EX-10.2



 Exhibit 10.2 

ALLAKOS INC. 
 2012
EQUITY INCENTIVE PLAN 
 (Amended and Restated May 17, 2017) 

1. Purposes of the Plan. The purposes of this Plan are: 
  

	 	•	to attract and retain the best available personnel for positions of substantial responsibility, 

  

	 	•	to provide additional incentive to Employees, Directors and Consultants, and 

  

	 	•	to promote the success of the Company’s business. 

 The Plan permits the grant of
Incentive Stock Options, Nonstatutory Stock Options, Stock Appreciation Rights, Restricted Stock and Restricted Stock Units. 
 2.
Definitions. As used herein, the following definitions will apply: 
 (a) “Administrator” means the Board or any of
its Committees as will be administering the Plan, in accordance with Section 4 of the Plan. 
 (b) “Applicable Laws”
means the requirements relating to the administration of equity-based awards under U.S. state corporate laws, U.S. federal and state securities laws, the Code, any stock exchange or quotation system on which the Common Stock is listed or quoted and
the applicable laws of any foreign country or jurisdiction where Awards are, or will be, granted under the Plan. 
 (c)
“Award” means, individually or collectively, a grant under the Plan of Options, Stock Appreciation Rights, Restricted Stock, or Restricted Stock Units. 

(d) “Award Agreement” means the written or electronic agreement setting forth the terms and provisions applicable to each
Award granted under the Plan. The Award Agreement is subject to the terms and conditions of the Plan. 
 (e) “Board” means
the Board of Directors of the Company. 
 (f) “Change in Control” means the occurrence of any of the following events: 

(i) Change in Ownership of the Company. A change in the ownership of the Company which occurs on the date that any one person, or more
than one person acting as a group (“Person”), acquires ownership of the stock of the Company that, together with the stock held by such Person, constitutes more than 50% of the total voting power of the stock of the Company, except that
any change in the ownership of the stock of the Company as a result of a private financing of the Company that is approved by the Board will not be considered a Change in Control; or 

  
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 (ii) Change in Effective Control of the Company. If the Company has a class of securities
registered pursuant to Section 12 of the Exchange Act, a change in the effective control of the Company which occurs on the date that a majority of members of the Board is replaced during any twelve (12) month period by Directors whose
appointment or election is not endorsed by a majority of the members of the Board prior to the date of the appointment or election. For purposes of this clause (ii), if any Person is considered to be in effective control of the Company, the
acquisition of additional control of the Company by the same Person will not be considered a Change in Control; or 
 (iii) Change in
Ownership of a Substantial Portion of the Company’s Assets. A change in the ownership of a substantial portion of the Company’s assets which occurs on the date that any Person acquires (or has acquired during the twelve (12) month
period ending on the date of the most recent acquisition by such person or persons) assets from the Company that have a total gross fair market value equal to or more than 50% of the total gross fair market value of all of the assets of the Company
immediately prior to such acquisition or acquisitions. For purposes of this subsection (iii), gross fair market value means the value of the assets of the Company, or the value of the assets being disposed of, determined without regard to any
liabilities associated with such assets. 
 For purposes of this Section 2(f), persons will be considered to be acting as a group if
they are owners of a corporation that enters into a merger, consolidation, purchase or acquisition of stock, or similar business transaction with the Company. 

Notwithstanding the foregoing, a transaction will not be deemed a Change in Control unless the transaction qualifies as a change in control
event within the meaning of Code Section 409A, as it has been and may be amended from time to time, and any proposed or final Treasury Regulations and Internal Revenue Service guidance that has been promulgated or may be promulgated thereunder
from time to time. 
 Further and for the avoidance of doubt, a transaction will not constitute a Change in Control if: (i) its sole
purpose is to change the jurisdiction of the Company’s incorporation, or (ii) its sole purpose is to create a holding company that will be owned in substantially the same proportions by the persons who held the Company’s securities
immediately before such transaction. 
 (g) “Code” means the Internal Revenue Code of 1986, as amended. Any reference to a
section of the Code herein will be a reference to any successor or amended section of the Code. 
 (h) “Committee” means a
committee of Directors or of other individuals satisfying Applicable Laws appointed by the Board, or by the compensation committee of the Board, in accordance with Section 4 hereof. 

(i) “Common Stock” means the common stock of the Company. 

  
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 (j) “Company” means Allakos Inc., a Delaware corporation, or any successor
thereto. 
 (k) Consultant” means any individual, including an advisor, engaged by the Company or a Parent or Subsidiary to
render services to such entity. For the avoidance of doubt, the term “Consultant” shall not include any entity or any non-natural person. 

(l) “Director” means a member of the Board. 

(m) “Disability” means total and permanent disability as defined in Code Section 22(e)(3), provided that in the case of
Awards other than Incentive Stock Options, the Administrator in its discretion may determine whether a permanent and total disability exists in accordance with uniform and non-discriminatory standards adopted
by the Administrator from time to time. 
 (n) “Employee” means any person, including officers and Directors, employed by
the Company or any Parent or Subsidiary of the Company. Neither service as a Director nor payment of a director’s fee by the Company will be sufficient to constitute “employment” by the Company. 

(o) “Exchange Act” means the Securities Exchange Act of 1934, as amended. 

(p) “Exchange Program” means a program under which (i) outstanding Awards are surrendered or cancelled in exchange for
Awards of the same type (which may have higher or lower exercise prices and different terms), Awards of a different type, and/or cash, (ii) Participants would have the opportunity to transfer any outstanding Awards to a financial institution or
other person or entity selected by the Administrator, and/or (iii) the exercise price of an outstanding Award is reduced or increased. The Administrator will determine the terms and conditions of any Exchange Program in its sole discretion.

 (q) “Fair Market Value” means, as of any date, the value of Common Stock determined as follows: 

(i) If the Common Stock is listed on any established stock exchange or a national market system, including without limitation the Nasdaq
Global Select Market, the Nasdaq Global Market or the Nasdaq Capital Market of The Nasdaq Stock Market, its Fair Market Value will be the closing sales price for such stock (or the closing bid, if no sales were reported) as quoted on such exchange
or system on the day of determination, as reported in The Wall Street Journal or such other source as the Administrator deems reliable; 

(ii) If the Common Stock is regularly quoted by a recognized securities dealer but selling prices are not reported, the Fair Market Value of a
Share will be the mean between the high bid and low asked prices for the Common Stock on the day of determination (or, if no bids and asks were reported on that date, as applicable, on the last trading date such bids and asks were reported), as
reported in The Wall Street Journal or such other source as the Administrator deems reliable; or 

  
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 (iii) In the absence of an established market for the Common Stock, the Fair Market Value will
be determined in good faith by the Administrator. 
 (r) “Incentive Stock Option” means an Option that by its terms
qualifies and is otherwise intended to qualify as an incentive stock option within the meaning of Code Section 422 and the regulations promulgated thereunder. 

(s) “Nonstatutory Stock Option” means an Option that by its terms does not qualify or is not intended to qualify as an
Incentive Stock Option. 
 (t) “Option” means a stock option granted pursuant to the Plan. 

(u) “Parent” means a “parent corporation,” whether now or hereafter existing, as defined in Code
Section 424(e). 
 (v) “Participant” means the holder of an outstanding Award. 

(w) “Period of Restriction” means the period during which the transfer of Shares of Restricted Stock are subject to
restrictions and therefore, the Shares are subject to a substantial risk of forfeiture. Such restrictions may be based on the passage of time, the achievement of target levels of performance, or the occurrence of other events as determined by the
Administrator. 
 (x) “Plan” means this 2012 Equity Incentive Plan. 

(y) “Restricted Stock” means Shares issued pursuant to an Award of Restricted Stock under Section 8 of the Plan, or
issued pursuant to the early exercise of an Option. 
 (z) “Restricted Stock Unit” means a bookkeeping entry representing an
amount equal to the Fair Market Value of one Share, granted pursuant to Section 9. Each Restricted Stock Unit represents an unfunded and unsecured obligation of the Company. 

(aa) “Service Provider” means an Employee, Director or Consultant. 

(bb) “Share” means a share of the Common Stock, as adjusted in accordance with Section 13 of the Plan. 

(cc) “Stock Appreciation Right” means an Award, granted alone or in connection with an Option, that pursuant to Section 7
is designated as a Stock Appreciation Right. 
 (dd) “Subsidiary” means a “subsidiary corporation,” whether now or
hereafter existing, as defined in Code Section 424(f). 
 3.
Stock Subject to the Plan. 
 (a) Stock Subject to the
Plan. Subject to the provisions of Section 13 of the Plan, the maximum aggregate number of Shares that may be subject to Awards and sold under the Plan is 10,568,807. The Shares may be authorized but unissued, or reacquired Common Stock.


  
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 (b) Lapsed Awards. If an Award expires or becomes unexercisable without having been
exercised in full, is surrendered pursuant to an Exchange Program, or, with respect to Restricted Stock or Restricted Stock Units, is forfeited to or repurchased by the Company due to the failure to vest, the unpurchased Shares (or for Awards other
than Options or Stock Appreciation Rights the forfeited or repurchased Shares) which were subject thereto will become available for future grant or sale under the Plan (unless the Plan has terminated). With respect to Stock Appreciation Rights, only
Shares actually issued pursuant to a Stock Appreciation Right will cease to be available under the Plan; all remaining Shares under Stock Appreciation Rights will remain available for future grant or sale under the Plan (unless the Plan has
terminated). Shares that have actually been issued under the Plan under any Award will not be returned to the Plan and will not become available for future distribution under the Plan; provided, however, that if Shares issued pursuant to Awards of
Restricted Stock or Restricted Stock Units are repurchased by the Company or are forfeited to the Company due to the failure to vest, such Shares will become available for future grant under the Plan. Shares used to pay the exercise price of an
Award or to satisfy the tax withholding obligations related to an Award will become available for future grant or sale under the Plan. To the extent an Award under the Plan is paid out in cash rather than Shares, such cash payment will not result in
reducing the number of Shares available for issuance under the Plan. Notwithstanding the foregoing and, subject to adjustment as provided in Section 13, the maximum number of Shares that may be issued upon the exercise of Incentive Stock
Options will equal the aggregate Share number stated in Section 3(a), plus, to the extent allowable under Code Section 422 and the Treasury Regulations promulgated thereunder, any Shares that become available for issuance under the Plan
pursuant to Section 3(b). 
 (c) Share Reserve. The Company, during the term of this Plan, will at all times reserve and keep
available such number of Shares as will be sufficient to satisfy the requirements of the Plan. 
 4. Administration of the Plan. 

(a) Procedure. 
 (i)
Multiple Administrative Bodies. Different Committees with respect to different groups of Service Providers may administer the Plan. 

(ii) Other Administration. Other than as provided above, the Plan will be administered by (A) the Board or (B) a Committee,
which Committee will be constituted to satisfy Applicable Laws. 
 (b) Powers of the Administrator. Subject to the provisions of the
Plan, and in the case of a Committee, subject to the specific duties delegated by the Board to such Committee, the Administrator will have the authority, in its discretion: 

(i) to determine the Fair Market Value; 

(ii) to select the Service Providers to whom Awards may be granted hereunder; 

  
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 (iii) to determine the number of Shares to be covered by each Award granted hereunder; 

(iv) to approve forms of Award Agreements for use under the Plan; 

(v) to determine the terms and conditions, not inconsistent with the terms of the Plan, of any Award granted hereunder. Such terms and
conditions include, but are not limited to, the exercise price, the time or times when Awards may be exercised (which may be based on performance criteria), any vesting acceleration or waiver of forfeiture restrictions, and any restriction or
limitation regarding any Award or the Shares relating thereto, based in each case on such factors as the Administrator will determine; 

(vi) to institute and determine the terms and conditions of an Exchange Program; 

(vii) to construe and interpret the terms of the Plan and Awards granted pursuant to the Plan; 

(viii) to prescribe, amend and rescind rules and regulations relating to the Plan, including rules and regulations relating to sub-plans established for the purpose of satisfying applicable foreign laws or for qualifying for favorable tax treatment under applicable foreign laws; 

(ix) to modify or amend each Award (subject to Section 18(c) of the Plan), including but not limited to the discretionary authority to
extend the post-termination exercisability period of Awards and to extend the maximum term of an Option (subject to Section 6(d)); 

(x) to allow Participants to satisfy withholding tax obligations in a manner prescribed in Section 14; 

(xi) to authorize any person to execute on behalf of the Company any instrument required to effect the grant of an Award previously granted by
the Administrator; 
 (xii) to allow a Participant to defer the receipt of the payment of cash or the delivery of Shares that otherwise
would be due to such Participant under an Award; and 
 (xiii) to make all other determinations deemed necessary or advisable for
administering the Plan. 
 (c) Effect of Administrator’s Decision. The Administrator’s decisions,
determinations and interpretations will be final and binding on all Participants and any other holders of Awards. 
 5. Eligibility.
Nonstatutory Stock Options, Stock Appreciation Rights, Restricted Stock, and Restricted Stock Units may be granted to Service Providers. Incentive Stock Options may be granted only to Employees. 

  
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 6. Stock Options. 

(a) Grant of Options. Subject to the terms and provisions of the Plan, the Administrator, at any time and from time to time, may grant
Options in such amounts as the Administrator, in its sole discretion, will determine. 
 (b) Option Agreement. Each Award of an Option
will be evidenced by an Award Agreement that will specify the exercise price, the term of the Option, the number of Shares subject to the Option, the exercise restrictions, if any, applicable to the Option, and such other terms and conditions as the
Administrator, in its sole discretion, will determine. 
 (c) Limitations. Each Option will be designated in the Award Agreement as
either an Incentive Stock Option or a Nonstatutory Stock Option. Notwithstanding such designation, however, to the extent that the aggregate Fair Market Value of the Shares with respect to which Incentive Stock Options are exercisable for the first
time by the Participant during any calendar year (under all plans of the Company and any Parent or Subsidiary) exceeds one hundred thousand dollars ($100,000), such Options will be treated as Nonstatutory Stock Options. For purposes of this
Section 6(c), Incentive Stock Options will be taken into account in the order in which they were granted, the Fair Market Value of the Shares will be determined as of the time the Option with respect to such Shares is granted, and calculation
will be performed in accordance with Code Section 422 and Treasury Regulations promulgated thereunder. 
 (d) Term of Option. The
term of each Option will be stated in the Award Agreement; provided, however, that the term will be no more than ten (10) years from the date of grant thereof. In the case of an Incentive Stock Option granted to a Participant who, at the time
the Incentive Stock Option is granted, owns stock representing more than ten percent (10%) of the total combined voting power of all classes of stock of the Company or any Parent or Subsidiary, the term of the Incentive Stock Option will be five
(5) years from the date of grant or such shorter term as may be provided in the Award Agreement. 
 (e) Option Exercise Price and
Consideration. 
 (i) Exercise Price. The per Share exercise price for the Shares to be issued pursuant to the exercise of an
Option will be determined by the Administrator, but will be no less than one hundred percent (100%) of the Fair Market Value per Share on the date of grant. In addition, in the case of an Incentive Stock Option granted to an Employee who owns stock
representing more than ten percent (10%) of the voting power of all classes of stock of the Company or any Parent or Subsidiary, the per Share exercise price will be no less than one hundred ten percent (110%) of the Fair Market Value per Share on
the date of grant. Notwithstanding the foregoing provisions of this Section 6(e)(i), Options may be granted with a per Share exercise price of less than one hundred percent (100%) of the Fair Market Value per Share on the date of grant pursuant
to a transaction described in, and in a manner consistent with, Code Section 424(a). 
 (ii) Waiting Period and Exercise Dates.
At the time an Option is granted, the Administrator will fix the period within which the Option may be exercised and will determine any conditions that must be satisfied before the Option may be exercised. 

  
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 (iii) Form of Consideration. The Administrator will determine the acceptable form of
consideration for exercising an Option, including the method of payment. In the case of an Incentive Stock Option, the Administrator will determine the acceptable form of consideration at the time of grant. Such consideration may consist entirely
of: (1) cash; (2) check; (3) promissory note, to the extent permitted by Applicable Laws, (4) other Shares, provided that such Shares have a Fair Market Value on the date of surrender equal to the aggregate exercise price of the
Shares as to which such Option will be exercised and provided further that accepting such Shares will not result in any adverse accounting consequences to the Company, as the Administrator determines in its sole discretion; (5) consideration
received by the Company under cashless exercise program (whether through a broker or otherwise) implemented by the Company in connection with the Plan; (6) by net exercise, (7) such other consideration and method of payment for the
issuance of Shares to the extent permitted by Applicable Laws, or (8) any combination of the foregoing methods of payment. In making its determination as to the type of consideration to accept, the Administrator will consider if acceptance of
such consideration may be reasonably expected to benefit the Company. 
 (f) Exercise of Option. 

(i) Procedure for Exercise; Rights as a Stockholder. Any Option granted hereunder will be exercisable according to the terms of the
Plan and at such times and under such conditions as determined by the Administrator and set forth in the Award Agreement. An Option may not be exercised for a fraction of a Share. 

An Option will be deemed exercised when the Company receives: (i) notice of exercise (in such form as the Administrator may specify from
time to time) from the person entitled to exercise the Option, and (ii) full payment for the Shares with respect to which the Option is exercised (together with applicable tax withholding). Full payment may consist of any consideration and
method of payment authorized by the Administrator and permitted by the Award Agreement and the Plan. Shares issued upon exercise of an Option will be issued in the name of the Participant or, if requested by the Participant, in the name of the
Participant and his or her spouse. Until the Shares are issued (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), no right to vote or receive dividends or any other rights as a
stockholder will exist with respect to the Shares subject to an Option, notwithstanding the exercise of the Option. The Company will issue (or cause to be issued) such Shares promptly after the Option is exercised. No adjustment will be made for a
dividend or other right for which the record date is prior to the date the Shares are issued, except as provided in Section 13 of the Plan. 

Exercising an Option in any manner will decrease the number of Shares thereafter available, both for purposes of the Plan and for sale under
the Option, by the number of Shares as to which the Option is exercised. 
 (ii) Termination of Relationship as a Service Provider.
If a Participant ceases to be a Service Provider, other than upon the Participant’s termination as the result of the Participant’s death or Disability, the Participant may exercise his or her Option within thirty (30) days of
termination, or such longer period of time as is specified in the Award Agreement (but in no event later than the expiration of the term of such Option as set forth in the Award Agreement) to the extent that the Option is vested on the date of
termination. Unless otherwise provided by the 

  
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Administrator, if on the date of termination the Participant is not vested as to his or her entire Option, the Shares covered by the unvested portion of the Option will revert to the Plan. If
after termination the Participant does not exercise his or her Option within the time specified by the Administrator, the Option will terminate, and the Shares covered by such Option will revert to the Plan. 

