Document:

EX-10.18

 Exhibit 10.18 

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE IT IS BOTH (I) NOT MATERIAL AND (II) WOULD BE
COMPETITIVELY HARMFUL IF PUBLICLY DISCLOSED. 
 Patent License Agreement 

Agreement No. [***] 
 This Patent License Agreement is between the
Licensor and the Licensee identified below (collectively, “Parties”, or singly, “Party”). 
 No binding agreement between the Parties will
exist until this Patent License Agreement has been signed by both Parties. Unsigned drafts of this Patent License Agreement shall not be considered offers. 

Background 
 Licensor owns or controls Patent Rights. Licensee
desires to secure the right and license to use, develop, manufacture, market, and commercialize the Patent Rights. Licensor has determined that such use, development, and commercialization of the Patent Rights is in the public’s best interest
and is consistent with Licensor’s educational and research missions and goals. Licensor desires to have the Patent Rights developed and used for the benefit of Licensee, the inventors, Licensor, and the public. 

NOW, THEREFORE, in consideration of the mutual covenants and premises herein contained, the Parties hereby agree as follows: 

The Terms and Conditions of Patent License attached hereto as Exhibit A are incorporated herein by reference in their entirety (the “Terms and Conditions”).
In the event of a conflict between provisions of this Patent License Agreement and the Terms and Conditions, the provisions in this Patent License Agreement shall govern. Unless defined in this Patent License Agreement, capitalized terms used in
this Patent License Agreement shall have the meanings given to them in the Terms and Conditions. 
 The section numbers used in the left hand column in the table
below correspond to the section numbers in the Terms and Conditions. 
  

													
	1.    Definitions
	
            
	 	Effective Date	 	June 2, 2021
	 	 	Licensor	 	The University of Texas at Austin, on behalf of the Board of Regents of the University of Texas
System, an agency of the State of Texas, whose address is 3925 W. Braker Lane, Suite 1.9A (R3500), Austin, Texas 78759.
	 	 	Licensee	 	Icosavax Inc., with its principal place of business at 1616 Eastlake Avenue E., Suite 208, Seattle,
WA 98102
	 	 	Contract Year and Contract Quarters	 	Contract Year is 12-month period ending on December 31
and Contract Quarters are 3-month periods ending on March 31, June 30, Sept. 30, Dec. 31
	 	 	Territory	 	Worldwide
	 	 	Field	 	 Field is the
Exclusive Field.
  
 “Exclusive Field” is defined as: all vaccine fields, excluding
mRNA based vaccines, for any use, including without limitation for the prevention, cure, amelioration or treatment of respiratory disease caused by metapneumovirus infection.

 
 All non-vaccine fields, such as test kits and
diagnostics, are also excluded.
  

													
	
            
	 	Patent Rights
	 	 	 App.
No./
 Date of Filing
	 	Title	  	Inventor(s)	 	Jointly Owned? (Y/N; if Y, with whom?)	 	Prosecution Counsel
	 	 	    [***]	 	    [***]	  	[***]	 	[***]	 	[***]

													
	
            
	 	USPTO Entity Status as of Effective Date	 	 Check one box:

☒ Small
 ☐ Large

													
	 2.4. Diligence Milestones

 

	
            
	 	Milestones and deadlines	 	 Milestone
Events
  
	 	
Deadlines
  

	 		 	Milestone 1: Submit report to Licensor for non-clinical immunogenicity studies
in animal models	 	[***]
	 		 	Milestone 2: Begin GMP manufacturing for clinical trials of Licensed Product	 	[***]
	 		 	Milestone 3: Dose first human patient with Licensed Product for Phase 1 Clinical Trials	 	[***]
	 		 	Milestone 4: Dose first human patient with Licensed Product for Phase 2b Clinical Trials	 	[***]
	 		 	Milestone 5: Dose first human patient with Licensed Product Phase 3 Clinical Trials	 	[***]
	 		 	Milestone 6: Marketing Approval of Licensed Product in the Territory by U.S. Food and Drug Administration or foreign
equivalent	 	[***]
	 3.    Compensation

 

	3.1(a)	 	Patent expenses due upon Effective Date	 	 Amount

 
	 	 based on invoices
received as of:
  

	 		 	[***]	 	April 8th, 2021
	3.1(b)	 	Milestone fees	 	 Milestone Events

 
	 	 Milestone Fees

 

	 		 	Milestone 1: Submit report to Licensor for non-clinical immunogenicity
studies in animal models	 	[***]
	 		 	Milestone 2: Begin GMP manufacturing for clinical trials of Licensed Product	 	[***]
	 		 	Milestone 3: Dose first human patient with Licensed Product for Phase 1 Clinical Trials	 	[***]
	 		 	Milestone 4: Dose first human patient with Licensed Product for Phase 2b Clinical Trials	 	[***]
	 		 	Milestone 5: Dose first human patient with Licensed Product Phase 3 Clinical Trials	 	[***]
	 	 	 	Milestone 6: Marketing Approval of Licensed Product in the Territory by U.S. Food and Drug Administration or
foreign equivalent	 	[***]

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA
	The University of Texas at Austin	 	Page 2	 	Agreement No. [***]

													
	 	 	 	 	Milestone 7: Net Product Sales of a Licensed Product incorporating licensed hMPV antigen of [***]	 	[***]
	 	 		 	Milestone 8: Net Product Sales of a Licensed Product incorporating licensed hMPV antigen of [***]	 	[***]
	            	 		 	Milestone 9: Net Product Sales of a Licensed Product incorporating licensed hMPV antigen of [***]	 	[***]
	3.1(c)	 	Scheduled license
fee payments	 	 [***] due on
Effective Date.
  
 [***] due on December 31 in Contract Years [***] through [***].

 
 [***] due on December 31 in Contract Years [***] and [***].

 
 [***] due on December 31 in every Contract Year beginning [***] and every Contract Year
until [***].

	3.1(d)	 	Sublicense Fees	 	 [***] of Non-Royalty Sublicensing Consideration received by Licensee before completion of Milestone [***] in section 2.4.
 [***] of Non-Royalty Sublicensing Consideration received by Licensee after completion of Milestone [***] in section 2.4 and before completion of Milestone [***] in section 2.4.

[***] of Non-Royalty Sublicensing Consideration received by Licensee after completion of Milestone [***] in section 2.4 and
before [***].
 [***] of Non-Royalty Sublicensing Consideration received by Licensee after [***].

	3.1(e)	 	Assignment fee	 	[***]
	3.2	 	Running royalty
rate (applies to
Sales by Licensee,
Affiliates
and
Sublicensees)	 	
[***] of Net Product Sales of Licensed Products that express only one unique antigen (“Single Vaccine Licensed Products”).

 
 [***] of Net Product Sales of Licensed Products that express more than one unique antigen
(“Multiple Vaccine Licensed Products”).

	3.2(c)	 	Stacking or third party royalty	 	If additional royalties are required to be paid to a Third Party for the use of such Third
Party’s patents in manufacturing and/or selling Licensed Products, royalties owed to Licensor may be reduced by [***] of royalties actually paid to the Third Party as set forth in Section 3.4 of the Terms and Conditions, except that the
royalty amount paid to Licensor shall not fall below [***] of Net Product Sales of Single Vaccine Licensed Products or [***] of Net Product Sales of Multiple Vaccine Licensed Products.
	3.3	 	Minimum royalty
(creditable to
royalties owed in
Contract Year)	 	
[***] due on December 31 in the first Contract Year after First Sale.
 [***] due
on December 31 in each Contract Year for years following such first Contract Year.

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA
	The University of Texas at Austin	 	Page 3	 	Agreement No. [***]

													
	3.5	 	Payment of ongoing patent costs	 	Licensee to pay [***] of ongoing patent costs. If an additional license is executed for this
technology for the mRNA Field, Licensee’s responsibility to reimburse ongoing patent costs shall be reduced to [***] of such costs.

					
	 18.
Contact Information

	
            
	 	
Licensee Contacts
	 	
Licensor Contacts

	 	 	 Contact for Notice:

[***]
  

With a copy to:

Icosavax, Inc.

1616 Eastlake Ave E., Suite 208,

Seattle, WA 98102
  

Accounting contact:
 ***]

 
 Patent prosecution contact:

[***]
	 	 Contact
for Notice:
 [***]
  

Payment and reporting contact:
 Checks payable to “The University of Texas at
Austin”
 [***]
  

Patent prosecution contact:

[***]

 20.  Reserved 

21.  No Other Promises and Agreements; Representation by Counsel.   Licensee expressly warrants and represents and does hereby
state and represent that no promise or agreement which is not herein expressed has been made to Licensee in executing this Patent License Agreement except those explicitly set forth herein and in the Terms and Conditions, and that Licensee is not
relying upon any other statement or representation of Licensor or its representatives. Licensee is relying on Licensee’s own judgment and has had the opportunity to be represented by legal counsel. Licensee hereby warrants and represents that
Licensee understands and agrees to all terms and conditions set forth in this Patent License Agreement and said Terms and Conditions. 

22.  Deadline for Execution by Licensee.  If this Patent License Agreement is executed first by the Licensor and is not
executed by the Licensee and received by the Licensor at the address and in the manner set forth in Section 18 of the Terms and Conditions within 30 days of the date of signature set forth under the Licensor’s signature below, then this
Patent License Agreement shall be null and void and of no further effect. 
 IN WITNESS WHEREOF, the Parties hereto have caused their duly authorized representatives
to execute this Patent License Agreement. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA
	The University of Texas at Austin	 	Page 4	 	Agreement No. [***]

									
	LICENSOR: THE UNIVERSITY OF TEXAS AT AUSTIN 
ON BEHALF OF THE BOARD OF REGENTS 
OF THE UNIVERSITY OF TEXAS SYSTEM	 		 	LICENSEE: Icosavax, Inc.
					
	By	 	 /s/ Les
Nichols                                        
        
	 		 	By	 	 /s/ Adam
Simpson                                        
    

									
			
	Les Nichols	 		 	 Adam Simpson

			
	Director	 		 	 Chief Executive Officer

				
	Office of Technology Commercialization	 		 	Date	 	 June 4,
2021                        

					
	Date	 	 June 3,
2021                    
	 		 		 	

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA
	The University of Texas at Austin	 	Page 5	 	Agreement No. [***]

 EXHIBIT A 

Terms and Conditions of Patent License 
 These Terms and Conditions of
Patent License (“Terms and Conditions”) are incorporated by reference into the Patent License Agreement to which they are attached. All Section references in these Terms and Conditions shall be references to provisions in these Terms and
Conditions unless explicitly stated otherwise. 
  

	1.	 Definitions 

“Affiliate” means corporation, firm, limited liability company, partnership or other entity that directly or indirectly Controls or is
Controlled by or is under common control with Licensee. For purposes of this definition, “Control” means (i) having the actual, present capacity to elect a majority of the directors of such entity; (ii) having the power to
direct at least fifty percent (50%) of the voting rights entitled to elect directors; or (iii) in any country where the local law will not permit foreign equity participation of a majority, ownership or control, directly or indirectly, of the
maximum percentage of such outstanding stock or voting rights permitted by local law. 
 “Agreement” means collectively
(i) these Terms and Conditions, and (ii) the Patent License Agreement. 
 “Contract Quarter” means any three-month period
indicated as the Contract Quarter in Section 1 of the Patent License Agreement, or any stub period thereof at the commencement of the Agreement or the expiration or termination of the Agreement. 

“Contract Year” means any 12-month period indicated as the Contract Year in Section 1 of
the Patent License Agreement, or any stub period thereof at the commencement of the Agreement or the expiration or termination of the Agreement. 

“Diligent and Commercially Reasonable Efforts” means, as the case may be, exerting such efforts and employing such resources as would
normally and objectively be exerted or employed by a similarly situated company for a product of similar market potential, profit potential and strategic value at a similar stage of its product life, taking into account the competitiveness of the
relevant marketplace, the patent, intellectual property and development positions of Third Parties, the applicable regulatory situation, the pricing/reimbursement situation, the commercial viability of the product and other relevant development and
commercialization factors based upon then prevailing conditions. 
 “Distributor” means a distributor or reseller to which Licensee,
its Affiliates, or Sublicensees sells a Licensed Product for resale of Licensed Product by the Distributor, and for which resale or distribution Licensee, its Affiliates, or Sublicensees receives no further consideration (including but not limited
to royalties and/or commissions) beyond the price for the initial sale of Licensed Product to the Distributor. 
 “Effective Date”
means the date indicated as the Effective Date in Section 1 of the Patent License Agreement. 
 “Fair Market Value” means the
cash consideration an unaffiliated, unrelated buyer would pay in an arm’s length sale of a substantially identical item sold in the same quantity, under the same terms, and at the same time and place. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-1	 	Agreement No. [***]

 “Field” means the field indicated as the Field identified in Section 1 of the
Patent License Agreement. 
 “First Sale” means the first commercial sale to any Third Party of a Licensed Product in the Territory.

 “Force Majeure” means an unforeseeable act that prevents or delays a Party from performing one or more of its duties under this
Agreement and that is outside of the reasonable control of the affected Party. A Force Majeure includes without limitation acts of war or of nature, insurrection and riot, strikes, lockouts, or other serious labor disputes, epidemics, pandemics, and
widespread disease, and floods, fires, explosions, or other natural disasters. A Force Majeure does not include delays encountered in enrolling or pursuing clinical trials, or in seeking or receiving the approval of vaccine or drug regulators. 

“Government” means any agency, department, or other unit of the United States of America or the State of Texas. 

“Gross Consideration” means all cash and non-cash consideration (e.g., securities). 

