Exhibit 4.3


 


FIRST SUPPLEMENTAL INDENTURE (this “Supplemental
Indenture”), dated as of December 1, 2021, among the entities listed on Schedule E hereto (each entity, a “New Guarantor”
and collectively the “New Guarantors”), each a subsidiary of Camelot UK Bidco Limited, a private limited liability
company incorporated under the laws of England and Wales (“UK Holdco”), Clarivate Science Holdings Corporation, a
Delaware corporation (the “Issuer”), and Wilmington Trust, National Association, as trustee (the “Trustee”).


 


W I T N E S E T H


 


WHEREAS the Issuer
has heretofore executed and delivered to the Trustee an Indenture (as amended, supplemented or otherwise modified, the “Indenture”)
dated as of August 19, 2021, providing for the issuance of the Issuer’s 4.875% Senior Notes due 2029 initially in the aggregate
principal amount of $921,399,000 (the “Securities”);


 


WHEREAS Section 4.10
of the Indenture provides that under certain circumstances the Issuer is required to cause the New Guarantors to execute and deliver to
the Trustee a supplemental indenture pursuant to which each New Guarantor shall unconditionally guarantee all the Issuer’s obligations
under the Securities pursuant to a Guarantee on the terms and conditions set forth herein; and


 


WHEREAS pursuant
to Section 9.01 of the Indenture, the Trustee and the Issuer are authorized to execute and deliver this Supplemental Indenture without
consent of the Holders;


 


NOW THEREFORE, in
consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, the New Guarantors,
the Issuer and the Trustee mutually covenant and agree for the equal and ratable benefit of the Holders as follows:


 


1.                  
Defined Terms. As used in this Supplemental Indenture, terms defined in the Indenture or in the preamble or recital hereto
are used herein as therein defined, except that the term “Holders” in this Supplemental Indenture shall refer to the term
 “Holders” as defined in the Indenture and the Trustee acting on behalf of and for the benefit of such Holders. The words “herein,”
 “hereof” and hereby and other words of similar import used in this Supplemental Indenture refer to this Supplemental Indenture
as a whole and not to any particular section hereof.


 


2.                  
Agreement to Guarantee. The New Guarantors hereby agree, jointly and severally with all existing Guarantors (if any), to
unconditionally guarantee the Issuer’s obligations under the Securities on the terms and subject to the conditions and limitations
set forth in Article 11 of the Indenture and to be bound by all other applicable provisions of the Indenture and the Securities and to
perform all of the obligations and agreements of a Guarantor under the Indenture.


 


3.                  
Ratification of Indenture; Supplemental Indentures Part of Indenture. Except as expressly amended hereby, the Indenture
is in all respects ratified and confirmed and all the terms, conditions and provisions thereof shall remain in full force and effect.
This Supplemental Indenture shall form a part of the Indenture for all purposes, and every holder of Securities heretofore or hereafter
authenticated and delivered shall be bound hereby.


 


4.                  
Notices. All notices or other communications to the New Guarantors shall be given as provided in Section 12.02 of the Indenture.





 






    


     


    

 


5.                  
 Governing Law. THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE INTERNAL LAWS OF
THE STATE OF NEW YORK APPLICABLE TO AGREEMENTS MADE AND TO BE PERFORMED IN SUCH STATE WITHOUT REGARD TO CONFLICTS OF LAW PRINCIPLES THEREOF
TO THE EXTENT THE LAW OF ANOTHER JURISDICTION WOULD BE APPLIED THEREBY.