(iii) Disability of Participant. If a Participant ceases to be a Service Provider as a result of the Participant’s Disability, the
Participant may exercise his or her Option within six (6) months of termination, or such longer period of time as is specified in the Award Agreement (but in no event later than the expiration of the term of such Option as set forth in the
Award Agreement) to the extent the Option is vested on the date of termination. Unless otherwise provided by the Administrator, if on the date of termination the Participant is not vested as to his or her entire Option, the Shares covered by the
unvested portion of the Option will revert to the Plan. If after termination the Participant does not exercise his or her Option within the time specified herein, the Option will terminate, and the Shares covered by such Option will revert to the
Plan. 
 (iv) Death of Participant. If a Participant dies while a Service Provider, the Option may be exercised within six
(6) months following the Participant’s death, or within such longer period of time as is specified in the Award Agreement (but in no event later than the expiration of the term of such Option as set forth in the Award Agreement) to the
extent that the Option is vested on the date of death, by the Participant’s designated beneficiary, provided such beneficiary has been designated prior to the Participant’s death in a form acceptable to the Administrator. If no such
beneficiary has been designated by the Participant, then such Option may be exercised by the personal representative of the Participant’s estate or by the person(s) to whom the Option is transferred pursuant to the Participant’s will or in
accordance with the laws of descent and distribution. Unless otherwise provided by the Administrator, if at the time of death Participant is not vested as to his or her entire Option, the Shares covered by the unvested portion of the Option will
immediately revert to the Plan. If the Option is not so exercised within the time specified herein, the Option will terminate, and the Shares covered by such Option will revert to the Plan. 

7. Stock Appreciation Rights. 

(a) Grant of Stock Appreciation Rights. Subject to the terms and conditions of the Plan, a Stock Appreciation Right may be granted to
Service Providers at any time and from time to time as will be determined by the Administrator, in its sole discretion. 
 (b) Number of
Shares. The Administrator will have complete discretion to determine the number of Shares subject to any Award of Stock Appreciation Rights. 

(c) Exercise Price and Other Terms. The per Share exercise price for the Shares that will determine the amount of the payment to be
received upon exercise of a Stock Appreciation Right as set forth in Section 7(f) will be determined by the Administrator and will be no less than one hundred percent (100%) of the Fair Market Value per Share on the date of grant. Otherwise,
the Administrator, subject to the provisions of the Plan, will have complete discretion to determine the terms and conditions of Stock Appreciation Rights granted under the Plan. 

  
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 (d) Stock Appreciation Right Agreement. Each Stock Appreciation Right grant will be
evidenced by an Award Agreement that will specify the exercise price, the term of the Stock Appreciation Right, the conditions of exercise, and such other terms and conditions as the Administrator, in its sole discretion, will determine. 

(e) Expiration of Stock Appreciation Rights. A Stock Appreciation Right granted under the Plan will expire upon the date determined by
the Administrator, in its sole discretion, and set forth in the Award Agreement. Notwithstanding the foregoing, the rules of Section 6(d) relating to the maximum term and Section 6(f) relating to exercise also will apply to Stock
Appreciation Rights. 
 (f) Payment of Stock Appreciation Right Amount. Upon exercise of a Stock Appreciation Right, a Participant
will be entitled to receive payment from the Company in an amount determined by multiplying: 
 (i) The difference between the Fair Market
Value of a Share on the date of exercise over the exercise price; times 
 (ii) The number of Shares with respect to which the Stock
Appreciation Right is exercised. 
 At the discretion of the Administrator, the payment upon Stock Appreciation Right exercise may be in
cash, in Shares of equivalent value, or in some combination thereof. 
 8. Restricted Stock. 

(a) Grant of Restricted Stock. Subject to the terms and provisions of the Plan, the Administrator, at any time and from time to time,
may grant Shares of Restricted Stock to Service Providers in such amounts as the Administrator, in its sole discretion, will determine. 

(b) Restricted Stock Agreement. Each Award of Restricted Stock will be evidenced by an Award Agreement that will specify the Period of
Restriction, the number of Shares granted, and such other terms and conditions as the Administrator, in its sole discretion, will determine. Unless the Administrator determines otherwise, the Company as escrow agent will hold Shares of Restricted
Stock until the restrictions on such Shares have lapsed. 
 (c) Transferability. Except as provided in this Section 8 or as the
Administrator determines, Shares of Restricted Stock may not be sold, transferred, pledged, assigned, or otherwise alienated or hypothecated until the end of the applicable Period of Restriction. 

(d) Other Restrictions. The Administrator, in its sole discretion, may impose such other restrictions on Shares of Restricted Stock as
it may deem advisable or appropriate. 
 (e) Removal of Restrictions. Except as otherwise provided in this Section 8, Shares of
Restricted Stock covered by each Restricted Stock grant made under the Plan will be released from escrow as soon as practicable after the last day of the Period of Restriction or at such other time as the Administrator may determine. The
Administrator, in its discretion, may accelerate the time at which any restrictions will lapse or be removed. 

  
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 (f) Voting Rights. During the Period of Restriction, Service Providers holding Shares of
Restricted Stock granted hereunder may exercise full voting rights with respect to those Shares, unless the Administrator determines otherwise. 

(g) Dividends and Other Distributions. During the Period of Restriction, Service Providers holding Shares of Restricted Stock will be
entitled to receive all dividends and other distributions paid with respect to such Shares, unless the Administrator provides otherwise. If any such dividends or distributions are paid in Shares, the Shares will be subject to the same restrictions
on transferability and forfeitability as the Shares of Restricted Stock with respect to which they were paid. 
 (h) Return of Restricted
Stock to Company. On the date set forth in the Award Agreement, the Restricted Stock for which restrictions have not lapsed will revert to the Company and again will become available for grant under the Plan. 

9. Restricted Stock Units. 

(a) Grant. Restricted Stock Units may be granted at any time and from time to time as determined by the Administrator. After the
Administrator determines that it will grant Restricted Stock Units, it will advise the Participant in an Award Agreement of the terms, conditions, and restrictions related to the grant, including the number of Restricted Stock Units. 

(b) Vesting Criteria and Other Terms. The Administrator will set vesting criteria in its discretion, which, depending on the extent to
which the criteria are met, will determine the number of Restricted Stock Units that will be paid out to the Participant. The Administrator may set vesting criteria based upon the achievement of Company-wide, business unit, or individual goals
(including, but not limited to, continued employment or service), or any other basis determined by the Administrator in its discretion. 

(c) Earning Restricted Stock Units. Upon meeting the applicable vesting criteria, the Participant will be entitled to receive a payout
as determined by the Administrator. Notwithstanding the foregoing, at any time after the grant of Restricted Stock Units, the Administrator, in its sole discretion, may reduce or waive any vesting criteria that must be met to receive a payout. 

(d) Form and Timing of Payment. Payment of earned Restricted Stock Units will be made as soon as practicable after the date(s)
determined by the Administrator and set forth in the Award Agreement. The Administrator, in its sole discretion, may settle earned Restricted Stock Units in cash, Shares, or a combination of both. 

(e) Cancellation. On the date set forth in the Award Agreement, all unearned Restricted Stock Units will be forfeited to the Company.

 10. Compliance With Code Section 409A. Awards will be designed and operated in such a manner that
they are either exempt from the application of, or comply with, the requirements of Code Section 409A, except as otherwise determined in the sole discretion of the Administrator. The Plan and each Award Agreement under the Plan is intended to
meet the requirements of Code Section 409A and will be construed and interpreted in accordance with such intent, except as 

  
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otherwise determined in the sole discretion of the Administrator. To the extent that an Award or payment, or the settlement or deferral thereof, is subject to Code Section 409A the Award
will be granted, paid, settled or deferred in a manner that will meet the requirements of Code Section 409A, such that the grant, payment, settlement or deferral will not be subject to the additional tax or interest applicable under Code
Section 409A. 
 11. Leaves of Absence/Transfer Between Locations. Unless the Administrator provides otherwise, vesting of
Awards granted hereunder will be suspended during any unpaid leave of absence. A Participant will not cease to be an Employee in the case of (i) any leave of absence approved by the Company or (ii) transfers between locations of the
Company or between the Company, its Parent, or any Subsidiary. For purposes of Incentive Stock Options, no such leave may exceed three (3) months, unless reemployment upon expiration of such leave is guaranteed by statute or contract. If
reemployment upon expiration of a leave of absence approved by the Company is not so guaranteed, then six (6) months following the first (1st) day of such leave, any Incentive Stock Option
held by the Participant will cease to be treated as an Incentive Stock Option and will be treated for tax purposes as a Nonstatutory Stock Option. 

12. Limited Transferability of Awards. 

(a) Unless determined otherwise by the Administrator, Awards may not be sold, pledged, assigned, hypothecated, or otherwise transferred in any
manner other than by will or by the laws of descent and distribution, and may be exercised, during the lifetime of the Participant, only by the Participant. If the Administrator makes an Award transferable, such Award may only be transferred
(i) by will, (ii) by the laws of descent and distribution, or (iii) as permitted by Rule 701 of the Securities Act of 1933, as amended (the “Securities Act”). 

(b) Further, until the Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Exchange Act, or after the
Administrator determines that it is, will, or may no longer be relying upon the exemption from registration under the Exchange Act as set forth in Rule 12h-1(f) promulgated under the Exchange Act, an Option,
or prior to exercise, the Shares subject to the Option, may not be pledged, hypothecated or otherwise transferred or disposed of, in any manner, including by entering into any short position, any “put equivalent position” or any “call
equivalent position” (as defined in Rule 16a-1(h) and Rule 16a-1(b) of the Exchange Act, respectively), other than to (i) persons who are “family
members” (as defined in Rule 701(c)(3) of the Securities Act) through gifts or domestic relations orders, or (ii) to an executor or guardian of the Participant upon the death or disability of the Participant. Notwithstanding the foregoing
sentence, the Administrator, in its sole discretion, may determine to permit transfers to the Company or in connection with a Change in Control or other acquisition transactions involving the Company to the extent permitted by Rule 12h-1(f). 
 13. Adjustments; Dissolution or Liquidation; Merger or Change in Control. 

(a) Adjustments. In the event that any dividend or other distribution (whether in the form of cash, Shares, other securities, or other
property), recapitalization, stock split, reverse stock split, reorganization, merger, consolidation, split-up, spin-off, combination, repurchase, or exchange of Shares
or other securities of the Company, or other change in the corporate structure of the Company affecting the Shares occurs, the Administrator, in order to prevent diminution or 

  
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enlargement of the benefits or potential benefits intended to be made available under the Plan, will adjust the number and class of shares of stock that may be delivered under the Plan and/or the
number, class, and price of shares of stock covered by each outstanding Award; provided, however, that the Administrator will make such adjustments to an Award required by Section 25102(o) of the California Corporations Code to the extent the
Company is relying upon the exemption afforded thereby with respect to the Award. 
 (b) Dissolution or Liquidation. In the event of
the proposed dissolution or liquidation of the Company, the Administrator will notify each Participant as soon as practicable prior to the effective date of such proposed transaction. To the extent it has not been previously exercised, an Award will
terminate immediately prior to the consummation of such proposed action. 
 (c) Merger or Change in Control. In the event of a merger
of the Company with or into another corporation or other entity or a Change in Control, each outstanding Award will be treated as the Administrator determines (subject to the provisions of the following paragraph) without a Participant’s
consent, including, without limitation, that (i) Awards will be assumed, or substantially equivalent Awards will be substituted, by the acquiring or succeeding corporation (or an affiliate thereof) with appropriate adjustments as to the number
and kind of shares and prices; (ii) upon written notice to a Participant, that the Participant’s Awards will terminate upon or immediately prior to the consummation of such merger or Change in Control; (iii) outstanding Awards will
vest and become exercisable, realizable, or payable, or restrictions applicable to an Award will lapse, in whole or in part prior to or upon consummation of such merger or Change in Control, and, to the extent the Administrator determines, terminate
upon or immediately prior to the effectiveness of such merger or Change in Control; (iv) (A) the termination of an Award in exchange for an amount of cash and/or property, if any, equal to the amount that would have been attained upon the
exercise of such Award or realization of the Participant’s rights as of the date of the occurrence of the transaction (and, for the avoidance of doubt, if as of the date of the occurrence of the transaction the Administrator determines in good
faith that no amount would have been attained upon the exercise of such Award or realization of the Participant’s rights, then such Award may be terminated by the Company without payment), or (B) the replacement of such Award with other
rights or property selected by the Administrator in its sole discretion; or (v) any combination of the foregoing. In taking any of the actions permitted under this subsection 13(c), the Administrator will not be obligated to treat all Awards,
all Awards held by a Participant, or all Awards of the same type, similarly. 
 In the event that the successor corporation does not assume
or substitute for the Award (or portion thereof), the Participant will fully vest in and have the right to exercise all of his or her outstanding Options and Stock Appreciation Rights, including Shares as to which such Awards would not otherwise be
vested or exercisable, all restrictions on Restricted Stock and Restricted Stock Units will lapse, and, with respect to Awards with performance-based vesting, all performance goals or other vesting criteria will be deemed achieved at one hundred
percent (100%) of target levels and all other terms and conditions met. In addition, if an Option or Stock Appreciation Right is not assumed or substituted in the event of a merger or Change in Control, the Administrator will notify the Participant
in writing or electronically that the Option or Stock Appreciation Right will be exercisable for a period of time determined by the Administrator in its sole discretion, and the Option or Stock Appreciation Right will terminate upon the expiration
of such period. 

  
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 For the purposes of this subsection 13(c), an Award will be considered assumed if, following the
merger or Change in Control, the Award confers the right to purchase or receive, for each Share subject to the Award immediately prior to the merger or Change in Control, the consideration (whether stock, cash, or other securities or property)
received in the merger or Change in Control by holders of Common Stock for each Share held on the effective date of the transaction (and if holders were offered a choice of consideration, the type of consideration chosen by the holders of a majority
of the outstanding Shares); provided, however, that if such consideration received in the merger or Change in Control is not solely common stock of the successor corporation or its Parent, the Administrator may, with the consent of the successor
corporation, provide for the consideration to be received upon the exercise of an Option or Stock Appreciation Right or upon the payout of a Restricted Stock Unit, for each Share subject to such Award, to be solely common stock of the successor
corporation or its Parent equal in fair market value to the per share consideration received by holders of Common Stock in the merger or Change in Control. 

Notwithstanding anything in this Section 13(c) to the contrary, an Award that vests, is earned or
paid-out upon the satisfaction of one or more performance goals will not be considered assumed if the Company or its successor modifies any of such performance goals without the Participant’s consent;
provided, however, a modification to such performance goals only to reflect the successor corporation’s post-Change in Control corporate structure will not be deemed to invalidate an otherwise valid Award assumption. 

Notwithstanding anything in this Section 13(c) to the contrary, if a payment under an Award Agreement is subject to Code
Section 409A and if the change in control definition contained in the Award Agreement does not comply with the definition of “change of control” for purposes of a distribution under Code Section 409A, then any payment of an
amount that is otherwise accelerated under this Section will be delayed until the earliest time that such payment would be permissible under Code Section 409A without triggering any penalties applicable under Code Section 409A. 

14. Tax Withholding. 
 (a)
Withholding Requirements. Prior to the delivery of any Shares or cash pursuant to an Award (or exercise thereof), the Company will have the power and the right to deduct or withhold, or require a Participant to remit to the Company, an amount
sufficient to satisfy federal, state, local, foreign or other taxes (including the Participant’s FICA obligation) required to be withheld with respect to such Award (or exercise thereof). 

(b) Withholding Arrangements. The Administrator, in its sole discretion and pursuant to such procedures as it may specify from time to
time, may permit a Participant to satisfy such tax withholding obligation, in whole or in part by (without limitation) (i) paying cash, (ii) electing to have the Company withhold otherwise deliverable Shares having a Fair Market Value
equal to the minimum statutory amount required to be withheld, (iii) delivering to the Company already-owned Shares having a Fair Market Value equal to the statutory amount required to be withheld, provided the delivery of such Shares will not
result in any adverse accounting consequences, as the Administrator determines in its sole discretion, or (iv) selling a sufficient number of Shares otherwise deliverable to the Participant through such means as the Administrator may determine
in its sole discretion (whether through a broker or otherwise) equal to the amount 

  
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required to be withheld. The amount of the withholding requirement will be deemed to include any amount which the Administrator agrees may be withheld at the time the election is made, not to
exceed the amount determined by using the maximum federal, state or local marginal income tax rates applicable to the Participant with respect to the Award on the date that the amount of tax to be withheld is to be determined. The Fair Market Value
of the Shares to be withheld or delivered will be determined as of the date that the taxes are required to be withheld. 
 15. No Effect
on Employment or Service. Neither the Plan nor any Award will confer upon a Participant any right with respect to continuing the Participant’s relationship as a Service Provider with the Company, nor will they interfere in any way with the
Participant’s right or the Company’s right to terminate such relationship at any time, with or without cause, to the extent permitted by Applicable Laws. 

16. Date of Grant. The date of grant of an Award will be, for all purposes, the date on which the Administrator makes the determination
granting such Award, or such other later date as is determined by the Administrator. Notice of the determination will be provided to each Participant within a reasonable time after the date of such grant. 

17. Term of Plan. Subject to Section 21 of the Plan, the Plan will become effective upon its adoption by the Board. Unless sooner
terminated under Section 18, it will continue in effect for a term of ten (10) years from the later of (a) the effective date of the Plan, or (b) the earlier of the most recent Board or stockholder approval of an increase in the
number of Shares reserved for issuance under the Plan. 
 18. Amendment and Termination of the Plan. 

(a) Amendment and Termination. The Board may at any time amend, alter, suspend or terminate the Plan. 

(b) Stockholder Approval. The Company will obtain stockholder approval of any Plan amendment to the extent necessary and desirable to
comply with Applicable Laws. 
 (c) Effect of Amendment or Termination. No amendment, alteration, suspension or termination of the
Plan will impair the rights of any Participant, unless mutually agreed otherwise between the Participant and the Administrator, which agreement must be in writing and signed by the Participant and the Company. Termination of the Plan will not affect
the Administrator’s ability to exercise the powers granted to it hereunder with respect to Awards granted under the Plan prior to the date of such termination. 

19. Conditions Upon Issuance of Shares. 

(a) Legal Compliance. Shares will not be issued pursuant to the exercise of an Award unless the exercise of such Award and the issuance
and delivery of such Shares will comply with Applicable Laws and will be further subject to the approval of counsel for the Company with respect to such compliance. 