“Improvements” means patentable inventions that (i) are owned by Licensor after the Effective Date, (ii) are not subject to
conflicting legal obligations under any other agreements, (iii) would require a license under the rights licensed under this Agreement to practice, and (iv) were developed in the laboratory of the principal investigator, [***], within
[***] of the Effective Date, and identified to Licensor as Improvements falling under this license. 
 “Licensed Process” means a
method or process whose practice or use of which would constitute, but for the license granted to Licensee under this Agreement, an infringement of any Valid Claim (or, in the case of an unissued Valid Claim, a method whose practice or use would be
covered by such Valid Claim). 
 “Licensed Product” means any product or component (i) whose manufacture, use, sale, offer for
sale or import would constitute, but for the license granted to Licensee under this Agreement, an infringement of any Valid Claim (or, in the case of an unissued Valid Claim, a product whose manufacture, use, sale, offer for sale or import would be
covered by such Valid Claim), or (ii) which is made using a Licensed Process. 
 “Licensee” means the Party identified as the
Licensee in Section 1 of the Patent License Agreement. 
 “Licensor” means the Party identified as the Licensor in
Section 1 of the Patent License Agreement. 
 “Milestone Fees” means all fees identified as Milestone Fees in
Section 3.1(b) of the Patent License Agreement. 
 “Net Product Sales” means the Sales to a Third Party of Licensed Products by
Licensee, its Affiliates, or Sublicensees less the following items directly attributable to such Sales that are specifically identified on the invoice for such Sales and borne by the Licensee, its Affiliates, or Sublicensees as the seller: [***]. On
sales of Licensed Products made in other than an arm’s length transaction, the value of the Net Product Sales attributed to such transaction will be equal to the customary sale price or, in if there is no customary sale price, the Fair Market
Value of such Licensed Products. Net Product Sales does not include [***], but does include [***]. For avoidance of doubt Net Product Sales are calculated on sales by [***]. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-2	 	Agreement No. [***]

 “Non-Royalty Sublicensing Consideration”
means the Gross Consideration received by the Licensee or its Affiliate from a Sublicensee in consideration of the grant of a sublicense under the Patent Rights [***], but excluding [***]. Non-Royalty
Sublicensing Consideration will not include: [***]. 
 “Patent License Agreement” means the particular Patent License Agreement to
which these Terms and Conditions are attached and incorporated into by reference. 
 “Patent Rights” means the Licensor’s rights
in (a) the patents and patent applications listed in Section 1 of the Patent License Agreement; (b) all non-provisional patent applications that claim priority to any provisional application
listed in Section 1 of the Patent License Agreement; and (c) all divisionals, continuations, and such claims of continuations-in-part as are entitled to claim
priority to the aforesaid patents and/or patent applications, and all reissues, reexaminations, extensions of, and foreign counterparts; and (e) any patents that issue with respect to the aforesaid patent applications. From time to time during
the term of the Agreement, upon written agreement by both Parties, Licensee and Licensor shall update the list of all patent applications and patents within the Patent Rights. 

“Prosecution Counsel” means the law firm or attorney who is handling the prosecution of the Patent Rights. Prosecution Counsel as of
the Effective Date is identified in Section 1 of the Patent License Agreement. 
 “Quarterly Payment Deadline” means the day
that is [***] after the last day of any particular Contract Quarter. 
 “Sell, Sale or Sold” means any transfer or other disposition
of Licensed Products for which consideration is received by Licensee, its Affiliates, or Sublicensees. A Sale of Licensed Products will be deemed completed at the time Licensee or its Affiliate or its Sublicensee receives such consideration. 

“Sublicense Agreement” means any agreement pursuant to which Licensee (or an Affiliate or Sublicensee) grants to any Sublicensee a
sublicense under the Patent Rights. 
 “Sublicense Fee” means the fee specified in Section 3.1(d) of the Patent License
Agreement. 
 “Sublicensee” means any entity to which an express sublicense has been granted by Licensee under the Patent Rights.

 “Technology Rights” means Licensor’s rights which are owned and controlled by Licensor in technical information, know-how, processes, procedures, compositions, methods, formulas, protocols, techniques, designs, and non-clinical data created before the Effective Date by individuals in the
laboratory of the Principal Investigator while employed at Licensor which may not covered by a Valid Claim but which are necessary for practicing inventions claimed or described in patents and/or patent applications listed in the definition of
Patent Rights whether outstanding, expired or abandoned. Notwithstanding the foregoing, it is understood by Licensee that the university does not ordinarily claim or own the knowledge or techniques of university researchers that are not claimed in
patent applications or embodied in copyrighted software, and that such knowledge or techniques are typically owned by the researchers themselves. It is further understood that nothing in this Agreement implies an obligation on the part of university
researchers to dedicate time to assisting Licensee to commercially develop the technology licensed hereunder. Any assistance that Licensee needs from university researchers to develop the technology would need to be obtained through other
agreements. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-3	 	Agreement No. [***]

 “Territory” means the territory so indicated as the Territory in Section 1 of
the Patent License Agreement. 
 “Third Party” means an individual or entity other than Licensee, any Affiliate, or Licensor. 

“Valid Claim” means a claim of (i) an issued and unexpired patent included within the Patent Rights unless the claim has been held
unenforceable or invalid by the final, un-reversed, and un-appealable decision of a court or other government body of competent jurisdiction, has been irretrievably
abandoned or disclaimed, or has otherwise been finally admitted or determined to be invalid, un-patentable or unenforceable, whether through reissue, reexamination, disclaimer or otherwise, or (ii) a
pending patent application within the Patent Rights to the extent the claim continues to be prosecuted in good faith. 
  

	2.	 License Grant and Commercialization 

 

	 	2.1	 Grant 

  

	 	(a)	 Licensor grants to Licensee and Affiliates a royalty-bearing exclusive license in the Exclusive Field, with the right to
sublicense through multiple tiers, under Patent Rights and Technology Rights, to manufacture, develop, use, Sell, distribute, lease, loan, offer for sale, import, and otherwise commercially exploit Licensed Products in the Field in the Territory,
and to have any of the foregoing performed. [***]. 

  

	 	(b)	 This grant is subject to (i) the payment by Licensee to Licensor of all consideration required under this Agreement,
(ii) any rights of, or obligations to, the Government as set forth in Section 11.2 (Government Rights), and (iii) non-commercial rights retained by Licensor to: 

 

	 	(1)	 Publish the scientific findings from research related to the Patent Rights; and 

 

	 	(2)	 Manufacture, have manufactured, and use the Patent Rights for teaching, academic research, education, and other
educationally-related purposes; and 

  

	 	(3)	 Grant rights to, and transfer material embodiments of, the Patent Rights to other academic institutions or non-profit research institutions for the purposes identified in clauses (1) and (2) above; 

provided that none of (1) through (3) include the right for Licensor to grant or transfer any rights exclusively licensed under this Agreement to
any Third Party for any commercial use. 
  

	 	(c)	 Licensor reserves all rights not expressly granted in the Agreement and disclaims the grant of any implied rights to
Licensee. 

  

	 	2.2	 Sublicensing 

Licensee has the right to grant Sublicense Agreements under the Patent Rights consistent with the terms of the Agreement, subject to the following: 

 

	 	(a)	 A Sublicense Agreement shall not exceed the scope and rights granted to Licensee hereunder. Sublicensee must agree in
writing to be bound by the applicable terms and conditions of the Agreement and shall indicate that Licensor is a third party 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-4	 	Agreement No. [***]

	 	
beneficiary and entitled to enforce the terms and conditions of the Sublicense Agreement applicable to the Agreement. In the event of termination of this Agreement, continued sublicense rights
shall be governed by Section 7.5(a) (Effect of Termination). Licensee may grant a Sublicensee the right to grant further sub-Sublicense Agreements, in which case such
sub-Sublicense Agreements shall be treated as “Sublicense Agreements” and such sub-Sublicensees shall be treated as “Sublicensees” for purposes of the Agreement. 

 

	 	(b)	 Licensee shall deliver to Licensor a true and correct copy (which may be redacted with respect to any terms that are not
relevant to Licensor’s rights and obligations under this Agreement) of each Sublicense Agreement granted by Licensee, Affiliate or Sublicensee, and any modification or termination thereof, within 30 days following the applicable execution,
modification, or termination of such Sublicense Agreement. If the Sublicense Agreement is not in English, Licensee shall provide Licensor an accurate English translation in addition to a copy of the original agreement. 

 

	 	(c)	 Notwithstanding any such Sublicense Agreement, Licensee will remain primarily liable to Licensor for all of the
Licensee’s duties and obligations contained in this Agreement, including without limitation the payment of running royalties due under Section 3.2 whether or not paid to Licensee by a Sublicensee. Any act or omission of a Sublicensee that
would be a breach of this Agreement if performed by Licensee will be deemed to be a breach by Licensee unless Licensee complies with the remaining provisions of this paragraph. Each Sublicense Agreement will contain a right of termination by
Licensee in the event that the Sublicensee breaches the payment or reporting obligations affecting Licensor or any other terms and conditions of the Sublicense Agreement that would constitute a breach of this Agreement if such acts were performed by
Licensee. In the event of a Sublicensee breach, and if after a reasonable opportunity to cure as provided in any such Sublicense Agreement (not to exceed 30 days for a payment breach and 90 days for a
non-payment breach), such Sublicensee fails to cure such Sublicensee breach, then the Licensee will terminate the Sublicense Agreement within 30 days thereafter, with copy of such written notice of termination
to Licensor, unless agreed to in writing otherwise by Licensor. 

  

	 	2.5	 Diligent Commercialization 

Licensee by itself or through its Affiliates and Sublicensees will use diligent efforts to make Licensed Products commercially available in the Field in
the Territory. Without limiting the foregoing, Licensee will fulfill the milestone events specified in Section 2.4 of the Patent License Agreement by the deadlines indicated therein and will use Diligent and Commercially Reasonable Efforts to
(a) maintain a reasonably funded, ongoing and active research, development, manufacturing, regulatory, marketing or sales program required to make License Products commercially available, and (b) perform and complete the plans described in
the annual report submitted pursuant to Section 4.2 (Annual Written Progress Report). The milestone event deadlines set forth in Section 2.4 of the Patent License Agreement will be extended by the number of days of delay reasonably
attributable to a Force Majeure. In the event of a Force Majeure Licensee will give prompt notice to Licensor and the Parties shall meet and confer regarding the length of the required extension. If the milestone events specified in Section 2.4
of the Patent License Agreement are not met by the indicated deadlines or if the obligations under this Section 2.4 are not fulfilled, Licensor may treat such failure as a breach in accordance with Section 7.3(b). 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-5	 	Agreement No. [***]

 If Licensee determines that it will be unable to achieve a milestone event set forth in
Section 2.4 of the Patent License Agreement by any applicable deadlines indicated therein, [***]. 
  

	 	2.6	 Improvements 

For a period of [***] after the Effective Date, Licensor will provide reasonable written notice to Licensee of any Improvements, by providing a copy of
any invention disclosure disclosing such Improvement to Licensee under confidentiality restriction. Licensee will have the option, exercisable within [***] of receipt of such invention disclosure, to add such Improvements to the Patent Rights. If
Licensee exercises its option to add Improvements to the Patent Rights, the Parties shall execute an amendment to this Agreement explicitly adding such Improvements to the Patent Rights. 

 

	3.	 Compensation 

In consideration of rights granted to Licensee, Licensee will pay Licensor the following fees and royalties. All fees and royalties are not refundable
and are not creditable against other fees and royalties except as expressly set forth in this Agreement. Each payment will reference the Patent License Agreement number and will be sent to Licensor’s payment and accounting contact in
Section 18 (Notices) of the Patent License Agreement. 
  

	 	3.1	 Non-Royalty Payments due from Licensee 

 

	 	(a)	 Patent Expenses. Licensee will reimburse Licensor for the past patent expenses stated in Section 3.1(a) of
the Patent License Agreement within 30 days after the Effective Date. The stated amount is the current estimate for past patent expenses based on invoices received by the Licensor through the stated date. Licensee’s obligations to pay all past
and future patent expenses pursuant to Section 6 (Patent Expenses and Prosecution) will not be limited by such amount. 

  

	 	(b)	 Milestone Fees. Licensee will pay Milestone Fees indicated in Section 3.1(b) of the Patent License Agreement
by the Quarterly Payment Deadline for the Contract Quarter in which the milestone events set forth in Section 3.1(b) of the Patent License Agreement are achieved. 

 

	 	(c)	 Scheduled License Fees. Licensee will pay license fees in the amounts set forth in Sections 3.1(c) of the Patent
License Agreement in accordance with the stated schedule. 

  

	 	(d)	 Sublicense Fees. Licensee will pay Sublicense Fees indicated in Section 3.1(d) of the Patent License
Agreement on or before the Quarterly Payment Deadline for the Contract Quarter in which the Non-Royalty Sublicensing Consideration resulting in such Sublicense Fees was received. 

 

	 	(e)	 Assignment Fee. Licensee will pay the assignment fee set forth in Section 3.1(e) of the Patent License
Agreement within 30 days after Licensee assigns all of Licensee’s right, title, and interest in and to this Agreement to a Third Party. 

  

	 	3.2	 Royalties 

Licensee will pay a running royalty at the rate set forth in Section 3.2 of the Patent License Agreement on Net Product Sales in each Contract
Quarter, payable on or before the Quarterly Payment Deadline for such Contract Quarter, subject to the following: 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-6	 	Agreement No. [***]

	 	(a)	 No more than one royalty shall be paid to Licensor hereunder with respect to the Sale of any one unit of Licensed
Product, whether or not more than one patent or Valid Claim is applicable to the Licensed Product, or the development, manufacture, or performance thereof. 

  

	 	(b)	 No royalty shall be payable under this Section 3.2 with respect to the Sale of Licensed Products between or among
Licensee, its Affiliates, and Sublicensees for re-sale purposes, provided Licensor is paid a royalty with respect to the re-sale, or (iii) payments that constitute Non-Royalty Sublicensing Consideration. 

  

	 	(c)	 If a Licensed Product cannot be exploited without infringing patent(s) or patent application(s) owned, licensed, or
controlled by a Third Party in the Territory, and Licensee licenses such Third Party patent(s) or patent application(s), then Licensee shall be entitled to deduct [***] of the royalty actually paid to any such Third Party for any such rights in the
Territory (such consideration, “Third Party Royalties”) from royalties due Licensor for the Net Product Sales of such Licensed Product in the Territory, provided that such amounts payable shall not be reduced, with respect to any
Contract Quarter, below [***] with respect to Single Vaccine Licensed Products and one and [***] of Net Product Sales with respect to Multiple Vaccine Licensed Products. 

 

	 	3.3	 Minimum Royalties 

If royalties paid to Licensor do not reach the minimum royalty amounts stated in Section 3.3 of the Patent License Agreement for the specified
periods, Licensee will pay Licensor on or before the Quarterly Payment Deadline for the last Contract Quarter in the stated period an additional amount equal to the difference between the stated minimum royalty amount and the actual royalties paid
to Licensor. 
  

	 	3.4	 Non-cash Consideration 

If Licensee receives or anticipates receipt of non-cash consideration from Sales or Sublicenses, the manner in
which Licensor will receive its compensation under the Agreement with respect to such non-cash consideration will be negotiated in good faith and timely agreed to by the Parties. 

 

	4.	 Reports and Plans 

The reports specified in this Section 4 will be sent to Licensor’s payment and reporting contact identified in Section 18 (Notices) of
the Patent License Agreement. If Licensor requests to have information submitted in a particular format, Licensee will use reasonable efforts to comply with such request. 
  

