EX-10.8





 Exhibit 10.8 

***Text Omitted and Filed Separately 

with the Securities and Exchange Commission. 

Confidential Treatment Requested 

Under 17 C.F.R. Sections 200.80(c) and Rule 406 of the 

Securities Act of 1933, as amended. 
  

 
  
  

 
  
  

RESEARCH FUNDING AND OPTION AGREEMENT 
 by and
between 
 THE SCRIPPS RESEARCH INSTITUTE 
 a
California nonprofit 
 public benefit corporation 

and         

Synthorx, Inc., 
 a Delaware corporation 

 












 RESEARCH FUNDING AND OPTION AGREEMENT 

This Agreement is entered into this 31st day of July, 2014 (the “Effective
Date”), by and between The Scripps Research Institute, a California nonprofit public benefit corporation located at 10550 North Torrey Pines Road, La Jolla, California 92037 (“TSRI”), and Synthorx, Inc., a Delaware corporation,
located at 11099 North Torrey Pines Road, La Jolla, California 92037 (“Sponsor”), with respect to the facts set forth below. 

RECITALS 

A.        TSRI is engaged in fundamental scientific biomedical and biochemical research
including research relating to synthetic DNA bases, as more particularly described herein. 

B.        Sponsor is engaged in the research and development of novel proteins, RNA and DNA for
medical applications. 
 C.        Sponsor desires to provide certain funding as part of
TSRI’s research activities described above. 
 D.        Subject to any non-exclusive rights of the U.S. Government, TSRI is willing to grant to Sponsor an option to acquire rights and licenses to certain intellectual property arising from the Research Program (as defined below). 

E.        TSRI and Sponsor are parties to a license agreement dated as of the Effective Date
(the “Exclusive License Agreement”), pursuant to which TSRI has granted Sponsor an exclusive license under certain technology, materials and other information existing on the Effective Date, including TSRI’s patent and other
intellectual property rights therein (collectively, the “Existing Technology”). 
 AGREEMENT 

NOW, THEREFORE, in consideration of the mutual covenants and conditions outlined herein, TSRI and Sponsor hereby agree as follows: 

1.        DEFINITIONS. 

1.1      Affiliate. The term “Affiliate” shall mean any entity which directly or
indirectly controls, or is controlled by Sponsor. The term “control” as used herein means (a) in the case of corporate entities, direct or indirect ownership of at least fifty percent (50%) of the stock or shares entitled to vote for
the election of directors; or (b) in the case of non-corporate entities, direct or indirect ownership of at least fifty percent (50%) of the equity interest with the power to direct the management and
policies of such non-corporate entities. Unless otherwise specified, the term Sponsor includes Affiliates. 

  
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 1.2      Agreement Number.  This
Agreement is TSRI number SFP-2143. 
 1.3      Biological
Materials.  The term “Biological Materials” shall mean any Technology in the form of tangible materials together with any progeny, mutants, or derivatives thereof developed in performance of the Research Program. 

1.4      Confidential Information.    The term “Confidential
Information” shall mean any and all proprietary information of TSRI or Sponsor which may be disclosed or made available by such party (the “disclosing party”) to the other party (the “receiving party”) at any time and from
time to time during the term hereof. The fact that a disclosing party may have marked or identified as confidential or proprietary any specific information shall be indicative that such disclosing party believes such information to be confidential
or proprietary, but the failure to so mark information shall not conclusively determine that such information was or was not considered confidential information by such disclosing party. Confidential Information shall also include any information
which, given the circumstances surrounding the disclosure, would be considered confidential by the disclosing party. Information shall not be considered confidential to the extent that the receiving party can demonstrate by competent proof that such
information: 
   a.        Is in the public domain at the time of disclosure to the
receiving party; or 
   b.        After disclosure to the receiving party, becomes
part of the public domain, by publication or otherwise, without any breach of this Agreement by the receiving party; or 

  c.        Was known to the receiving party prior to the Effective Date, which
knowledge was acquired independently and not from the disclosing party (including the disclosing party’s employees); or 

  d.        Is subsequently disclosed to the receiving party in good faith by a third
party who has a right to make such disclosure. 
 1.5      Field. The term
“Field” shall mean [...***...]. 
 1.6      Joint Technology.  The term
“Joint Technology” shall mean any Technology made or developed jointly by at least one employee or consultant of Sponsor (it being understood that, for purposes of this paragraph, no TSRI employee shall be considered a consultant of
Sponsor) and at least one employee of TSRI, as determined under principles of inventorship under US patent law. 