  
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 (b) Investment Representations. As a condition to the exercise of an Award, the Company
may require the person exercising such Award to represent and warrant at the time of any such exercise that the Shares are being purchased only for investment and without any present intention to sell or distribute such Shares if, in the opinion of
counsel for the Company, such a representation is required. 
 20. Inability to Obtain Authority. The inability of the Company to
obtain authority from any regulatory body having jurisdiction, which authority is deemed by the Company’s counsel to be necessary to the lawful issuance and sale of any Shares hereunder, will relieve the Company of any liability in respect of
the failure to issue or sell such Shares as to which such requisite authority will not have been obtained. 
 21. Stockholder
Approval. The Plan will be subject to approval by the stockholders of the Company within twelve (12) months after the date the Plan is adopted by the Board. Such stockholder approval will be obtained in the manner and to the degree required
under Applicable Laws. 
 22. Information to Participants. Beginning on the earlier of (i) the date that the aggregate number of
Participants under this Plan is five hundred (500) or more and the Company is relying on the exemption provided by Rule 12h-1(f)(1) under the Exchange Act and (ii) the date that the Company is
required to deliver information to Participants pursuant to Rule 701 under the Securities Act, and until such time as the Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Exchange Act, is no longer relying on
the exemption provided by Rule 12h-1(f)(1) under the Exchange Act or is no longer required to deliver information to Participants pursuant to Rule 701 under the Securities Act, the Company shall provide to
each Participant the information described in paragraphs (e)(3), (4), and (5) of Rule 701 under the Securities Act not less frequently than every six (6) months with the financial statements being not more than 180 days old and with such
information provided either by physical or electronic delivery to the Participants or by written notice to the Participants of the availability of the information on an Internet site that may be password-protected and of any password needed to
access the information. The Company may request that Participants agree to keep the information to be provided pursuant to this section confidential. If a Participant does not agree to keep the information to be provided pursuant to this section
confidential, then the Company will not be required to provide the information unless otherwise required pursuant to Rule 12h-1(f)(1) under the Exchange Act or Rule 701 of the Securities Act. 

  
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 ALLAKOS INC. 

2012 EQUITY INCENTIVE PLAN 

STOCK OPTION AGREEMENT 

Unless otherwise defined herein, the terms defined in the 2012 Equity Incentive Plan (the “Plan”) shall have the same defined
meanings in this Stock Option Agreement (the “Option Agreement”). 
  

	I.	NOTICE OF STOCK OPTION GRANT 

 Name: 

Address: 
 The undersigned
Participant has been granted an Option to purchase Common Stock of the Company, subject to the terms and conditions of the Plan and this Option Agreement, as follows: 

 

			
	Date of Grant:	  	  

		
	Vesting Commencement Date:	  	  

		
	Exercise Price per Share:	  	  

		
	Total Number of Shares Granted:	  	  

		
	Total Exercise Price:	  	  

		
	Type of Option:	  	_______ Incentive Stock Option (ISO)
		
		  	_______ Nonstatutory Stock Option (NSO)
		
	Term/Expiration Date:	  	  



 Vesting Schedule: 

This Option shall be exercisable, in whole or in part, according to the following vesting schedule: 

Twenty-five percent (25%) of the Shares subject to the Option shall vest on the one (1) year anniversary of the Vesting Commencement
Date, and one forty-eighth (1/48th) of the Shares subject to the Option shall vest each month thereafter on the same day of the month as the Vesting Commencement Date (and if there is no
corresponding day, on the last day of the month), subject to Participant continuing to be a Service Provider through each such date. 







 Termination Period: 

This Option shall be exercisable for three (3) months after Participant ceases to be a Service Provider, unless such termination is due to
Participant’s death or Disability, in which case this Option shall be exercisable for twelve (12) months after Participant ceases to be a Service Provider. Notwithstanding the foregoing sentence, in no event may this Option be exercised
after the Term/Expiration Date as provided above and this Option may be subject to earlier termination as provided in Section 13 of the Plan. 
  

	II.	AGREEMENT 

 1. Grant of Option. The Administrator of the Company hereby
grants to the Participant named in the Notice of Stock Option Grant in Part I of this Agreement (“Participant”), an option (the “Option”) to purchase the number of Shares set forth in the Notice of Stock Option Grant, at the
exercise price per Share set forth in the Notice of Stock Option Grant (the “Exercise Price”), and subject to the terms and conditions of the Plan, which is incorporated herein by reference. Subject to Section 18 of the Plan, in the
event of a conflict between the terms and conditions of the Plan and this Option Agreement, the terms and conditions of the Plan shall prevail. 

If designated in the Notice of Stock Option Grant as an Incentive Stock Option (“ISO”), this Option is intended to qualify as an
Incentive Stock Option as defined in Section 422 of the Code. Nevertheless, to the extent that it exceeds the $100,000 rule of Code Section 422(d), this Option shall be treated as a Nonstatutory Stock Option (“NSO”). Further, if
for any reason this Option (or portion thereof) shall not qualify as an ISO, then, to the extent of such nonqualification, such Option (or portion thereof) shall be regarded as a NSO granted under the Plan. In no event shall the Administrator, the
Company or any Parent or Subsidiary or any of their respective employees or directors have any liability to Participant (or any other person) due to the failure of the Option to qualify for any reason as an ISO. 

2. Exercise of Option. 

(a) Right to Exercise. This Option shall be exercisable during its term in accordance with the Vesting Schedule set out in the Notice of
Stock Option Grant and with the applicable provisions of the Plan and this Option Agreement. 
 (b) Method of Exercise. This Option
shall be exercisable by delivery of an exercise notice in the form attached as Exhibit A (the “Exercise Notice”) or in a manner and pursuant to such procedures as the Administrator may determine, which shall state
the election to exercise the Option, the number of Shares with respect to which the Option is being exercised (the “Exercised Shares”), and such other representations and agreements as may be required by the Company. The Exercise Notice
shall be accompanied by payment of the aggregate Exercise Price as to all Exercised Shares, together with any applicable tax withholding. This Option shall be deemed to be exercised upon receipt by the Company of such fully executed Exercise Notice
accompanied by the aggregate Exercise Price, together with any applicable tax withholding. 

  
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 No Shares shall be issued pursuant to the exercise of an Option unless such issuance and such
exercise comply with Applicable Laws. Assuming such compliance, for income tax purposes the Shares shall be considered transferred to Participant on the date on which the Option is exercised with respect to such Shares. 

3. Participant’s Representations. In the event the Shares have not been registered under the Securities Act of 1933, as amended
(the “Securities Act”), at the time this Option is exercised, Participant shall, if required by the Company, concurrently with the exercise of all or any portion of this Option, deliver to the Company his or her Investment Representation
Statement in the form attached hereto as Exhibit B. 
 4. Lock-Up
Period. Participant hereby agrees that Participant shall not offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or
otherwise transfer or dispose of, directly or indirectly, any Common Stock (or other securities) of the Company or enter into any swap, hedging or other arrangement that transfers to another, in whole or in part, any of the economic consequences of
ownership of any Common Stock (or other securities) of the Company held by Participant (other than those included in the registration) for a period specified by the representative of the underwriters of Common Stock (or other securities) of the
Company not to exceed one hundred and eighty (180) days following the effective date of any registration statement of the Company filed under the Securities Act (or such other period as may be requested by the Company or the underwriters to
accommodate regulatory restrictions on (i) the publication or other distribution of research reports and (ii) analyst recommendations and opinions, including, but not limited to, the restrictions contained in NASD Rule 2711(f)(4) or
NYSE Rule 472(f)(4), or any successor provisions or amendments thereto). 
 Participant agrees to execute and deliver such other
agreements as may be reasonably requested by the Company or the underwriter which are consistent with the foregoing or which are necessary to give further effect thereto. In addition, if requested by the Company or the representative of the
underwriters of Common Stock (or other securities) of the Company, Participant shall provide, within ten (10) days of such request, such information as may be required by the Company or such representative in connection with the completion of
any public offering of the Company’s securities pursuant to a registration statement filed under the Securities Act. The obligations described in this Section 4 shall not apply to a registration relating solely to employee benefit plans on
Form S-1 or Form S-8 or similar forms that may be promulgated in the future, or a registration relating solely to a Commission Rule 145 transaction on Form S-4 or similar forms that may be promulgated in the future. The Company may impose stop-transfer instructions with respect to the shares of Common Stock (or other securities) subject to the foregoing restriction
until the end of said one hundred and eighty (180) day (or other) period. Participant agrees that any transferee of the Option or shares acquired pursuant to the Option shall be bound by this Section 4. 

5. Method of Payment. Payment of the aggregate Exercise Price shall be by any of the following, or a combination thereof, at the
election of the Participant: 
 (a) cash; 

  
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 (b) check; 

(c) consideration received by the Company under a formal cashless exercise program adopted by the Company in connection with the Plan; or 

(d) surrender of other Shares which (i) shall be valued at its Fair Market Value on the date of exercise, and (ii) must be owned free
and clear of any liens, claims, encumbrances or security interests, if accepting such Shares, in the sole discretion of the Administrator, shall not result in any adverse accounting consequences to the Company. 

6. Restrictions on Exercise. This Option may not be exercised until such time as the Plan has been approved by the stockholders of the
Company, or if the issuance of such Shares upon such exercise or the method of payment of consideration for such shares would constitute a violation of any Applicable Law. 

7. Non-Transferability of Option. 

(a) This Option may not be transferred in any manner otherwise than by will or by the laws of descent or distribution and may be exercised
during the lifetime of Participant only by Participant. The terms of the Plan and this Option Agreement shall be binding upon the executors, administrators, heirs, successors and assigns of Participant. 

(b) Further, until the Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Exchange Act, or after the
Administrator determines that it is, will, or may no longer be relying upon the exemption from registration of Options under the Exchange Act as set forth in Rule 12h-1(f) promulgated under the Exchange Act
(the “Reliance End Date”), Participant shall not transfer this Option or, prior to exercise, the Shares subject to this Option, in any manner other than (i) to persons who are “family members” (as defined in Rule 701(c)(3)
of the Securities Act) through gifts or domestic relations orders, or (ii) to an executor or guardian of Participant upon the death or disability of Participant. Until the Reliance End Date, the Options and, prior to exercise, the Shares
subject to this Option, may not be pledged, hypothecated or otherwise transferred or disposed of, including by entering into any short position, any “put equivalent position” or any “call equivalent position” (as defined in Rule 16a-1(h) and Rule 16a-1(b) of the Exchange Act, respectively), other than as permitted in clauses (i) and (ii) of this paragraph. 

8. Term of Option. This Option may be exercised only within the term set out in the Notice of Stock Option Grant, and may be exercised
during such term only in accordance with the Plan and the terms of this Option Agreement. 

  
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 9. Tax Obligations. 

(a) Tax Withholding. Participant agrees to make appropriate arrangements with the Company (or the Parent or Subsidiary employing or
retaining Participant) for the satisfaction of all Federal, state, local and foreign income and employment tax withholding requirements applicable to the Option exercise. Participant acknowledges and agrees that the Company may refuse to honor the
exercise and refuse to deliver the Shares if such withholding amounts are not delivered at the time of exercise. 
 (b) Notice of
Disqualifying Disposition of ISO Shares. If the Option granted to Participant herein is an ISO, and if Participant sells or otherwise disposes of any of the Shares acquired pursuant to the ISO on or before the later of (i) the date two
(2) years after the Date of Grant, or (ii) the date one (1) year after the date of exercise, Participant shall immediately notify the Company in writing of such disposition. Participant agrees that Participant may be subject to income
tax withholding by the Company on the compensation income recognized by Participant. 
 (c) Code Section 409A.
Under Code Section 409A, an Option that vests after December 31, 2004 (or that vested on or prior to such date but which was materially modified after October 3, 2004) that was granted with a per Share exercise price that is
determined by the Internal Revenue Service (the “IRS”) to be less than the Fair Market Value of a Share on the date of grant (a “discount option”) may be considered “deferred compensation.” An Option that is a
“discount option” may result in (i) income recognition by Participant prior to the exercise of the Option, (ii) an additional twenty percent (20%) federal income tax, and (iii) potential penalty and interest charges. The
“discount option” may also result in additional state income, penalty and interest tax to the Participant. Participant acknowledges that the Company cannot and has not guaranteed that the IRS will agree that the per Share exercise price of
this Option equals or exceeds the Fair Market Value of a Share on the date of grant in a later examination. Participant agrees that if the IRS determines that the Option was granted with a per Share exercise price that was less than the Fair Market
Value of a Share on the date of grant, Participant shall be solely responsible for Participant’s costs related to such a determination. 

10. Entire Agreement; Governing Law. The Plan is incorporated herein by reference. The Plan and this Option Agreement constitute the
entire agreement of the parties with respect to the subject matter hereof and supersede in their entirety all prior undertakings and agreements of the Company and Participant with respect to the subject matter hereof, and may not be modified
adversely to the Participant’s interest except by means of a writing signed by the Company and Participant. This Option Agreement is governed by the internal substantive laws but not the choice of law rules of California. 

11. No Guarantee of Continued Service. PARTICIPANT ACKNOWLEDGES AND AGREES THAT THE VESTING OF SHARES PURSUANT TO THE VESTING SCHEDULE
HEREOF IS EARNED ONLY BY CONTINUING AS A SERVICE PROVIDER AT THE WILL OF THE COMPANY (OR THE PARENT OR SUBSIDIARY EMPLOYING OR RETAINING PARTICIPANT) AND NOT THROUGH THE ACT OF BEING HIRED, BEING GRANTED THIS OPTION OR ACQUIRING SHARES HEREUNDER.
PARTICIPANT FURTHER ACKNOWLEDGES AND AGREES THAT THIS AGREEMENT, THE TRANSACTIONS 

  
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CONTEMPLATED HEREUNDER AND THE VESTING SCHEDULE SET FORTH HEREIN DO NOT CONSTITUTE AN EXPRESS OR IMPLIED PROMISE OF CONTINUED ENGAGEMENT AS A SERVICE PROVIDER FOR THE VESTING PERIOD, FOR ANY
PERIOD, OR AT ALL, AND SHALL NOT INTERFERE IN ANY WAY WITH PARTICIPANT’S RIGHT OR THE RIGHT OF THE COMPANY (OR THE PARENT OR SUBSIDIARY EMPLOYING OR RETAINING PARTICIPANT) TO TERMINATE PARTICIPANT’S RELATIONSHIP AS A SERVICE PROVIDER AT
ANY TIME, WITH OR WITHOUT CAUSE. 
 Participant acknowledges receipt of a copy of the Plan and represents that he or she is familiar with
the terms and provisions thereof, and hereby accepts this Option subject to all of the terms and provisions thereof. Participant has reviewed the Plan and this Option in their entirety, has had an opportunity to obtain the advice of counsel prior to
executing this Option and fully understands all provisions of the Option. Participant hereby agrees to accept as binding, conclusive and final all decisions or interpretations of the Administrator upon any questions arising under the Plan or this
Option. Participant further agrees to notify the Company upon any change in the residence address indicated below. 
  

					
	PARTICIPANT	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
			
	  
	  		  	  

		  		  	Title
			
	  
	  		  	
	Residence Address	  		  	
			
	  
	  		  	
	Date	  		  	


  
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 EXHIBIT A 

2012 EQUITY INCENTIVE PLAN 

EXERCISE NOTICE 
 Allakos Inc. 

75 Shoreway Road 
 San Carlos, CA 94070 

Attention: Secretary 
 1. Exercise of
Option. Effective as of today,                     ,         , the undersigned (“Participant”)
hereby elects to exercise Participant’s option (the “Option”) to purchase                      shares of the Common Stock (the
“Shares”) of Allakos Inc. (the “Company”) under and pursuant to the 2012 Equity Incentive Plan (the “Plan”) and the Stock Option Agreement dated
                 (the “Option Agreement”). 
 2.
Delivery of Payment. Participant herewith delivers to the Company the full purchase price of the Shares, as set forth in the Option Agreement, and any and all withholding taxes due in connection with the exercise of the Option. 

3. Representations of Participant. Participant acknowledges that Participant has received, read and understood the Plan and the Option
Agreement and agrees to abide by and be bound by their terms and conditions. 
 4. Rights as Stockholder. Until the issuance of the
Shares (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), no right to vote or receive dividends or any other rights as a stockholder shall exist with respect to the Common Stock
subject to an Award, notwithstanding the exercise of the Option. The Shares shall be issued to Participant as soon as practicable after the Option is exercised in accordance with the Option Agreement. No adjustment shall be made for a dividend or
other right for which the record date is prior to the date of issuance except as provided in Section 13 of the Plan. 
 5.
Company’s Right of First Refusal. Before any Shares held by Participant or any transferee (either being sometimes referred to herein as the “Holder”) may be sold or otherwise transferred (including transfer by
gift or operation of law), the Company or its assignee(s) shall have a right of first refusal to purchase the Shares on the terms and conditions set forth in this Section 5 (the “Right of First Refusal”). 

(a) Notice of Proposed Transfer. The Holder of the Shares shall deliver to the Company a written notice (the “Notice”)
stating: (i) the Holder’s bona fide intention to sell or otherwise transfer such Shares; (ii) the name of each proposed purchaser or other transferee (“Proposed Transferee”); (iii) the number of Shares to be transferred
to each Proposed Transferee; and (iv) the bona fide cash price or other consideration for which the Holder proposes to transfer the Shares (the “Offered Price”), and the Holder shall offer the Shares at the Offered Price to the
Company or its assignee(s). 







 (b) Exercise of Right of First Refusal. At any time within thirty (30) days after
receipt of the Notice, the Company and/or its assignee(s) may, by giving written notice to the Holder, elect to purchase all, but not less than all, of the Shares proposed to be transferred to any one or more of the Proposed Transferees, at the
purchase price determined in accordance with subsection (c) below. 
 (c) Purchase Price. The purchase price (“Purchase
Price”) for the Shares purchased by the Company or its assignee(s) under this Section 5 shall be the Offered Price. If the Offered Price includes consideration other than cash, the cash equivalent value of the non-cash consideration shall be determined by the Board of Directors of the Company in good faith. 
 (d)
Payment. Payment of the Purchase Price shall be made, at the option of the Company or its assignee(s), in cash (by check), by cancellation of all or a portion of any outstanding indebtedness of the Holder to the Company (or, in the case of
repurchase by an assignee, to the assignee), or by any combination thereof within thirty (30) days after receipt of the Notice or in the manner and at the times set forth in the Notice. 