	 	4.1	 Quarterly Royalty Payment and Milestone Reports 

On or before each Quarterly Payment Deadline, Licensee will deliver to Licensor a true and accurate report, certified by an officer of Licensee, giving
such particulars of the business conducted by Licensee, its Affiliates and its Sublicensees (including copies of reports provided by Sublicensees and Affiliates to Licensee) during the preceding Contract Quarter under the Agreement as necessary for
Licensor to account for Licensee’s payments hereunder, even if no payments are due. The reports shall continue to be delivered after the termination or expiration of the Agreement until such time as all Licensed Products permitted to be Sold
after termination or expiration have been Sold or destroyed. Licensee shall provide information in sufficient detail to enable the royalties payable hereunder to be determined and to calculate all of the amounts payable under the Agreement. The
report shall include: 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-7	 	Agreement No. [***]

	 	(a)	 The name of the Licensee, the Patent License Agreement number, and the period covered by the report;

  

	 	(b)	 The name of any Affiliates and Sublicensees whose activities are also covered by the report; 

 

	 	(c)	 Identification of each Licensed Product for which any royalty payments have become payable; 

 

	 	(d)	 Net Product Sales segregated on a
product-by-product basis, and a country-by-country basis, or an affirmative statement
that no Sales were made. The report shall also itemize the permitted deductions from the gross Sales used to arrive at the resulting Net Product Sales, on a
product-by-product and country-by-country basis; 

 

	 	(e)	 The applicable royalty rate; 

  

	 	(f)	 An affirmative statement of whether any milestones with deadlines in that Contract Quarter under Section 2.4 and any
milestones under Section 3.1(b) were met or not, and the resulting Milestone Fee payable; 

  

	 	(g)	 Non-Royalty Sublicensing Consideration received by Licensee segregated on a Sublicense-by-Sublicense basis, or an affirmative statement that none was received; 

 

	 	(h)	 If any consideration was received in currencies other than U.S. dollars, the report shall describe the currency exchange
calculations; and 

  

	 	(i)	 Any changes in accounting methodologies used to account for and calculate the items included in the report since the
previous report. 

  

	 	4.2	 Annual Written Progress Report and Commercialization Plan 

Within [***] following the end of each Contract Year, Licensee will deliver to Licensor a true and accurate written progress report and
commercialization plan that summarizes (i) Licensee’s efforts and accomplishments during the Contract Year to use Diligence and Commercially Reasonable Efforts to develop and commercialize Licensed Products, and (ii) Licensee’s
development and commercialization plans with respect to Licensed Products for the next Contract Year. The report shall also cover such activities by Affiliates and Sublicensees. The report shall contain the following information to the extent
relevant to the activities under the Agreement: 
  

	 	(a)	 The name of the Licensee, the Patent License Agreement number, the names of any Affiliates and Sublicensees, and the
products being developed and/or commercialized; 

  

	 	(b)	 The progress toward completing and the plans for completing the applicable milestone events pursuant to Sections 2.4 and
3.1(b); 

  

	 	(c)	 The research and development activities, including status and plans for clinical trial initiations or readouts as well as
obtaining any necessary governmental approvals, completed during the past year, and the plans for research and development activities for the next year; and 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-8	 	Agreement No. [***]

	 	(d)	 The marketing activities for the past year. 

 

	 	4.3	 Government and Economic Development Reporting 

If Licensor requests, Licensee will provide the information required under Federal and state law for Licensor’s Government and economic development
reporting purposes. This information shall be treated as Licensee’s Confidential Information; provided that Licensor is entitled to combine such information with similar information from other Licensor licensees and publicly report such
combined aggregate information, without identifying Licensee’s separate specific applicable numbers. If and when Licensee has more than 200 full-time employees, then no further economic development reports will be required from Licensee. 

 

	5.	 Payment, Records, and Audits 

 

	 	5.1	 Payments 

All amounts referred to in the Patent License Agreement are expressed in U.S. dollars without deductions for taxes, assessments, fees, or charges of any
kind. Each payment will reference the agreement number set forth at the beginning of the Patent License Agreement. All payments to Licensor will be made in U.S. dollars by check or wire transfer (Licensee to pay all wire transfer fees) payable to
the payee identified in Section 18 of the Patent License Agreement and sent to the payment and reporting contact in Section 18 (Notices) of the Patent License Agreement. 

 

	 	5.2	 Sales Outside the U.S. 

If any currency conversion shall be required in connection with the calculation of payments hereunder, such conversion shall be made using the rate used
by Licensee for its financial reporting purposes in accordance with U.S. Generally Accepted Accounting Principles (or foreign equivalent) or, in the absence of such rate, using the average of the buying and selling exchange rate for conversion
between the foreign currency and U.S. Dollars, for current transactions as reported in The Wall Street Journal on the last business days of the Contract Quarter to which such payment pertains. Licensor agrees to supply to Licensee, upon
written request, appropriate evidence from appropriate U.S. governmental agencies showing that Licensor is a resident of the United States of America for purposes of the U.S. income tax laws and is
tax-exempt under such income tax laws. 
  

	 	5.3	 Late Payments 

Amounts that are not paid within [***] after due will accrue a late charge from the due date until paid, at the prime rate as reported in The Wall
Street Journal on the last business days of the Contract Quarter to which such payment pertains (or the maximum allowed by law, if less). 
  

	 	5.4	 Records 

For a period of [***] after the Contract Quarter to which the records pertain, Licensee agrees that it and its Affiliates and Sublicensees will each
keep complete and accurate records of their Sales, Net Product Sales, Milestone Fees, and Non-Royalty Sublicensing Consideration in sufficient detail to enable such payments to be determined and audited. 

 

	 	5.5	 Auditing 

Licensee and its Affiliates will permit Licensor or its representatives, at Licensor’s expense, to periodically examine books, ledgers, and records
during regular business hours, at Licensee’s or its Affiliate’s place of business, on at least 30 days advance notice, to the extent necessary to verify any payment or report required under the Agreement. For each

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-9	 	Agreement No. [***]

 
Sublicensee, Licensee shall obtain such audit rights for Licensor or itself. If Licensee obtains such audit rights for itself, it will promptly conduct an audit of the Sublicensee’s records
upon Licensor’s request, and Licensee will furnish to Licensor a copy of the findings from such audit. No more than one audit of Licensee, each Affiliate, and each Sublicensee shall be conducted under this Section 5.5 in any calendar year.
If any amounts due Licensor have been underpaid, then Licensee shall immediately pay Licensor the amount of such underpayment plus accrued interest due in accordance with Section 5.3. If the amount of underpayment is equal to or greater than
[***] of the total amount due for the records so examined, Licensee will pay the cost of such audit. Such audits may, at Licensor’s sole discretion, consist of a self-audit conducted by Licensee at Licensee’s expense and certified in
writing by an authorized officer of Licensee. All information examined pursuant to this Section 5.5 shall be deemed to be the Confidential Information of the Licensee. Further, whenever Licensee and/or its Affiliates and Sublicensees has its
books and records audited by an independent certified public accountant, Licensee and/or its Affiliates and Sublicensees will, within [***] of the conclusion of such audit, at Licensor’s written request, provide Licensor with a written
statement of said auditor, setting forth the calculation of amounts due to Licensor over the time period audited, as determined from the books and records of the Licensee, Affiliate or Sublicensee; but said auditor does not need to give any audit
opinion with said statement. 
  

	6.	 Patent Expenses and Prosecution 

 

	 	6.1	 Patent Expenses 

[***], and [***] incurred by Licensor, for so long as, and in such countries as the Agreement remains in effect. [***]. Licensee will pay such patent
expenses (except for the payment called for under Section 3.1(a), [***] that have not been invoiced as of the date indicated in Section 3.1(a) of the Patent License Agreement and future expenses, within 30 days after Licensee’s
receipt of an invoice. Patent expense payment delinquencies will be considered a payment default under Section 7.3(a). 
  

	 	6.2	 Direction of Prosecution 

Licensor will confer with Licensee, [***], to develop a strategy for the prosecution and maintenance of Patent Rights. Licensor will request that copies
of all documents prepared by the Prosecution Counsel for submission to governmental patent offices be provided to Licensee for review and comment prior to filing, to the extent practicable under the circumstances and shall consider suggestions of
Licensee [***] in good faith. Licensor will defer to the prosecution strategy chosen by Licensee [***] except to the extent such strategy would materially impair commercialization of the Patent Rights in fields outside of the Exclusive Field, [***].
Notwithstanding the foregoing, Licensor [***] and Licensor reserves the right to instruct prosecution of additional claims to cover products or services outside the Exclusive Field, such as [***], at the Licensor’s own expense. The Parties
agree that they share a common legal interest to get valid enforceable patents and that Licensee will maintain as privileged all information received pursuant to this Section. 

 

	 	6.3	 Ownership 

All patent applications and patents will be in the name of Licensor (and any co-owner identified in
Section 1 of the Patent License Agreement) and owned by Licensor (and such co-owner, if any). No payments due under the Agreement will be reduced as the result of
co-ownership interests in the Patent Rights by Licensee or any other party. 
  

	 	6.4	 Foreign Filings 

In addition to the U.S., the Patent Rights shall, subject to applicable bar dates, be pursued in such foreign countries as Licensee so designates in
writing to Licensor in sufficient time 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-10	 	Agreement No. [***]

 
to reasonably enable the preparation of such additional filings, and in those foreign countries in which Licensor has filed applications prior to the Effective Date. If Licensee does not choose
to pursue patent rights in a particular foreign country and Licensor chooses to do so, Licensor shall so notify Licensee and thereafter said patent application or patent shall no longer be included in the Patent Rights and Licensee shall have no
further rights thereto. Licensor shall have the right to make alternative arrangements with Licensee for upfront payment of foreign patent expenses. 
  

	 	6.5	 Withdrawal from Paying Patent Costs 

If at any time Licensee wishes to cease paying for any costs for a particular Patent Right or for patent prosecution in a particular jurisdiction,
Licensee must give Licensor at least 90 days prior written notice and Licensee will continue to be obligated to pay for the patent costs which reasonably accrue during said notice period. Thereafter, said patent application or patent shall no longer
be included in the Patent Rights and Licensee shall have no further rights thereto. 
  

	 	6.6	 U.S. Patent and Trademark Office Entity Size Status 

Licensee represents that as of the Effective Date the entity size status of Licensee in accordance with the regulations of the U.S. Patent and Trademark
Office is as set forth in Section 1 of the Patent License Agreement. Licensee will inform Licensor in writing on a timely basis of any change in its U.S. Patent and Trademark Office entity size status. 

 

	7.	 Term and Termination 

  

	 	7.1	 Term 

Unless earlier terminated as provided herein, the term of this Agreement will commence on the Effective Date and continue until the last date of
expiration or termination of the Patent Rights. 
  

	 	7.2	 Termination by Licensee 

Licensee, at its option, may terminate this Agreement by providing Licensor written notice of intent to terminate, which such termination effective will
be 30 days following receipt of such notice by Licensor. 
  

	 	7.3	 Termination by Licensor 

Licensor, at its option, may immediately terminate the Agreement, or any part of Patent Rights, or any part of Field, or any part of Territory, or the
exclusive nature of the license grant, upon delivery of written notice to Licensee of Licensor’s decision to terminate, if any of the following occur: 
  

	 	(a)	 Licensee becomes in arrears in any payments due under the Agreement, and Licensee fails to make the required payment
within [***] days after delivery of written notice from Licensor, [***]; or 

  

	 	(b)	 Licensee is in breach of any non-payment provision of the Agreement, and does not
cure such breach within [***] days after delivery of written notice from Licensor; or 

  

	 	(c)	 Licensor delivers notice to Licensee of three or more actual breaches of the Agreement in any [***], even in the event
that Licensee cures such breaches in the allowed period; or 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-11	 	Agreement No. [***]

	 	(d)	 Licensee or its Affiliate or Sublicensee initiates any proceeding or action to challenge the validity, enforceability, or
scope of one or more of the Patent Rights, or assist a third party in pursuing such a proceeding or action. 

[***]. 
  

	 	7.4	 Other Conditions of Termination 

The Agreement will terminate: 
  

	 	(a)	 Immediately (but only to the extent permitted by applicable law), (i) if Licensee becomes bankrupt or insolvent, or
(ii) Licensee’s Board of Directors elects to liquidate its assets or dissolve its business, or (iii) Licensee ceases its business operations, or (iv) Licensee makes an assignment for the benefit of creditors or (v) if the
business or assets of Licensee are otherwise placed in the hands of a receiver or trustee, whether by voluntary act of Licensee or otherwise; or 

  

	 	(b)	 At any time by mutual written agreement between Licensee and Licensor. 

 

	 	7.5	 Effect of Termination 

If the Agreement is terminated for any reason: 
  

	 	(a)	 All rights and licenses of Sublicensees shall terminate upon termination of the Agreement; provided however, if the
Sublicense Agreement is in good standing and agrees in writing to assume all of the obligations of Licensee with respect to the rights sublicensed under this Agreement and provides Licensor with written notice thereof within 30 days after
termination of the Agreement, then such Sublicense Agreement shall survive; and 

  

	 	(b)	 Licensee shall cease making, having made, distributing, having distributed, using, selling, offering to sell, leasing,
loaning and importing any Licensed Products by the effective date of termination; and 

  

	 	(c)	 Licensee shall tender payment of all accrued royalties and other payments due to Licensor as of the effective date of
termination; and 

  

	 	(d)	 Nothing in the Agreement will be construed to release either Party from any obligation that matured prior to the
effective date of termination; and 

  

	 	(e)	 The provisions of Section 2.1 (with respect to Technology Rights), Sections 8 (Confidentiality), 9 (Infringement and
Litigation), 11 (Representations and Disclaimers), 12 (Limit of Liability), 13 (Indemnification), 14 (Insurance), 17 (Use of Name), 18 (Notices), and 19 (General Provisions) will survive any termination or expiration of the Agreement. In addition,
the provisions of Sections 3 (Compensation), 4.1 (Quarterly Payment and Milestone Reports), 5 (Payment, Records and Audits), and 6.1 (Patent Expenses) shall survive with respect to all activities and payment obligations accruing prior to the
termination or expiration of the Agreement. 

  

	8.	 Confidentiality 

  

	 	8.1	 Definition 

“Confidential Information” means all information that is of a confidential and proprietary nature to Licensor or Licensee and provided
by one Party to the other Party under this 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-12	 	Agreement No. [***]

 
Agreement or the [***], provided that, except as set forth in section 8.3 below, the provisions applicable to Confidential Information herein are not intended to replace any additional or more
restrictive requirements for handling Confidential Information, if any, imposed under [***]. 
  

