Licensed Patent Rights (the Patent Rights
described in the foregoing clause (ii), the “C4 First Right Patent Rights” and the Patent Rights described in clauses (i) and (ii), collectively, the “C4-Prosecuted Patent
Rights”). C4 will be the Prosecuting Party with respect to all C4-Prosecuted Patent Rights. C4 will be responsible for and pay all future costs and expenses incurred in connection with the
preparation, filing, prosecution, and maintenance of the C4-Prosecuted Patent Rights and will keep Biogen reasonably informed as to material developments with respect to the preparation, filing, prosecution,
issuance, and maintenance of the C4 First Right Patent Rights, including providing notice in advance of abandoning any such C4 First Right Patent Rights. 

  

	 	(c)	 Coordination in Prosecution. Notwithstanding Biogen’s right to prepare, file, prosecute, and maintain the
Biogen-Prosecuted Patent Rights or C4’s right to prepare, file, prosecute, and maintain the C4-Prosecuted Patent Rights, the Parties will, and will cause their Affiliates to, cooperate and implement
reasonable patent 

  
 53 

	 	
filing and prosecution strategies (including filing divisionals, continuations or otherwise) so that, to the extent reasonably feasible Product-Specific Patent Rights, Target-Specific Patent
Rights, and Collaboration Platform Patent Rights are pursued in mutually exclusive patent applications. 

  

	 	10.4.2	 Step-In Right. 

 

	 	(a)	 C4’s Rights. If, during the Term, Biogen decides that it is no longer interested in
the preparation, filing, prosecution, or maintenance of a particular Biogen First Right Patent Right, then it will promptly provide written notice to C4 of such decision. C4 may, upon written notice to Biogen, assume the preparation, filing,
prosecution, and maintenance of such Patent Right at C4’s sole cost and expense. In such event C4 will be responsible for [***] of the costs and expenses of the preparation, filing, prosecution, and maintenance of such Patent Right, and
C4 will thereafter be the “Prosecuting Party” with respect thereto for all purposes under this Agreement. 

  

	 	(b)	 Biogen’s Rights. If, during the Term, C4 decides that it is no longer interested in
the preparation, filing, prosecution, or maintenance of a particular C4 First Right Patent Right, then it will promptly provide written notice to Biogen of such decision. Biogen may, upon written notice to C4, assume the preparation, filing,
prosecution, and maintenance of such Patent Right at Biogen’s sole cost and expense. In such event Biogen will be responsible for [***] of the costs and expenses of the preparation, filing, prosecution, and maintenance of such Patent
Right and Biogen will thereafter be the “Prosecuting Party” with respect thereto for all purposes under this Agreement. 

  

	 	10.4.3	 Defense of Patent Rights. As between the Parties, the Party controlling the preparation, filing,
prosecution, and maintenance of any Patent Right under this Section 10.4 (Patent Prosecution and Maintenance) will have the right, but not the obligation, to defend against a declaratory judgment action, inter partes review,
opposition proceeding, interference, or other action challenging any such patent, other than with respect to (a) any counter-claims or defenses in any Infringement Action brought by the other Party
pursuant to Section 10.5.2 (Infringement Actions), or (b) any action by a Third Party in response to an Infringement Action brought by the other Party, which, in both cases ((a) and (b)), will be controlled by such other Party.

  

	 	10.4.4	 Cooperation and Coordination. The non-Prosecuting Party
will (a) obtain and deliver to the Prosecuting Party any necessary documents for the Prosecuting Party to exercise its rights to prepare, prosecute, defend, and maintain all Patent Rights pursuant to Section 10.4.1 (Right to File and
Prosecute) or Section 10.4.2 (Step-In Right), as applicable, (b) render all signatures that will be necessary in connection with all such patent filings, and (c) assist the Prosecuting Party in
all other reasonable ways that are necessary for the issuance of those Patent Rights for which such Prosecuting Party is responsible, as well as for the preparation, prosecution, defense, and maintenance of such Patent Rights. Additionally, prior to
the assignment of Product-Specific Technology and Target-Specific Technology to Biogen in accordance with Section 10.2.2(a) (Assignment), the Parties will consult no less than [***] per Calendar Year regarding the prosecution, defense,
and maintenance of all Patent Rights pursuant to Section 10.4.1 (Right to File and Prosecute) or Section 10.4.2 (Step-In Right), as applicable. The purpose of such consultation will be to ensure, to
the extent reasonable, that the prosecution, defense, and maintenance of the C4-Prosecuted Patent Rights does not adversely affect the prosecution, defense, and maintenance of the Biogen-Prosecuted Patent
Rights, and vice versa. 