(e) Holder’s Right to Transfer. If all of the Shares proposed in the Notice to be transferred to a given Proposed Transferee are
not purchased by the Company and/or its assignee(s) as provided in this Section 5, then the Holder may sell or otherwise transfer such Shares to that Proposed Transferee at the Offered Price or at a higher price, provided that such sale
or other transfer is consummated within one hundred and twenty (120) days after the date of the Notice, that any such sale or other transfer is effected in accordance with any applicable securities laws and that the Proposed Transferee agrees
in writing that the provisions of this Section 5 shall continue to apply to the Shares in the hands of such Proposed Transferee. If the Shares described in the Notice are not transferred to the Proposed Transferee within such period, a new
Notice shall be given to the Company, and the Company and/or its assignees shall again be offered the Right of First Refusal before any Shares held by the Holder may be sold or otherwise transferred. 

(f) Exception for Certain Family Transfers. Anything to the contrary contained in this Section 5 notwithstanding, the transfer of
any or all of the Shares during the Participant’s lifetime or on the Participant’s death by will or intestacy to the Participant’s immediate family or a trust for the benefit of the Participant’s immediate family shall be exempt
from the provisions of this Section 5. “Immediate Family” as used herein shall mean spouse, lineal descendant or antecedent, father, mother, brother or sister. In such case, the transferee or other recipient shall receive and hold the
Shares so transferred subject to the provisions of this Section 5, and there shall be no further transfer of such Shares except in accordance with the terms of this Section 5. 

(g) Termination of Right of First Refusal. The Right of First Refusal shall terminate as to any Shares upon the earlier of (i) the
first sale of Common Stock of the Company to the general public, or (ii) a Change in Control in which the successor corporation has equity securities that are publicly traded. 

  
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 6. Tax Consultation. Participant understands that Participant may suffer adverse tax
consequences as a result of Participant’s purchase or disposition of the Shares. Participant represents that Participant has consulted with any tax consultants Participant deems advisable in connection with the purchase or disposition of the
Shares and that Participant is not relying on the Company for any tax advice. 
 7. Restrictive Legends and Stop-Transfer Orders.

 (a) Legends. Participant understands and agrees that the Company shall cause the legends set forth below or legends substantially
equivalent thereto, to be placed upon any certificate(s) evidencing ownership of the Shares together with any other legends that may be required by the Company or by state or federal securities laws: 

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 (THE “ACT”) AND MAY NOT BE OFFERED, SOLD
OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTIL REGISTERED UNDER THE ACT OR, IN THE OPINION OF COUNSEL SATISFACTORY TO THE ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR TRANSFER, PLEDGE OR HYPOTHECATION IS IN COMPLIANCE
THEREWITH. 
 THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON TRANSFER AND A RIGHT OF FIRST REFUSAL HELD BY
THE ISSUER OR ITS ASSIGNEE(S) AS SET FORTH IN THE EXERCISE NOTICE BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH TRANSFER RESTRICTIONS AND RIGHT OF FIRST
REFUSAL ARE BINDING ON TRANSFEREES OF THESE SHARES. 
 THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO RESTRICTIONS ON TRANSFER FOR
A PERIOD OF TIME FOLLOWING THE EFFECTIVE DATE OF THE UNDERWRITTEN PUBLIC OFFERING OF THE COMPANY’S SECURITIES SET FORTH IN AN AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES AND MAY NOT BE SOLD OR OTHERWISE DISPOSED OF BY
THE HOLDER PRIOR TO THE EXPIRATION OF SUCH PERIOD WITHOUT THE CONSENT OF THE COMPANY OR THE MANAGING UNDERWRITER. 
 (b) Stop-Transfer
Notices. Participant agrees that, in order to ensure compliance with the restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers
its own securities, it may make appropriate notations to the same effect in its own records. 

  
 -3- 








 (c) Refusal to Transfer. The Company shall not be required (i) to transfer on its
books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Exercise Notice or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or other
transferee to whom such Shares shall have been so transferred. 
 8. Successors and Assigns. The Company may assign any of its rights
under this Exercise Notice to single or multiple assignees, and this Exercise Notice shall inure to the benefit of the successors and assigns of the Company. Subject to the restrictions on transfer herein set forth, this Exercise Notice shall be
binding upon Participant and his or her heirs, executors, administrators, successors and assigns. 
 9. Interpretation. Any dispute
regarding the interpretation of this Exercise Notice shall be submitted by Participant or by the Company forthwith to the Administrator, which shall review such dispute at its next regular meeting. The resolution of such a dispute by the
Administrator shall be final and binding on all parties. 
 10. Governing Law; Severability. This Exercise Notice is governed by the
internal substantive laws, but not the choice of law rules, of California. In the event that any provision hereof becomes or is declared by a court of competent jurisdiction to be illegal, unenforceable or void, this Exercise Notice shall continue
in full force and effect. 
 11. Entire Agreement. The Plan and Option Agreement are incorporated herein by reference. This Exercise
Notice, the Plan, the Option Agreement and the Investment Representation Statement constitute the entire agreement of the parties with respect to the subject matter hereof and supersede in their entirety all prior undertakings and agreements of the
Company and Participant with respect to the subject matter hereof, and may not be modified adversely to the Participant’s interest except by means of a writing signed by the Company and Participant. 

 

					
	Submitted by:	  		  	Accepted by:
	PARTICIPANT	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
		  		  	  

		  		  	Title
			
	Address:	  		  	Address:
			
	  
	  		  	 75 Shoreway Road

			
	  
	  		  	 San Carlos, CA 94070

			
		  		  	  

		  		  	Date Received


  
 -4- 








 EXHIBIT B 

INVESTMENT REPRESENTATION STATEMENT 
  

					
	PARTICIPANT	    	:	    	
			
	COMPANY	    	:	    	ALLAKOS INC.
			
	SECURITY	    	:	    	COMMON STOCK
			
	AMOUNT	    	:	    	
			
	DATE	    	:	    	

 In connection with the purchase of the above-listed Securities, the undersigned Participant represents to the
Company the following: 
 (a) Participant is aware of the Company’s business affairs and financial condition and has acquired sufficient
information about the Company to reach an informed and knowledgeable decision to acquire the Securities. Participant is acquiring these Securities for investment for Participant’s own account only and not with a view to, or for resale in
connection with, any “distribution” thereof within the meaning of the Securities Act of 1933, as amended (the “Securities Act”). 

(b) Participant acknowledges and understands that the Securities constitute “restricted securities” under the Securities Act and have
not been registered under the Securities Act in reliance upon a specific exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Participant’s investment intent as expressed herein. In this connection,
Participant understands that, in the view of the Securities and Exchange Commission, the statutory basis for such exemption may be unavailable if Participant’s representation was predicated solely upon a present intention to hold these
Securities for the minimum capital gains period specified under tax statutes, for a deferred sale, for or until an increase or decrease in the market price of the Securities, or for a period of one (1) year or any other fixed period in the
future. Participant further understands that the Securities must be held indefinitely unless they are subsequently registered under the Securities Act or an exemption from such registration is available. Participant further acknowledges and
understands that the Company is under no obligation to register the Securities. Participant understands that the certificate evidencing the Securities shall be imprinted with any legend required under applicable state securities laws. 

(c) Participant is familiar with the provisions of Rule 701 and Rule 144, each promulgated under the Securities Act, which, in
substance, permit limited public resale of “restricted securities” acquired, directly or indirectly from the issuer thereof, in a non-public offering subject to the satisfaction of certain
conditions. Rule 701 provides that if the issuer qualifies under Rule 701 at the time of the grant of the Option to Participant, the exercise shall be exempt from registration under the Securities Act. In the event the Company becomes
subject to the reporting requirements of 







 
Section 13 or 15(d) of the Securities Exchange Act of 1934, ninety (90) days thereafter (or such longer period as any market stand-off agreement
may require) the Securities exempt under Rule 701 may be resold, subject to the satisfaction of the applicable conditions specified by Rule 144, including in the case of affiliates (1) the availability of certain public information
about the Company, (2) the amount of Securities being sold during any three (3) month period not exceeding specified limitations, (3) the resale being made in an unsolicited “broker’s transaction”, transactions directly
with a “market maker” or “riskless principal transactions” (as those terms are defined under the Securities Exchange Act of 1934) and (4) the timely filing of a Form 144, if applicable. 

In the event that the Company does not qualify under Rule 701 at the time of grant of the Option, then the Securities may be resold in
certain limited circumstances subject to the provisions of Rule 144, which may require (i) the availability of current public information about the Company; (ii) the resale to occur more than a specified period after the purchase and
full payment (within the meaning of Rule 144) for the Securities; and (iii) in the case of the sale of Securities by an affiliate, the satisfaction of the conditions set forth in sections (2), (3) and (4) of the paragraph
immediately above. 
 (d) Participant further understands that in the event all of the applicable requirements of Rule 701 or 144 are
not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption shall be required; and that, notwithstanding the fact that Rules 144 and 701 are not exclusive, the Staff of the Securities
and Exchange Commission has expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rules 144 or 701 shall have a substantial burden of proof in
establishing that an exemption from registration is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk. Participant understands that no assurances can
be given that any such other registration exemption shall be available in such event. 
  

	
	PARTICIPANT
	
	  

	Signature
	
	  

	Print Name
	
	  

	Date



  
 -2- 








 ALLAKOS INC. 

2012 EQUITY INCENTIVE PLAN 

STOCK OPTION AGREEMENT — EARLY EXERCISE 

Unless otherwise defined herein, the terms defined in the 2012 Equity Incentive Plan (the “Plan”) shall have the same defined
meanings in this Stock Option Agreement – Early Exercise (the “Option Agreement”). 
  

	I.	NOTICE OF STOCK OPTION GRANT 

 Name: 

Address: 
 The undersigned
Participant has been granted an Option to purchase Common Stock of the Company, subject to the terms and conditions of the Plan and this Option Agreement, as follows: 

 

			
	Date of Grant:	  	  

		
	Vesting Commencement Date:	  	  

		
	Exercise Price per Share:	  	  

		
	Total Number of Shares Granted:	  	
		
	Total Exercise Price:	  	
		
	Type of Option:	  	________ Incentive Stock Option (ISO)
		
		  	________ Nonstatutory Stock Option (NSO)
		
	Term/Expiration Date:	  	


 Vesting Schedule: 

This Option shall be exercisable, in whole or in part, according to the following vesting schedule: 

Twenty-five percent (25%) of the Shares subject to the Option shall vest on the one (1) year anniversary of the Vesting Commencement Date,
and one forty-eighth (1/48th) of the Shares subject to the Option shall vest each month thereafter on the same day of the month as the Vesting Commencement Date (and if there is no corresponding
day, on the last day of the month), subject to Participant continuing to be a Service Provider through each such date. 







 Termination Period: 

This Option shall be exercisable for three (3) months after Participant ceases to be a Service Provider, unless such termination is due to
Participant’s death or Disability, in which case this Option shall be exercisable for twelve (12) months after Participant ceases to be a Service Provider. Notwithstanding the foregoing sentence, in no event may this Option be exercised
after the Term/Expiration Date as provided above and this Option may be subject to earlier termination as provided in Section 13 of the Plan. 
  

	II.	AGREEMENT 

 1. Grant of Option. The Administrator of the Company hereby
grants to the Participant named in the Notice of Stock Option Grant in Part I of this Agreement (“Participant”), an option (the “Option”) to purchase the number of Shares set forth in the Notice of Stock Option Grant, at the
exercise price per Share set forth in the Notice of Stock Option Grant (the “Exercise Price”), and subject to the terms and conditions of the Plan, which is incorporated herein by reference. Subject to Section 18 of the Plan, in the
event of a conflict between the terms and conditions of the Plan and this Option Agreement, the terms and conditions of the Plan shall prevail. 

If designated in the Notice of Stock Option Grant as an Incentive Stock Option (“ISO”), this Option is intended to qualify as an
Incentive Stock Option as defined in Section 422 of the Code. Nevertheless, to the extent that it exceeds the $100,000 rule of Code Section 422(d), this Option shall be treated as a Nonstatutory Stock Option (“NSO”). Further, if
for any reason this Option (or portion thereof) shall not qualify as an ISO, then, to the extent of such nonqualification, such Option (or portion thereof) shall be regarded as a NSO granted under the Plan. In no event shall the Administrator, the
Company or any Parent or Subsidiary or any of their respective employees or directors have any liability to Participant (or any other person) due to the failure of the Option to qualify for any reason as an ISO. 

2. Exercise of Option. This Option shall be exercisable during its term in accordance with the provisions of Section 6 of the Plan
as follows: 
 (a) Right to Exercise. 

(i) Subject to subsections 2(a)(ii) and 2(a)(iii) below, this Option shall be exercisable cumulatively according to the vesting schedule
set forth in the Notice of Stock Option Grant. Alternatively, at the election of Participant, this Option may be exercised in whole or in part at any time as to Shares that have not yet vested. Vested Shares shall not be subject to the
Company’s repurchase right (as set forth in the Restricted Stock Purchase Agreement, attached hereto as Exhibit C-1). 

(ii) As a condition to exercising this Option for unvested Shares, Participant shall execute the Restricted Stock Purchase Agreement. 

(iii) This Option may not be exercised for a fraction of a Share. 

  
 -2- 








 (b) Method of Exercise. This Option shall be exercisable by delivery of an exercise notice
in the form attached as Exhibit A (the “Exercise Notice”) or in a manner and pursuant to such procedures as the Administrator may determine, which shall state the election to exercise the Option, the number of Shares with respect to
which the Option is being exercised (the “Exercised Shares”), and such other representations and agreements as may be required by the Company. The Exercise Notice shall be accompanied by payment of the aggregate Exercise Price as to all
Exercised Shares, together with any applicable tax withholding. This Option shall be deemed to be exercised upon receipt by the Company of such fully executed Exercise Notice accompanied by the aggregate Exercise Price, together with any applicable
tax withholding. 
 No Shares shall be issued pursuant to the exercise of an Option unless such issuance and such exercise comply with
Applicable Laws. Assuming such compliance, for income tax purposes the Shares shall be considered transferred to Participant on the date on which the Option is exercised with respect to such Shares. 

3. Participant’s Representations. In the event the Shares have not been registered under the Securities Act of 1933, as amended
(the “Securities Act”), at the time this Option is exercised, Participant shall, if required by the Company, concurrently with the exercise of all or any portion of this Option, deliver to the Company his or her Investment Representation
Statement in the form attached hereto as Exhibit B. 
 4. Lock-Up
Period. Participant hereby agrees that Participant shall not offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or
otherwise transfer or dispose of, directly or indirectly, any Common Stock (or other securities) of the Company or enter into any swap, hedging or other arrangement that transfers to another, in whole or in part, any of the economic consequences of
ownership of any Common Stock (or other securities) of the Company held by Participant (other than those included in the registration) for a period specified by the representative of the underwriters of Common Stock (or other securities) of the
Company not to exceed one hundred and eighty (180) days following the effective date of any registration statement of the Company filed under the Securities Act (or such other period as may be requested by the Company or the underwriters to
accommodate regulatory restrictions on (i) the publication or other distribution of research reports and (ii) analyst recommendations and opinions, including, but not limited to, the restrictions contained in NASD Rule 2711(f)(4) or
NYSE Rule 472(f)(4), or any successor provisions or amendments thereto). 
 Participant agrees to execute and deliver such other
agreements as may be reasonably requested by the Company or the underwriter which are consistent with the foregoing or which are necessary to give further effect thereto. In addition, if requested by the Company or the representative of the
underwriters of Common Stock (or other securities) of the Company, Participant shall provide, within ten (10) days of such request, such information as may be required by the Company or such representative in connection with the completion of
any public offering of the Company’s securities pursuant to a registration statement filed under the Securities Act. The obligations described in this Section 4 shall not apply to a registration relating solely to employee benefit plans on
Form S-1 or Form S-8 or similar forms that may be promulgated in the future, or a registration relating solely to a Commission Rule 145 transaction on Form S-4 or similar forms that may be promulgated in the future. The Company may impose stop-transfer instructions with respect to the shares of Common Stock (or other securities) subject to the foregoing restriction
until the end of said one hundred and eighty (180) day (or other) period. Participant agrees that any transferee of the Option or shares acquired pursuant to the Option shall be bound by this Section 4. 

  
 -3- 








 5. Method of Payment. Payment of the aggregate Exercise Price shall be by any of the
following, or a combination thereof, at the election of the Participant: 
 (a) cash; 

(b) check; 
 (c) consideration
received by the Company under a formal cashless exercise program adopted by the Company in connection with the Plan; or 
 (d) surrender of
other Shares which (i) shall be valued at its Fair Market Value on the date of exercise, and (ii) must be owned free and clear of any liens, claims, encumbrances or security interests, if accepting such Shares, in the sole discretion of
the Administrator, shall not result in any adverse accounting consequences to the Company. 
 6. Restrictions on Exercise. This
Option may not be exercised until such time as the Plan has been approved by the stockholders of the Company, or if the issuance of such Shares upon such exercise or the method of payment of consideration for such shares would constitute a violation
of any Applicable Law. 
 7. Non-Transferability of Option. 

(a) This Option may not be transferred in any manner otherwise than by will or by the laws of descent or distribution and may be exercised
during the lifetime of Participant only by Participant. The terms of the Plan and this Option Agreement shall be binding upon the executors, administrators, heirs, successors and assigns of Participant. 

(b) Further, until the Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Exchange Act, or after the
Administrator determines that it is, will, or may no longer be relying upon the exemption from registration of Options under the Exchange Act as set forth in Rule 12h-1(f) promulgated under the Exchange Act
(the “Reliance End Date”), Participant shall not transfer this Option or, prior to exercise, the Shares subject to this Option, in any manner other than (i) to persons who are “family members” (as defined in Rule 701(c)(3)
of the Securities Act) through gifts or domestic relations orders, or (ii) to an executor or guardian of Participant upon the death or disability of Participant. Until the Reliance End Date, the Options and, prior to exercise, the Shares
subject to this Option, may not be pledged, hypothecated or otherwise transferred or disposed of, including by entering into any short position, any “put equivalent position” or any “call equivalent position” (as defined in Rule 16a-1(h) and Rule 16a-1(b) of the Exchange Act, respectively), other than as permitted in clauses (i) and (ii) of this paragraph. 

8. Term of Option. This Option may be exercised only within the term set out in the Notice of Stock Option Grant, and may be exercised
during such term only in accordance with the Plan and the terms of this Option Agreement. 