1.7      Patent Rights.  The term “Patent Rights” shall mean rights arising out
of or resulting from (a) U.S./PCT patent application(s) directed to the Technology; (b) divisionals, continuations, reissues, reexaminations, and extensions of any patent or application set forth in sub clause (a) above;
(c) foreign counterparts of any of the foregoing; 

  
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 (d) patents issued from the application(s) referenced in sub clauses (a) – (c) above; and (e) all
claims of continuations-in-part that are entitled to the benefit of the priority date of the application(s) referenced in sub clause (a) above. 

1.8      Principal Investigator.    The term “Principal Investigator”
shall mean Dr. Floyd E. Romesberg, together with such replacement persons selected in accordance with the provisions of Section 2.2 below. 

1.9      Research Program.  The term “Research Program” shall mean the research
program to be undertaken by TSRI under the direction and control of the Principal Investigator as expressly set forth on Exhibit A hereto. 

1.10    Research Tool.    The term “Research Tool” shall mean any Technology
which is designed or utilized for basic research purposes or internal drug discovery purposes and which is not utilized to produce, or incorporated into, a product. 

1.11    Technology.    The term “Technology” shall mean any invention,
discovery, know-how, biological material, software, information and data, whether patentable or not, conceived and reduced to practice during the performance of the Research Program. 

1.12    TSRI Technology.    The term “TSRI Technology” shall mean any
Technology, made or developed solely by one or more employees of TSRI, as determined under principles of inventorship under U.S. patent law. 

2.        CONDUCT OF RESEARCH PROGRAM. 

2.1      Conduct of Research Program.  TSRI hereby agrees to use [...***...] to
perform the Research Program subject to the provisions of this Agreement. Notwithstanding the foregoing, TSRI makes no warranties or representations regarding its ability to achieve, nor shall it be bound to accomplish, any particular research
objective or results. 
 2.2      Supervision of Research Program.  TSRI agrees that
the Research Program at TSRI shall be conducted by or under the direct supervision of the Principal Investigator. In the event that the Principal Investigator leaves TSRI, or terminates his/her involvement in the Research Program, TSRI shall use its
best efforts to find a replacement Principal Investigator acceptable to Sponsor, which acceptance shall not be unreasonably withheld. In the event that TSRI shall fail to appoint a replacement Principal Investigator reasonably acceptable to Sponsor,
Sponsor shall have a right to terminate this Agreement upon delivery to TSRI of written notice of termination pursuant to this Section 2.2, which notice must be delivered to TSRI not more than ninety (90) days after delivery by TSRI to
Sponsor of the name of the proposed replacement Principal Investigator. 

2.3      Reports.  TSRI and the Principal Investigator shall keep complete and accurate
records of the results of the Research Program. TSRI agrees to provide oral 

  
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reports on a monthly basis, and Sponsor shall have the right, upon reasonable request from time to time, to discuss with TSRI, the Principal Investigator and other appropriate TSRI personnel, in
person or otherwise, the Research Program and the results thereof. TSRI agrees that within [...***...] following the last day of each calendar year during the term of this Agreement, TSRI shall furnish Sponsor with a written report summarizing
the results of the research included within the scope of the Research Program conducted by TSRI, during the immediately preceding calendar year, including but not limited to all data, conclusions, results, observations and a detailed description of
all procedures. Subject to Section 5.1, all such reports shall be treated as Confidential Information by Sponsor. In the event that Sponsor identifies any Technology disclosed in such report as to which it would like to exercise its option and
which has not been previously disclosed to Sponsor by TSRI in accordance with Section 3.2, Sponsor shall notify TSRI of such Technology in writing. Promptly following such notification, TSRI shall provide Sponsor with a Technology Disclosure in
accordance with Section 3.2. 
 2.4      Financial and Staffing Obligations 

  a.        Contributions of Parties to Research Program. Contributions in the
form of financial support, equipment, personnel, technology and other necessary components for the conduct of the Research Program shall be made by the parties in accordance with the terms set forth on Exhibit B. All payments due to TSRI by
Sponsor shall be payable in U.S. Dollars in quarterly installments in advance, within [...***...] of the dates set forth in the following payment schedule: 
  

							
	 1st payment:
	    	 due: [.***.]
	  		  	 amount (USD): $[.***.]