	 	8.2	 Protection and Marking 

Licensor and Licensee each agree that all Confidential Information disclosed in tangible form, and marked “confidential” and forwarded to the
receiving Party by the disclosing Party, or if disclosed orally, is designated as confidential at the time of disclosure: (i) is to be held in strict confidence by the receiving Party, (ii) is to be used by and under authority of the
receiving Party only as authorized in the Agreement, and (iii) shall not be disclosed by the receiving Party, its agents or employees without the prior written consent of the disclosing Party or as authorized in the Agreement. Licensee has the
right to use and disclose Confidential Information of Licensor reasonably in connection with the exercise of its rights under the Agreement, including without limitation disclosing to Affiliates, actual or potential Sublicensees, investors,
acquirers, and others on a need to know basis, if such Confidential Information is provided under conditions which reasonably protect the confidentiality thereof. Each Party’s obligation of confidence hereunder includes, without limitation,
using at least the same degree of care with the disclosing Party’s Confidential Information as it uses to protect its own Confidential Information, but always at least a reasonable degree of care. 

 

	 	8.3	 Confidentiality or Terms of Agreement 

Each Party agrees not to disclose to any Third Party the terms of the Agreement without the prior written consent of the other Party hereto, except each
Party may disclose the Confidential Information of the other Party and the terms of the Agreement or the MTA (including without limitation any data or results obtained by the Licensee under the MTA): (a) to advisors, actual or potential
Sublicensees, investors, acquirers, and others on a need to know basis, in each case, under appropriate confidentiality obligations substantially similar to those of this Section 8; and (b) to the extent necessary to comply with applicable
laws (including the rules of regulatory agencies and securities exchanges) and court orders (including, without limitation, The Texas Public Information Act, as may be amended from time to time, other open records laws, decisions and rulings, and
securities laws, regulations and guidance). Licensee may also disclose Licensor’s Confidential Information to the extent (and only to the extent) such disclosure is reasonably necessary in connection with preparing, filing or seeking marketing
approvals and other regulatory filings for the Licensed Product, to the Government and applicable regulatory agencies. If the Agreement is not for all fields of use, then Licensor may disclose the Field to other potential third party licensees.
Notwithstanding the foregoing, the existence of the Agreement shall not be considered Confidential Information. 
  

	 	8.4	 Disclosure Required by Court Order or Law 

If the receiving Party is required to disclose Confidential Information of another Party hereto, or any terms of the Agreement, pursuant to the order or
requirement of a court, administrative agency, or other governmental body or applicable law, the receiving Party may disclose such Confidential Information or terms to the extent required, provided that the receiving Party shall use reasonable
efforts to provide the disclosing Party with reasonable advance notice thereof to enable the disclosing Party to seek a protective order and otherwise seek to prevent such disclosure. To the extent that Confidential Information so disclosed does not
become part of the public domain by virtue of such disclosure, it shall remain Confidential Information protected pursuant to Section 8. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-13	 	Agreement No. [***]

	 	8.5	 Copies 

Each Party agrees not to copy or record any of the Confidential Information of the other Party, except as reasonably necessary to exercise its rights or
perform its obligations under the Agreement, and for archival and legal purposes. 
  

	 	8.6	 Continuing Obligations 

Subject to the exclusions listed in Section 8.7, the Parties’ confidentiality obligations under the Agreement will survive termination of the
Agreement and will continue for a period of [***] thereafter. 
  

	 	8.7	 Exclusions 

Information shall not be considered Confidential Information of a disclosing Party under the Agreement to the extent that the receiving Party can
establish by competent written proof that such information: 
  

	 	(a)	 Was in the public domain at the time of disclosure; or 

 

	 	(b)	 Later became part of the public domain through no act or omission of the recipient Party, its employees, agents,
successors or assigns in breach of the Agreement; or 

  

	 	(c)	 Was lawfully disclosed to the recipient Party by a third party having the right to disclose it not under an obligation of
confidentiality; or 

  

	 	(d)	 Was already known by the recipient Party at the time of disclosure; or 

 

	 	(e)	 Was independently developed by the recipient Party without use of the disclosing Party’s Confidential Information.

  

	 	8.8	 Copyright Notice 

The placement of a copyright notice on any Confidential Information will not be construed to mean that such information has been published and will not
release the other Party from its obligation of confidentiality hereunder 
  

	9.	 Infringement and Litigation 

 

	 	9.1	 Infringement Notification and Conference  

If either Licensee or Licensor’s designated office for technology commercialization becomes aware of any suspected infringement of Patent Rights in
the Field, such Party shall promptly notify the other Party of such in writing; and the Parties will confer regarding any such suspected infringement. Notice of infringement may be given to a suspected infringer only with the prior written consent
of each of the Parties, not to be unreasonably withheld, delayed, or conditioned. If any suit is to be commenced, Licensor and Licensee will endeavor to reach mutual agreement as to how best to prosecute, manage, and fund such suit. Any net recovery
resulting from such suit shall be first used to reimburse each Party’s expenses incurred directly in such prosecution and management, and the remainder shall [***]. 
  

	 	9.2	 Licensee’s Enforcement Rights 

Licensee has the first right to institute an infringement suit, but only with the prior written consent of Licensor, which will not be unreasonably
withheld, delayed or conditioned, and only for an infringement of Patent Rights that have been licensed exclusively to Licensee in the Exclusive Field. In such case, Licensee will keep Licensor reasonably informed of the developments and status of
the suit. Licensee will obtain Licensor’s input and approval on 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-14	 	Agreement No. [***]

 
any substantive positions taken in the suit regarding the scope, validity, and enforceability of the Patent Rights. Licensee shall not prosecute, settle, or otherwise compromise any such suit in
a manner that adversely affects Licensor’s interests or the public’s interests, without Licensor’s prior written consent. 
  

	 	9.4	 Indispensable Party 

If it is necessary to name Licensor as a party plaintiff in such infringement suit, then Licensee must first obtain Licensor’s prior written
permission, which permission shall not be unreasonably withheld, delayed, or conditioned, provided that (i) Licensor shall have reasonable prior input on choice of counsel on any matter where such counsel represents Licensor’s interests,
and (ii) Licensee and such counsel agree to follow all required procedures of the Texas Attorney General regarding retention of outside counsel for state entities, and (iii) Licensee shall bear, and indemnify Licensor for, all costs and
liabilities related to Licensor being named a party plaintiff in such suit. 
  

	 	9.5	 Cooperation between Licensor and Licensee 

In any infringement suit matter, the Parties agree to cooperate fully with each other. At the request of the Party bringing suit, the other Party will
permit reasonable access after reasonable advance notice, to all relevant personnel, records, papers, information, samples, specimens, etc., during regular business hours. 
  

	10.	 Export Compliance 

Licensee understands that the Arms Export Control Act (AECA), including its implementing International Traffic In Arms Regulations (ITAR), and the
Export Administration Act (EAA), including its Export Administration Regulations (EAR), are some (but not all) of the laws and regulations that comprise the U.S. export laws and regulations. Licensee further understands that the U.S. export laws and
regulations include (but are not limited to): (a) ITAR and EAR product/service/data-specific requirements; (b) ITAR and EAR ultimate destination-specific requirements; (c) ITAR and EAR end user-specific requirements; (d) Foreign
Corrupt Practices Act; and (e) anti-boycott laws and regulations. Licensee will comply with all then-current applicable export laws and regulations of the U.S. Government (and other applicable U.S. laws and regulations) pertaining to the
Licensed Products (including any associated products, items, articles, computer software, media, services, technical data, and other information). Licensee certifies that it will not, directly or indirectly, export (including any deemed export), nor
re-export (including any deemed re-export) the Licensed Products (including any associated products, items, articles, computer software, media, services, technical data,
and other information) in violation of applicable U.S. laws and regulations. Licensee will include a provision in its agreements, substantially similar to this Section 10, with its Sublicensees, third party wholesalers and distributors, and
physicians, hospitals or other healthcare providers who purchase a Licensed Product, requiring that these parties comply with all then-current applicable U.S. export laws and regulations and other applicable U.S. laws and regulations. 

 

	11.	 Representations and Disclaimers 

 

	 	11.1	 Licensor Representations 

Except for the rights, if any, of the Government as set forth in Section 11.2, Licensor represents and warrants to Licensee that to the knowledge
of Licensor’s designated office for technology commercialization (i) Licensor is the owner or agent of the entire right, title, and interest in and to Patent Rights (other than the right, title and interest of any joint owner identified in
Section 1 of the Patent License Agreement), (ii) Licensor has the right to grant licenses hereunder, and (iii) Licensor has not knowingly granted and will not knowingly grant licenses or other rights under the Patent Rights that are in
conflict with the terms and conditions in the Agreement. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-15	 	Agreement No. [***]

	 	11.2	 Government Rights 

Licensee understands that Improvements may be developed under a funding agreement with Government and, if so, that Government may have certain rights
relative thereto. The Agreement is made subject to the Government’s rights under any such agreement and under any applicable Government law or regulation. To the extent that there is a conflict between any such agreement, such applicable law or
regulation and the Agreement, the terms of such Government agreement, and applicable law or regulation, shall prevail. Licensee agrees that, to the extent required by U.S. laws and regulations, Licensed Products used or Sold in the U.S. will be
manufactured substantially in the U.S., unless a written waiver is obtained in advance from the U.S. Government. 
  

	 	11.3	 Licensor Disclaimers 

EXCEPT AS SPECIFICALLY SET FORTH IN SECTION 11.1, LICENSEE UNDERSTANDS AND AGREES THAT LICENSOR MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, AS TO THE LICENSED PRODUCTS, OR AS TO THE OPERABILITY OR FITNESS FOR ANY USE OR PARTICULAR PURPOSE, MERCHANTABILITY, SAFETY, EFFICACY, APPROVABILITY BY REGULATORY AUTHORITIES, TIME AND COST OF
DEVELOPMENT, PATENTABILITY, AND/OR BREADTH OF PATENT RIGHTS. LICENSOR MAKES NO REPRESENTATION AS TO WHETHER ANY PATENT WITHIN PATENT RIGHTS IS VALID, OR AS TO WHETHER THERE ARE ANY PATENTS NOW HELD, OR WHICH WILL BE HELD, BY OTHERS OR BY LICENSOR
THAT MIGHT BE REQUIRED FOR USE OF PATENT RIGHTS IN FIELD. NOTHING IN THIS AGREEMENT WILL BE CONSTRUED AS CONFERRING BY IMPLICATION, ESTOPPEL OR OTHERWISE ANY LICENSE OR RIGHTS TO ANY PATENTS OR TECHNOLOGY OTHER THAN THE PATENT RIGHTS, WHETHER SUCH
PATENTS ARE DOMINANT OR SUBORDINATE TO THE PATENT RIGHTS. 
  

	 	11.4	 Licensee Representation 

By execution of the Agreement, Licensee represents, acknowledges, covenants and agrees (a) that Licensee has not been induced in any way by
Licensor or its employees to enter into the Agreement, and (b) that Licensee has been given an opportunity to conduct sufficient due diligence with respect to all items and issues pertaining to this Section 11 (Representations and
Disclaimers) and all other matters pertaining to the Agreement; and (c) that Licensee has adequate knowledge and expertise, or has utilized knowledgeable and expert consultants, to adequately conduct the due diligence. Licensee represents that
it is a duly organized, validly existing entity of the form indicated in Section 1 of the Patent License Agreement, and is in good standing under the laws of its jurisdiction of organization as indicated in Section 1 of the Patent License
Agreement, and has all necessary corporate or other appropriate power and authority to execute, deliver and perform its obligations hereunder. 
  

	12.	 Limit of Liability 

IN NO EVENT SHALL LICENSOR, THE UNIVERSITY SYSTEM IT GOVERNS, ITS MEMBER INSTITUTIONS, INVENTORS, REGENTS, OFFICERS, EMPLOYEES, STUDENTS, AGENTS OR
AFFILIATED ENTERPRISES, BE LIABLE FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL, EXEMPLARY, OR PUNITIVE DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS OR REVENUE) ARISING OUT OF OR IN CONNECTION WITH THE AGREEMENT OR ITS
SUBJECT MATTER, REGARDLESS OF WHETHER ANY SUCH PARTY KNOWS OR SHOULD KNOW OF THE POSSIBILITY OF SUCH DAMAGES. OTHER THAN FOR CLAIMS AGAINST LICENSEE FOR INDEMNIFICATION (SECTION 13) OR FOR MISUSE OR MISAPPROPRIATION OR INFRINGEMENT OF
LICENSOR’S INTELLECTUAL PROPERTY RIGHTS, LICENSEE AND ITS AFFILIATES WILL NOT BE LIABLE TO LICENSOR FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL OR PUNITIVE DAMAGES (INCLUDING, WITHOUT 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-16	 	Agreement No. [***]

 
LIMITATION, DAMAGES FOR LOSS OF PROFITS OR REVENUE) ARISING OUT OF OR IN CONNECTION WITH THE AGREEMENT OR ITS SUBJECT MATTER, REGARDLESS OF WHETHER LICENSEE KNOWS OR SHOULD HAVE KNOWN OF THE
POSSIBILITY OF SUCH DAMAGES. 
  

	13.	 Indemnification 

  

	 	13.1	 Indemnification Obligation 

Subject to Section 13.2, Licensee agrees to hold harmless, defend and indemnify Licensor, the university system it governs, its member
institutions, its Regents, officers, employees, students and agents (“Indemnified Parties”) from and against any liabilities, damages, causes of action, suits, judgments, liens, penalties, fines, losses, costs and expenses
(including, without limitation, reasonable attorneys’ fees and other expenses of litigation) (collectively “Liabilities”) resulting from claims or demands brought by Third Parties against an Indemnified Party on account of any
injury or death of persons, damage to property, or any other damage or loss arising out of or in connection with the Agreement or the exercise or practice by or under authority of Licensee, its Affiliates or their Sublicensees, or Third Party
wholesalers or distributors, or physicians, hospitals or other healthcare providers who purchase a Licensed Product, of the rights granted hereunder. 
  

	 	13.2	 Conditions of Indemnification 

Licensee shall have no responsibility or obligation under Section 13.1 for any Liabilities to the extent caused by the gross negligence or willful
misconduct any Indemnified Party or breach of this Agreement by Licensor. Obligations to indemnify, and hold harmless under Section 13.1 are subject to: (a) to the extent authorized by the Texas Constitution and the laws of the State of
Texas, and subject to the statutory duties of the Texas Attorney General, the Indemnified Party giving Licensee control of the defense and settlement of the claim and demand; and (b) to the extent authorized by the Texas Constitution and the
laws of the State of Texas and subject to statutory duties of the Texas Attorney General, the Indemnified Party providing assistance reasonably requested by Licensee, at Licensee’s expense. 