  
 -4- 








 9. Tax Obligations. 

(a) Tax Withholding. Participant agrees to make appropriate arrangements with the Company (or the Parent or Subsidiary employing or
retaining Participant) for the satisfaction of all Federal, state, local and foreign income and employment tax withholding requirements applicable to the Option exercise. Participant acknowledges and agrees that the Company may refuse to honor the
exercise and refuse to deliver the Shares if such withholding amounts are not delivered at the time of exercise. 
 (b) Notice of
Disqualifying Disposition of ISO Shares. If the Option granted to Participant herein is an ISO, and if Participant sells or otherwise disposes of any of the Shares acquired pursuant to the ISO on or before the later of (i) the date two
(2) years after the Date of Grant, or (ii) the date one (1) year after the date of exercise, Participant shall immediately notify the Company in writing of such disposition. Participant agrees that Participant may be subject to income
tax withholding by the Company on the compensation income recognized by Participant. 
 (c) Code Section 409A.
Under Code Section 409A, an Option that vests after December 31, 2004 (or that vested on or prior to such date but which was materially modified after October 3, 2004) that was granted with a per Share exercise price that is
determined by the Internal Revenue Service (the “IRS”) to be less than the Fair Market Value of a Share on the date of grant (a “discount option”) may be considered “deferred compensation.” An Option that is a
“discount option” may result in (i) income recognition by Participant prior to the exercise of the Option, (ii) an additional twenty percent (20%) federal income tax, and (iii) potential penalty and interest charges. The
“discount option” may also result in additional state income, penalty and interest tax to the Participant. Participant acknowledges that the Company cannot and has not guaranteed that the IRS will agree that the per Share exercise price of
this Option equals or exceeds the Fair Market Value of a Share on the date of grant in a later examination. Participant agrees that if the IRS determines that the Option was granted with a per Share exercise price that was less than the Fair Market
Value of a Share on the date of grant, Participant shall be solely responsible for Participant’s costs related to such a determination. 

10. Entire Agreement; Governing Law. The Plan is incorporated herein by reference. The Plan and this Option Agreement constitute the
entire agreement of the parties with respect to the subject matter hereof and supersede in their entirety all prior undertakings and agreements of the Company and Participant with respect to the subject matter hereof, and may not be modified
adversely to the Participant’s interest except by means of a writing signed by the Company and Participant. This Option Agreement is governed by the internal substantive laws but not the choice of law rules of California. 

11. No Guarantee of Continued Service. PARTICIPANT ACKNOWLEDGES AND AGREES THAT THE VESTING OF SHARES PURSUANT TO THE VESTING SCHEDULE
HEREOF IS EARNED ONLY BY CONTINUING AS A SERVICE PROVIDER AT THE WILL OF THE COMPANY (OR THE PARENT OR SUBSIDIARY EMPLOYING OR RETAINING PARTICIPANT) AND NOT THROUGH THE ACT OF BEING HIRED, BEING GRANTED THIS OPTION OR ACQUIRING SHARES HEREUNDER.
PARTICIPANT FURTHER ACKNOWLEDGES AND AGREES THAT THIS AGREEMENT, THE TRANSACTIONS CONTEMPLATED HEREUNDER AND THE VESTING SCHEDULE SET FORTH HEREIN DO NOT CONSTITUTE AN EXPRESS OR IMPLIED PROMISE OF CONTINUED ENGAGEMENT AS A SERVICE PROVIDER FOR THE
VESTING PERIOD, FOR ANY PERIOD, OR AT ALL, 

  
 -5- 








 
AND SHALL NOT INTERFERE IN ANY WAY WITH PARTICIPANT’S RIGHT OR THE RIGHT OF THE COMPANY (OR THE PARENT OR SUBSIDIARY EMPLOYING OR RETAINING PARTICIPANT) TO TERMINATE PARTICIPANT’S
RELATIONSHIP AS A SERVICE PROVIDER AT ANY TIME, WITH OR WITHOUT CAUSE. 
 Participant acknowledges receipt of a copy of the Plan and
represents that he or she is familiar with the terms and provisions thereof, and hereby accepts this Option subject to all of the terms and provisions thereof. Participant has reviewed the Plan and this Option in their entirety, has had an
opportunity to obtain the advice of counsel prior to executing this Option and fully understands all provisions of the Option. Participant hereby agrees to accept as binding, conclusive and final all decisions or interpretations of the Administrator
upon any questions arising under the Plan or this Option. Participant further agrees to notify the Company upon any change in the residence address indicated below. 
  

					
	PARTICIPANT	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
			
	  
	  		  	  

		  		  	Title
			
	  
	  		  	
	Residence Address	  		  	
			
	  
	  		  	
	Date	  		  	


  
 -6- 








 EXHIBIT A 

2012 EQUITY INCENTIVE PLAN 

EXERCISE NOTICE 
 Allakos Inc. 

75 Shoreway Road 
 San Carlos, CA 94070 

Attention: Secretary 
 1. Exercise of
Option. Effective as of today,                     ,             , the undersigned
(“Participant”) hereby elects to exercise Participant’s option (the “Option”) to purchase                      shares of the
Common Stock (the “Shares”) of Allakos Inc. (the “Company”) under and pursuant to the 2012 Equity Incentive Plan (the “Plan”) and the Stock Option Agreement – Early Exercise
dated             (the “Option Agreement”). 
 2. Delivery of
Payment. Participant herewith delivers to the Company the full purchase price of the Shares, as set forth in the Option Agreement, and any and all withholding taxes due in connection with the exercise of the Option. 

3. Representations of Participant. Participant acknowledges that Participant has received, read and understood the Plan and the Option
Agreement and agrees to abide by and be bound by their terms and conditions. 
 4. Rights as Stockholder. Until the issuance of the
Shares (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), no right to vote or receive dividends or any other rights as a stockholder shall exist with respect to the Common Stock
subject to an Award, notwithstanding the exercise of the Option. The Shares shall be issued to Participant as soon as practicable after the Option is exercised in accordance with the Option Agreement. No adjustment shall be made for a dividend or
other right for which the record date is prior to the date of issuance except as provided in Section 13 of the Plan. 
 5.
Company’s Right of First Refusal. Before any Shares held by Participant or any transferee (either being sometimes referred to herein as the “Holder”) may be sold or otherwise transferred (including transfer by gift or operation
of law), the Company or its assignee(s) shall have a right of first refusal to purchase the Shares on the terms and conditions set forth in this Section 5 (the “Right of First Refusal”). 

(a) Notice of Proposed Transfer. The Holder of the Shares shall deliver to the Company a written notice (the “Notice”)
stating: (i) the Holder’s bona fide intention to sell or otherwise transfer such Shares; (ii) the name of each proposed purchaser or other transferee (“Proposed Transferee”); (iii) the number of Shares to be transferred
to each Proposed Transferee; and (iv) the bona fide cash price or other consideration for which the Holder proposes to transfer the Shares (the “Offered Price”), and the Holder shall offer the Shares at the Offered Price to the
Company or its assignee(s). 







 (b) Exercise of Right of First Refusal. At any time within thirty (30) days after
receipt of the Notice, the Company and/or its assignee(s) may, by giving written notice to the Holder, elect to purchase all, but not less than all, of the Shares proposed to be transferred to any one or more of the Proposed Transferees, at the
purchase price determined in accordance with subsection (c) below. 
 (c) Purchase Price. The purchase price (“Purchase
Price”) for the Shares purchased by the Company or its assignee(s) under this Section 5 shall be the Offered Price. If the Offered Price includes consideration other than cash, the cash equivalent value of the non-cash consideration shall be determined by the Board of Directors of the Company in good faith. 
 (d)
Payment. Payment of the Purchase Price shall be made, at the option of the Company or its assignee(s), in cash (by check), by cancellation of all or a portion of any outstanding indebtedness of the Holder to the Company (or, in the case of
repurchase by an assignee, to the assignee), or by any combination thereof within thirty (30) days after receipt of the Notice or in the manner and at the times set forth in the Notice. 

(e) Holder’s Right to Transfer. If all of the Shares proposed in the Notice to be transferred to a given Proposed Transferee are
not purchased by the Company and/or its assignee(s) as provided in this Section 5, then the Holder may sell or otherwise transfer such Shares to that Proposed Transferee at the Offered Price or at a higher price, provided that such sale or
other transfer is consummated within one hundred and twenty (120) days after the date of the Notice, that any such sale or other transfer is effected in accordance with any applicable securities laws and that the Proposed Transferee agrees in
writing that the provisions of this Section 5 shall continue to apply to the Shares in the hands of such Proposed Transferee. If the Shares described in the Notice are not transferred to the Proposed Transferee within such period, a new Notice
shall be given to the Company, and the Company and/or its assignees shall again be offered the Right of First Refusal before any Shares held by the Holder may be sold or otherwise transferred. 

(f) Exception for Certain Family Transfers. Anything to the contrary contained in this Section 5 notwithstanding, the transfer of
any or all of the Shares during the Participant’s lifetime or on the Participant’s death by will or intestacy to the Participant’s immediate family or a trust for the benefit of the Participant’s immediate family shall be exempt
from the provisions of this Section 5. “Immediate Family” as used herein shall mean spouse, lineal descendant or antecedent, father, mother, brother or sister. In such case, the transferee or other recipient shall receive and hold the
Shares so transferred subject to the provisions of this Section 5, and there shall be no further transfer of such Shares except in accordance with the terms of this Section 5. 

(g) Termination of Right of First Refusal. The Right of First Refusal shall terminate as to any Shares upon the earlier of (i) the
first sale of Common Stock of the Company to the general public, or (ii) a Change in Control in which the successor corporation has equity securities that are publicly traded. 

6. Tax Consultation. Participant understands that Participant may suffer adverse tax consequences as a result of Participant’s
purchase or disposition of the Shares. Participant represents that Participant has consulted with any tax consultants Participant deems advisable in connection with the purchase or disposition of the Shares and that Participant is not relying on the
Company for any tax advice. 

  
 -2- 








 7. Restrictive Legends and Stop-Transfer Orders. 

(a) Legends. Participant understands and agrees that the Company shall cause the legends set forth below or legends substantially
equivalent thereto, to be placed upon any certificate(s) evidencing ownership of the Shares together with any other legends that may be required by the Company or by state or federal securities laws: 

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 (THE “ACT”) AND MAY NOT BE OFFERED, SOLD
OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTIL REGISTERED UNDER THE ACT OR, IN THE OPINION OF COUNSEL SATISFACTORY TO THE ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR TRANSFER, PLEDGE OR HYPOTHECATION IS IN COMPLIANCE
THEREWITH. 
 THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON TRANSFER AND A RIGHT OF FIRST REFUSAL HELD BY
THE ISSUER OR ITS ASSIGNEE(S) AS SET FORTH IN THE EXERCISE NOTICE BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH TRANSFER RESTRICTIONS AND RIGHT OF FIRST
REFUSAL ARE BINDING ON TRANSFEREES OF THESE SHARES. 
 THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO RESTRICTIONS ON TRANSFER FOR
A PERIOD OF TIME FOLLOWING THE EFFECTIVE DATE OF THE UNDERWRITTEN PUBLIC OFFERING OF THE COMPANY’S SECURITIES SET FORTH IN AN AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES AND MAY NOT BE SOLD OR OTHERWISE DISPOSED OF BY
THE HOLDER PRIOR TO THE EXPIRATION OF SUCH PERIOD WITHOUT THE CONSENT OF THE COMPANY OR THE MANAGING UNDERWRITER. 
 (b) Stop-Transfer
Notices. Participant agrees that, in order to ensure compliance with the restrictions referred to herein, the Company may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers
its own securities, it may make appropriate notations to the same effect in its own records. 
 (c) Refusal to Transfer. The
Company shall not be required (i) to transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Exercise Notice or (ii) to treat as owner of such Shares or to accord the
right to vote or pay dividends to any purchaser or other transferee to whom such Shares shall have been so transferred. 

  
 -3- 








 8. Successors and Assigns. The Company may assign any of its rights under this Exercise
Notice to single or multiple assignees, and this Exercise Notice shall inure to the benefit of the successors and assigns of the Company. Subject to the restrictions on transfer herein set forth, this Exercise Notice shall be binding upon
Participant and his or her heirs, executors, administrators, successors and assigns. 
 9. Interpretation. Any dispute regarding the
interpretation of this Exercise Notice shall be submitted by Participant or by the Company forthwith to the Administrator, which shall review such dispute at its next regular meeting. The resolution of such a dispute by the Administrator shall be
final and binding on all parties. 
 10. Governing Law; Severability. This Exercise Notice is governed by the internal substantive
laws, but not the choice of law rules, of California. In the event that any provision hereof becomes or is declared by a court of competent jurisdiction to be illegal, unenforceable or void, this Exercise Notice shall continue in full force and
effect. 
 11. Entire Agreement. The Plan and Option Agreement are incorporated herein by reference. This Exercise Notice, the Plan,
the Restricted Stock Purchase Agreement, the Option Agreement and the Investment Representation Statement constitute the entire agreement of the parties with respect to the subject matter hereof and supersede in their entirety all prior undertakings
and agreements of the Company and Participant with respect to the subject matter hereof, and may not be modified adversely to the Participant’s interest except by means of a writing signed by the Company and Participant. 

 

					
	Submitted by:	  		  	Accepted by:
	PARTICIPANT	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
		  		  	  

		  		  	Title
			
	Address:	  		  	Address:
			
	  
	  		  	 75 Shoreway Road

			
	  
	  		  	 San Carlos, CA 94070

			
		  		  	  

		  		  	Date Received


  
 -4- 








 EXHIBIT B 

INVESTMENT REPRESENTATION STATEMENT 
  

					
	PARTICIPANT	 	:	    	
			
	COMPANY	 	:	    	ALLAKOS INC.
			
	SECURITY	 	:	    	COMMON STOCK
			
	AMOUNT	 	:	    	
			
	DATE	 	:	    	

 In connection with the purchase of the above-listed Securities, the undersigned Participant represents to the Company the
following: 
 (a) Participant is aware of the Company’s business affairs and financial condition and has acquired sufficient information
about the Company to reach an informed and knowledgeable decision to acquire the Securities. Participant is acquiring these Securities for investment for Participant’s own account only and not with a view to, or for resale in connection with,
any “distribution” thereof within the meaning of the Securities Act of 1933, as amended (the “Securities Act”). 
 (b)
Participant acknowledges and understands that the Securities constitute “restricted securities” under the Securities Act and have not been registered under the Securities Act in reliance upon a specific exemption therefrom, which exemption
depends upon, among other things, the bona fide nature of Participant’s investment intent as expressed herein. In this connection, Participant understands that, in the view of the Securities and Exchange Commission, the statutory basis for such
exemption may be unavailable if Participant’s representation was predicated solely upon a present intention to hold these Securities for the minimum capital gains period specified under tax statutes, for a deferred sale, for or until an
increase or decrease in the market price of the Securities, or for a period of one (1) year or any other fixed period in the future. Participant further understands that the Securities must be held indefinitely unless they are subsequently
registered under the Securities Act or an exemption from such registration is available. Participant further acknowledges and understands that the Company is under no obligation to register the Securities. Participant understands that the
certificate evidencing the Securities shall be imprinted with any legend required under applicable state securities laws. 
 (c) Participant
is familiar with the provisions of Rule 701 and Rule 144, each promulgated under the Securities Act, which, in substance, permit limited public resale of “restricted securities” acquired, directly or indirectly from the issuer
thereof, in a non-public offering subject to the satisfaction of certain conditions. Rule 701 provides that if the issuer qualifies under Rule 701 at the time of the grant of the Option to
Participant, the exercise shall be exempt from registration under the Securities Act. In the event the Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, ninety (90) days
thereafter (or such 







 
longer period as any market stand-off agreement may require) the Securities exempt under Rule 701 may be resold, subject to the satisfaction of the
applicable conditions specified by Rule 144, including in the case of affiliates (1) the availability of certain public information about the Company, (2) the amount of Securities being sold during any three (3) month period not
exceeding specified limitations, (3) the resale being made in an unsolicited “broker’s transaction”, transactions directly with a “market maker” or “riskless principal transactions” (as those terms are defined
under the Securities Exchange Act of 1934) and (4) the timely filing of a Form 144, if applicable. 
 In the event that the
Company does not qualify under Rule 701 at the time of grant of the Option, then the Securities may be resold in certain limited circumstances subject to the provisions of Rule 144, which may require (i) the availability of current
public information about the Company; (ii) the resale to occur more than a specified period after the purchase and full payment (within the meaning of Rule 144) for the Securities; and (iii) in the case of the sale of Securities by an
affiliate, the satisfaction of the conditions set forth in sections (2), (3) and (4) of the paragraph immediately above. 
 (d)
Participant further understands that in the event all of the applicable requirements of Rule 701 or 144 are not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption shall be
required; and that, notwithstanding the fact that Rules 144 and 701 are not exclusive, the Staff of the Securities and Exchange Commission has expressed its opinion that persons proposing to sell private placement securities other than in a
registered offering and otherwise than pursuant to Rules 144 or 701 shall have a substantial burden of proof in establishing that an exemption from registration is available for such offers or sales, and that such persons and their respective
brokers who participate in such transactions do so at their own risk. Participant understands that no assurances can be given that any such other registration exemption shall be available in such event. 

 

	
	PARTICIPANT
	
	  

	Signature
	
	  

	Print Name
	
	  

	Date



  
 -2- 








 EXHIBIT C-1 

ALLAKOS INC. 
 2012
EQUITY INCENTIVE PLAN 
 RESTRICTED STOCK PURCHASE AGREEMENT 

THIS RESTRICTED STOCK PURCHASE AGREEMENT (the “Agreement”) is made between
                     (the “Purchaser”) and Allakos Inc. (the “Company”) or its assignees of rights hereunder as of
                    ,             . 

Unless otherwise defined herein, the terms defined in the 2012 Equity Incentive Plan shall have the same defined meanings in this Agreement.

  
 RECITALS 

A. Pursuant to the exercise of the option (grant number             ) granted to
Purchaser under the Plan and pursuant to the Stock Option Agreement – Early Exercise (the “Option Agreement”) dated
                    ,              by and between the Company and Purchaser with respect
to such grant (the “Option”), which Plan and Option Agreement are hereby incorporated by reference, Purchaser has elected to purchase                  of those
shares of Common Stock which have not become vested under the vesting schedule set forth in the Option Agreement (“Unvested Shares”). The Unvested Shares and the shares subject to the Option Agreement, which have become vested are
sometimes collectively referred to herein as the “Shares.” 
 B. As required by the Option Agreement, as a condition to
Purchaser’s election to exercise the option, Purchaser must execute this Agreement, which sets forth the rights and obligations of the parties with respect to Shares acquired upon exercise of the Option. 