  
 54 

	10.5	 Patent Enforcement. 

 

	 	10.5.1	 Third Party Infringement. During the Term, the Parties will promptly inform each other in writing if
either Party becomes aware of any suspected, threatened, or actual infringement by any Third Party of any Biogen Licensed Patent Rights, C4 Licensed Patent Rights, or Joint Patent Rights (an “Infringement”), including any
Infringement that arises as a result of the making, using, offering to sell, selling, or importing of a product that would be competitive with a Product in the Territory (a “Competing Infringement”). Each Party will provide any
available evidence of such Infringement with such notification. 

  

	 	10.5.2	 Infringement Actions. 

 

	 	(a)	 Infringement Actions for Competing Infringements. 

 

	 	(i)	 Biogen Rights. During the Term, Biogen will have (A) the sole right, but not the obligation, to
initiate an infringement, misappropriation, or other appropriate suit (an “Infringement Action”) against any Competing Infringement with respect to any Biogen Patent Rights, and (B) the first right, but not the obligation, to
initiate an Infringement Action against a Competing Infringement with respect to any C4 Licensed Patent Rights or Joint Patent Rights, in each case ((A) and (B)), at Biogen’s sole discretion and at Biogen’s sole cost and expense.

  

	 	(ii)	 C4 Rights. During the Term, if Biogen fails to initiate an Infringement Action against any Competing
Infringement with respect to any C4 Licensed Patent Rights, or Joint Patent Rights within [***] after written notice of such Competing Infringement is first provided by a Party under Section 10.5.1 (Third Party Infringement), then C4
will have the right to initiate and control an Infringement Action with respect to such Competing Infringement by counsel of its own choice, at its own discretion and at C4’s cost and expense and Biogen will have the right, at its own expense,
to be represented in any such action by counsel of its own choice; provided that if Biogen notifies C4 during such [***] period that it is electing in good faith not to institute any Infringement Action against such Competing
Infringement for strategic reasons, then C4 will not have the right to initiate and control any Infringement Action with respect to such Competing Infringement. 

 

	 	(b)	 Infringement Actions for Other Infringements. During the Term, (i) Biogen will have the sole right,
but not the obligation, to initiate an Infringement Action against any Infringement that is not a Competing Infringement with respect to any Biogen-Prosecuted Patent Rights, at Biogen’s sole discretion and at Biogen’s sole cost and
expense, and (ii) C4 will have the sole right, but not the obligation, to initiate an Infringement Action against any Infringement that is not a Competing Infringement with respect to any C4-Prosecuted
Patent Rights, at C4’s sole discretion and at C4’s sole cost and expense. 

  
 55 

	 	(c)	 Procedures. If the Party having the right to initiate an Infringement Action under this
Section 10.5.2 (Infringement Actions) (the “Initiating Party”) desires to initiate such Infringement Action but may not do so due to Applicable Law or regulation (even as the assignee or exclusive licensee of such infringed
Patent Right), then such Initiating Party may require that the other Party join as a named party in such action or itself initiate such Infringement Action, at the Initiating Party’s sole cost and expense. The Initiating Party will take the
lead in the control and conduct of any such Infringement Action under this Section 10.5.2 (Infringement Actions) and will keep the other Party reasonably informed of any such Infringement Action, and the other Party will reasonably assist the
Initiating Party in any such Infringement Action under this Section 10.5.2 (Infringement Actions) at the Initiating Party’s expense. In no event may the Initiating Party settle any such Infringement Action in a manner that would limit the
rights of the other Party or impose any obligation on the other Party, in each case, without the other Party’s prior written consent, which consent will not be unreasonably withheld, delayed, or conditioned. 

 

	 	(d)	 Recoveries. Any amount recovered in any Infringement Action under this Section 10.5.2 (Infringement
Actions), including any amount recovered in any settlement of such Infringement Action, will first be used to reimburse each Party’s costs and expenses with respect to such Infringement Action (which reimbursement will be on a pro rata
basis to the extent such costs and expenses exceed such recovered amount, provided that Biogen may carry forward and deduct from any future payments due to C4 under this Agreement any such costs and expenses of Biogen that are not reimbursed)
and will thereafter be for (a) with respect to any Competing Infringement, the benefit of Biogen; provided, however, that to the extent any such amount is awarded as compensation for lost profits relating to sales of Products,
then such amount will, on a Product-by-Product basis, be deemed to be Net Sales of such Product and C4 will receive royalties on such deemed Net Sales pursuant to
Section 7.6 (Royalties), and (b) with respect to any Infringement that is not a Competing Infringement, for the benefit of the Initiating Party.  