 

	14.	 Insurance 

  

	 	14.1	 Insurance Requirements 

Prior to any Licensed Product being used or Sold (including for the purpose of obtaining regulatory approvals), by Licensee, an Affiliate, or by a
Sublicensee, and for a period of [***] after the Agreement expires or is terminated, Licensee shall, at its sole cost and expense, procure and maintain commercial general liability insurance in commercially reasonable and appropriate amounts for the
Licensed Product being used or Sold. Licensee shall use commercially reasonable efforts to have Licensor, the university system it governs, its member institutions, Regents, officers, employees, students, and agents named as additional insureds.
Such commercial general liability insurance shall provide, without limitation: [***]. 
  

	 	14.2	 Evidence of Insurance and Notice of Changes 

Upon request by Licensor, Licensee shall provide Licensor with written evidence of such insurance. Additionally, Licensee shall provide Licensor with
written notice of at least 60 days prior to Licensee cancelling, not renewing, or changing such insurance to the extent materially adversely impacting Licensor. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-17	 	Agreement No. [***]

	15.	 Assignment 

The Agreement may not be assigned by Licensee without the prior written consent of Licensor, which consent will not be unreasonably withheld, delayed or
conditioned. A merger or other transaction in which the equity holders of Licensee prior to such event hold less than a majority of the equity of the surviving or acquiring entity shall be considered an assignment of the Agreement. [***]. For any
permitted assignment to be effective, (a) Licensee must be in good standing under this Agreement, (b) the Licensee must pay Licensor the assignment fee pursuant to Section 3.1(e) (except in the case of any assignment to an Affiliate),
and (c) the assignee must assume in writing (a copy of which shall be promptly provided to Licensor) all of Licensee’s rights, duties and obligations (including curing all Licensee defaults existing at the time of assignment within 30 days
of execution of the assignment) under the Agreement and agree to comply with all terms and conditions of the Agreement as if assignee were an original Party to the Agreement. 
  

	16.	 Governmental Markings 

  

	 	16.1	 Patent Markings 

Licensee agrees to use Diligence and Commercially Reasonable Efforts to ensure that all Licensed Products Sold by Licensee, Affiliates, or Sublicensees
will be legibly marked with the number of any applicable patent(s) licensed hereunder as part of the Patent Rights in accordance with each country’s patent marking laws, including Title 35, U.S. Code, or if such marking is not practicable,
to mark the accompanying outer box or product insert for Licensed Products accordingly. 
  

	 	16.2	 Governmental Approvals and Marketing of Licensed Products  

Licensee will be responsible for obtaining all necessary governmental approvals for the development, production, distribution, Sale, and use of any
Licensed Product, at Licensee’s expense, including, without limitation, any safety studies. Licensee will have sole responsibility for any warning labels, packaging and instructions as to the use and the quality control for any Licensed
Product. 
  

	 	16.3	 Foreign Registration and Laws  

Licensee agrees to register the Agreement with any foreign governmental agency that requires such registration; and Licensee will pay all costs and
legal fees in connection with such registration. Licensee is responsible for compliance with all foreign laws affecting the Agreement or the Sale of Licensed Products to the extent there is no conflict with United States law, in which case United
States law will control. 
  

	17.	 Use of Name 

Licensee will not use the name, trademarks or other marks of Licensor (or the name of the university system it governs, its member institutions, any of
its Regents or employees) without the advance written consent of Licensor. Licensor may use Licensee’s name and logo for annual reports, brochures, website, and internal reports without prior consent. 

 

	18.	 Notices 

Any notice or other communication of the Parties required or permitted to be given or made under the Agreement will be in writing and will be deemed
effective when sent in a manner that provides confirmation or acknowledgement of delivery and received at the address set forth in Section 18 of the Patent License Agreement (or as changed by written notice pursuant to this Section 18).
Notices required under the Agreement may be delivered via E-mail provided such notice is confirmed in writing as indicated. 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-18	 	Agreement No. [***]

 Notices shall be provided to each Party as specified in the “Contact for Notice” address set
forth in Section 18 of the Patent License Agreement. Each Party shall update the other Party in writing with any changes in such contact information. 
  

	19.	 General Provisions 

  

	 	19.1	 Binding Effect 

The Agreement is binding upon and inures to the benefit of the Parties hereto, their respective executors, administrators, heirs, permitted assigns, and
permitted successors in interest. 
  

	 	19.2	 Construction of Agreement 

Headings are included for convenience only and will not be used to construe the Agreement. The Parties acknowledge and agree that both Parties
substantially participated in negotiating the provisions of the Agreement; therefore, both Parties agree that any ambiguity in the Agreement shall not be construed more favorably toward one Party than the other Party, regardless of which Party
primarily drafted the Agreement. 
  

	 	19.3	 Counterparts and Signatures 

The Agreement may be executed in multiple counterparts, each of which shall be deemed an original, but all of which taken together shall constitute one
and the same instrument. A Party may evidence its execution and delivery of the Agreement by transmission of a signed copy of the Agreement via facsimile or email. 
  

	 	19.4	 Compliance with Laws 

Licensee will comply with all applicable federal, state, and local laws and regulations, including, without limitation, all export laws and regulations.

  

	 	19.5	 Force Majeure 

Neither Party shall be liable to the other for its failure to perform any of its obligations under this Agreement, except for payment obligations,
during any period in which such performance is delayed because rendered impracticable or impossible due to Force Majeure, provided that the Party experiencing the delay promptly notifies the other Party of the delay. 

 

	 	19.6	 Governing Law 

The Agreement will be construed and enforced in accordance with laws of the U.S. and the State of Texas, without regard to choice of law and conflicts
of law principles. 
  

	 	19.7	 Modification 

Any modification of the Agreement will be effective only if it is in writing and signed by duly authorized representatives of both Parties. No
modification will be made by email communications. 
  

	 	19.8	 Severability 

If any provision hereof is held to be invalid, illegal or unenforceable in any jurisdiction, the Parties hereto shall negotiate in good faith a valid,
legal and enforceable substitute provision that most nearly reflects the original intent of the Parties, and all other provisions hereof shall remain in full force and effect in such jurisdiction and shall be construed in order to carry out the
intentions of the Parties hereto as nearly as may be possible. Such invalidity, illegality, or unenforceability shall not affect the validity, legality, or enforceability 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-19	 	Agreement No. [***]

 
of such other provisions in any other jurisdiction, so long as the essential essence of the Agreement remains enforceable. 

 

	 	19.9	 Third Party Beneficiaries 

Nothing in the Agreement, express or implied, is intended to confer any benefits, rights or remedies on any entity, other than the Parties and their
permitted successors and assigns. However, if there is a joint owner of any Patent Rights identified in Section 1 of the Patent License Agreement (other than Licensee), then Licensee hereby agrees that the following provisions of these Terms
and Conditions extend to the benefit of the co-owner identified therein (excluding the Licensee to the extent it is a co-owner) as if such
co-owner was identified in each reference to the Licensor: the retained rights under clause (b) of Section 2.1; Section 11.3 (Licensor Disclaimers); Section 12 (Limitation of Liability);
Section 13 (Indemnification); Section 14.1 (Insurance Requirements); Section 17 (Use of Name); and Section 19.10 (Sovereign Immunity, if applicable). 
  

	 	19.10	 Waiver 

Neither Party will be deemed to have waived any of its rights under the Agreement unless the waiver is in writing and signed by such Party. No delay or
omission of a Party in exercising or enforcing a right or remedy under the Agreement shall operate as a waiver thereof. 
  

	 	19.11	 Sovereign Immunity 

Nothing in the Agreement shall be deemed or treated as any waiver of Licensor’s sovereign immunity. 

 

	 	19.12	 Entire Agreement 

The Agreement and the MTA constitute the entire Agreement between the Parties regarding the subject matter hereof, and supersedes all prior written or
verbal agreements, representations and understandings relative to such matters. 
  

	 	19.13	 Claims Against Licensor for Breach of Agreement 

Licensee acknowledges that any claim for breach of the Agreement asserted by Licensee against Licensor shall be subject to Chapter 2260 of the Texas
Government Code and that the process provided therein shall be Licensee’s sole and exclusive process for seeking a remedy for any and all alleged breaches of the Agreement by Licensor or the State of Texas. 

— END OF EXHIBIT A — 

  

					
	Licensee:  Icosavax, Inc.	 	CONFIDENTIAL	 	Exclusive PLA Exhibit A
	The University of Texas at Austin	 	Page A-20	 	Agreement No. [***]EX-4.2

 Exhibit 4.2 

AMERICAN HOMES 4 RENT, L.P., 
 AS
ISSUER, 
 AND 
 U.S. BANK
NATIONAL ASSOCIATION, 
 AS TRUSTEE 

THIRD SUPPLEMENTAL INDENTURE 
 Dated
as of July 8, 2021 
 $450,000,000 2.375% SENIOR NOTES DUE 2031 

SUPPLEMENT TO INDENTURE 
 DATED AS
OF FEBRUARY 7, 2018, BETWEEN 
 AMERICAN HOMES 4 RENT, L.P., AS ISSUER, 

AND 
 U.S. BANK NATIONAL
ASSOCIATION, AS TRUSTEE 

 THIRD SUPPLEMENTAL INDENTURE, dated as of July 8, 2021 (this “Third
Supplemental Indenture”), between AMERICAN HOMES 4 RENT, L.P., a Delaware limited partnership (the “Operating Partnership”), having its principal executive office located at 23975 Park Sorrento, Suite 300, Calabasas,
California 91302, and U.S. BANK NATIONAL ASSOCIATION, a national banking association organized and existing under the laws of the United States, as trustee (the “Trustee”), which supplements that certain Indenture, dated as of
February 7, 2018, by and between the Operating Partnership and the Trustee (the “Base Indenture,” and together with this Third Supplemental Indenture, the “Indenture”). 

RECITALS 
 WHEREAS, the
Operating Partnership has duly authorized the execution and delivery of the Base Indenture to the Trustee to provide for the issuance from time to time for its lawful purposes of debt securities evidencing the Operating Partnership’s
debentures, notes or other evidences of indebtedness. 
 WHEREAS, Section 301 of the Base Indenture provides that by means of a
supplemental indenture the Operating Partnership may create one or more series of the Operating Partnership’s debt securities and establish the form, terms and provisions thereof. 

WHEREAS, the Operating Partnership intends by this Third Supplemental Indenture to (i) create a series of the Operating
Partnership’s debt securities, in an initial aggregate principal amount equal to $450,000,000, entitled “2.375% Senior Notes due 2031” (the “Notes”) and (ii) establish the form and the terms and provisions of the
Notes. 
 WHEREAS, the consent of Holders to the execution and delivery of this Third Supplemental Indenture is not required, and all other
actions required to be taken under the Base Indenture with respect to this Third Supplemental Indenture have been taken. 
 NOW, THEREFORE
IT IS AGREED: 
 ARTICLE ONE 

DEFINITIONS, CREATION, FORM AND TERMS AND CONDITIONS OF THE DEBT SECURITIES 

Section 1.1    Definitions. Capitalized terms used but not otherwise defined in this Third Supplemental
Indenture shall have the meanings ascribed to them in the Base Indenture. In addition, the following terms shall have the following meanings to be equally applicable to both the singular and the plural forms of the terms set forth below: 

“Company” means American Homes 4 Rent, a Maryland real estate investment trust. 

“Consolidated Income Available for Debt Service” means, for any period of time, the Operating Partnership’s Consolidated
Net Income for such period, plus amounts which have been deducted and minus amounts which have been added for such period, without duplication: (a) Interest Expense on Indebtedness; (b) provision for taxes based on income;
(c) depreciation, amortization and all other non-cash items deducted at arriving at Consolidated Net Income and premium and deferred financing costs; (d) provision for gains, losses or impairments on
sales or other dispositions of properties and other investments; (e) extraordinary and non-recurring items, as the Operating Partnership determined in good faith; and
(f) non-controlling interests (other than with respect to cash dividends and distributions actually received and included in the definition of “Consolidated Net Income” as set forth below). In
each case for such period, the Operating Partnership will reasonably determine amounts in accordance with GAAP, except to the extent GAAP is not applicable with respect to the determination of non-cash and non-recurring items. 
 “Consolidated Net Income” means, for any period of time, the
amount of net income, or loss, for the Operating Partnership and its Consolidated Subsidiaries for such period, excluding, net income (or losses) attributable to non-controlling interests in unconsolidated
Persons except to the extent of cash dividends and 

  
 2 

 
distributions actually received by the Operating Partnership or one of its Consolidated Subsidiaries during such period, all determined in accordance with GAAP. 

“Consolidated Financial Statements” means, with respect to any Person, collectively, the consolidated financial statements
and notes to those financial statements of that Person and its consolidated subsidiaries prepared in accordance with GAAP. 

“Consolidated Subsidiary” means each Subsidiary of the Operating Partnership that is consolidated in its Consolidated
Financial Statements. 
 “Credit Agreement” means the Amended and Restated Credit Agreement, dated April 15, 2021, by
and among the Operating Partnership, as borrower, the Company, as parent, Wells Fargo Bank, National Association, as administrative agent, and the other lending institutions that are parties thereto, as lenders, as it may be amended, supplemented,
modified, extended, restructured, renewed, refinanced, restated, refunded or replaced (in whole or in part, including with any new credit agreement or facility) from time to time. 

“Depository” means The Depository Trust Company or any successor securities clearing agency. 

“GAAP” means generally accepted accounting principles in the United States of America as in effect on the date of any
required calculation or determination. 
 “Incur” means, with respect to any Indebtedness or other obligation of any
Person, to create, assume, guarantee or otherwise become liable in respect of the Indebtedness or other obligation, and “Incurrence” and “Incurred” have meanings correlative to the foregoing. Indebtedness or other obligation of
the Operating Partnership or any Subsidiary of the Operating Partnership will be deemed to be Incurred by the Operating Partnership or such Subsidiary whenever the Operating Partnership or such Subsidiary shall create, assume, guarantee or otherwise
become liable in respect thereof. Indebtedness or other obligation of a Subsidiary of the Operating Partnership existing prior to the time it became a Subsidiary of the Operating Partnership will be deemed to be Incurred upon such Subsidiary
becoming a Subsidiary of the Operating Partnership; and Indebtedness or other obligation of a Person existing prior to a merger or consolidation of such Person with the Operating Partnership or any Subsidiary of the Operating Partnership in which
such Person is the successor to the Operating Partnership or such Subsidiary will be deemed to be Incurred upon the consummation of such merger or consolidation. Any issuance or transfer of capital stock that results in Indebtedness constituting
Intercompany Indebtedness being held by a Person other than the Operating Partnership, the Company or any Consolidated Subsidiary or any sale or other transfer of any Indebtedness constituting Intercompany Indebtedness to a Person that is not the
Operating Partnership, the Company or any Consolidated Subsidiary, will be deemed, in each case, to be an Incurrence of Indebtedness that is not Intercompany Indebtedness at the time of such issuance, transfer or sale, as the case may be. 