1. Repurchase Option. 

(a) If Purchaser’s status as a Service Provider is terminated for any reason, including for death and Disability, the Company shall have
the right and option for ninety (90) days from such date to purchase from Purchaser, or Purchaser’s personal representative, as the case may be, all of the Purchaser’s Unvested Shares as of the date of such termination at the price
paid by the Purchaser for such Shares (the “Repurchase Option”). 
 (b) Upon the occurrence of such termination, the Company may
exercise its Repurchase Option by delivering personally or by registered mail, to Purchaser (or his or her transferee or legal representative, as the case may be) with a copy to the escrow agent described in Section 2 below, a notice in writing
indicating the Company’s intention to exercise the Repurchase Option AND, at the Company’s option, (i) by delivering to the Purchaser (or the Purchaser’s transferee or legal representative) a check in the amount of the aggregate
repurchase price, or (ii) by the Company canceling an amount of the Purchaser’s indebtedness to the Company equal to the aggregate repurchase price, or (iii) by a combination of (i) and (ii) so that the combined payment and








 
cancellation of indebtedness equals such aggregate repurchase price. Upon delivery of such notice and payment of the aggregate repurchase price in any of the ways described above, the Company
shall become the legal and beneficial owner of the Unvested Shares being repurchased and the rights and interests therein or relating thereto, and the Company shall have the right to retain and transfer to its own name the number of Unvested Shares
being repurchased by the Company. 
 (c) Whenever the Company shall have the right to repurchase Unvested Shares hereunder, the Company may
designate and assign one or more employees, officers, directors or stockholders of the Company or other persons or organizations to exercise all or a part of the Company’s Repurchase Option under this Agreement and purchase all or a part of
such Unvested Shares. 
 (d) If the Company does not elect to exercise the Repurchase Option conferred above by giving the requisite notice
within ninety (90) days following the termination, the Repurchase Option shall terminate. 
 (e) The Repurchase Option shall terminate
in accordance with the vesting schedule contained in Purchaser’s Option Agreement. 
 2. Transferability of the Shares; Escrow.

 (a) Purchaser hereby authorizes and directs the Secretary of the Company, or such other person designated by the Company, to transfer the
Unvested Shares as to which the Repurchase Option has been exercised from Purchaser to the Company. 
 (b) To insure the availability for
delivery of Purchaser’s Unvested Shares upon repurchase by the Company pursuant to the Repurchase Option under Section 1, Purchaser hereby appoints the Secretary, or any other person designated by the Company as escrow agent (the
“Escrow Agent”), as its attorney-in-fact to sell, assign and transfer unto the Company, such Unvested Shares, if any, repurchased by the Company pursuant to
the Repurchase Option and shall, upon execution of this Agreement, deliver and deposit with the Escrow Agent, the share certificates representing the Unvested Shares, together with the stock assignment duly endorsed in blank, attached hereto as
Exhibit C-2. The Unvested Shares and stock assignment shall be held by the Escrow Agent in escrow, pursuant to the Joint Escrow Instructions of the Company and Purchaser attached as Exhibit C-3 hereto, until the Company exercises its Repurchase Option, until such Unvested Shares are vested, or until such time as this Agreement no longer is in effect. Upon vesting of the Unvested Shares, the Escrow
Agent shall promptly deliver to the Purchaser the certificate or certificates representing such Shares in the Escrow Agent’s possession belonging to the Purchaser, and the Escrow Agent shall be discharged of all further obligations hereunder;
provided, however, that the Escrow Agent shall nevertheless retain such certificate or certificates as Escrow Agent if so required pursuant to other restrictions imposed pursuant to this Agreement. 

(c) Neither the Company nor the Escrow Agent shall be liable for any act it may do or omit to do with respect to holding the Shares in escrow
and while acting in good faith and in the exercise of its judgment. 

  
 -2- 








 (d) Transfer or sale of the Shares is subject to restrictions on transfer imposed by any
applicable state and federal securities laws. Any transferee shall hold such Shares subject to all the provisions hereof and the Exercise Notice executed by the Purchaser with respect to any Unvested Shares purchased by Purchaser and shall
acknowledge the same by signing a copy of this Agreement. 
 3. Ownership, Voting Rights, Duties. This Agreement shall not affect in
any way the ownership, voting rights or other rights or duties of Purchaser, except as specifically provided herein. 
 4. Legends.
The share certificate evidencing the Shares issued hereunder shall be endorsed with the following legend (in addition to any legend required under applicable federal and state securities laws): 

THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS UPON TRANSFER AND RIGHTS OF REPURCHASE AS SET FORTH IN AN
AGREEMENT BETWEEN THE COMPANY AND THE STOCKHOLDER, A COPY OF WHICH IS ON FILE WITH THE SECRETARY OF THE COMPANY. 
 5. Adjustment for
Stock Split. All references to the number of Shares and the purchase price of the Shares in this Agreement shall be appropriately adjusted to reflect any stock split, stock dividend or other change in the Shares, which may be made by the Company
pursuant to Section 13 of the Plan after the date of this Agreement. 
 6. Notices. Notices required hereunder shall be given in
person or by registered mail to the address of Purchaser shown on the records of the Company, and to the Company at their respective principal executive offices. 

7. Survival of Terms. This Agreement shall apply to and bind Purchaser and the Company and their respective permitted assignees and
transferees, heirs, legatees, executors, administrators and legal successors. 
 8. Section 83(b) Election.
Purchaser hereby acknowledges that he or she has been informed that, with respect to the exercise of an Option for Unvested Shares, an election (the “Election”) may be filed by the Purchaser with the Internal Revenue Service, within thirty
(30) days of the purchase of the exercised Shares, electing pursuant to Section 83(b) of the Code to be taxed currently on any difference between the purchase price of the exercised Shares and their Fair Market Value on the date of
purchase. In the case of a Nonstatutory Stock Option, this will result in the recognition of taxable income to the Purchaser on the date of exercise, measured by the excess, if any, of the Fair Market Value of the exercised Shares, at the time the
Option is exercised over the purchase price for the exercised Shares. Absent such an Election, taxable income will be measured and recognized by Purchaser at the time or times on which the Company’s Repurchase Option lapses. In the case of an
Incentive Stock Option, such an Election will result in a recognition of income to the Purchaser for alternative minimum tax purposes on the date of exercise, measured by the excess, if any, of the Fair Market Value of the exercised Shares, at the
time the option is exercised, over the purchase price for the exercised Shares. Absent such an Election, alternative minimum taxable income will be measured and recognized by Purchaser at the time or times on which the Company’s Repurchase
Option lapses. 

  
 -3- 








 This discussion is intended only as a summary of the general United States income tax laws that
apply to exercising Options as to Shares that have not yet vested and is accurate only as of the date this form Agreement was approved by the Board. The federal, state and local tax consequences to any particular taxpayer will depend upon his or her
individual circumstances. Purchaser is strongly encouraged to seek the advice of his or her own tax consultants in connection with the purchase of the Shares and the advisability of filing of the Election under Section 83(b) of the Code. A form
of Election under Section 83(b) is attached hereto as Exhibit C-4 for reference. 

PURCHASER ACKNOWLEDGES THAT IT IS PURCHASER’S SOLE RESPONSIBILITY AND NOT THE COMPANY’S TO FILE TIMELY THE ELECTION UNDER
SECTION 83(b) OF THE CODE, EVEN IF PURCHASER REQUESTS THE COMPANY OR ITS REPRESENTATIVE TO MAKE THIS FILING ON PURCHASER’S BEHALF. 

9. Representations. Purchaser has reviewed with his or her own tax advisors the federal, state, local and foreign tax consequences of
this investment and the transactions contemplated by this Agreement. Purchaser is relying solely on such advisors and not on any statements or representations of the Company or any of its agents. Purchaser understands that he or she (and not the
Company) shall be responsible for his or her own tax liability that may arise as a result of this investment or the transactions contemplated by this Agreement. 

10. Entire Agreement; Governing Law. The Plan and Option Agreement are incorporated herein by reference. The Plan, the Option
Agreement, the Exercise Notice, this Agreement, and the Investment Representation Statement constitute the entire agreement of the parties with respect to the subject matter hereof and supersede in their entirety all prior undertakings and
agreements of the Company and Purchaser with respect to the subject matter hereof, and may not be modified adversely to the Purchaser’s interest except by means of a writing signed by the Company and Purchaser. This Agreement is governed by the
internal substantive laws but not the choice of law rules of California. 
 Purchaser represents that he or she has read this Agreement and
is familiar with its terms and provisions. Purchaser hereby agrees to accept as binding, conclusive and final all decisions or interpretations of the Board upon any questions arising under this Agreement. 

IN WITNESS WHEREOF, this Agreement is deemed made as of the date first set forth above. 

 

					
	PARTICIPANT	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
			
	  
	  		  	  

		  		  	Title
			
	  
	  		  	
	Residence Address	  		  	
			
	Dated: _____________________,_____	  		  	


  
 -4- 








 EXHIBIT C-2 

ASSIGNMENT SEPARATE FROM CERTIFICATE 

FOR VALUE RECEIVED I,
                    , hereby sell, assign and transfer unto Allakos Inc.
                 shares of the Common Stock of Allakos Inc. standing in my name of the books of said corporation represented by Certificate No.
                 herewith and do hereby irrevocably constitute and appoint
                     to transfer the said stock on the books of the within named corporation with full power of substitution in the premises. 

This Stock Assignment may be used only in accordance with the Restricted Stock Purchase Agreement between Allakos Inc. and the undersigned
dated                     ,              (the “Agreement”). 

 

			
	Dated: _______________,____	  	Signature:____________________

 INSTRUCTIONS: Please do not fill in any blanks other than the signature line. The purpose of this assignment
is to enable the Company to exercise its “repurchase option,” as set forth in the Agreement, without requiring additional signatures on the part of the Purchaser. 







 EXHIBIT C-3 

JOINT ESCROW INSTRUCTIONS 

_________________, ____ 
 Corporate
SecretaryAllakos Inc. 
 75 Shoreway Road 
 San Carlos, CA 94070

 Dear _________________: 
 As Escrow Agent
for both Allakos Inc. (the “Company”), and the undersigned purchaser of stock of the Company (the “Purchaser”), you are hereby authorized and directed to hold the documents delivered to you pursuant to the terms of that certain
Restricted Stock Purchase Agreement (the “Agreement”) between the Company and the undersigned, in accordance with the following instructions: 

1. In the event the Company and/or any assignee of the Company (referred to collectively for convenience herein as the “Company”)
exercises the Company’s repurchase option set forth in the Agreement, the Company shall give to Purchaser and you a written notice specifying the number of shares of stock to be purchased, the purchase price, and the time for a closing
hereunder at the principal office of the Company. Purchaser and the Company hereby irrevocably authorize and direct you to close the transaction contemplated by such notice in accordance with the terms of said notice. 

2. At the closing, you are directed (a) to date the stock assignments necessary for the transfer in question, (b) to fill in the
number of shares being transferred, and (c) to deliver the stock assignments, together with the certificate evidencing the shares of stock to be transferred, to the Company or its assignee, against the simultaneous delivery to you of the
purchase price (by cash, a check, or some combination thereof) for the number of shares of stock being purchased pursuant to the exercise of the Company’s repurchase option. 

3. Purchaser irrevocably authorizes the Company to deposit with you any certificates evidencing shares of stock to be held by you hereunder
and any additions and substitutions to said shares as defined in the Agreement. Purchaser does hereby irrevocably constitute and appoint you as Purchaser’s
attorney-in-fact and agent for the term of this escrow to execute with respect to such securities all documents necessary or appropriate to make such securities
negotiable and to complete any transaction herein contemplated, including but not limited to the filing with any applicable state blue sky authority of any required applications for consent to, or notice of transfer of, the securities. Subject to
the provisions of this paragraph 3, Purchaser shall exercise all rights and privileges of a stockholder of the Company while the stock is held by you. 

4. Upon written request of the Purchaser, but no more than once per calendar year, unless the Company’s repurchase option has been
exercised, you shall deliver to Purchaser a certificate or certificates representing so many shares of stock as are not then subject to the Company’s repurchase option. Within one hundred and twenty (120) days after cessation of 







 
Purchaser’s continuous employment by or services to the Company, or any parent or subsidiary of the Company, you shall deliver to Purchaser a certificate or certificates representing the
aggregate number of shares held or issued pursuant to the Agreement and not purchased by the Company or its assignees pursuant to exercise of the Company’s repurchase option. 

5. If at the time of termination of this escrow you should have in your possession any documents, securities, or other property belonging to
Purchaser, you shall deliver all of the same to Purchaser and shall be discharged of all further obligations hereunder. 
 6. Your duties
hereunder may be altered, amended, modified or revoked only by a writing signed by all of the parties hereto. 
 7. You shall be obligated
only for the performance of such duties as are specifically set forth herein and may rely and shall be protected in relying or refraining from acting on any instrument reasonably believed by you to be genuine and to have been signed or presented by
the proper party or parties. You shall not be personally liable for any act you may do or omit to do hereunder as Escrow Agent or as attorney-in-fact for Purchaser while
acting in good faith, and any act done or omitted by you pursuant to the advice of your own attorneys shall be conclusive evidence of such good faith. 

8. You are hereby expressly authorized to disregard any and all warnings given by any of the parties hereto or by any other person or
corporation, excepting only orders or process of courts of law and are hereby expressly authorized to comply with and obey orders, judgments or decrees of any court. In case you obey or comply with any such order, judgment or decree, you shall not
be liable to any of the parties hereto or to any other person, firm or corporation by reason of such compliance, notwithstanding any such order, judgment or decree being subsequently reversed, modified, annulled, set aside, vacated or found to have
been entered without jurisdiction. 
 9. You shall not be liable in any respect on account of the identity, authorities or rights of the
parties executing or delivering or purporting to execute or deliver the Agreement or any documents or papers deposited or called for hereunder. 

10. You shall not be liable for the outlawing of any rights under the Statute of Limitations with respect to these Joint Escrow Instructions
or any documents deposited with you. 
 11. You shall be entitled to employ such legal counsel and other experts as you may deem necessary
properly to advise you in connection with your obligations hereunder, may rely upon the advice of such counsel, and may pay such counsel reasonable compensation therefor. 

12. Your responsibilities as Escrow Agent hereunder shall terminate if you shall cease to be an officer or agent of the Company or if you
shall resign by written notice to each party. In the event of any such termination, the Company shall appoint a successor Escrow Agent. 

13. If you reasonably require other or further instruments in connection with these Joint Escrow Instructions or obligations in respect
hereto, the necessary parties hereto shall join in furnishing such instruments. 

  
 -2- 








 14. It is understood and agreed that should any dispute arise with respect to the delivery and/or
ownership or right of possession of the securities held by you hereunder, you are authorized and directed to retain in your possession without liability to anyone all or any part of said securities until such disputes shall have been settled either
by mutual written agreement of the parties concerned or by a final order, decree or judgment of a court of competent jurisdiction after the time for appeal has expired and no appeal has been perfected, but you shall be under no duty whatsoever to
institute or defend any such proceedings. 
 15. Any notice required or permitted hereunder shall be given in writing and shall be deemed
effectively given upon personal delivery or upon deposit in the United States Post Office, by registered or certified mail with postage and fees prepaid, addressed to each of the other parties thereunto entitled at the following addresses or at such
other addresses as a party may designate by ten (10) days’ advance written notice to each of the other parties hereto. 
 16. By
signing these Joint Escrow Instructions, you become a party hereto only for the purpose of said Joint Escrow Instructions; you do not become a party to the Agreement. 

17. This instrument shall be binding upon and inure to the benefit of the parties hereto, and their respective successors and permitted
assigns. 
 18. These Joint Escrow Instructions shall be governed by the internal substantive laws, but not the choice of law rules, of
California. 
  

					
	PURCHASER	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
			
	  
	  		  	  

		  		  	Title
			
	  
	  		  	
	Residence Address	  		  	
			
	ESCROW AGENT	  		  	
			
	  
	  		  	
	Corporate Secretary	  		  	
			
	Dated:______________________________	  		  	


  
 -3- 








 EXHIBIT C-4 

ELECTION UNDER SECTION 83(b) 

OF THE INTERNAL REVENUE CODE OF 1986 
 The
undersigned taxpayer hereby elects, pursuant to Sections 55 and 83(b) of the Internal Revenue Code of 1986, as amended, to include in taxpayer’s gross income or alternative minimum taxable income, as the case may be, for the current taxable
year the amount of any compensation taxable to taxpayer in connection with taxpayer’s receipt of the property described below. 
  

	1.	The name, address, taxpayer identification number and taxable year of the undersigned are as follows: 

  

							
		  	TAXPAYER	  		  	SPOUSE
	NAME:	  	  
	  		  	  

	ADDRESS:	  	  
	  		  	  

		  	  
	  		  	  

	TAX ID NO.:	  	  
	  		  	  

	TAXABLE YEAR:      	  	_______	  		  	


  

	2.	The property with respect to which the election is made is described as follows: __________ shares (the “Shares”) of the Common Stock of Allakos Inc. (the “Company”). 


 

	3.	The date on which the property was transferred is:___________________ ,______. 

  

	4.	The property is subject to the following restrictions: 

 The Shares may not be transferred and
are subject to forfeiture under the terms of an agreement between the taxpayer and the Company. These restrictions lapse upon the satisfaction of certain conditions contained in such agreement. 

 

	5.	The Fair Market Value at the time of transfer, determined without regard to any restriction other than a restriction which by its terms shall never lapse, of such property is: $_________________. 


 

	6.	The amount (if any) paid for such property is: $_________________. 

 The undersigned has submitted a copy of
this statement to the person for whom the services were performed in connection with the undersigned’s receipt of the above-described property. The transferee of such property is the person performing the services in connection with the
transfer of said property. 
 The undersigned understands that the foregoing election may not be revoked except with the consent of the Commissioner.

  

			
	Dated: ______________________, _____	 	  

		 	Taxpayer
		
	The undersigned spouse of taxpayer joins in this election.	 	
		
	Dated: ______________________, _____	 	  

		 	Spouse of Taxpayer








 ALLAKOS INC. 

2012 EQUITY INCENTIVE PLAN 

RESTRICTED STOCK PURCHASE AGREEMENT 

Unless otherwise defined herein, the terms defined in the 2012 Equity Incentive Plan (the “Plan”) shall have the same defined
meanings in this Restricted Stock Purchase Agreement (the “Agreement”). 
  