 


(a)       Consent
to Jurisdiction. Any legal suit, action or proceeding arising out of or based upon the Indenture, this Supplemental Indenture, the
Securities, the Guarantees or the transactions contemplated hereby (“Related Proceedings”) may be instituted in the
federal courts of the United States of America located in the City and County of New York or the courts of the State of New York in each
case located in the City and County of New York (collectively, the “Specified Courts”), and, subject to the final sentence
of this Section 5(a), each party irrevocably submits to the non-exclusive jurisdiction of the Specified Courts in any Related Proceeding.
Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of
process for any Related Proceeding brought in any Specified Court. The parties irrevocably and unconditionally waive any objection to
the laying of venue of any Related Proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead
or claim in any Specified Court that any Related Proceeding brought in any Specified Court has been brought in an inconvenient forum.
The Trustee reserves the right to bring an action in any court that has jurisdiction over the trust estate, which may be a court other
than the Specified Courts, when seeking a direction from a court in the administration of the trust estate. Each New Guarantor not located
in the United States hereby appoints the Issuer as its agent for service of process or other legal summons for purposes of any Related
Proceedings that may be instituted in any Specified Courts. The address for Clarivate Science Holdings Corporation, the initial agent
for service of process, is Clarivate Science Holdings Corporation, c/o Clarivate Plc, Friar’s House, 160 Blackfriars Road, London
SEI 8EZ, UK, Attention: General Counsel.


 


(b)       Waiver
of Immunity. With respect to any Related Proceeding, each party irrevocably waives, to the fullest extent permitted by applicable
law, all immunity (whether on the basis of sovereignty or otherwise) from jurisdiction, service of process, attachment (both before and
after judgment) and execution to which it might otherwise be entitled in the Specified Courts, and with respect to any suits, actions,
or proceedings instituted in regard to the enforcement of a judgment of any Specified Court in a Related Proceeding (a “Related
Judgment”), each party waives any such immunity in the Specified Courts or any other court of competent jurisdiction, and will
not raise or claim or cause to be pleaded any such immunity at or in respect of any such Related Proceeding or Related Judgment, including,
without limitation, any immunity pursuant to the United States Foreign Sovereign Immunities Act of 1976, as amended.


 


6.                  Trustee Makes No Representation. The Trustee makes no representation as to the validity or sufficiency of this Supplemental
Indenture.


 


7.                  
Counterparts. The parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an original,
but all of them together represent the same agreement. One signed copy is enough to prove this Supplemental Indenture. The exchange of
copies of this Supplemental Indenture and of signature pages by facsimile, PDF or other electronic 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
for all purposes. Signatures of the parties hereto transmitted by facsimile, PDF or other electronic methods shall be deemed to be their
original signatures for all purposes.





 


8.                  
 Effect of Headings. The Section headings herein are for convenience only and shall not affect the construction thereof.





 






    


     


    

 


IN WITNESS WHEREOF,
the parties hereto have caused this Supplemental Indenture to be duly executed as of the date first above written.


  


	 	On behalf of the entities listed on Schedule A and Schedule
    B




 


	 	By:	/s/
    Kathy Sullivan






	 	 	Name:	Kathy Sullivan
	 	 	Title:	Chief Tax & Revenue Operations
    Officer




 


	 	On behalf of the entities listed on Schedule C




 


	 	By:	/s/
    Richard Hanks






	 	 	Name:	Richard Hanks
	 	 	Title:	Treasurer




 


	 	CLARIVATE SCIENCE HOLDINGS CORPORATION,




 


	 	By:	/s/
    Richard Hanks



 


	 	 	Name:	Richard Hanks
	 	 	Title:	Chief Financial Officer




 


	 	On behalf of the entities listed on Schedule D




 


	 	By:	/s/ Andrew Graham Wright
	 	 	Name:	Andrew
    Graham Wright
	 	 	Title:	Director




 









    


     


    

 


	 	WILMINGTON TRUST, NATIONAL ASSOCIATION,
	 	as Trustee




 


	 	By:	/s/
Quinton M. DePompolo
	 	 	Name: Quinton M. DePompolo
	 	 	Title: Banking Officer




 






    


     


    

 





SCHEDULE A


 


CAMELOT U.S. ACQUISITION 1 CO.