 

	10.6	 Defense of Claims. C4 will promptly inform Biogen in writing if C4 receives written, or otherwise
becomes aware, of alleged infringement, misappropriation, or other violation of a Third Party’s Intellectual Property based upon C4’s performance of its obligations or exercise of its rights hereunder. Except as otherwise set forth under
this Agreement (including under Article 11 (Indemnification)), C4 will be solely responsible for the defense of any such claim brought against it. C4 will each keep Biogen advised of all material developments in the conduct of any proceedings in
defending any claim of alleged infringement, misappropriation, or other violation related to any Degraders or Products and will reasonably cooperate with Biogen in the conduct of such defense. In no event may C4 settle any such infringement,
misappropriation, or other violation claim in a manner that would limit the rights of Biogen or impose any obligation on Biogen, in each case, without Biogen’s prior written consent, which consent will not be unreasonably withheld, delayed, or
conditioned. 

  

	10.7	 Patent Listing. Biogen will have the full and exclusive right, in its sole discretion, to determine and
control the listing of any C4 Licensed Patent Right, Joint Collaboration Patent Right, or Biogen Patent Right in the then-current edition of the United States Food and Drug Administration publication “Approved Drug Products with Therapeutic
Equivalence Evaluations” in connection with the Regulatory Approval of any Product, or in equivalent patent listings in any other country within the Territory. 

  
 56 

	10.8	 Patent Term Extensions. Biogen will have the full and exclusive right and discretion to determine and
control all filings of requests for patent term extensions, supplementary protection certificates, or equivalents thereto in any country in the Territory, in each case where applicable to a Product (hereinafter “Patent Term
Extensions”), including for any C4 Licensed Patent Right, Joint Collaboration Patent Right, or Biogen Patent Right. All costs and expenses relating to the Patent Term Extensions will be born solely by Biogen. Upon request of Biogen and at
Biogen’s cost and expense, C4 will provide support, assistance, and all necessary documents, in full executed form if needed, to Biogen for the purpose of supporting, filing, obtaining, and maintaining Patent Term Extensions.

  

	10.9	 Summary of Activities. Upon the request of either Party, the Prosecuting Party will provide to the other
Party, no more frequently than on an annual basis, a written report summarizing all material activities undertaken by such Prosecuting Party in the preceding Calendar Year with respect to the preparation, filing, prosecution, maintenance,
enforcement, and defense of the Biogen-Prosecuted Patent Rights or C4-Prosecuted Patent Rights (as applicable) in the exercise of the rights granted to such Prosecuting Party under this Article 10
(Intellectual Property). Such report will be considered the Confidential Information of the Prosecuting Party. 

ARTICLE 11 INDEMNIFICATION 
  

	11.1	 Indemnification by C4. C4 will indemnify, defend, and hold harmless Biogen, its Affiliates,
Sublicensees, distributors and each of its and their respective employees, officers, directors, and agents (each, a “Biogen Indemnified Party”) from and against any and all liabilities, losses, damages, expenses (including
reasonable attorneys’ fees and expenses), and costs (collectively, a “Liability”) that the Biogen Indemnified Party may be required to pay to one or more Third Parties resulting from or arising out of: 

[***] 
  

	11.2	 Indemnification by Biogen. Biogen will indemnify, defend, and hold harmless C4, each of its Affiliates,
and each of its and its Affiliates’ employees, officers, directors, and agents (each, a “C4 Indemnified Party”) from and against any and all Liabilities that the C4 Indemnified Party may be required to pay to one or more Third
Parties resulting from or arising out of: 

 [***] 

 

	11.3	 Procedure. Each Party will notify the other Party in writing in the event it becomes aware of a claim
for which indemnification may be sought hereunder. In case any proceeding (including any governmental investigation) will be instituted involving any Party in respect of which indemnity may be sought pursuant to this Article 11 (Indemnification),
such Party (the “Indemnified Party”) will promptly notify the other Party (the “Indemnifying Party”) in writing and the Indemnifying Party and Indemnified Party will meet to discuss how to respond to any claims that
are the subject matter of such proceeding. The Indemnified Party will cooperate fully with the Indemnifying Party in defense of such matter. In any such proceeding, the Indemnified Party will have the right to retain its own counsel, but the fees
and expenses of such counsel will be at the expense of the Indemnified Party unless (a) the Indemnifying Party and the Indemnified Party will have agreed to the retention of such counsel or (b) the named parties to any such proceeding
(including any impleaded parties) include both the Indemnifying Party and the Indemnified Party and representation of both Parties by the same counsel would be inappropriate due to actual or potential differing interests between them. All such fees
and expenses will be reimbursed as they are incurred. The Indemnifying Party will not be liable for any settlement of any proceeding effected 

  
 57 

	 	
without its written consent, but, if settled with such consent or if there is a final judgment for the plaintiff, then the Indemnifying Party agrees to indemnify the Indemnified Party from and
against any Liability by reason of such settlement or judgment. The Indemnifying Party will not, without the written consent of the Indemnified Party, effect any settlement of any pending or threatened proceeding in respect of which the Indemnified
Party is, or could have been, a party and indemnity could have been sought hereunder by the Indemnified Party, unless such settlement includes an unconditional release of the Indemnified Party from all liability on claims that are the subject matter
of such proceeding. 