“Indebtedness,” of the Operating Partnership or any Consolidated Subsidiary means, without duplication, any of the Operating
Partnership’s indebtedness or that of any Consolidated Subsidiary, whether or not contingent, in respect of: (a) borrowed money evidenced by bonds, notes, debentures or similar instruments whether or not such indebtedness is secured by any
lien existing on property owned by the Operating Partnership or any Consolidated Subsidiary; (b) indebtedness for borrowed money of a Person other than the Operating Partnership or a Consolidated Subsidiary which is secured by any lien on
property or other asset owned by the Operating Partnership or any Consolidated Subsidiary, to the extent of the lesser of (i) the amount of indebtedness so secured, and (ii) the fair market value (determined in good faith by the Operating
Partnership) of the property subject to such lien; (c) reimbursement obligations, contingent or otherwise, in connection with any letters of credit actually issued; or (d) any lease of property by the Operating Partnership or any
Consolidated Subsidiary as lessee which is reflected on the Operating Partnership’s consolidated balance sheet as a finance lease in accordance with GAAP; to the extent, in the case of indebtedness under (a) through (c) above, that any
such items (other than letters of credit) would appear as a liability on the Operating Partnership’s consolidated balance sheet in accordance with GAAP. Indebtedness also (1) includes, to the extent not otherwise included, any non-contingent obligation by the Operating Partnership or any Consolidated Subsidiary to be liable for, or to pay, as obligor, guarantor or otherwise (other than for purposes of collection in the ordinary course of
business), indebtedness of another Person (other than the Operating Partnership or any Consolidated Subsidiary) of the type described in clauses (a)-(d) of this definition, other than obligations to be liable for the Indebtedness of another Person
solely as a result of customary exceptions to non-

  
 3 

 
recourse indebtedness, such as for fraud, misapplication of funds, environmental indemnities, voluntary bankruptcy, collusive involuntary bankruptcy and other similar exceptions, and
(2) excludes, any such indebtedness (or obligation referenced in clause (1) above) that has been the subject of an “in substance” defeasance in accordance with GAAP. 

“Intercompany Indebtedness” means Indebtedness to which the only parties are any of the Operating Partnership and any
Consolidated Subsidiary; provided, however, that with respect to any such Indebtedness of which the Operating Partnership or any Guarantor is the borrower or issuer, such Indebtedness is subordinate in right of payment to the Notes.

 “Interest Expense” means, for any period of time, the interest expense of, the Operating Partnership and its
Subsidiaries’ Indebtedness, determined on a consolidated basis in accordance with GAAP, but excluding: (i) interest reserves funded from the proceeds of any loan; (ii) amortization of deferred financing costs, including gains or
losses on early extinguishment of debt; (iii) prepayment penalties; (iv) non-cash swap ineffectiveness charges; and (v) any expenses resulting from the discounting of any indebtedness in
connection with the application of purchase accounting in connection with any acquisition; and including, without duplication, effective interest in respect of original issue discount as determined in accordance with GAAP. 

“Make-Whole Amount” means the excess of (1) the net present value, on the Redemption Date, of the principal being
redeemed and the amount of interest (exclusive of interest accrued to the date of redemption) that would have been payable if such redemption had not been made (calculated as if the maturity date of the Notes was the Par Call Date), over
(2) the aggregate principal amount of the Notes being redeemed. Net present value shall be calculated by discounting, on a semi-annual basis, such principal and interest at the Reinvestment Rate (as determined on the third Business Day
preceding the date of the notice of redemption) from the respective dates on which such principal and interest would have been payable if such redemption had not been made, to the date of redemption. 

“Reinvestment Rate” means 0.20%, plus the weekly yield for the most recent week set forth in the most recent Statistical
Release (as defined below) for the constant maturity U.S. Treasury security (rounded to the nearest month) corresponding to the remaining life to maturity (assuming, for the purposes of this definition, that the Notes mature on the Par Call Date),
as of the payment date of the principal being redeemed. If no maturity exactly corresponds to such maturity, yields for the two published maturities most closely corresponding to such maturity shall be calculated pursuant to the immediately
preceding sentence and the Reinvestment Rate shall be interpolated or extrapolated from such yields on a straight-line basis, rounding in each of such relevant periods to the nearest month. For the purpose of calculating the Reinvestment Rate, the
most recent Statistical Release published prior to the date of determination of the Make-Whole Amount shall be used. If the format or content of the Statistical Release changes in a manner that precludes determination of the yield in the above
manner, then the yield will be determined in the manner that most closely approximates the above manner, as the Operating Partnership reasonably determine. 

“Reporting Date” means each fiscal quarter covered in the Operating Partnership’s annual or quarterly report most
recently furnished to Holders of the Notes or filed with the Commission, as the case may be. 
 “Secured Debt” means, as of
any date, that portion of principal amount of outstanding Indebtedness, excluding Intercompany Indebtedness, of the Operating Partnership and its Consolidated Subsidiaries as of that date that is secured by a mortgage, trust deed, deed of trust,
deeds to secure Indebtedness, pledge, security interest, assignment for collateral purposes, deposit arrangement, or other security agreement, excluding any right of setoff but including, without limitation, any conditional sale or other title
retention agreement, any financing lease having substantially the same economic effect as any of the foregoing, and any other like agreement granting or conveying a security interest. 

“Statistical Release” means the statistical release designated “H.15” or any successor publication that is
published weekly by the Federal Reserve System (or comparable online data source or publication) which establishes yields on actively traded U.S. government securities adjusted to constant maturities, or, if such Statistical Release is not published
at the time of any determination under the Indenture, then such other reasonably comparable index which shall be designated by the Operating Partnership. 

  
 4 

 “Subsidiary” means (1) any corporation at least a majority of the
total voting power of whose outstanding Voting Stock is owned, directly or indirectly, at the date of determination by the Operating Partnership and/or one or more other Subsidiaries, and (2) any other Person in which the Operating Partnership,
and/or one or more other Subsidiaries, directly or indirectly, at the date of determination, (x) own at least a majority of the outstanding ownership interests or (y) have the power to elect or direct the election of, or to appoint or
approve the appointment of, at least a majority of the directors, trustees or managing members of, or other persons holding similar positions with, such Person. 

“Total Assets” means, as of any time, the sum of, without duplication, Undepreciated Real Estate Assets and all other assets,
excluding accounts receivable and non-real estate intangibles, of the Operating Partnership and its Consolidated Subsidiaries, all determined in accordance with GAAP. 

“Total Unencumbered Assets” means, as of any time, the sum of, without duplication, those Undepreciated Real Estate Assets
which are not subject to a lien securing Indebtedness and all other assets, excluding accounts receivable and non-real estate intangibles, of the Operating Partnership and its Consolidated Subsidiaries not
subject to a lien securing Indebtedness, all determined in accordance with GAAP; provided, however, that all investments by the Operating Partnership or its Consolidated Subsidiaries in unconsolidated joint ventures, unconsolidated
limited partnerships, unconsolidated limited liability companies and other unconsolidated entities shall be excluded from Total Unencumbered Assets to the extent that such investments would have otherwise been included for the purposes of
Section 2.1(c). 
 “Undepreciated Real Estate Assets” means, as of any time, the cost (original cost plus capital
improvements) of the Operating Partnership’s real estate assets, right of use assets associated with a finance lease in accordance with GAAP and related intangibles and the real estate assets and related intangibles of the Operating
Partnership’s Consolidated Subsidiaries on such date, before depreciation and amortization, all determined in accordance with GAAP; provided, however, that “Undepreciated Real Estate Assets” shall not include the right
of use assets associated with an operating lease in accordance with GAAP. 
 “Unsecured Debt” means that portion of the
outstanding principal amount of the Operating Partnership and its Consolidated Subsidiaries’ Indebtedness, excluding Intercompany Indebtedness, that is not Secured Debt. 

“Voting Stock” means, with respect to any Person, any class or series of capital stock of, or other equity interests in, such
Person the holders of which are ordinarily, in the absence of contingencies, entitled to vote for the election of, or to appoint or to approve the appointment of, the directors, trustees or managing members of, or other persons holding similar
positions with, such Person. 
 Section 1.2    Creation of the Notes. In accordance with Section 301 of
the Base Indenture, the Operating Partnership hereby creates the Notes as a separate series of its senior unsecured debt securities, entitled “2.375% Senior Notes due 2031”, issued pursuant to the Indenture. The Notes shall initially be
limited to an aggregate principal amount equal to $450,000,000, subject to the exceptions set forth in Section 301(2) of the Base Indenture and Section 1.4(f) hereof. 

Section 1.3    Form of the Notes. The Notes will be issued in the form of one or more permanent fully
registered global securities (the “Global Note”) that will be deposited with, or on behalf of the Depository, and registered in the name of the Depository or its nominee, as the case may be, subject to Section 305 of the Base
Indenture. So long as the Depository, or its nominee, is the registered owner of the Global Note, the Depository or its nominee, as the case may be, will be considered the sole Holder of the Notes represented by the Global Note for all purposes
under the Indenture. 
 Section 1.4    Terms and Provisions of the Notes. The Notes shall be governed by all
of the terms and provisions of the Base Indenture, as supplemented and amended by this Third Supplemental Indenture, and in particular, the following provisions shall be terms of the Notes: 

(a)    Registration and Form. The Notes shall be issuable in registered form without coupons in minimum
denominations of $2,000 and integral multiples of $1,000 in excess thereof. Each Note shall be dated the 

  
 5 

 
date of its authentication and shall be substantially in the form of Exhibit A attached hereto. The Operating Partnership, any Guarantor, the Trustee and any agent of the Operating Partnership,
any Guarantor or the Trustee shall treat the Person in whose name a Note is registered in the Security Register as the owner of such Note for all purposes whatsoever, and none of the Operating Partnership, any Guarantor, the Trustee or any agent of
the Operating Partnership, any Guarantor or the Trustee shall be affected by notice to the contrary. 

(b)    Payment of Principal and Interest. All payments of principal, Make-Whole Amount, if any, and interest in
respect of the Global Notes will be made by the Operating Partnership in immediately available funds to the Depository or its nominee, as the case may be, as the Holder of each of the Global Notes. The Notes shall mature, and the unpaid principal
thereon, shall be payable, on July 15, 2031, subject to the provisions of the Base Indenture. The rate per annum at which interest shall be payable on the Notes shall be 2.375%. Interest on the Notes will be payable semi-annually in arrears on
each January 15 and July 15, commencing January 15, 2022 (each, an “Interest Payment Date”) and on the Stated Maturity as specified in this Section 1.4(b), to the Persons in whose names the Notes are registered
in the Security Register applicable to the Notes at the close of business on January 1 for Interest Payment Dates of January 15 and July 1 for Interest Payment Dates of July 15 (in each case, whether or not a Business Day) (each,
a “Record Date”). Interest on the Notes shall be computed on the basis of a 360-day year consisting of twelve 30-day months. Interest on the Notes shall
accrue from July 8, 2021. 
 (c)    Sinking Fund. There shall be no sinking fund provided for the Notes.

 (d)    Redemption at the Option of the Operating Partnership. 

(1)    The Operating Partnership shall have the right to redeem the Notes at its option and in its sole discretion in
whole at any time or in part from time to time, (x) prior to April 15, 2031 (the “Par Call Date”), at a Redemption Price equal to the sum of: (1) 100% of the principal amount being redeemed, plus accrued and unpaid
interest thereon to, but not including, the Redemption Date; and (2) the Make-Whole Amount, if any, and (y) on or after the Par Call Date, at a Redemption Price equal to 100% of the principal amount of the Notes being redeemed plus accrued
and unpaid interest thereon to, but not including, the Redemption Date. 
 (2)    The Operating Partnership shall not
redeem the Notes pursuant to Section 1.4(d)(1) hereof on any date if the principal amount of the Notes has been accelerated, and such acceleration has not been rescinded or annulled on or prior to such date (except in the case of an
acceleration resulting from a default by the Operating Partnership in the payment of the Redemption Price with respect to the Notes to be redeemed). 

(e)    Payment of Notes Called for Redemption by the Operating Partnership. 

(1)    If notice of redemption has been given as provided in Article Eleven of the Base Indenture, the Notes or portion of
Notes with respect to which such notice has been given shall become irrevocably due and payable on the Redemption Date and at the place or places stated in such notice at the Redemption Price, and unless the Operating Partnership shall default in
the payment of the Redemption Price, so long as the Paying Agent holds funds irrevocably deposited with it sufficient to pay the Redemption Price of the Notes to be redeemed on the Redemption Date, then (a) such Notes will cease to be
Outstanding on and after the date of the deposit, (b) interest on the Notes or portion of Notes so called for redemption shall cease to accrue on and after the Redemption Date, and (c) the Holders of the Notes being redeemed shall have no
right in respect of such Notes except the right to receive the Redemption Price thereof. On surrender of such Notes at the place of payment specified in such notice of redemption, the said Notes or the specified portions thereof shall be paid and
redeemed by the Operating Partnership at the Redemption Price. 
 (2)    The Notes will not be convertible or
exchangeable for any other security or property. 
 (f)    Additional Issues. The Operating Partnership may, from
time to time, without notice to or the consent of the Holders of the Notes, increase the principal amount of the Notes by issuing additional debt securities, in which case any additional debt securities so issued will have the same form and terms
(other than the date of issuance and, under certain circumstances, the public offering price and the date from which interest thereon will begin to accrue), and will carry the same right to receive accrued and unpaid interest, as the Notes.
Additional debt 

  
 6 

 
securities issued in this manner will be consolidated with, and form a single series of debt securities with, the Notes; provided, however, that such additional debt securities will not be
issued with the same CUSIP number as the Notes unless such additional debt securities are treated as part of the same issue as the Notes for U.S. federal income tax purposes. 

(g)    Other. The public offering price of the Notes issued on the date hereof was 98.513% of par value. 

Section 1.5    Book-Entry Provisions. This Section 1.5 shall apply only to the Global Notes deposited
with or on behalf of the Depository. 
 (a)    The Operating Partnership shall execute and the Trustee shall, in
accordance with this Section 1.5 and Section 303 of the Base Indenture, authenticate and deliver the Global Notes that shall be registered in the name of the Depository or its nominee and shall be held by the Trustee as custodian for the
Depository. 
 (b)    Participants of the Depository shall have no rights either under the Indenture or with respect to
the Global Notes. The Depository or its nominee, as applicable, shall be treated by the Operating Partnership, the Trustee and any agent of the Operating Partnership or the Trustee as the absolute owner and Holder of each such Global Note for all
purposes under the Indenture. Notwithstanding the foregoing, nothing herein shall prevent the Operating Partnership or the Trustee from giving effect to any written certification, proxy or other authorization furnished by the Depository or its
nominee, as applicable, or impair, as between the Depository and its participants, the operation of customary practices of such Depository governing the exercise of the rights of an owner of a beneficial interest in the Global Notes. 