CAMELOT U.S. ACQUISITION 2 CO.


CAMELOT U.S. ACQUISITION 4 CO.


CAMELOT U.S. ACQUISITION 5 CO.


CAMELOT U.S. ACQUISITION 6 CO.


CAMELOT U.S. ACQUISITION 8 CO.


CAMELOT U.S. ACQUISITION 9 CO.


CAMELOT U.S. ACQUISITION 10 CO.


CAMELOT U.S. ACQUISITION 11 CO.


CAMELOT U.S. ACQUISITION 12 CO.


CAMELOT U.S. ACQUISITION 13 CO.


CAMELOT U.S. ACQUISITION LLC


CHURCHILL CAPITAL CORP


CROSSBOW IP SERVICES LLC


TRADEMARK VISION USA, LLC


CLARIVATE IP (US) HOLDINGS CORPORATION





 






    


     


    

 


SCHEDULE B


 


ATOZDOMAINSMARKET, LLC


CLARIVATE ANALYTICS (COMPUMARK) INC.


CLARIVATE ANALYTICS (US) HOLDINGS INC.


CLARIVATE ANALYTICS (US) LLC


COLLECTIVETRUST SOLUTIONS, INC.


DATA DOCKET INC.


DECISION RESOURCES, INC.


DECISION RESOURCES INTERNATIONAL, INC.


DISCOVERY LOGIC, INC.


DNSTINATION INC.


DOMAIN FORTRESS INC.


DR/DECISION RESOURCES, LLC


DRG HOLDCO INC.


EBANNERMONITOR INC.


ENTERPRISE PROTECTION INC.


INFORMATION VENTURES LLC


LONGBOW LEGAL SERVICES INC.


MARKMANAGER INC.


MARKMONITOR (ALL-D) INC.


MARKMONITOR CORPORATE SERVICES INC.


MARKMONITOR EU REGISTRATIONS INC.


MARKMONITOR INC.


MARKMONITOR PROFESSIONAL SERVICES INC.


MICROPATENT LLC


MUCKYMUCK INC.


PATENT BOUNTY INC.


RISKSMART INC.


TECHNOLOGY UNIVERSE COMPANY, INC.





 






    


     


    

 


SCHEDULE C


 


CAMELOT U.S. ACQUISITION 3 CO.


CPA GLOBAL (FIP) LLC


CPA GLOBAL (FTF) INC.


CPA GLOBAL (IPAN) LLC


CPA GLOBAL (IPENDO) INC


CPA GLOBAL (LANDON IP) INC.


CPA GLOBAL NORTH AMERICA LLC


CPA GLOBAL PATENT RESEARCH LLC


CPA GLOBAL SERVICES US INC.


CPA GLOBAL SUPPORT SERVICES LLC


CPA SOFTWARE SOLUTIONS (NORTH AMERICA) LIMITED


CPA US HOLDINGS, INC.


INFORMATION HOLDINGS INC.


INNOGRAPHY, INC.


IPFOLIO CORPORATION


MARKPRO US LLC


MASTER DATA CENTER, INC.


OLCOTT INTERNATIONAL & CO., L.L.C.


PATENT RESOURCES GROUP, INC





 






    


     


    

 


SCHEDULE D


 


CAMELOT UK HOLDCO LIMITED


CAMELOT UK BIDCO LIMITED


CAMELOT FINANCE S.A.