 ARTICLE 12 TERM AND TERMINATION 

 

	12.1	 Term. This Agreement will commence upon the Effective Date and, if not otherwise terminated earlier
pursuant to this Article 12 (Term and Termination), will continue, on a Product-by-Product and
country-by-country basis, in full force and effect until the expiration of the Royalty Term applicable to such Product and such country (the “Term”).

  

	12.2	 Termination for Cause. 

 

	 	12.2.1	 By Biogen. In the event of a material breach of this Agreement by C4, which material breach
remains uncured for [***] measured from the date of written notice of such material breach by Biogen that identifies the material breach and the actions or conduct that Biogen considers would be an acceptable cure of such material breach,
Biogen may terminate this Agreement in whole or with respect to one or more Development Candidates, Products, or Collaboration Targets at any time during the Term of this Agreement by written notice of termination to C4. 

 

	 	12.2.2	 By C4. In the event of a material breach of this Agreement by Biogen, which material breach
remains uncured for [***] measured from the date written of written notice of such material breach by C4 that identifies the material breach and the actions or conduct that it considers would be an acceptable cure of such material breach, C4
may terminate this Agreement solely with respect to those Development Candidates, Products, or Collaboration Targets to which such material breach relates at any time during the Term of this Agreement by written notice of termination to Biogen.

  

	 	12.2.3	 Disputes Regarding Material Breach. In case the Party alleged by the other Party to have committed a
material breach under Section 12.2.1 (By Biogen) or Section 12.2.2 (By C4) (the “Defaulting Party”) disputes occurrence of such material breach (the “Non-Defaulting
Party”), then the issue of whether the Non-Defaulting Party may properly terminate this Agreement on expiration of the applicable cure period will be resolved in accordance with Section 13.8
(Dispute Resolution). If as a result of such dispute resolution process, it is determined that the Defaulting Party committed a material breach of this Agreement and the Defaulting Party does not cure such material breach within [***] after
the date of such determination, (the “Additional Cure Period”), then such termination will be effective as of the expiration of the Additional Cure Period. If the Parties dispute whether such material breach was so cured, then such
dispute will also be determined in accordance with Section 13.8 (Dispute Resolution). This Agreement will remain in full force and effect during the pendency of any such dispute resolution proceeding and the cure periods set forth in
Section 12.2.1 (By Biogen) or Section 12.2.2 (By C4), as applicable, and any Additional Cure Period, in each case, will be tolled during any such dispute resolution proceeding, such proceeding will not suspend any obligations of either
Party hereunder, and each Party will use reasonable efforts to mitigate any damage. If as 

  
 58 

	 	
a result of such dispute resolution proceeding it is determined that the Defaulting Party did not commit such material breach (or such material breach was cured in accordance with this
Section 12.2 (Termination for Cause)), then no termination will be effective, and this Agreement will continue in full force and effect. 

  

	12.3	 Termination for Insolvency. To the extent permitted by Applicable Law, either Party may terminate this
Agreement upon the filing or institution of bankruptcy, reorganization, liquidation, or receivership proceedings, upon the appointment of a receiver or trustee over all or substantially all property, or upon an assignment of a substantial portion of
the assets for the benefit of creditors by the other Party; provided, however, that in the case of any involuntary bankruptcy proceeding such right to terminate will only become effective if the Party consents to the involuntary
bankruptcy or such proceeding is not dismissed within [***] after the filing thereof. In the event of any termination pursuant to this Section 12.3 (Termination for Insolvency): 

 

	 	12.3.1	 All rights and licenses now or hereafter granted by C4 to Biogen under or pursuant to this Agreement are, for
all purposes of Section 365(n) of the U.S. Bankruptcy Code, licenses of rights to “intellectual property” as defined in the U.S. Bankruptcy Code. Upon the filing or institution of bankruptcy, reorganization, liquidation, or
receivership proceedings, upon the appointment of a receiver or trustee over all or substantially all property, or upon an assignment of a substantial portion of the assets for the benefit of creditors by C4, C4 agrees that Biogen, as licensee of
such rights under this Agreement, will retain and may fully exercise all of its rights and elections under the U.S. Bankruptcy Code. C4 will, during the Term, create and maintain current copies or, if not amenable to copying, detailed descriptions
or other appropriate embodiments, to the extent feasible, of all intellectual property rights licensed under this Agreement. Each Party acknowledges and agrees that “embodiments” of intellectual property rights within the meaning of
Section 365(n) include laboratory notebooks, cell lines, product samples, and inventory, research studies and data, all Regulatory Approvals (and all applications for Regulatory Approval) and rights of reference therein, the C4 Licensed
Technology, Results, and all information related to the C4 Licensed Technology. If (A) a case under the U.S. Bankruptcy Code is commenced by or against C4, (B) this Agreement is rejected as provided in the U.S. Bankruptcy Code, and
(C) Biogen elects to retain its rights hereunder as provided in Section 365(n) of the U.S. Bankruptcy Code, C4 (in any capacity, including
debtor-in-possession) and its successors and assigns (including a trustee) will: 

