EX-10.23





 Certain identified information has been excluded from this exhibit because it is both not material and
is the type that the registrant treats as private or confidential. Information that was omitted has been noted in this document with a placeholder identified by the mark “[***]”. 

Exhibit 10.23 

Confidential 
 Amendment
No. 3 to Exclusive License Agreement for 
 Methods and Compositions for RNA-Directed
Target DNA Modification 
 and for RNA-Directed Modulation of Transcription 

This Amendment No. 3 is made to the Exclusive License Agreement for Methods and Compositions for
RNA-Directed Target DNA Modification and for RNA-Directed Modulation of Transcription, dated April 16, 2013, as amended by an Amendment Agreement, dated
April 17, 2013, and as further amended by Amendment No. 2 to Exclusive License Agreement for Methods and Compositions for RNA-Directed Target DNA Modification and for
RNA-Directed Modulation of Transcription, dated March 14, 2019, and as clarified in the Memorandum of Understanding, dated March 14, 2019 (collectively, the “License Agreement”), by and
among The Regents of the University of California, the University of Vienna, and Caribou Biosciences, Inc., and is effective April 16, 2021 (the “Amendment Effective Date”). Caribou Biosciences, Inc. is referred to as
“LICENSEE” and The Regents of the University of California (“REGENTS”) and the University of Vienna are collectively referred to as “LICENSORS.” Capitalized terms not defined herein shall have the meaning set forth in
the License Agreement. 
 WHEREAS, LICENSEE and LICENSORS wish to further amend the License Agreement, as set forth herein. 

NOW, THEREFORE, in consideration of the mutual covenants contained herein, and for other good and valid consideration, the amount and
sufficiency of which are hereby acknowledged, LICENSEE and LICENSORS agree as follows: 
 1. Notwithstanding Section 7.2.3 of the License Agreement,
LICENSEE and LICENSORS agree that LICENSEE, its Affiliate, or Sublicensee must [***]; provided, however, that, as consideration for this Amendment No. 3: 
  

	 	(a)	 LICENSEE shall pay REGENTS [***] on or before [***]; 



 

	 	(b)	 The following additional milestones payments are hereby added to Section 5.1.4: 



[***] 
 2. An additional milestone is hereby
added to Section 7.2 of the License Agreement: 
 [***] 

3. All other terms of the License Agreement shall remain in full force and effect. 

4. This Amendment No. 3 may be executed in one or more counterparts, including by electronic signatures, each of which shall be deemed an original, and
all of which together will be deemed to be one and the same instrument. PDF or facsimile execution and delivery of this Amendment No. 3 by a party will constitute a legal, valid, and binding execution and delivery of this Amendment No. 3
by such party. 












 IN WITNESS WHEREOF, the parties hereto have executed this Amendment No. 3 as of the
Amendment Effective Date by their duly authorized officers or representatives. 
  

													
	THE REGENTS OF THE	 		 		 		 	THE UNIVERSITY OF VIENNA
	UNIVERSITY OF CALIFORNIA	 		 		 		 	
							
	By:	 	/s/ Terri Sale, J.D.	 		 		 		 	By:	 	/s/ Ronald Maier
							
	Name:	 	Terri Sale, J.D.	 		 		 		 	Name:	 	Ronald Maier
							
	Title:	 	Associate Director—OTL	 		 		 		 	Title:	 	Vice-Rector for Digitalisation and Knowledge Transfer

  

			
	CARIBOU BIOSCIENCES, INC.
		
	By:	 	/s/ Rachel E. Haurwitz
	Name:	 	Rachel E. Haurwitz, Ph.D.
	Title:	 	President & CEO