CAMELOT UK HOLDCO 2 LIMITED


CENTRE FOR INNOVATION IN REGULATORY SCIENCE LIMITED


CENTRE FOR MEDICINES RESEARCH INTERNATIONAL LIMITED


CLARIVATE ANALYTICS (COMPUMARK) LIMITED


CLARIVATE ANALYTICS (INTERNATIONAL) LIMITED


CLARIVATE ANALYTICS (IP&S) LIMITED


CLARIVATE ANALYTICS (UK) LIMITED


DECISION RESOURCES GROUP UK LIMITED


MARKMONITOR GLOBAL SERVICES LIMITED


MARKMONITOR INTERNATIONAL LIMITED


MARKMONITOR LIMITED


SIGMATIC LIMITED


CPA GLOBAL LEGAL SUPPORT SERVICES UK LIMITED


CPA GLOBAL RENEWALS (UK) LIMITED


CPA GLOBAL SOFTWARE SOLUTIONS (UK) LIMITED


CPA GLOBAL MANAGEMENT SERVICES LTD


CPA GLOBAL (PATRAFEE) LIMITED


CPA GLOBAL (LANDON IP) LIMITED


CPAUSH LTD


WIRO LIMITED


IPSS EUROPE LIMITED


COMPUTER PATENT ANNUITIES INTERNATIONAL LIMITED


CPA GLOBAL FINCO LIMITED







 






    


     


    

 


SCHEDULE E


 


	Guarantor
    Name	 	Jurisdiction
	 	 
	ATOZDOMAINSMARKET, LLC	 	US - Washington
	 
	CAMELOT FINANCE S.A.	
     

     
	Société anonyme, 14, rue Edward Steichen, L - 2540 Luxembourg,
    RCS number: B208514 

     

	 
	 
	 
	CAMELOT U.S. ACQUISITION 1 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 10 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 11 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 12 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 13 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 2 CO.	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 3 CO.	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 4 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 5 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 6 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 8 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION 9 CO.	 	US - Delaware
	 
	CAMELOT U.S. ACQUISITION LLC	 	US - Delaware
	 
	CAMELOT UK BIDCO LIMITED	 	England & Wales
	 
	CAMELOT UK HOLDCO 2 LIMITED	 	England & Wales
	 
	CAMELOT UK HOLDCO LIMITED	 	England & Wales
	 
	CENTRE FOR INNOVATION IN REGULATORY SCIENCE	 	England & Wales
	LIMITED
	 
	CENTRE FOR MEDICINES RESEARCH INTERNATIONAL	 	England & Wales
	LIMITED
	 	 	 
	CHURCHILL CAPITAL CORP	 	US - Delaware
	 
	CLARIVATE ANALYTICS (COMPUMARK) INC.	 	US - Delaware
	 
	CLARIVATE ANALYTICS (COMPUMARK) LIMITED	 	England & Wales





 






    


     


    

 