 

	 	(a)	 provide Biogen with all such intellectual property rights (including all embodiments thereof) held by C4 and
such successors and assigns, or otherwise available to them, immediately upon Biogen’s written request. Whenever C4 or any of its successors or assigns provides to Biogen any of the intellectual property rights licensed hereunder (or any
embodiment thereof) pursuant to this Section 12.3.1(a) (Termination for Insolvency), Biogen will have the right to perform C4’s obligations hereunder with respect to such intellectual property rights, but neither such provision nor such
performance by Biogen will release C4 from liability resulting from rejection of the license or the failure to perform such obligations; and 

  

	 	(b)	 not interfere with Biogen’s rights under this Agreement, or any agreement supplemental hereto, to such
intellectual property rights (including such embodiments), including any right to obtain such intellectual property rights (or such embodiments) from another entity, to the extent provided in Section 365(n) of the U.S. Bankruptcy Code.

  
 59 

	 	12.3.2	 All rights, powers, and remedies of Biogen provided in this Section 12.3 (Termination for Insolvency) are
in addition to and not in substitution for any other rights, powers, and remedies now or hereafter existing at law or in equity (including the U.S. Bankruptcy Code) in the event of the commencement of a case under the U.S. Bankruptcy Code with
respect to C4. The Parties intend the following rights to extend to the maximum extent permitted by Applicable Law, and to be enforceable under U.S. Bankruptcy Code Section 365(n): 

 

	 	(a)	 the right of access to any intellectual property rights (and all embodiments thereof) of C4, or any Third Party
with whom C4 contracts to perform any obligation of C4 under this Agreement, and, in the case of any such Third Party, that is necessary for the Exploitation of Degraders or Products; and 

 

	 	(b)	 the right to contract directly with any Third Party to complete the contracted work. 

 

	12.4	 Termination for Convenience. Biogen will be entitled to terminate this Agreement, in whole or with
respect to one or more Development Candidates, Products, or Collaboration Targets, at its sole discretion at any time upon [***] prior written notice to C4 thereof. 

 

	12.5	 Effects of Termination. 

 

	 	12.5.1	 Generally. Upon termination of the Agreement in whole or with respect to one or more Development
Candidates, Products, or Collaboration Targets: 

  

	 	(a)	 The Receiving Party will promptly return to the other Party or destroy all Confidential Information of the
Disclosing Party that is solely related to any terminated Development Candidate, Product, or Collaboration Target in accordance with Section 9.3 (Return of Confidential Information); and 

 

	 	(b)	 Except as expressly set forth in this Agreement, all licenses granted by a Party to the other Party under this
Agreement with respect to any terminated Development Candidate, Product, or Collaboration Target will immediately terminate. 

  

	 	12.5.2	 Knowledge Transfer. Upon termination of the Agreement in its entirety or with respect to one or more
Development Candidates, Products, or Collaboration Targets by Biogen (a) pursuant to Section 12.2.1 (By Biogen) in the event of an uncured material breach by C4 or (b) Section 12.3 (Termination for Insolvency) in the event of
C4’s insolvency, in each case ((a) and (b)), to the extent not provided by the effective date of termination of this Agreement pursuant to Section 5.1 (Technology Transfer) or Section 6.3 (Manufacturing Technology Transfer): C4 will
promptly transfer to Biogen, on a Product-by-Product basis, all Results, Deliverables, and Sandbox Technology, the costs of which transfer will be borne by C4.

  

	 	12.5.3	 C4 Right of Reversion. Upon termination of the Agreement by C4 pursuant to Section 12.2.2
(By C4) or Section 12.4 (Termination for Convenience), in whole or with respect to one or more Development Candidates, Products, or Collaboration Targets: Biogen will assign to C4 Biogen’s rights, title, and interests in and to any
Product-Specific Patent Rights that (a) were assigned to Biogen pursuant to Section 10.2.2(a) (Assignment) and (b) Cover such terminated Development Candidates, Products, or Collaboration Targets. 

  
 60 

	12.6	 Alternative Remedy in Lieu of Termination. If, during the Collaboration Term, Biogen has the right to
terminate this Agreement pursuant to [***], then in addition to any other remedies available to Biogen at law or in equity, in lieu of terminating this Agreement Biogen may, in its sole discretion, exercise an alternative remedy as follows:

 [***] 
 For the avoidance
of doubt, except as set forth in this Section 12.6 (Alternate Remedy in Lieu of Termination), if Biogen exercises the alternative remedy set forth above in this Section 12.6 (Alternate Remedy in Lieu of Termination), then all rights and
obligations of both Parties under this Agreement will continue unaffected, unless and until this Agreement is subsequently terminated by either Party pursuant to this Article 12 (Term and Termination). 