ARTICLE TWO 
 ADDITIONAL
COVENANTS FOR THE BENEFIT OF HOLDERS OF NOTES 
 In addition to the covenants set forth in the Base Indenture, the Operating Partnership
hereby further covenants as follows, the following covenants being for the sole benefit of the Holders of the Notes: 

Section 2.1    Negative Covenants. 

(a)    Limitation on Indebtedness. The Operating Partnership will not, and will not permit any of its Subsidiaries
to, Incur any Indebtedness, other than Intercompany Indebtedness and guarantees of Indebtedness Incurred by the Operating Partnership or any of its Subsidiaries in compliance with the Indenture, if, immediately after giving effect to the Incurrence
of such Indebtedness and the application of the proceeds thereof, the aggregate principal amount of the Operating Partnership and its Consolidated Subsidiaries’ outstanding Indebtedness, excluding Intercompany Indebtedness, would be greater
than 60% of the sum of, without duplication: (1) Total Assets as of the end of the most recent Reporting Date; and (2) the aggregate purchase price of any assets acquired, and the aggregate amount of any debt or securities offering
proceeds received (to the extent that such proceeds were not used to acquire assets or used to reduce Indebtedness), by the Operating Partnership or any of its Subsidiaries since the end of the most recent Reporting Date, including those proceeds
obtained in connection with the Incurrence of such additional Indebtedness. 
 (b)    Limitation on Secured Debt.
The Operating Partnership will not, and will not permit any of its Subsidiaries to, Incur any Secured Debt, other than Intercompany Indebtedness and guarantees of Secured Debt Incurred by the Operating Partnership or any of its Subsidiaries in
compliance with the Indenture, if, immediately after giving effect to the Incurrence of such Secured Debt and the application of the proceeds thereof, the aggregate principal amount of Secured Debt would be greater than 40% of the sum of, without
duplication: (1) Total Assets as of the end of the most recent Reporting Date; and (2) the aggregate purchase price of any assets acquired, and the aggregate amount of any debt or securities offering proceeds received (to the extent that
such proceeds were not used to acquire assets or used to reduce Indebtedness), by the Operating Partnership or any of its Subsidiaries since the end of the most recent Reporting Date, including those proceeds obtained in connection with the
Incurrence of such additional Secured Indebtedness. 

  
 7 

 (c)    Maintenance of Unencumbered Assets. The Operating
Partnership will have at all times Total Unencumbered Assets of not less than 150% of the aggregate principal amount of all of the Operating Partnership and its Subsidiaries’ outstanding total Unsecured Debt, determined on a consolidated basis
in accordance with GAAP. 
 (d)    Debt Service Ratio. The Operating Partnership will not permit the ratio of
Consolidated Income Available for Debt Service to Interest Expense for the period consisting of the four consecutive fiscal quarters ended on the most recent Reporting Date to be less than 1.5:1 as of such Reporting Date. 

Section 2.2    Guarantees. 

(a)    Future Guarantors. If on or after the date of this Third Supplemental Indenture, the Company or any
Subsidiary of the Operating Partnership guarantees the Operating Partnership’s indebtedness under, or otherwise becomes an obligor with respect to, the Credit Agreement (if the Company or such Subsidiary, as the case may be, is not already a
Guarantor of the Notes), such entity (each, a “Possible Future Guarantor”) shall immediately be and become, automatically and without the execution or delivery of any supplemental indenture or other instrument or other action by any
Person, jointly and severally with any other Guarantors of the Notes, a Guarantor of the Notes and shall be subject to and bound by all of the terms and provisions of the Indenture applicable to a Guarantor of the Notes (subject to
Section 2.2(b)); provided that the Operating Partnership shall cause such Possible Future Guarantor to within thirty (30) calendar days, (i) execute and deliver to the Trustee a supplemental indenture substantially in the form
of Exhibit B to acknowledge such Guarantee in accordance with this Section 2.2 and Article Sixteen of the Indenture, and (ii) deliver to the Trustee, in addition to any other documents to be delivered to the Trustee pursuant to
Section 903 of the Base Indenture, an Opinion of Counsel to the effect that (x) the execution of such supplemental indenture is authorized or permitted by the Base Indenture, and (y) such supplemental indenture, has been duly
authorized, executed and delivered by, and is a valid and binding obligation of such entity, enforceable against such entity in accordance with its terms, subject to customary exceptions. For so long as any Possible Future Guarantor provides a
Guarantee, such Possible Future Guarantor shall agree that it waives and will not in any manner whatsoever claim or take the benefit or advantage of any right of reimbursement, indemnity or subrogation or any other rights against the Operating
Partnership as a result of any payment by it under its guarantee until the Notes have been paid in full. 

(b)    Release of Guarantee. The Guarantee of any Guarantor shall automatically and unconditionally terminate and
be released and the Indenture and any supplemental indenture, to the extent relating thereto, shall no longer have any effect, upon: (i) such Guarantor no longer guaranteeing or otherwise being an obligor with respect to the Credit Agreement;
provided that the foregoing provisions of this clause (i) and any release of such Guarantor’s Guarantee pursuant to this clause (i) shall not limit the obligation of such Guarantor to guarantee the Notes at any time thereafter
pursuant to this Section 2.2; or (ii) legal defeasance, covenant defeasance or discharge of the Notes, as provided under Article Four of the Base Indenture. 

Section 2.3    Covenant Defeasance and Waiver of Covenant. The covenants set forth in Sections 2.1 and 2.2
shall be subject to covenant defeasance under Section 402(3) of the Base Indenture and subject to waiver under Section 1006 thereof. 

ARTICLE THREE 

ADDITIONAL AMENDMENTS 

Section 3.1    Events of Default. Section 3.1(a) shall replace Section 501(5) of the Base Indenture
with respect to the Notes only. 
 (a)    failure to pay any recourse indebtedness for monies borrowed by the Operating
Partnership in an outstanding principal amount in excess of $50,000,000 at final maturity or upon acceleration after the expiration of any applicable notice and grace period, which recourse indebtedness is not discharged, or such default in payment
or acceleration is not cured or rescinded, within thirty (30) calendar days after written notice to the Operating Partnership from the Trustee (or to the Operating Partnership and the Trustee from Holders of at least twenty five percent (25%)
in aggregate principal amount of the Notes then outstanding); 

  
 8 

 ARTICLE FOUR 

TRUSTEE 

Section 4.1    Trustee. The Trustee is appointed as the principal paying agent, transfer agent and registrar
for the Notes and for the purposes of Section 1002 of the Base Indenture. The Notes may be presented for payment at the Corporate Trust Office of the Trustee or at any other agency as may be appointed from time to time by the Operating
Partnership in the United States of America (or otherwise in accordance with applicable procedures of DTC in the case of global notes). The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of
this Third Supplemental Indenture or the due execution hereof by the Operating Partnership. The recitals of fact contained herein shall be taken as the statements solely of the Operating Partnership and the Trustee assumes no responsibility for the
correctness thereof. 
 Section 4.2    Preferential Collection of Claims. If the Trustee shall be or become
a creditor of the Operating Partnership (or any other obligor upon the Notes), the Trustee shall be subject to the provisions of the Trust Indenture Act regarding the collection of the claims against the Operating Partnership (or any such other
obligor). The Trustee is permitted to engage in other transactions with the Operating Partnership and its Affiliates. If, however, it acquires any conflicting interest under the Trust Indenture Act relating to any of its duties with respect to the
Notes, it must eliminate that conflict or resign, subject to its right under the Trust Indenture Act to seek a stay of its duty to resign. 

Section 4.3    Calculation with Respect to the Notes. The Operating Partnership shall be responsible for
making all calculations required under this Third Supplemental Indenture or with respect to the Notes. The Operating Partnership will make such calculations in good faith and, absent manifest error, the Operating Partnership’s calculations will
be final and binding on the Trustee and the Holders of the Notes. The Operating Partnership shall provide a schedule of its calculations to the Trustee promptly after it makes such calculations, and the Trustee shall be entitled to rely upon the
accuracy of the Operating Partnership’s calculations without independent verification. The Trustee shall forward the Operating Partnership’s calculations to any Holder of the Notes upon request. 

Section 4.4    Additional Provisions Concerning the Trustee. U.S. Bank National Association is acting under
this Third Supplemental Indenture solely in its capacity as Trustee under the Base Indenture and not in its individual capacity. In acting hereunder, the Trustee shall be entitled to all of the rights, privileges and immunities granted to it under
the Base Indenture, as if such rights, privileges and immunities were set forth herein. 
 ARTICLE FIVE 

MISCELLANEOUS PROVISIONS 

Section 5.1    Ratification of Base Indenture. This Third Supplemental Indenture is executed and shall be
construed as an indenture supplemental to the Base Indenture, and as supplemented and modified hereby, the Base Indenture is in all respects ratified and confirmed, and the Base Indenture and this Third Supplemental Indenture shall be read, taken
and construed as one and the same instrument. In the event of a conflict between the language of this Third Supplemental Indenture and the Base Indenture, the language of this Third Supplemental Indenture shall control. 

Section 5.2    Effect of Headings. The Article and Section headings herein are for convenience only and shall
not affect the construction hereof. 
 Section 5.3    Successors and Assigns. All covenants and agreements
in this Third Supplemental Indenture by the Operating Partnership shall bind its successors and assigns, whether so expressed or not. 

Section 5.4    Separability Clause. In case any one or more of the provisions contained in this Third
Supplemental Indenture shall for any reason be held to be invalid, illegal or unenforceable in any respect, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby. 

  
 9 

 Section 5.5    GOVERNING LAW. THIS THIRD
SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK. THIS THIRD SUPPLEMENTAL INDENTURE IS SUBJECT TO THE PROVISIONS OF THE TRUST INDENTURE ACT, THAT ARE REQUIRED TO BE
PART OF THIS THIRD SUPPLEMENTAL INDENTURE AND SHALL, TO THE EXTENT APPLICABLE, BE GOVERNED BY SUCH PROVISIONS. 

Section 5.6    Counterparts. This Third Supplemental Indenture may be executed in several counterparts, each
of which shall be an original and all of which shall constitute one and the same instrument. The exchange of copies of this Third Supplemental Indenture and of signature pages by facsimile or PDF transmission shall constitute effective execution and
delivery of this Third Supplemental Indenture as to the parties hereto and may be used in lieu of the original Third Supplemental Indenture and signature pages for all purposes. Signatures of the parties hereto transmitted by facsimile or PDF shall
be deemed to be their original signatures for all purposes. All notices, approvals, consents, requests and any communications hereunder must be in writing (provided that any such communication sent to the Trustee hereunder must be in the form of a
document that is signed manually or by way of a digital signature provided by DocuSign (or such other digital signature provider as specified in writing to the Trustee by the authorized representative), in English. The Operating Partnership
agrees to assume all risks arising out of the use of using digital signatures and electronic methods to submit communications to the Trustee, including without limitation the risk of the Trustee acting on unauthorized instructions, and the risk of
interception and misuse by third parties. 

  
 10 

 IN WITNESS WHEREOF, the parties hereto have caused this Third Supplemental Indenture to be
duly executed all as of the day and year first above written. 
  

					
	AMERICAN HOMES 4 RENT, L.P.
		
	By:	 	American Homes 4 Rent, its general partner
		
	By:	 	 /s/ Christopher C. Lau

		 	Name:	 	Christopher C. Lau
		 	Title:	 	Chief Financial Officer

  
 11 

 
					
	U.S. BANK NATIONAL ASSOCIATION,
as Trustee
		
	By:	 	 /s/ Bradley E. Scarbrough

		 	Name:	 	Bradley E. Scarbrough
		 	Title:	 	Vice President

  
 12 

 EXHIBIT A 

Form of 2.375% Senior Notes due 2031 
 THIS
GLOBAL NOTE IS HELD BY OR ON BEHALF OF THE DEPOSITORY (AS DEFINED IN THE THIRD SUPPLEMENTAL INDENTURE GOVERNING THIS NOTE) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY
CIRCUMSTANCES EXCEPT THAT (1) THE TRUSTEE MAY MAKE SUCH NOTATIONS HEREON AS MAY BE REQUIRED PURSUANT TO SECTION 305 OF THE BASE INDENTURE, (2) THIS GLOBAL NOTE MAY BE EXCHANGED IN WHOLE BUT NOT IN PART PURSUANT TO SECTION 305 OF THE BASE
INDENTURE, (3) THIS GLOBAL NOTE MAY BE DELIVERED TO THE TRUSTEE FOR CANCELLATION PURSUANT TO SECTION 309 OF THE BASE INDENTURE AND (4) THIS GLOBAL NOTE MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITORY WITH THE PRIOR WRITTEN CONSENT OF THE
ISSUER. 
 UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN DEFINITIVE FORM, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE
DEPOSITORY TO A NOMINEE OF THE DEPOSITORY OR BY A NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY OR ANOTHER NOMINEE OF THE DEPOSITORY OR BY THE DEPOSITORY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITORY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITORY. UNLESS
THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) (“DTC”), TO THE ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE
ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR SUCH OTHER ENTITY AS MAY BE REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN. 

 AMERICAN HOMES 4 RENT, L.P. 

2.375% SENIOR NOTES DUE 2031 
 No.
[●] 
 CUSIP No.:         02666T AC1 

ISIN:                   US02666TAC18 

$[●] 
 AMERICAN HOMES 4 RENT, L.P., a
Delaware limited partnership (herein called the “Operating Partnership,” which term includes any successor entity under the Indenture referred to on the reverse hereof), for value received hereby promises to pay to [Cede &
Co.]*, or its registered assigns, the principal sum of [●] ($[●]), [or such lesser amount as is set forth in the Schedule of Increases or Decreases In the Global Note on the other side
of this Note]*, on July 15, 2031 at the office or agency of the Operating Partnership maintained for that purpose in accordance with the terms of the Indenture, in such coin or currency of the United States of America as at the time of payment
shall be legal tender for the payment of public and private debts, and to pay interest, semi-annually on January 15 and July 15 of each year, commencing January 15, 2022 on said principal sum at said office or agency, in like coin or
currency, at the rate per annum of 2.375%, from the January 15 or July 15, as the case may be, next preceding such Interest Payment Date to which interest has been paid or duly provided for, unless no interest has been paid or duly
provided for on the Notes, in which case from July 8, 2021 until payment of said principal sum has been paid or duly provided for. Unless otherwise provided in or pursuant to the Indenture, at the option of the Operating Partnership, interest
on the Notes due and payable on any Interest Payment Date may be paid by mailing a check to the address of the Person entitled thereto as such Person’s name and address shall appear in the Security Register or by transfer to an account
maintained by such Person with a bank located in the United States of America. Any such interest which is punctually paid or duly provided for on any Interest Payment Date shall be paid to the Person in whose name this Note (or one or more
Predecessor Securities) is registered in the Security Register as of the close of business on the January 1 or July 1 (whether or not a Business Day) next preceding such Interest Payment Date. 

