Exhibit
10.20


 


***Text
Omitted and Filed Separately with the Securities and Exchange Commission.


Confidential
Treatment Requested Under 17 C.F.R. Sections 200.80(b)(4) and 240.24b-2





	 	1. CONTRACT
    ID CODE	PAGE OF PAGES
	AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT	 	1	     2







	2.  AMENDMENT/MODIFICATION NO.	3.  EFFECTIVE
    DATE	4.  REQUISITION/PURCHASE REQ. NO	5.  PROJECT NO. (if applicable)
	0015	See
    Block 16C	N/A	 










	6.  ISSUED
    BY	CODE	ASPR-BARDA	7.
                                         ADMINISTERED BY (If other than Item 6)

        
	CODE	ASPR-BARDA02
	 

                                                                                                                                                   ASPR-BARDA

        200 Independence
        Ave., S.W.

        Room 640-G

        Washington DC
        20201
	 

                                                                                                                      ASPR-BARDA

         330 Independence
        Ave, SW, Rm G640

         Washington DC
        20201






	8.  NAME
    AND ADDRESS OF CONTRACTOR (No., Street,Ccounty, State and Zip Code)	x	9A.  AMENDMENT
    OF SOLICITATION NO.	 
	

                                                                                  CHIMERIX, INC. 1377270

        CHIMERIX, INC.      2505
        MERIDIAN P

        2505 MERIDIAN PKWY STE
        340

        DURHAM NC 277135246
	 	 	 
	9B.  DATED
    (SEE ITEM 11)	 
	 	 	 
	x	10A. MODIFICATION OF CONTRACT/ORDER
        NO.

        HHSO100201100013C
	 
	 	 	 
	10B.
    DATED (SEE ITEM 11) 02/16/2011	 
	CODE:
         1377270	FACILITY
    CODE:	 		 










	11.  THIS
    ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS





	£
    The above numbered, solicitation is amended as set forth in item 14. The hour and date
    specified for receipt of Offers £ is extended £
    is not extended. 
 
 Offers must acknowledge receipt of this amendment prior
    to the hour and date specified in the solicitation or as amended by one of the following methods:

    
 (a) By completing Items 8 and 15, and returning               copies
    of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted; or (c) By separate letter
    or telegram which includes a reference to the solicitation and amendment numbers, FAILURE OF YOUR ACKNOWLEDGEMENT TO BE RECEIVED
    AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN REJECTION OF YOUR OFFER.
    If by virtue of this amendment you desire to change an offer already submitted, such change may be made by telegram or letter,
    provided each telegram or letter makes reference to the solicitation and this amendment, and is received prior to the opening
    hour and date specified.










	12.
ACCOUNTING AND APPROPRIATION DATA (If Required)

        N/A.






	13.  THIS
ITEM APPLIES ONLY TO MODIFICATIONS OF CONTRACTS/ORDERS,

IT MODIFIES THE CONTRACT/ORDER NO., AS DESCRIBED IN ITEM 14
	£	A. THIS
    CHANGE ORDER IS ISSUED PURSUANT TO:  (Specify Authority)  THE CHANGES SET FORTH IN ITEM 14 ARE
    MADE IN THE CONTRACT ORDER NO. IN ITEM 10A.
	 
	£	B. THE
    ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, appropriation
    date, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43,103 (b).
	 	 
	£	C. THIS
    SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:
	 	 
	x	D.
OTHER
                                                                                               (Specify type of modification
                                                                                               and authority)

         Bilateral:
        Mutual Agreement of the Parties.

         






	E.  IMPORTANT: Contractor      ̈  is
NOT    x  is required to sign this document and return
       1       copies to the issuing
office.





	14.  DESCRIPTION
OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.





	Tax
                                                  ID Number:      33-0903395

        DUNS Number:       121785997

        A.          The
        purpose of this modification is to incorporate the following change into the contract:

         

        1.          Under
        Article B.4. PROVISIONS APPLICABLE TO DIRECT COSTS, b. Travel Costs, 1. Travel,

        a.          is
        deleted and replaced with the following:

         

        a.          Total
        expenditures for all domestic and foreign travel (transportation, lodging,

        subsistence, and incidental expenses) incurred in direct preformance of this contract shall not exceed $[...***...]
        during the base segment /CLIN 0001 and $[...***...] during Option Period Continued ...






	 
	Except as provided herein,
    all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full
    force and effect.





	15A.  NAME
AND TITLE OF SIGNER	16A.  NAME
AND TITLE OF CONTRACTING OFFICER 
	

Michael Rogers Chief Development
Officer




	ETHAN
    J. MUELLER
	15B.  CONTRACTOR/OFFEROR	15C.  DATE SIGNED	16B.  UNITED
    STATES OF AMERICA	16C.  DATE
    SIGNED
	   /s/
        Michael Rogers

            (Signature
        of person authorized to sign)
	8/28/13	/s/Ethan
J. Mueller                  

        (Signature
        of Contracting Officer)
	8/28/13

         






	NSN 7540-01-152-8070	 	STANDARD FORM 30 (REV. 10-83)
	Previous Edition Unusable	 	Prescribed by GSA FAR (48 CFR) 53.243


***Confidential
Treatment Requested


 




    	 



    	 



    

 





	CONTINUATION
    SHEET	REFERENCE
        NO. OF DOCUMENT BEING CONTINUED

        HHSO100201100013C/0015
	PAGE   OF	 
	2	      2













	NAME
        OF OFFEROR OR CONTRACTOR

        CHIMERIX, INC. 1377270






	ITEM NO.

        (A)
	SUPPLIER/SERVICES

        (B)
	QUANTITY

        (C)
	UNIT

        (D)
	UNIT PRICE

        (E)
	AMOUNT

        (F)

	 	1/CLIN
                                         0002 without the prior written approval of
                                         the Contracting Officer.


        

        

        B. This is a bilateral, no cost modification. The scope, period
        of performance and the total contract amount remain unchanged and all other terms and conditions of the contract remain
        unchanged. 

        

        Period of Performance: 02/16/2011 to 05/31/2014 

         

         

         

         

         
	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 
	 	 	 	 	 	 











	
	NSN 7540-01-152-8067	OPTIONAL FORM 336 (4-86)
	 	Sponsored by GSA 

	 	FAR (48 CFR) 53.110