 

	12.7	 Rights Accruing Prior to Expiration or Termination. Expiration or termination of this Agreement will not
relieve the Parties of any obligation accruing prior to such expiration or termination. Any expiration or termination of this Agreement will be without prejudice to the rights of either Party against the other accrued or accruing under this
Agreement prior to expiration or termination, including any payment obligation that accrued prior to the effective date of such expiration or termination. 

  

	12.8	 Survival. The following provisions, as well as any other provisions which by their nature are intended
to survive termination or expiration, will survive termination or expiration of this Agreement: Article 1 (Definitions), Section 2.1.3 (C4 Collaboration Technology License), Section 3.3 (Records), Section 7.11 (Financial Audits),
Section 8.4 (Disclaimer of Warranties), Section 8.5 (Limitation of Liability), Article 9 (Confidentiality), Section 10.1.1 (Inventions), Section 10.3 (Joint Technology), Section 10.4 (Patent Prosecution and Maintenance),
Section 

  

	12.9	 (Patent Enforcement), Section 10.6 (Defense of Claims), Section 10.7 (Patent Listing),
Section 10.8 (Patent Term Extensions), Article 11 (Indemnification), Section 12.1 (solely in the case of expiration), Section 12.5 (Effects of Termination), this Section 12.8 (Survival), and Article 13 (Miscellaneous).

 ARTICLE 13 MISCELLANEOUS 
  

	13.1	 Assignment. Neither this Agreement nor any interest hereunder will be assignable by C4 without the prior
written consent of Biogen, except as follows: (a) C4 may, subject to the terms of this Agreement, assign its rights and obligations under this Agreement in whole to its
successor-in- interest in connection with the sale of all or substantially all of its assets to which this Agreement relates, whether in a merger, acquisition, or
similar transaction or series of related transactions, provided that such sale is not primarily for the benefit of its creditors, and (b) C4 may assign its rights and obligations under this Agreement to any of its Affiliates,
provided that C4 will remain liable for all of its rights and obligations under this Agreement. Biogen may freely assign this Agreement or any interest hereunder, in whole or in part. C4 will promptly notify Biogen of any assignment or
transfer under the provisions of this Section 13.1 (Assignment). This Agreement will be binding upon the successors and permitted assigns of the Parties and the name of a Party appearing herein will be deemed to include the names of such
Party’s successors and permitted assigns to the extent necessary to carry out the intent of this Agreement. Any assignment not in accordance with this Section 13.1 (Assignment) will be null, void, and of no legal effect.

  
 61 

	13.2	 Entire Agreement; Amendments. This Agreement sets forth the entire agreement between the Parties and
supersedes all previous and contemporaneous negotiations, representations, or agreements, written or oral, regarding the subject matter hereof. Any other express or implied agreements and understandings, negotiations, writings and commitments,
either oral or written, with respect to the Candidate Development Programs and the licenses granted hereunder are superseded by the terms of this Agreement, including the Confidentiality Agreement, which Confidentiality Agreement is hereby
terminated effective as of the Effective Date. This Agreement may be amended only by an instrument in writing duly executed on behalf of the Parties. In case of inconsistencies between this Agreement and any Schedule hereof, the terms of this
Agreement will prevail unless agreed to explicitly that the Schedule should prevail. 

  

	13.3	 Force Majeure. Neither Party will be liable or deemed in default for failure to perform any duty or
obligation that such Party may have under this Agreement where such failure has been occasioned by any act of God, fires, earthquakes, strikes and labor disputes, acts of war, terrorism, civil unrest, or intervention of any Governmental Authority,
and occurring without its fault or negligence; provided that the Party affected will promptly notify the other of the force majeure condition and will exert all reasonable efforts to eliminate, cure, or overcome any such causes and to resume
performance of its obligations as soon as possible. 

  

	13.4	 Waiver. The failure of either Party to require performance by the other Party of any of that other
Party’s obligations under this Agreement will in no manner affect the right of such Party to enforce the same at a later time. No waiver by any Party of any condition, or of the breach of any provision, term, representation or warranty
contained in this Agreement will be deemed to be or construed as a further or continuing waiver of any such condition or breach, or of any other condition or of the breach of any other provision, term, representation, or warranty hereof. The
remedies provided in this Agreement are not exclusive and the Party suffering from a breach or default of this Agreement may pursue all other remedies, both legal and equitable, alternatively, or cumulatively. 