	I.	NOTICE OF GRANT OF RESTRICTED STOCK 

 Name: 

Address: 
 The undersigned
Participant has been granted a right to purchase Common Stock of the Company, subject to the terms and conditions of the Plan and this Agreement, as follows: 

 

							
	Date of Grant:	  		  	  
	  	
				
	Vesting Commencement Date:	  		  	  
	  	
				
	Purchase Price per Share:	  		  	 $
	  	
				
	Total Number of Shares Granted:	  		  	  
	  	
				
	Total Purchase Price:	  		  	 $
	  	
				
	Expiration Date:	  		  	  
	  	


 Vesting Schedule: 

Subject to any accelerated vesting provisions in the Plan, twenty-five percent (25%) of the Shares subject to this Agreement shall be released
from the Company’s Repurchase Option on the one (1) year anniversary of the Vesting Commencement Date, and one forty-eighth (1/48th) of the Shares subject to this Agreement shall be
released each month thereafter on the same day of the month as the Vesting Commencement Date (and if there is no corresponding day, on the last day of the month), subject to Participant continuing to be a Service Provider through each such date.

 Any of the Shares which have not yet been released from the Company’s Repurchase Option are referred to herein as “Unreleased
Shares.” The Shares which have been released from the Company’s Repurchase Option shall be delivered to Participant at Participant’s request (see Section 11 of Part II of this Agreement). 







 YOU MUST EXERCISE THIS RESTRICTED STOCK AWARD BEFORE THE EXPIRATION DATE OR IT WILL TERMINATE AND
YOU WILL HAVE NO FURTHER RIGHT TO PURCHASE THE SHARES. 
  

	II.	AGREEMENT 

 1. Sale of Stock. The Administrator of the Company hereby agrees to
sell to the Participant named in the Notice of Grant of Restricted Stock in Part I of this Agreement (“Participant”), and Participant hereby agrees to purchase the number of Shares set forth in the Notice of Grant of Restricted Stock,
at the Purchase Price per Share set forth in the Notice of Grant of Restricted Stock (the “Purchase Price”), and subject to the terms and conditions of the Plan, which is incorporated herein by reference. Subject to Section 18(c) of
the Plan, in the event of a conflict between the terms and conditions of the Plan and this Agreement, the terms and conditions of the Plan shall prevail. 

2. Payment of Purchase Price. Participant herewith delivers to the Company the aggregate Purchase Price for the Shares by cash or
check, together with any and all withholding taxes due in connection with the purchase of the Shares. 
 3. Participant’s
Representations. In the event the Shares have not been registered under the Securities Act of 1933, as amended, at the time this Restricted Stock Award is exercised, Participant shall, if required by the Company, concurrently with the exercise
of all or any portion of this Restricted Stock Award, deliver to the Company his or her Investment Representation Statement in the form attached hereto as Exhibit A. 

4. Lock-Up Period. Participant hereby agrees that Participant shall not offer, pledge, sell,
contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any Common Stock (or other
securities) of the Company or enter into any swap, hedging or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any Common Stock (or other securities) of the Company held by
Participant (other than those included in the registration) for a period specified by the representative of the underwriters of Common Stock (or other securities) of the Company not to exceed one hundred and eighty (180) days following the
effective date of any registration statement of the Company filed under the Securities Act (or such other period as may be requested by the Company or the underwriters to accommodate regulatory restrictions on (i) the publication or other
distribution of research reports and (ii) analyst recommendations and opinions, including, but not limited to, the restrictions contained in NASD Rule 2711(f)(4) or NYSE Rule 472(f)(4), or any successor provisions or amendments
thereto). 
 Participant agrees to execute and deliver such other agreements as may be reasonably requested by the Company or the
underwriter which are consistent with the foregoing or which are necessary to give further effect thereto. In addition, if requested by the Company or the representative of the underwriters of Common Stock (or other securities) of the Company,
Participant shall provide, within ten (10) days of such request, such information as may be required by the Company or such representative in connection with the completion of any public offering of


  
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the Company’s securities pursuant to a registration statement filed under the Securities Act. The obligations described in this Section 4 shall not apply to a registration relating
solely to employee benefit plans on Form S-1 or Form S-8 or similar forms that may be promulgated in the future, or a registration relating solely to a Commission Rule
145 transaction on Form S-4 or similar forms that may be promulgated in the future. The Company may impose stop-transfer instructions with respect to the shares of Common Stock (or other securities) subject to
the foregoing restriction until the end of said one hundred and eighty (180) day (or other) period. Participant agrees that any transferee of the Restricted Stock Award or shares acquired pursuant to the Restricted Stock Award shall be bound by
this Section 4. 
 5. Non-Transferability of Restricted Stock. This Restricted Stock
Award may not be transferred in any manner otherwise than by will or by the laws of descent or distribution and may be exercised during the lifetime of Participant only by Participant. The terms of the Plan and this Agreement shall be binding upon
the executors, administrators, heirs, successors and assigns of Participant. 
 6. Tax Consequences. Participant has reviewed with
Participant’s own tax advisors the federal, state, local and foreign tax consequences of this investment and the transactions contemplated by this Agreement. Participant is relying solely on such advisors and not on any statements or
representations of the Company or any of its agents. Participant understands that Participant (and not the Company) shall be responsible for Participant’s own tax liability that may arise as a result of the transactions contemplated by this
Agreement. Participant understands that Section 83 of the Internal Revenue Code of 1986, as amended (the “Code”), taxes as ordinary income the difference between the purchase price for the Shares and the Fair Market Value of the
Shares as of the date any restrictions on the Shares lapse. In this context, “restriction” includes the right of the Company to buy back the Shares pursuant to the Repurchase Option. Participant understands that Participant may elect to be
taxed at the time the Shares are purchased rather than when and as the Repurchase Option expires by filing an election under Section 83(b) of the Code with the IRS within thirty (30) days from the date of purchase. The form for making this
election is attached as Exhibit B-3 hereto. 
 THE PARTICIPANT
ACKNOWLEDGES THAT IT IS THE PARTICIPANT’S SOLE RESPONSIBILITY AND NOT THE COMPANY’S TO FILE TIMELY THE ELECTION UNDER SECTION 83(b), EVEN IF THE PARTICIPANT REQUESTS THE COMPANY OR ITS REPRESENTATIVES TO MAKE THIS FILING ON THE
PARTICIPANT’S BEHALF. 
 7. Tax Withholding. Pursuant to such procedures as the Administrator may specify from time to time, the
Company shall withhold the minimum amount required to be withheld for the payment of income, employment and other taxes which the Company determines must be withheld (the “Withholding Taxes”) with respect to Shares released from the
Company’s Repurchase Option by, in the Administrator’s discretion: (i) withholding otherwise deliverable Shares upon release from the Company’s Repurchase Option having a Fair Market Value equal the amount of such Withholding
Taxes, (ii) withholding the amount of such Withholding Taxes from Participant’s paycheck(s), (iii) requiring Participant to make appropriate arrangements with the Company (or the Parent or Subsidiary employing or retaining Participant) for
the satisfaction of all Withholding Taxes, or (iv) a combination of the foregoing. The Company shall not retain fractional Shares to 

  
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satisfy any portion of the Withholding Taxes. Accordingly, if any withholding is done through the withholding of Shares, Participant shall pay to the Company an amount in cash sufficient to
satisfy the remaining Withholding Taxes due and payable as a result of the Company not retaining fractional Shares. Should the Company be unable to procure such cash amounts from Participant, Participant agrees and acknowledges that Participant is
giving the Company permission to withhold from Participant’s paycheck(s) an amount equal to the remaining Withholding Taxes due and payable as a result of the Company not retaining fractional Shares. Participant acknowledges and agrees that the
Company may refuse to honor the exercise and refuse to deliver the Shares if such withholding amounts are not delivered at the time of purchase. 

8. No Guarantee of Continued Service. PARTICIPANT ACKNOWLEDGES AND AGREES THAT THE RELEASE OF SHARES FROM THE REPURCHASE OPTION OF THE
COMPANY PURSUANT TO THE VESTING SCHEDULE HEREOF IS EARNED ONLY BY CONTINUING AS A SERVICE PROVIDER AT THE WILL OF THE COMPANY (OR THE PARENT OR SUBSIDIARY EMPLOYING OR RETAINING PARTICIPANT) AND NOT THROUGH THE ACT OF BEING HIRED OR PURCHASING
SHARES HEREUNDER. PARTICIPANT FURTHER ACKNOWLEDGES AND AGREES THAT THIS AGREEMENT, THE TRANSACTIONS CONTEMPLATED HEREUNDER AND THE VESTING SCHEDULE SET FORTH HEREIN DO NOT CONSTITUTE AN EXPRESS OR IMPLIED PROMISE OF CONTINUED ENGAGEMENT AS A SERVICE
PROVIDER FOR THE VESTING PERIOD, FOR ANY PERIOD, OR AT ALL, AND SHALL NOT INTERFERE IN ANY WAY WITH PARTICIPANT’S RIGHT OR THE RIGHT OF THE COMPANY (OR THE PARENT OR SUBSIDIARY EMPLOYING OR RETAINING PARTICIPANT) TO TERMINATE PARTICIPANT’S
RELATIONSHIP AS A SERVICE PROVIDER AT ANY TIME, WITH OR WITHOUT CAUSE. 
 9. Repurchase Option. 

(a) In the event Participant’s continuous status as a Service Provider terminates for any or no reason (including death or Disability),
the Company shall, from the date of such termination (as reasonably fixed and determined by the Company), have an irrevocable, exclusive option to repurchase up to that number of Shares which constitute the Unreleased Shares (as defined in
Part I of this Agreement) at the Purchase Price per share (the “Repurchase Price”) (the “Repurchase Option”). The Company may exercise its Repurchase Option as to any or all of the Unreleased Shares at any time after the
Participant ceases to be a Service Provider; provided, however, that without requirement of further action on the part of either party hereto, the Repurchase Option shall be deemed to have been automatically exercised as to all Unreleased Shares at
5:00 p.m. (Pacific Time) as of the date that is 60 days following the date the Participant ceases to be a Service Provider, unless the Company declines in writing to exercise its Repurchase Option prior to such time. 

(b) If the Company decides not to exercise its Repurchase Option, it shall notify the Participant in writing within 60 days of the date the
Participant ceases to be a Service Provider. If the Repurchase Option is exercised or deemed exercised by the Company, the Company shall deliver written notice to Participant or Participant’s executor (with a copy to the Escrow Holder (as
defined in Section 11)) AND, at the Company’s option, (i) deliver to Participant or Participant’s 

  
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executor a check in the amount of the aggregate Repurchase Price, or (ii) by the Company canceling an amount of Participant’s indebtedness to the Company equal to the aggregate
Repurchase Price, or (iii) by a combination of (i) and (ii) so that the combined payment and cancellation of indebtedness equals such aggregate Repurchase Price. Upon delivery of such notice and the payment of the aggregate Repurchase
Price in any of the ways described above, the Company shall become the legal and beneficial owner of the Unreleased Shares being repurchased and all rights and interests therein or relating thereto, and the Company shall have the right to retain and
transfer to its own name the number of Unreleased Shares being repurchased by the Company. 
 (c) Whenever the Company shall have the right
to repurchase the Unreleased Shares hereunder, the Company may designate and assign one or more employees, officers, directors or shareholders of the Company or other persons or organizations to exercise all or a part of the Company’s
Repurchase Option to purchase all or a part of the Unreleased Shares. If the Fair Market Value of the Unreleased Shares to be repurchased on the date of such designation or assignment (the “Repurchase FMV”) exceeds the aggregate Repurchase
Price of the Unreleased Shares, then each such designee or assignee shall pay the Company cash equal to the difference between the Repurchase FMV and the aggregate Repurchase Price of Unreleased Shares to be purchased. 

(d) If the Company or its assignee does not elect to exercise the Repurchase Option conferred above by giving the requisite notice within
ninety (90) days following Participant’s termination as a Service Provider, the Repurchase Option shall terminate. 
 10.
Restriction on Transfer. Except for the escrow described in Section 11 or transfer of the Shares to the Company or its assignees contemplated by this Agreement, none of the Shares or any beneficial interest therein shall be transferred,
encumbered or otherwise disposed of in any way until the release of such Shares from the Company’s Repurchase Option in accordance with the provisions of this Agreement, other than by will or the laws of descent and distribution. Any
distribution or delivery to be made to Participant under this Agreement shall, if Participant is then deceased, be made to Participant’s designated beneficiary, or if no beneficiary survives Participant, to the administrator or executor of
Participant’s estate. Any such transferee must furnish the Company with (a) written notice of his or her status as transferee, and (b) evidence satisfactory to the Company to establish the validity of the transfer and compliance with
any laws or regulations pertaining to said transfer. 
 11. Escrow of Shares. 

(a) To ensure the availability for delivery of Participant’s Unreleased Shares upon exercise of the Repurchase Option by the Company,
Participant will, upon execution of this Agreement, deliver and deposit with an escrow holder designated by the Company (the “Escrow Holder”) the share certificates representing the Unreleased Shares, together with the Assignment Separate
from Certificate (the “Stock Assignment”) duly endorsed in blank, attached hereto as Exhibit B-1. The Unreleased Shares and Stock Assignment shall be held by the Escrow Holder, pursuant to the
Joint Escrow Instructions of the Company and Participant attached as Exhibit B-2 hereto, until such time as the Company’s Repurchase Option expires. 

  
 -5- 








 (b) The Escrow Holder shall not be liable for any act it may do or omit to do with respect to
holding the Unreleased Shares in escrow and while acting in good faith and in the exercise of its judgment. 
 (c) If the Company or any
assignee exercises its Repurchase Option hereunder, the Escrow Holder, upon receipt of written notice of such option exercise from the proposed transferee, shall take all steps necessary to accomplish such transfer. Participant hereby appoints the
Escrow Holder with full power of substitution, as Participant’s true and lawful attorney-in-fact with irrevocable power and authority in the name and on behalf of
Participant to take any action and execute all documents and instruments, including, without limitation, stock powers which may be necessary to transfer the certificate or certificates evidencing such Unreleased Shares to the Company upon such
termination. 
 (d) When the Repurchase Option has been exercised or expires unexercised or a portion of the Shares has been released from
such Repurchase Option, upon Participant’s request the Escrow Holder shall promptly cause a new certificate to be issued for such released Shares and shall deliver such certificate to the Company or Participant, as the case may be. 

(e) Subject to the terms hereof, Participant shall have all the rights of a shareholder with respect to such Shares while they are held in
escrow, including without limitation, the right to vote the Shares and receive any cash dividends declared thereon. 
 (f) In the event of
any merger, reorganization, consolidation, recapitalization, separation, liquidation, stock dividend, split-up, share combination, or other change in the corporate structure of the Company affecting the Common
Stock, the Shares shall be increased, reduced or otherwise changed, and by virtue of any such change Participant shall in his or her capacity as owner of Unreleased Shares that have been awarded to him or her be entitled to new or additional or
different shares of stock, cash or securities (other than rights or warrants to purchase securities); such new or additional or different shares, cash or securities shall thereupon be considered to be “Unreleased Shares” and shall be
subject to all of the conditions and restrictions which were applicable to the Unreleased Shares pursuant to this Agreement. If Participant receives rights or warrants with respect to any Unreleased Shares, such rights or warrants may be held or
exercised by Participant, provided that until such exercise any such rights or warrants and after such exercise any shares or other securities acquired by the exercise of such rights or warrants shall be considered to be Unreleased Shares and shall
be subject to all of the conditions and restrictions which were applicable to the Unreleased Shares pursuant to this Agreement. The Administrator in its absolute discretion at any time may accelerate the vesting of all or any portion of such new or
additional shares of stock, cash or securities, rights or warrants to purchase securities or shares or other securities acquired by the exercise of such rights or warrants. 

12. Company’s Right of First Refusal. Subject to Section 10, before any Shares held by Participant or any
transferee (either being sometimes referred to herein as the “Holder”) may be sold or otherwise transferred (including transfer by gift or operation of law), the Company or its assignee(s) shall have a right of first refusal to purchase
the Shares on the terms and conditions set forth in this Section 12 (the “Right of First Refusal”). 

  
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 (a) Notice of Proposed Transfer. The Holder of the Shares shall deliver to the Company a
written notice (the “Notice”) stating: (i) the Holder’s bona fide intention to sell or otherwise transfer such Shares; (ii) the name of each proposed purchaser or other transferee (“Proposed Transferee”); (iii) the
number of Shares to be transferred to each Proposed Transferee; and (iv) the bona fide cash price or other consideration for which the Holder proposes to transfer the Shares (the “Offered Price”), and the Holder shall offer the Shares
at the Offered Price to the Company or its assignee(s). 
 (b) Exercise of Right of First Refusal. At any time within thirty
(30) days after receipt of the Notice, the Company and/or its assignee(s) may, by giving written notice to the Holder, elect to purchase all, but not less than all, of the Shares proposed to be transferred to any one or more of the Proposed
Transferees, at the purchase price determined in accordance with subsection (c) below. 
 (c) Purchase Price. The purchase price
(“Right of First Refusal Price”) for the Shares purchased by the Company or its assignee(s) under this Section 12 shall be the Offered Price. If the Offered Price includes consideration other than cash, the cash equivalent value of
the non-cash consideration shall be determined by the Board in good faith. 
 (d) Payment.
Payment of the Right of First Refusal Price shall be made, at the option of the Company or its assignee(s), in cash (by check), by cancellation of all or a portion of any outstanding indebtedness of the Holder to the Company (or, in the case of
repurchase by an assignee, to the assignee), or by any combination thereof within thirty (30) days after receipt of the Notice or in the manner and at the times set forth in the Notice. 

(e) Holder’s Right to Transfer. If all of the Shares proposed in the Notice to be transferred to a given Proposed Transferee are
not purchased by the Company and/or its assignee(s) as provided in this Section 12, then the Holder may sell or otherwise transfer such Shares to that Proposed Transferee at the Offered Price or at a higher price, provided that such sale or
other transfer is consummated within one hundred and twenty (120) days after the date of the Notice, that any such sale or other transfer is effected in accordance with any applicable securities laws and that the Proposed Transferee agrees in
writing that the provisions of this Section 12 shall continue to apply to the Shares in the hands of such Proposed Transferee. If the Shares described in the Notice are not transferred to the Proposed Transferee within such period, a new Notice
shall be given to the Company, and the Company and/or its assignees shall again be offered the Right of First Refusal before any Shares held by the Holder may be sold or otherwise transferred. 

(f) Exception for Certain Family Transfers. Anything to the contrary contained in this Section 12 notwithstanding, the transfer of
any or all of the Shares during Participant’s lifetime or on Participant’s death by will or intestacy to Participant’s immediate family or a trust for the benefit of Participant’s immediate family shall be exempt from the
provisions of this Section 12. “Immediate Family” as used herein shall mean spouse, lineal descendant or antecedent, father, mother, brother or sister. In such case, the transferee or other recipient shall receive and hold the Shares
so transferred subject to the provisions of this Agreement, including but not limited to this Section 12 and Section 9, and there shall be no further transfer of such Shares except in accordance with the terms of this Section 12. 