Reference is made to the further provisions of this Note set forth on the reverse hereof and the Indenture governing this Note. Such further provisions shall
for all purposes have the same effect as though fully set forth at this place. In the event of a conflict between the terms of this Note and the terms of the Indenture, the terms of the Indenture shall control. 

This Note shall not be valid or become obligatory for any purpose until the certificate of authentication hereon shall have been signed manually by the
Trustee or a duly authorized authenticating agent under the Indenture. 

	 	 

 

	* 	 Include only if the Note is issued in global form. 

  
 A-2 

 IN WITNESS WHEREOF, the Operating Partnership has caused this Note to be duly executed. 

Dated: [●] 
  

					
	AMERICAN HOMES 4 RENT, L.P.
		
	By:	 	American Homes 4 Rent, its general partner
			
		 	By:	 	
                    

		 		 	Name:
		 		 	Title:

  
 A-3 

 TRUSTEE’S CERTIFICATE OF AUTHENTICATION 

This is one of the Securities of the series designated therein referred to in the within-named Indenture. 

Dated: [●] 
  

			
	U.S. BANK NATIONAL ASSOCIATION,
as Trustee
		
	By:	 	
                    

		 	Name:
		 	Title:

  
 A-4 

 REVERSE SIDE OF NOTE 

AMERICAN HOMES 4 RENT, L.P. 

2.375% SENIOR NOTES DUE 2031 
 This Note is
one of a duly authorized issue of Notes of the Operating Partnership, designated as its 2.375% Senior Notes due 2031 (herein called the “Notes”), issued under and pursuant to an Indenture dated as of February 7, 2018 (herein
called the “Base Indenture”), between the Operating Partnership and U.S. Bank National Association, as trustee (herein called the “Trustee”), as supplemented by the Third Supplemental Indenture dated as of
July 8, 2021 (herein called the “Third Supplemental Indenture,” and together with the Base Indenture, the “Indenture”), between the Operating Partnership and the Trustee, to which Indenture and any indentures
supplemental thereto reference is hereby made for a description of the rights, limitations of rights, obligations, duties and immunities thereunder of the Trustee, the Operating Partnership and the Holders of the Notes. Defined terms used but not
otherwise defined in this Note shall have the respective meanings ascribed thereto in the Indenture. 
 The Operating Partnership shall have the right to
redeem the Notes at its option and in its sole discretion in whole at any time or in part from time to time, (x) prior to April 15, 2031 (the “Par Call Date”), at a Redemption Price equal to the sum of: (1) 100% of the
principal amount being redeemed, plus accrued and unpaid interest thereon to, but not including, the Redemption Date; and (2) the Make-Whole Amount, if any, and (y) on or after the Par Call Date, at a Redemption Price equal to 100% of the
principal amount of the Notes being redeemed plus accrued and unpaid interest thereon to, but not including, the Redemption Date. 
 The Operating
Partnership shall not redeem the Notes pursuant to Section 1.4(d)(1) of the Third Supplemental Indenture on any date if the principal amount of the Notes has been accelerated, and such acceleration has not been rescinded or annulled on or prior
to such date (except in the case of an acceleration resulting from a default by the Operating Partnership in the payment of the Redemption Price with respect to the Notes to be redeemed). 

If an Event of Default (other than an Event of Default specified in Section 501(6), 501(7) or 501(8) of the Base Indenture) occurs and is continuing, the
principal of, premium, if any, and accrued and unpaid interest on all the Notes may be declared to be due and payable immediately by either the Trustee or the Holders of at least twenty five percent (25%) in aggregate principal amount of the Notes
then outstanding, and, upon said declaration the same shall be immediately due and payable. If an Event of Default specified in Section 501(6), 501(7) or 501(8) of the Base Indenture occurs, the principal of and premium, if any, and accrued and
unpaid interest on all the Notes shall be immediately due and payable without any declaration or other act on the part of the Trustee or the Holders. 
 The
Indenture contains provisions permitting the Operating Partnership and the Trustee, with the consent of the Holders of not less than a majority in aggregate principal amount of the Notes at the time outstanding, to execute supplemental indentures
adding any provisions to or changing in any manner or eliminating any of the provisions of the Indenture or of any supplemental indenture with respect to the Notes or any Guarantee or modifying in any manner the rights of the Holders of the Notes,
subject to exceptions set forth in Section 901 and Section 902 of the Base Indenture. Subject to the provisions of the Indenture, the Holders of not less than a majority in aggregate principal amount of the Notes at the time outstanding
may, on behalf of the Holders of all of the Notes, waive any past default or Event of Default with respect to the Notes, subject to exceptions set forth in the Indenture. 

No reference herein to the Indenture and no provision of this Note or of the Indenture shall impair, as among the Operating Partnership and the Holder of the
Notes, the obligation of the Operating Partnership, which is absolute and unconditional, to pay the principal of, premium, if any, on and interest on this Note at the place, at the respective times, at the rate and in the coin or currency herein and
in the Indenture prescribed. 
 Interest on the Notes shall be computed on the basis of a 360-day year consisting of
twelve 30-day months. 
 The Notes are issuable in fully registered form, without coupons, in minimum denominations
of $2,000 and integral multiples of $1,000 in excess thereof. At the office or agency of the Operating Partnership referred to on the face hereof, and in the manner and subject to the limitations provided in the Indenture, without payment of any
service charge but with payment of a sum sufficient to cover any tax, assessment or other governmental charge that may be imposed in connection with any registration of transfer or exchange of Notes, Notes may be transferred or may be exchanged for
a like aggregate principal amount of Notes of any other authorized denominations. The Operating 

  
 A-5 

 
Partnership, any Guarantor, the Trustee and any agent of the Operating Partnership, any Guarantor or the Trustee shall treat the Person in whose name a Note is registered in the Security Register
as the owner of such Note for all purposes whatsoever, and none of the Operating Partnership, any Guarantor, the Trustee or any agent of the Operating Partnership, any Guarantor or the Trustee shall be affected by notice to the contrary. 

The Notes are not subject to redemption through the operation of any sinking fund. 

No recourse for the payment of the principal of or any premium or interest on this Note, or for any claim based hereon or otherwise in respect hereof, and no
recourse under or upon any obligation, covenant or agreement of the Operating Partnership in the Indenture or any supplemental indenture or in any Note, or because of any indebtedness evidenced thereby, shall be had against any past, present or
future general partner, limited partner, member, employee, incorporator, controlling person, shareholder, officer, trustee, director or agent, as such, of the Operating Partnership, the Company, any Possible Future Guarantor or of any of the
Operating Partnership’s, the Company’s or any Possible Future Guarantor’s predecessors or successors, either directly or through the Operating Partnership, the Company or any Possible Future Guarantor or any predecessor or successor
of the Operating Partnership, Company or any Possible Future Guarantor, under any rule of law, statute or constitutional provision or by the enforcement of any assessment or by any legal or equitable proceeding or otherwise, all such liability being
expressly waived and released by the acceptance of the Notes by the Holders thereof and as part of the consideration for the issue of the Notes. 

  
 A-6 

 ASSIGNMENT FORM 

To assign this Note, fill in the form below: 

(I) or (we) assign and transfer this Note to: 
  

	
	  

	
	  

	(Insert assignee’s legal name)
	  

	
	  

	
	  

	
	  

	
	  

 (Print or type assignee’s name, address and zip code) 

and irrevocably appoint                      to
transfer this Note on the books of the Operating Partnership. The agent may substitute another to act for him. 
 Date:
                     

	
	Your Signature:
	
	
                    

	
	(Sign exactly as your name appears
	on the face of this Note)                  

 Signature Guarantee*:
                                         
                            
  

	*	 Participant in a recognized Signature Guarantee Medallion Program (or other signature guarantor acceptable to
the Trustee). 

  
 A-7 

 SCHEDULE OF INCREASES OR DECREASES IN THE GLOBAL NOTE * 
 The following increases or decreases in the principal amount of this Global Note
have been made: 
  

																	
	 Date of

Increase or

Decrease
	  	 Amount of

decrease in

Principal Amount
 at
maturity of
 this Global Note
	 	  	 Amount of

increase in

Principal Amount
 at
maturity of
 this Global Note
	 	  	 Principal Amount

at maturity of
 this Global
Note
following such
 decrease (or

increase)
	 	  	 Signature of

authorized officer
 of
Trustee or
 Custodian
	 
	
                   
 
	  				  				  				  			
	
                   
 
	  				  				  				  			
	
                   
 
	  				  				  				  			

  

	* 	 This schedule should be included only if the Note is issued in global form. 

  
 A-8 

 EXHIBIT B 

[FORM OF SUPPLEMENTAL INDENTURE TO BE DELIVERED BY 

POSSIBLE FUTURE GUARANTORS] 

Supplemental Indenture (this “Supplemental Indenture”), dated as of [●], among AMERICAN HOMES 4 RENT, L.P., a Delaware
limited partnership (the “Operating Partnership”), [POSSIBLE FUTURE GUARANTOR] (the “New Guarantor”), an affiliate of the Operating Partnership, and U.S. BANK NATIONAL ASSOCIATION, a national banking association
organized and existing under the laws of the United States, as trustee (the “Trustee”). 
 RECITALS 

WHEREAS, the Operating Partnership and the Trustee are parties to an Indenture, dated as of February 7, 2018 (the “Base
Indenture”), providing for the issuance from time to time for its lawful purposes of debt securities evidencing the Operating Partnership’s debentures, notes or other evidences of indebtedness, which may be guaranteed by certain
entities. 
 WHEREAS, the Operating Partnership and the Trustee are parties to the Third Supplemental Indenture, dated as of July 8,
2021 (the “Third Supplemental Indenture,” and together with the Base Indenture, as amended from time to time, the “Indenture”), entered into pursuant to the Base Indenture, which established and provided for the
issuance of, in an initial aggregate principal amount of $450,000,000, a series of the Operating Partnership’s debt securities designated as the “2.375% Senior Notes due 2031” (the “Notes”); 

WHEREAS, the Indenture provides, among other things, that under certain circumstances the New Guarantor shall execute and deliver to the
Trustee a supplemental indenture pursuant to which the New Guarantor shall guarantee the Notes on the terms and conditions set forth in Article Sixteen of the Base Indenture and Section 2.2 of the Third Supplemental Indenture; and 

WHEREAS, pursuant to Section 901 of the Base Indenture, the Trustee is authorized to execute and deliver this Supplemental Indenture
without the consent of the Holders. 
 NOW, THEREFORE IT IS AGREED: 

Section 1.    Capitalized terms used herein and not otherwise defined herein are used as defined in the Indenture.

 Section 2.    The New Guarantor hereby agrees in accordance with Article Sixteen of the Base Indenture and
Section 2.2 of the Third Supplemental Indenture to, jointly and severally with any other Guarantors of the Notes, fully and unconditionally guarantee the Operating Partnership’s obligations under the Notes on a direct, unsecured and
unsubordinated basis, including the due and punctual payment of principal of, premium, if any, and interest on, the Notes, whether at Stated Maturity, upon redemption, by acceleration or otherwise until released in accordance with the Indenture.

 Section 3.    The New Guarantor acknowledges that it has received and reviewed a copy of the Indenture and all
other documents it deems necessary to review in order to enter into this Supplemental Indenture, and acknowledges and agrees to (i) join and become a party to the Indenture as indicated by its signature below; (ii) be bound by the
Indenture, as of the date hereof, as if made by, and with respect to, each signatory hereto; and (iii) perform all obligations and duties required of a Guarantor pursuant to the Indenture. 

Section 4.    All notices or other communications to the New Guarantor shall be given as provided in Section 105
of the Base Indenture. 
 Section 5.    Except as expressly amended hereby, all the terms, conditions and
provisions of the Indenture shall remain in full force and effect. This Supplemental Indenture shall form a part of the Indenture for all purposes, and every Holder of Notes heretofore or hereafter authenticated and delivered shall be bound hereby.

 Section 6.    THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY,
AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK. THIS SUPPLEMENTAL INDENTURE IS SUBJECT TO THE PROVISIONS OF THE TRUST INDENTURE ACT, THAT ARE REQUIRED TO BE PART OF THIS SUPPLEMENTAL INDENTURE AND SHALL, TO THE EXTENT
APPLICABLE, BE GOVERNED BY SUCH PROVISIONS. 
 Section 7.    This Supplemental Indenture may be executed in
several counterparts, each of which shall be an original and all of which shall constitute one and the same instrument. The exchange of copies of this Supplemental Indenture and of signature pages by facsimile or PDF transmission shall constitute
effective execution and delivery of this Supplemental Indenture as to the parties hereto and may be used in lieu of the original Supplemental Indenture and signature pages for all purposes. Signatures of the parties hereto transmitted by facsimile
or PDF shall be deemed to be their original signatures for all purposes. 
 Section 8.    This Supplemental
Indenture is an indenture supplemental to the Indenture, and the Indenture and this Supplemental Indenture will henceforth be read together. 

Section 9.    The Trustee makes no representation as to and shall not be responsible in any manner whatsoever for or
in respect of the validity or sufficiency of this Supplemental Indenture, the Guarantee of the New Guarantor or for or in respect of the recitals contained herein, all of which recitals are made solely by the Operating Partnership and the New
Guarantor, and the Trustee assumes no responsibility for the same. This Supplemental Indenture is executed and accepted by the Trustee subject to all the terms and conditions set forth in the Indenture with the same force and effect as if those
terms and conditions were repeated at length herein and made applicable to the Trustee with respect hereto. In entering into this Supplemental Indenture, the Trustee shall be entitled to the benefit of every provision of the Indenture relating to
the conduct or affecting the liability or affording protection to the Trustee, whether or not elsewhere herein so provided. 
 [Signature
Page Follows] 

  
 B-2 

 
					
	AMERICAN HOMES 4 RENT, L.P.
		
	By:	 	American Homes 4 Rent, its general partner
			
		 	By:	 	
                    

		 		 	Name:
		 		 	Title:
	
	[POSSIBLE FUTURE GUARANTOR]
		
	By:	 	
                    

		 	Name:
		 	Title:
	
	[TRUSTEE]
		
	By:	 	
                    

		 	Name:
		 	Title:

  
 B-3

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