 

	13.5	 Severability. If any provision or portion thereof in this Agreement is for any reason held to be
invalid, illegal, or unenforceable, then the same will not affect any other portion of this Agreement and its validity, as it is the intent of the Parties that this Agreement will be construed in such fashion as to maintain its existence, validity,
and enforceability to the greatest extent possible. In any such event, this Agreement will be construed as if such provision or portion thereof had never been contained in this Agreement, and there will be deemed substituted therefore such provision
as will most nearly carry out the intent of the Parties as expressed in this Agreement to the fullest extent permitted by Applicable Law unless doing so would have the effect of materially altering the right and obligations of the Parties in which
event this Agreement may be terminated by mutual written agreement of the Parties. 

  

	13.6	 Notices. All notices that are required or permitted hereunder will be in writing and sufficient if
delivered by internationally-recognized overnight courier or sent by registered or certified mail, postage prepaid, return receipt requested, and in each case, addressed as follows (with a courtesy copy sent by email, which will not constitute
notice): 

 If to C4: 

C4 Therapeutics, Inc. 
 490
Arsenal Street 
 Watertown, MA 02474 

U.S.A. 
 Attention: Chief
Executive Officer 
 E-mail: aphillips@c4therapeutics.com 

  
 62 

 With a copy to: 

Goodwin Procter LLP 
 100 Northern
Avenue 
 Boston, MA 02210 

Attention: Lawrence S. Wittenberg 

E-mail: lwittenberg@goodwinprocter.com 

If to Biogen: 
 Biogen MA Inc.

 225 Binney Street 

Cambridge, MA 02142 
 Attention:
Chief Legal Officer 
 E-mail: legaldepartment@biogen.com 

With a copy to: 
 Ropes &
Gray LLP 
 Prudential Tower 

800 Boylston Street 
 Boston, MA
02199-3600 
 Attention: Mark W. Bellomy, Esq. 

Email: mark.bellomy@ropesgray.com 

or to such other address as the Party to whom notice is to be given may have furnished to the other Party in writing in accordance herewith.
Any such notice will be deemed to have been given: (a) on the Business Day after dispatch if sent by internationally-recognized overnight courier; or (b) on the fifth Business Day after dispatch if sent by registered or certified mail,
postage prepaid, return receipt requested. 
  

	13.7	 Governing Law. This Agreement, and all claims arising under or in connection therewith, will be governed
by and interpreted in accordance with the substantive laws of the State of New York, without regard to conflict of law principles thereof. 

  

	13.8	 Dispute Resolution. Any dispute arising out of or in connection with this Agreement (except for disputes
arising at the JSC, which will be resolved pursuant to Section 4.2.4 (Decision Making Authority)) will be settled, if possible, through good faith negotiations between the Parties. If the Parties are unable to settle such dispute within
[***] after first considering such dispute, then such dispute will be referred to the Chief Executive Officer of C4 and the Executive Vice President, Research & Development of Biogen (the “Executive Officers”). The
Executive Officers of both Parties will meet to attempt to resolve such dispute. Such resolution, if any, of a referred issue will be final and binding on the Parties. All negotiations pursuant to this Section 13.8 (Dispute Resolution) are
confidential and will be treated as compromise and settlement negotiations for purposes of applicable rules of evidence. If the Executive Officers cannot resolve such dispute within [***] after either Party requests such a meeting in writing,
then either Party will have the right to pursue any and all remedies available at law or equity, consistent with Section 13.9 (Jurisdiction; Venue). 

  

	13.9	 Jurisdiction; Venue. Each Party irrevocably submits to the exclusive jurisdiction of (a) the
Supreme Court of the State of New York, New York County, and (b) the United States District Court for the Southern District of New York, for the purposes of any suit, action, or other proceeding arising out of this Agreement or out of any
transaction contemplated hereby. Each Party 

  
 63 

	 	
agrees to commence any such action, suit, or proceeding either in the United States District Court for the Southern District of New York or if such suit, action, or other proceeding may not be
brought in such court for jurisdictional reasons, in the Supreme Court of the State of New York, New York County. Each Party irrevocably and unconditionally waives any objection to the laying of venue of any action, suit, or proceeding arising out
of this Agreement or the transactions contemplated hereby in (i) the Supreme Court of the State of New York, New York County or (ii) the United States District Court for the Southern District of New York, and hereby and thereby further
irrevocably and unconditionally waives and agrees not to plead or claim in any such court that any such action, suit, or proceeding brought in any such court has been brought in an inconvenient forum. Each Party irrevocable consents to service of
process in the manner provided under Section 13.6 (Notices) or by first class certified mail, return receipt requested, postage prepaid. THE PARTIES EXPRESSLY, IRREVOCABLY, AND UNCONDITIONALLY WAIVE AND FOREGO ANY RIGHT TO TRIAL BY JURY.

  

	13.10	 Relationship of the Parties. Nothing in this Agreement is intended or will be deemed to constitute a
partnership, agency, employer-employee or joint venture relationship between the Parties. No Party will incur any debts or make any commitments for the other. There are no express or implied third party beneficiaries hereunder (except for Biogen
Indemnified Parties and C4 Indemnified Parties for purposes of Sections 11.1 (Indemnification by C4) or 11.2 (Indemnification by Biogen), as applicable). 