  
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 (g) Termination of Right of First Refusal. The Right of First Refusal shall terminate as
to any Shares upon the earlier of (i) the first sale of Common Stock of the Company to the general public, or (ii) a Change in Control in which the successor corporation has equity securities that are publicly traded. 

13. Restrictive Legends and Stop-Transfer Orders. 

(a) Legends. Participant understands and agrees that the Company shall cause the legends set forth below or legends substantially
equivalent thereto, to be placed upon any certificate(s) evidencing ownership of the Shares together with any other legends that may be required by the Company or by state or federal securities laws: 

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 (THE “ACT”) AND MAY NOT BE OFFERED, SOLD
OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTIL REGISTERED UNDER THE ACT OR, IN THE OPINION OF COUNSEL SATISFACTORY TO THE ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR TRANSFER, PLEDGE OR HYPOTHECATION IS IN COMPLIANCE
THEREWITH. 
 THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RESTRICTIONS ON TRANSFER, A RIGHT OF FIRST REFUSAL, AND A
REPURCHASE OPTION HELD BY THE ISSUER OR ITS ASSIGNEE(S) AS SET FORTH IN THE RESTRICTED STOCK PURCHASE AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH
TRANSFER RESTRICTIONS, RIGHT OF FIRST REFUSAL AND REPURCHASE OPTION ARE BINDING ON TRANSFEREES OF THESE SHARES. 
 THE SHARES REPRESENTED BY
THIS CERTIFICATE ARE SUBJECT TO RESTRICTIONS ON TRANSFER FOR A PERIOD OF TIME FOLLOWING THE EFFECTIVE DATE OF THE UNDERWRITTEN PUBLIC OFFERING OF THE COMPANY’S SECURITIES SET FORTH IN AN AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF
THESE SHARES AND MAY NOT BE SOLD OR OTHERWISE DISPOSED OF BY THE HOLDER PRIOR TO THE EXPIRATION OF SUCH PERIOD WITHOUT THE CONSENT OF THE COMPANY OR THE MANAGING UNDERWRITER. 

(b) Stop-Transfer Notices. Participant agrees that, in order to ensure compliance with the restrictions referred to herein, the Company
may issue appropriate “stop transfer” instructions to its transfer agent, if any, and that, if the Company transfers its own securities, it may make appropriate notations to the same effect in its own records. 

  
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 (c) Refusal to Transfer. The Company shall not be required (i) to transfer on its
books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividends to any purchaser or other transferee
to whom such Shares shall have been so transferred. 
 14. Notices. Any notice, demand or request required or permitted to be given
by either the Company or Participant pursuant to the terms of this Agreement shall be in writing and shall be deemed given when delivered personally or deposited in the U.S. mail, First Class with postage prepaid, and addressed to the parties
at the addresses of the parties set forth at the end of this Agreement or such other address as a party may request by notifying the other in writing. 

Any notice to the Escrow Holder shall be sent to the Company’s address with a copy to the other party not sending the notice. 

15. No Waiver. Either party’s failure to enforce any provision or provisions of this Agreement shall not in any way be construed
as a waiver of any such provision or provisions, nor prevent that party from thereafter enforcing each and every other provision of this Agreement. The rights granted both parties herein are cumulative and shall not constitute a waiver of either
party’s right to assert all other legal remedies available to it under the circumstances. 
 16. Successors and Assigns. The
Company may assign any of its rights under this Agreement to single or multiple assignees, and this Agreement shall inure to the benefit of the successors and assigns of the Company. Subject to the restrictions on transfer herein set forth, this
Agreement shall be binding upon Participant and his or her heirs, executors, administrators, successors and assigns. The rights and obligations of Participant under this Agreement may only be assigned with the prior written consent of the Company.

 17. Interpretation. Any dispute regarding the interpretation of this Agreement shall be submitted by Participant or by the Company
forthwith to the Administrator, which shall review such dispute at its next regular meeting. The resolution of such a dispute by the Administrator shall be final and binding on all parties. 

18. Additional Documents. Participant agrees upon request to execute any further documents or instruments necessary or desirable to
carry out the purposes or intent of this Agreement. 
 19. Governing Law; Severability. This Agreement is governed by the internal
substantive laws, but not the choice of law rules, of California. In the event that any provision hereof becomes or is declared by a court of competent jurisdiction to be illegal, unenforceable or void, this Agreement shall continue in full force
and effect. 
 20. Entire Agreement. The Plan is incorporated herein by reference. The Plan and this Agreement (including the
exhibits referenced herein) constitute the entire agreement of the parties with respect to the subject matter hereof and supersede in their entirety all prior undertakings and agreements of the Company and Participant with respect to the subject
matter hereof, and may not be modified adversely to the Participant’s interest except by means of a writing signed by the Company and Participant. 

  
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 Participant acknowledges receipt of a copy of the Plan and represents that he or she is familiar
with the terms and provisions thereof, and hereby accepts this Agreement subject to all of the terms and provisions thereof. Participant has reviewed the Plan and this Agreement in their entirety, has had an opportunity to obtain the advice of
counsel prior to executing this Agreement and fully understands all provisions of this Agreement. Participant hereby agrees to accept as binding, conclusive and final all decisions or interpretations of the Administrator upon any questions arising
under the Plan or this Agreement. Participant further agrees to notify the Company upon any change in the residence address indicated below. 
  

					
	PARTICIPANT	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
			
	  
	  		  	  

		  		  	Title
			
	  
	  		  	
	Residence Address	  		  	


  
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 EXHIBIT A 

INVESTMENT REPRESENTATION STATEMENT 
  

					
	PARTICIPANT	 	:	  	
			
	COMPANY	 	:	  	ALLAKOS INC.
			
	SECURITY	 	:	  	COMMON STOCK
			
	AMOUNT	 	:	  	
			
	DATE	 	:	  	

 In connection with the purchase of the above-listed Securities, the undersigned Participant represents to the
Company the following: 
 (a) Participant is aware of the Company’s business affairs and financial condition and has acquired sufficient
information about the Company to reach an informed and knowledgeable decision to acquire the Securities. Participant is acquiring these Securities for investment for Participant’s own account only and not with a view to, or for resale in
connection with, any “distribution” thereof within the meaning of the Securities Act of 1933, as amended (the “Securities Act”). 

(b) Participant acknowledges and understands that the Securities constitute “restricted securities” under the Securities Act and have
not been registered under the Securities Act in reliance upon a specific exemption therefrom, which exemption depends upon, among other things, the bona fide nature of Participant’s investment intent as expressed herein. In this connection,
Participant understands that, in the view of the Securities and Exchange Commission, the statutory basis for such exemption may be unavailable if Participant’s representation was predicated solely upon a present intention to hold these
Securities for the minimum capital gains period specified under tax statutes, for a deferred sale, for or until an increase or decrease in the market price of the Securities, or for a period of one year or any other fixed period in the future.
Participant further understands that the Securities must be held indefinitely unless they are subsequently registered under the Securities Act or an exemption from such registration is available. Participant further acknowledges and understands that
the Company is under no obligation to register the Securities. Participant understands that the certificate evidencing the Securities shall be imprinted with any legend required under applicable state securities laws. 

(c) Participant is familiar with the provisions of Rule 701 and Rule 144, each promulgated under the Securities Act, which, in
substance, permit limited public resale of “restricted securities” acquired, directly or indirectly from the issuer thereof, in a non-public offering subject to the satisfaction of certain
conditions. Rule 701 provides that if the issuer qualifies under Rule 701 at the time of the grant of the Restricted Stock Award to Participant, the exercise shall be exempt from registration under the Securities Act. In the event the
Company becomes subject to the reporting requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, ninety (90) days thereafter (or such longer period as any market stand-off
agreement may require) the Securities 

  
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exempt under Rule 701 may be resold, subject to the satisfaction of the applicable conditions specified by Rule 144, including in the case of affiliates (1) the availability of
certain public information about the Company, (2) the amount of Securities being sold during any three (3) month period not exceeding specified limitations, (3) the resale being made in an unsolicited “broker’s
transaction”, transactions directly with a “market maker” or “riskless principal transactions” (as those terms are defined under the Securities Exchange Act of 1934) and (4) the timely filing of a Form 144, if
applicable. 
 In the event that the Company does not qualify under Rule 701 at the time of grant of the Restricted Stock Award, then
the Securities may be resold in certain limited circumstances subject to the provisions of Rule 144, which may require (i) the availability of current public information about the Company; (ii) the resale to occur more than a
specified period after the purchase and full payment (within the meaning of Rule 144) for the Securities; and (iii) in the case of the sale of Securities by an affiliate, the satisfaction of the conditions set forth in sections (2),
(3) and (4) of the paragraph immediately above. 
 (d) Participant further understands that in the event all of the applicable
requirements of Rule 701 or 144 are not satisfied, registration under the Securities Act, compliance with Regulation A, or some other registration exemption shall be required; and that, notwithstanding the fact that Rules 144 and 701 are
not exclusive, the Staff of the Securities and Exchange Commission has expressed its opinion that persons proposing to sell private placement securities other than in a registered offering and otherwise than pursuant to Rules 144 or 701 shall
have a substantial burden of proof in establishing that an exemption from registration is available for such offers or sales, and that such persons and their respective brokers who participate in such transactions do so at their own risk.
Participant understands that no assurances can be given that any such other registration exemption shall be available in such event. 
  

	
	PARTICIPANT
	
	  

	Signature
	
	  

	Print Name
	
	  

	Date



  
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 EXHIBIT B-1 

ASSIGNMENT SEPARATE FROM CERTIFICATE 

FOR VALUE RECEIVED I,
                    , hereby sell, assign and transfer unto Allakos Inc.
                 shares of the Common Stock of Allakos Inc. standing in my name on the books of said corporation represented by Certificate No.
             herewith and do hereby irrevocably constitute and appoint
                         to transfer the said stock on the books of the within named corporation with full power of substitution
in the premises. 
 This Stock Assignment may be used only in accordance with the Restricted Stock Purchase Agreement between Allakos Inc.
and the undersigned dated                     ,              (the “Agreement”).

  

			
	 Dated: _______________,____
	  	 Signature:_______________________________


 INSTRUCTIONS: Please do not fill in any blanks other than the signature line. The purpose of this assignment is to
enable the Company to exercise its “repurchase option,” as set forth in the Agreement, without requiring additional signatures on the part of the Participant. 

  
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 EXHIBIT B-2 

JOINT ESCROW INSTRUCTIONS 

_________________, ____ 
 Corporate Secretary 

Allakos Inc. 
 75 Shoreway Road 

San Carlos, CA 94070 
 Dear _________________: 

As Escrow Agent for both Allakos Inc. (the “Company”), and the undersigned purchaser of stock of the Company (the
“Participant”), you are hereby authorized and directed to hold the documents delivered to you pursuant to the terms of that certain Restricted Stock Purchase Agreement (the “Agreement”) between the Company and the undersigned, in
accordance with the following instructions: 
 1. In the event the Company and/or any assignee of the Company (referred to collectively for
convenience herein as the “Company”) exercises the Company’s repurchase option set forth in the Agreement, the Company shall give to Participant and you a written notice specifying the number of shares of stock to be purchased, the
purchase price, and the time for a closing hereunder at the principal office of the Company. Participant and the Company hereby irrevocably authorize and direct you to close the transaction contemplated by such notice in accordance with the terms of
said notice. 
 2. At the closing, you are directed (a) to date the stock assignments necessary for the transfer in question,
(b) to fill in the number of shares being transferred, and (c) to deliver the stock assignments, together with the certificate evidencing the shares of stock to be transferred, to the Company or its assignee, against the simultaneous
delivery to you of the purchase price (by cash, a check, or some combination thereof) for the number of shares of stock being purchased pursuant to the exercise of the Company’s repurchase option. 

3. Participant irrevocably authorizes the Company to deposit with you any certificates evidencing shares of stock to be held by you hereunder
and any additions and substitutions to said shares as defined in the Agreement. Participant does hereby irrevocably constitute and appoint you as Participant’s
attorney-in-fact and agent for the term of this escrow to execute with respect to such securities all documents necessary or appropriate to make such securities
negotiable and to complete any transaction herein contemplated, including but not limited to the filing with any applicable state blue sky authority of any required applications for consent to, or notice of transfer of, the securities. Subject to
the provisions of this paragraph 3, Participant shall exercise all rights and privileges of a stockholder of the Company while the stock is held by you. 







 4. Upon written request of the Participant, but no more than once per calendar year, unless the
Company’s repurchase option has been exercised, you shall deliver to Participant a certificate or certificates representing so many shares of stock as are not then subject to the Company’s repurchase option. Within one hundred and twenty
(120) days after cessation of Participant’s continuous employment by or services to the Company, or any parent or subsidiary of the Company, you shall deliver to Participant a certificate or certificates representing the aggregate number
of shares held or issued pursuant to the Agreement and not purchased by the Company or its assignees pursuant to exercise of the Company’s repurchase option. 

5. If at the time of termination of this escrow you should have in your possession any documents, securities, or other property belonging to
Participant, you shall deliver all of the same to Participant and shall be discharged of all further obligations hereunder. 
 6. Your
duties hereunder may be altered, amended, modified or revoked only by a writing signed by all of the parties hereto. 
 7. You shall be
obligated only for the performance of such duties as are specifically set forth herein and may rely and shall be protected in relying or refraining from acting on any instrument reasonably believed by you to be genuine and to have been signed or
presented by the proper party or parties. You shall not be personally liable for any act you may do or omit to do hereunder as Escrow Agent or as attorney-in-fact for
Participant while acting in good faith, and any act done or omitted by you pursuant to the advice of your own attorneys shall be conclusive evidence of such good faith. 

8. You are hereby expressly authorized to disregard any and all warnings given by any of the parties hereto or by any other person or
corporation, excepting only orders or process of courts of law and are hereby expressly authorized to comply with and obey orders, judgments or decrees of any court. In case you obey or comply with any such order, judgment or decree, you shall not
be liable to any of the parties hereto or to any other person, firm or corporation by reason of such compliance, notwithstanding any such order, judgment or decree being subsequently reversed, modified, annulled, set aside, vacated or found to have
been entered without jurisdiction. 
 9. You shall not be liable in any respect on account of the identity, authorities or rights of the
parties executing or delivering or purporting to execute or deliver the Agreement or any documents or papers deposited or called for hereunder. 

10. You shall not be liable for the outlawing of any rights under the Statute of Limitations with respect to these Joint Escrow Instructions
or any documents deposited with you. 
 11. You shall be entitled to employ such legal counsel and other experts as you may deem necessary
properly to advise you in connection with your obligations hereunder, may rely upon the advice of such counsel, and may pay such counsel reasonable compensation therefor. 

12. Your responsibilities as Escrow Agent hereunder shall terminate if you shall cease to be an officer or agent of the Company or if you
shall resign by written notice to each party. In the event of any such termination, the Company shall appoint a successor Escrow Agent. 

  
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 13. If you reasonably require other or further instruments in connection with these Joint Escrow
Instructions or obligations in respect hereto, the necessary parties hereto shall join in furnishing such instruments. 
 14. It is
understood and agreed that should any dispute arise with respect to the delivery and/or ownership or right of possession of the securities held by you hereunder, you are authorized and directed to retain in your possession without liability to
anyone all or any part of said securities until such disputes shall have been settled either by mutual written agreement of the parties concerned or by a final order, decree or judgment of a court of competent jurisdiction after the time for appeal
has expired and no appeal has been perfected, but you shall be under no duty whatsoever to institute or defend any such proceedings. 
 15.
Any notice required or permitted hereunder shall be given in writing and shall be deemed effectively given upon personal delivery or upon deposit in the United States Post Office, by registered or certified mail with postage and fees prepaid,
addressed to each of the other parties thereunto entitled at the following addresses or at such other addresses as a party may designate by ten (10) days advance written notice to each of the other parties hereto. 

16. By signing these Joint Escrow Instructions, you become a party hereto only for the purpose of said Joint Escrow Instructions; you do not
become a party to the Agreement. 
 17. This instrument shall be binding upon and inure to the benefit of the parties hereto, and their
respective successors and permitted assigns. 
 18. These Joint Escrow Instructions shall be governed by the internal substantive laws, but
not the choice of law rules, of California. 
  

					
	PARTICIPANT	  		  	ALLAKOS INC.
			
	  
	  		  	  

	Signature	  		  	By
			
	  
	  		  	  

	Print Name	  		  	Print Name
			
	  
	  		  	  

		  		  	Title
			
	  
	  		  	
	Residence Address	  		  	
			
	ESCROW AGENT	  		  	
			
	  
	  		  	
	Corporate Secretary	  		  	
			
	Dated:________________________	  		  	


  
 -3- 








 EXHIBIT B-3 

ELECTION UNDER SECTION 83(b) 

OF THE INTERNAL REVENUE CODE OF 1986 
 The
undersigned taxpayer hereby elects, pursuant to Sections 55 and 83(b) of the Internal Revenue Code of 1986, as amended, to include in taxpayer’s gross income or alternative minimum taxable income, as the case may be, for the current taxable
year the amount of any compensation taxable to taxpayer in connection with taxpayer’s receipt of the property described below. 
  

	1.	The name, address, taxpayer identification number and taxable year of the undersigned are as follows: 

  

					
	NAME:	  	____________________________	  	SPOUSE: _______________________
			
	ADDRESS:	  	____________________________	  	
			
		  	____________________________	  	


  

			
	TAXPAYER IDENTIFICATION NO.: ___________________	  	TAXABLE YEAR: ________


  

	2.	The property with respect to which the election is made is described as follows: __________ shares (the “Shares”) of the Common Stock of Allakos Inc. (the “Company”). 


 

	3.	The date on which the property was transferred is:___________________ ,______. 

  

	4.	The property is subject to the following restrictions: 

 The Shares may not be transferred and
are subject to forfeiture under the terms of an agreement between the taxpayer and the Company. These restrictions lapse upon the satisfaction of certain conditions contained in such agreement. 

 

	5.	The Fair Market Value at the time of transfer, determined without regard to any restriction other than a restriction which by its terms shall never lapse, of such property is: $_________________. 


 

	6.	The amount (if any) paid for such property is: $_________________. 

 The undersigned has submitted a copy of
this statement to the person for whom the services were performed in connection with the undersigned’s receipt of the above-described property. The transferee of such property is the person performing the services in connection with the
transfer of said property. 
 The undersigned understands that the foregoing election may not be revoked except with the consent of the Commissioner.

  

			
	Dated: ______________________, _____	 	  

		 	Taxpayer
		
	The undersigned spouse of taxpayer joins in this election.	 	
		
	Dated: ______________________, _____	 	  

		 	Spouse of Taxpayer