EX-10.3





 Exhibit 10.3 

NKARTA, INC. 
 2015
EQUITY INCENTIVE PLAN 
 STOCK OPTION AGREEMENT 

Unless otherwise defined herein, the terms defined in the 2015 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:
	 	 	 	
			
	 Term/Expiration Date:
	 	 	 	

 Vesting Schedule: 

This Option shall be exercisable, in whole or in part, according to the following vesting schedule; subject to Participant continuing to be a
Service Provider through each applicable vesting 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. 
 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. 

  
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 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; 

(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. 

  
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 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. 
 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. 

  
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 (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, 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. 

  
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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 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	  	    	  	NKARTA, INC.
			
	 	  		  	  

	Signature	  		  	By
			
	 	  		  	  

	Print Name	  		  	Print Name
			
	 	  		  	  

		  		  	Title
			
	 	  		  	
	Residence Address	  		  	


  
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 EXHIBIT A 

2015 EQUITY INCENTIVE PLAN 

EXERCISE NOTICE 
 Nkarta, Inc. 

6000 Shoreline Court, Suite 102 
 South San Francisco, California
94080 
 Attention: President 
 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 Nkarta, Inc. (the “Company”) under and pursuant to the 2015 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. 
 (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. 

  
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 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	 		  	NKARTA, INC.
			
	 	 		  	  

	Signature	 		  	By
			
	 	 		  	  

	Print Name	 		  	Print Name
			
		 		  	  

		 		  	Title
			
	Address:	 		  	Address:
			
	 	 		  	6000 Shoreline Court, Suite 102, South San Francisco, California 94080
			
	 	 		  	
			
		 		  	  

		 		  	Date Received


  
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 EXHIBIT B 

INVESTMENT REPRESENTATION STATEMENT 

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