EX-10.23



 Exhibit 10.23 

[ * ] = Certain confidential information contained in this document, marked by brackets, has been omitted and filed separately with the
Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933, as amended. 
 AMENDMENT NO. 2 

TO 
 RESEARCH AND COMMERCIALIZATION
AGREEMENT 
 THIS AMENDMENT NO. 2 TO RESEARCH
AND COMMERCIALIZATION AGREEMENT (“Amendment”) is made and entered into effective as of January 28, 2002 (the “Amendment Date”) by and between MEDAREX,
INC., 707 State Road, Suite 206, Princeton, NJ 08540, GENPHARM INTERNATIONAL INC., a wholly-owned subsidiary of Medarex, Inc.
(together, “Medarex”), and FibroGen, Inc., a Delaware corporation, 225 Gateway Boulevard, South San Francisco, California 94080 and FIBROPHARMA, INC., a wholly-owned subsidiary of
FIBROGEN, INC. (collectively, “FibroGen”). Capitalized terms used in this Amendment that are not otherwise defined herein shall have the same meanings as such terms are defined in the
Agreement (as defined below). 
 WHEREAS, Medarex and FibroGen entered into a Research and Commercialization Agreement dated as of
July 9, 1998 (the “Agreement”), as amended as of June 30, 2001, under which FibroGen acquired a research license and an option to acquire commercial licenses under the Medarex Technology. 

WHEREAS, the parties desire to amend the Agreement to extend the term of the Research Period under the Agreement and to clarify the scope of
the licenses granted under the Agreement. 
 Now, THEREFORE, the parties agree as follows: 

 

	1.	Amendment of the Agreement. 

 The parties hereby agree to amend the terms of the Agreement as
of the Amendment Date as provided below. 
  

	 	1.1	Amendment of Section 2.6.2. Section 2.6.2 of the Agreement is hereby amended to read in its entirety as follows: 


“2.6.2 With notice to Medarex at least thirty (30) days prior to the first anniversary of the Effective Date, FibroGen may
extend the term of the Research Period until the second anniversary of the Effective Date and, with notice to Medarex at least thirty (30) days prior to the second anniversary of the Effective Date, FibroGen may extend the term of the Research
Period until the third anniversary of the Effective Date and, with notice to Medarex at least thirty (30) days prior to the third anniversary of the Effective Date, FibroGen may extend the term of the Research Period until February 28,
2002 and, with notice to Medarex at least thirty (30) days prior to February 28, 2002, FibroGen may extend the term of the Research Period until March 31, 2002, and in each case, FibroGen shall








 
continue to make quarterly research support payments (or, if research services are provided by Medarex for less than a full calendar quarter, a research support payment equivalent to a pro rata
portion of such quarterly research support payment as applicable) as provided in Section 2.2. If 
 FibroGen (i) extends the
Research Period for at least six (6) months (so that the Research Period is at least eighteen (18) months and Medarex has received at least five hundred seventy thousand dollars ($570,000) of research support payments pursuant to
Section 2.2), and (ii) exercises its option and acquires a commercial license pursuant to Section 3.1.2, then FibroGen shall be considered to have exclusivity of all the Antigens listed on Exhibit A in accordance with
Section 2.6.5.” 
  

	2.	Scope of Agreement. 

  

	 	2.1	Mice. For purposes of clarity, the parties acknowledge and agree that [ * ] and [ * ] (as such terms are defined below) are not included in the definition of Mice under the Agreement.


 For purposes of this Amendment and the Agreement, “[ * ]” shall mean any mice comprising both
(i) [ * ] developed by Medarex or otherwise developed through use of Medarex’s proprietary HuMAb Mouse; and (ii) [ * ], including, without limitation, any mouse comprising the nucleic acids described in clause
(i) and clause (ii) of this Section that is derived by (X) [ * ] HuMAb Mouse [ * ], (Y) introducing nucleic acids obtained, isolated, or derived from a HuMAb Mouse [ * ], or (Z) introducing
nucleic acids obtained, isolated, or derived from a [ * ] into one or more cells obtained from a HuMAb Mouse. 
 For purposes of
this Amendment and the Agreement, “[ * ]” shall mean any immunizable [ * ] mouse developed by [ * ] that contains [ * ] thereof that include [ * ] that provide for [ * ], and
which [ * ] comprises an [ * ]. 
  

	3.	Miscellaneous. 

  

	 	3.1	No Other Changes. Except as expressly provided in this Amendment, all terms of the Agreement shall remain in full force and effect. 

  


	 	3.2	Counterparts. This Amendment may be executed in two or more counterparts, each of which shall be deemed an original, but both of which together shall constitute one and the same instrument. 


  
 [ * ] = Certain
confidential information contained in this document, marked by brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933, as amended. 








 IN WITNESS WHEREOF, the parties have caused this Amendment to be executed by their respective
authorized officers. 
  

									
	MEDAREX, INC.	 		 	FIBROGEN, INC.
					
	By:	 	 /s/ Jim Cornett
	 		 	By:	 	 /s/ Jack Anthony

					
	Name:	 	Jim Cornett	 		 	Name:	 	Jack Anthony
					
	Title:	 	VP Business Development	 		 	Title:	 	VP Business Development
					
	Date:	 	16 July 2001	 		 	Date:	 	6/28/01
			
	GENPHARM INTERNATIONAL, INC.	 		 	FIBROPHARMA, INC.
					
	By:	 	 /s/ Jim Cornett
	 		 	By:	 	 /s/ Jack Anthony

					
	Name:	 	Jim Cornett	 		 	Name:	 	Jack Anthony
					
	Title:	 	VP Business Development	 		 	Title:	 	VP Business Development
					
	Date:	 	16 July 2001	 		 	Date:	 	6/29/01

 [ * ] = Certain confidential information contained in this document, marked by brackets, has been omitted and
filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933, as amended.