	CLARIVATE ANALYTICS (INTERNATIONAL) LIMITED	 	England & Wales
	 
	CLARIVATE ANALYTICS (IP&S) LIMITED	 	England & Wales
	 
	CLARIVATE ANALYTICS (UK) LIMITED	 	England & Wales
	 
	CLARIVATE ANALYTICS (US) HOLDINGS INC.	 	US - Delaware
	 
	CLARIVATE ANALYTICS (US) LLC	 	US - Delaware
	 
	CLARIVATE IP (US) HOLDINGS CORPORATION	 	US - Delaware
	 
	COLLECTIVETRUST SOLUTIONS INC.	 	US - California
	 
	COMPUTER PATENT ANNUITIES INTERNATIONAL	 	England & Wales
	LIMITED
	 
	CPA GLOBAL (FIP) LLC	 	US - Delaware
	 
	CPA GLOBAL (FTF) INC.	 	US - Delaware
	 
	CPA GLOBAL (IPAN) LLC	 	US - Delaware
	 
	CPA GLOBAL (IPENDO) INC	 	US - Delaware
	 
	CPA GLOBAL (LANDON IP) INC.	 	US - Virginia
	 
	CPA GLOBAL (LANDON IP) LIMITED	 	England & Wales
	 
	CPA GLOBAL (PATRAFEE) LIMITED	 	England & Wales
	 
	CPA GLOBAL FINCO LIMITED	 	England & Wales
	 
	CPA GLOBAL LEGAL SUPPORT SERVICES UK LIMITED	 	England & Wales
	 
	CPA GLOBAL MANAGEMENT SERVICES LTD	 	England & Wales
	 
	CPA GLOBAL NORTH AMERICA LLC	 	US - Delaware
	 
	CPA GLOBAL PATENT RESEARCH LLC	 	US - Virginia
	 
	CPA GLOBAL RENEWALS (UK) LIMITED	 	England & Wales
	 
	CPA GLOBAL SERVICES US, INC.	 	US - Delaware
	 
	CPA GLOBAL SOFTWARE SOLUTIONS (UK) LIMITED	 	England & Wales
	 
	CPA GLOBAL SUPPORT SERVICES LLC	 	US - Delaware
	 
	CPA SOFTWARE SOLUTIONS (NORTH AMERICA)	 	US - Virginia
	LIMITED





 






    


     


    

 


	CPA US HOLDINGS, INC	 	US - Delaware
	 
	CPAUSH LTD	 	England & Wales
	 
	CROSSBOW IP SERVICES LLC	 	US - Delaware
	 
	DATA DOCKET INC.	 	US - Delaware
	 
	DECISION RESOURCES GROUP UK LIMITED	 	England & Wales
	 
	DECISION RESOURCES INTERNATIONAL, INC.	 	US - Massachusetts
	 
	DECISION RESOURCES, INC.	 	US - Delaware
	 
	DISCOVERY LOGIC, INC.	 	US - Delaware
	 
	DNSTINATION INC.	 	US - Delaware
	 
	DOMAIN FORTRESS INC.	 	US - Delaware
	 
	DR/DECISION RESOURCES, LLC	 	US - Delaware
	 
	DRG HOLDCO INC.	 	US - Delaware
	 
	EBANNERMONITOR INC.	 	US - Idaho
	 
	ENTERPRISE PROTECTION INC.	 	US - Idaho
	 
	INFORMATION HOLDINGS INC.	 	US - Delaware
	 
	INFORMATION VENTURES LLC	 	US - Delaware
	 
	INNOGRAPHY INC.	 	US - Delaware
	 
	IPFOLIO CORPORATION	 	US - Delaware
	 
	IPSS EUROPE LIMITED	 	England & Wales
	 
	LONGBOW LEGAL SERVICES INC.	 	US - Delaware
	 
	MARKMONITOR (ALL-D) INC.	 	US - Delaware
	 
	MARKMANAGER INC.	 	US - Delaware
	 	 	 
	MARKMONITOR CORPORATE SERVICES INC.	 	US - Delaware
	 
	MARKMONITOR EU REGISTRATIONS INC.	 	US - Delaware
	 
	MARKMONITOR GLOBAL SERVICES LIMITED	 	England & Wales
	 
	MARKMONITOR INC.	 	US - Delaware
	 




    	 



    	 



    

 


	MARKMONITOR INTERNATIONAL LIMITED	 	England & Wales
	 
	MARKMONITOR LIMITED	 	England & Wales
	 
	MARKMONITOR PROFESSIONAL SERVICES INC.	 	US - Delaware
	 
	MARKPRO US LLC	 	US - Delaware
	 
	MASTER DATA CENTER, INC.	 	US - Michigan
	 
	MICROPATENT LLC	 	US - Delaware
	 
	MUCKYMUCK INC.	 	US - Delaware
	 
	OLCOTT INTERNATIONAL & CO. L.L.C.	 	US - Delaware
	 
	PATENT BOUNTY INC.	 	US - Delaware
	 
	PATENT RESOURCES GROUP, INC.	 	US - Virginia
	 
	RISKSMART INC.	 	US - Idaho
	 
	SIGMATIC LIMITED	 	England & Wales
	 
	TECHNOLOGY UNIVERSE COMPANY, INC.	 	US - Delaware
	 
	TRADEMARK VISION (USA) LLC	 	US - Delaware
	 
	WIRO LIMITED	 	England & Wales