EX-10.18





 Exhibit 10.18 

AMBRX BIOPHARMA INC. 
 NON-EMPLOYEE DIRECTOR COMPENSATION POLICY 
 Each member of the Board of Directors (the
“Board”) who is not also serving as an employee of or consultant to Ambrx Biopharma Inc. (the “Company”) or any of its subsidiaries (each such member, an “Eligible Director”)
will receive the compensation described in this Non-Employee Director Compensation Policy for his or her Board service upon and following the date of the underwriting agreement between the Company and the
underwriters managing the initial public offering of the Company’s ordinary shares (the “Ordinary Shares”), pursuant to which the Ordinary Shares are priced in such initial public offering (the “Effective
Date”). An Eligible Director may decline all or any portion of his or her compensation by giving notice to the Company prior to the date cash may be paid or equity awards are to be granted, as the case may be. This policy is effective
as of the Effective Date and may be amended at any time in the sole discretion of the Board or Compensation Committee of the Board. 
 Annual Cash
Compensation 
 The annual cash compensation amount set forth below is payable to Eligible Directors in equal quarterly installments, payable in arrears
on the last day of each fiscal quarter in which the service occurred. If an Eligible Director joins the Board or a committee of the Board at a time other than effective as of the first day of a fiscal quarter, each annual retainer set forth below
will be pro-rated based on days served in the applicable fiscal quarter, with the pro-rated amount paid on the last day of the first fiscal quarter in which the Eligible
Director provides the service and regular full quarterly payments thereafter. All annual cash fees are vested upon payment. 
  

	1.	 Annual Board Service Retainer: 



 

	 	a.	 All Eligible Directors: $40,000 



 

	2.	 Annual Committee Chair Service Retainer: 



 

	 	a.	 Chair of the Audit Committee: $15,000 



 

	 	b.	 Chair of the Compensation Committee: $10,000 



 

	 	c.	 Chair of the Nominating and Corporate Governance Committee: $8,000 



 

	3.	 Annual Committee Member Service Retainer: 



 

	 	a.	 Member of the Audit Committee: $7,500 



 

	 	b.	 Member of the Compensation Committee: $5,000 



 

	 	c.	 Member of the Nominating and Corporate Governance Committee: $4,000 



Equity Compensation 
 The equity compensation set forth
below will be granted under the Company’s 2021 Equity Incentive Plan (the “Plan”), subject to the approval of the Plan by the Company’s shareholders. All share options granted under this policy will be nonstatutory
share options, with an exercise price per share equal to 100% of the Fair Market Value (as defined in the Plan) of the underlying Ordinary Shares on the date of grant, and a term of ten years from the date of grant (subject to earlier termination in
connection with a termination of service as provided in the Plan, provided that upon a termination of service other than for death, Disability or Cause (as each such term is defined in the Plan), the post-termination exercise period will be three
months from the date of termination). 

  
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 1. Initial Grant: For each Eligible Director who is first elected or appointed to the Board following
the Effective Date, on the date of such Eligible Director’s initial election or appointment to the Board (or, if such date is not a market trading day, the first market trading day thereafter), the Eligible Director will be automatically, and
without further action by the Board or Compensation Committee of the Board, granted a share option to purchase 210,000 Ordinary Shares (the “Initial Grant”). The shares subject to each Initial Grant will vest in 36 successive
equal monthly installments over a three year period such that the option is fully vested on the third anniversary of the date of grant, subject to the Eligible Director’s Continuous Service (as defined in the Plan) through each such vesting
date and will vest in full upon a Change in Control (as defined in the Plan). 
 2. Annual Grant: On the date of each annual shareholder meeting of
the Company held after the Effective Date (each, an “Annual Meeting”), each Eligible Director who continues to serve as a non-employee member of the Board following such Annual Meeting
will be automatically, and without further action by the Board or Compensation Committee of the Board, granted a share option to purchase 105,000 Ordinary Shares (the “Annual Grant”). If an Eligible Director is elected or
appointed for the first time to be an Eligible Director after the date of the Company’s first Annual Meeting and prior to the date of an Annual Meeting, then the Eligible Director will be automatically, and without further action by the Board
or the Compensation Committee of the Board, granted a prorated Annual Grant on the date of the Eligible Director’s election or appointment (the “Prorated Annual Grant”) that will be subject to the number of Ordinary
Shares equal to 105,000 multiplied by a fraction (the numerator of which is equal to (i) 12 minus (ii) the number of completed months since the most recent Annual Meeting as of the Eligible Director’s date of election or
appointment, and the denominator of which is 12) with the resulting number of shares rounded down to the nearest whole share. The shares subject to the Annual Grant or Prorated Annual Grant will vest on the earlier of (i) the one-year anniversary of the date of grant, and (ii) the day immediately prior to the date of the Company’s next Annual Meeting, subject to the Eligible Director’s Continuous Service (as defined in the
Plan) through such vesting date; and provided that the shares subject to the Annual Grant or Prorated Annual Grant will vest in full upon a Change in Control (as defined in the Plan). 

Non-Employee Director Compensation Limit 

Notwithstanding the foregoing, the aggregate value of all compensation granted or paid, as applicable, to any individual for service as a Non-Employee Director (as defined in the Plan) shall in no event exceed the limits set forth in Section 3(d) of the Plan. 

  
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