  

	13.11	 Performance by Affiliates. Each Party recognizes that the other Party may perform some or all of its
obligations under this Agreement through Affiliates to the extent permitted under this Agreement; provided, however, that such other Party will remain responsible for the performance by its Affiliates as if such obligations were
performed by such other Party. 

  

	13.12	 Interpretation. Except where the context expressly requires otherwise, (a) the use of any gender
herein will be deemed to encompass references to either or both genders, and the use of the singular will be deemed to include the plural (and vice versa), (b) the words “include”, “includes” and “including” will
be deemed to be followed by the phrase “without limitation,” (c) the word “will” will be construed to have the same meaning and effect as the word “shall,” (d) any definition of or reference to any agreement,
instrument or other document herein will be construed as referring to such agreement, instrument or other document as from time to time amended, supplemented or otherwise modified (subject to any restrictions on such amendments, supplements or
modifications set forth herein), (e) any reference herein to any person or entity will be construed to include the person’s or entity’s successors and assigns, (f) the words “herein,” “hereof,” and
“hereunder”, and words of similar import, will be construed to refer to this Agreement in its entirety and not to any particular provision hereof, (g) all references herein to Sections or Schedules will be construed to refer to
Sections or Schedules of this Agreement, and references to this Agreement include all Schedules hereto, (h) the word “notice” means notice in writing (whether or not specifically stated) and will include notices, consents, approvals
and other written communications contemplated under this Agreement, (i) provisions that require that a Party, the Parties or any committee hereunder “agree,” “consent,” or “approve” or the like will require that
such agreement, consent or approval be specific and in writing, whether by written agreement, letter, approved minutes or otherwise (but excluding e-mail and instant messaging), (j) references to any specific
law, rule or regulation, or article, section or other division thereof, will be deemed to include the then-current amendments thereto or any replacement or successor law, rule or regulation thereof, (k) the term “or” will be
interpreted in the inclusive sense commonly associated with the term “and/or,” and (l) references to any Sections include Sections and subsections that are part of the related Section (e.g., a section numbered
“Section 2.2” would be part of “Section 2”, and references to “Section 2.2” would also refer to material contained in the subsection described as “Section 2.2(a)”). 

  
 64 

	13.13	 Further Assurances. Each of C4 and Biogen agrees to duly execute and deliver, or cause to be duly
executed or delivered, such further instruments and do and cause to be done such further acts, including the filing of additional assignments, agreements, documents and instruments, as the other Party may at any time and from time to time reasonably
request in connection with this Agreement or to carry out more effectively the provisions and purposes of, or to better assure and confirm unto such other Party its rights and remedies under, this Agreement. 

 

	13.14	 Counterparts. This Agreement may be executed in counterparts, all of which taken together will be
regarded as one and the same instrument. Counterparts may be delivered via electronic mail, including AdobeTM Portable Document Format (PDF) or any electronic signature complying with the U.S.
Federal ESIGN Act of 2000, and any counterpart so delivered will be deemed to be original signatures, will be valid and binding upon the Parties, and, upon delivery, will constitute due execution of this Agreement. 

  
 65 

 IN WITNESS WHEREOF, the Parties have caused this Agreement to be executed by their
respective duly authorized officers. 
  

			
	BIOGEN MA INC.
		
	By:	 	 /s/ Anabella Villalobos

	Name:	 	Anabella Villalobos
	Title:	 	Senior Vice President
		
	Date:	 	December 28, 2018
	
	C4 THERAPEUTICS, INC.
		
	By:	 	 /s/ Andrew J. Phillips

	Name:	 	Andrew J. Phillips
	Title:	 	CEO & President
		
	Date:	 	December 28, 2018

 [Signature Page to Collaborative Research and License Agreement] 

 SCHEDULE 1.42 

C4 LICENSED PATENT RIGHTS 

[***] 

 [***] 

CANDIDATE DEVELOPMENT PLAN FOR [***] 

[***] 

 SCHEDULE 3.1.3(B) 

CANDIDATE DEVELOPMENT PLAN FOR [***] 

[***] 

 [***] 

CANDIDATE DEVELOPMENT PLAN FOR [***] 

[***] 

 SCHEDULE 3.1.9 

FORM OF CANDIDATE DEVELOPMENT FINANCIAL REPORT 
  

															
	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]	  	[***]

  
 A-6 

 SCHEDULE 4.1.1 

CONTACT LIST 
  

							
	 Name
	  	 Role
	  	 Email
	  	 Phone Number

	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]

 SCHEDULE 9.9.2 

PRESS RELEASE 
 [To be
provided]

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00313-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00313-of-00352.parquet"}]]