	 2nd payment:
	    	 due: [.***.]
	  		  	 amount (USD): $[.***.]

	 3rd payment:
	    	 due: [.***.]
	  		  	 amount (USD): $[.***.]

	 4th payment:
	    	 due: [.***.]
	  		  	 amount (USD): $[.***.]


 The amounts specified above include all expense, overhead and other related costs due by Sponsor to TSRI in connection
with the Research Program, and no other amounts shall be due or payable by Sponsor to TSRI or the Principal Investigator for performance of the Research Program. Each payment must reference the Research Project title, Agreement Number and Principal
Investigator for purposes of identification. Payments under this Section 2.4.a shall be sent to: 
 The Scripps Research
Institute 
 10550 North Torrey Pines Road, TPC-7 

La Jolla, California 92037 

Attn: Vice President, Sponsored Programs 

Fax No.: (858) 784-8037 

  
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 With a copy of Sponsor’s notice of payment or other accompanying correspondence
to:     
 The Scripps Research Institute 

10550 North Torrey Pines Road, TPC-9 

La Jolla, California 92037 

Attn: Director, Technology Development 

Fax No.: (858) 784-9910 

TSRI shall not be obligated to perform any of the research specified herein or to take any other action required under this Agreement if the funding is
not provided as set forth in Exhibit B and in accordance with the payment schedule as set forth in this Section 2.4.a. Furthermore, should Sponsor fail to make the first payment to TSRI in accordance with this Section 2.4.a., TSRI
shall have the right to immediately terminate this Agreement and this Agreement shall be null and void ab initio. 

  b.        Capital Equipment.    Equipment purchased by
TSRI with funds provided by Sponsor shall be the property of TSRI. All capital equipment provided under this Agreement by Sponsor for the use of TSRI remains the property of the Sponsor unless other disposition is mutually agreed upon in writing by
the Parties. If title to this equipment remains with the Sponsor, Sponsor is responsible for maintenance and repair of the equipment, insuring the equipment against damage or loss, and the costs of its transportation to and from the site where it
will be used. 
   c.        Indirect Cost
Adjustment.    TSRI shall have the right to adjust the payment amounts referenced above to reflect changes in the indirect cost rate negotiated between TSRI and the U.S. Government and that will be in effect during the
quarter that the work is performed. TSRI will notify Sponsor in writing of any change in the indirect cost rate before the effective date of such change. The corresponding direct costs will remain fixed as specified in Exhibit B. 

3.        OPTION FOR LICENSE. 

Notwithstanding the provisions of Sections 3.1 through 3.6 or any other provision of this Agreement to the contrary, TSRI and Sponsor agree that
the Patent Rights and Technology (including, without limitation, Joint Technology) are exclusively licensed to Sponsor, together with the Existing Technology, pursuant to the Exclusive License Agreement on the terms and conditions set forth therein.
For so long as the Exclusive License Agreement remains in effect: (a) all Patent Rights and Technology (including, without limitation, Joint Technology) arising under this Agreement are automatically deemed included in the subject matter
exclusively licensed to Sponsor under the Exclusive License Agreement, effective upon Sponsor’s delivery of written notice to TSRI pursuant to the first sentence of Section 3.4, and without any other action on the part of either party
pursuant to Section 3.3, 3.4 or 3.6 or otherwise; (b) Section 3.2 hereof shall continue in full force and effect; and (c) preparation, filing, 

  
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prosecution and maintenance of Patent Rights shall be governed by the Exclusive License Agreement (and not Section 3.5 hereof). 

3.1      Grant of Option. Subject to the terms of this Agreement and the reservation of rights
specified in Sections 4.2 and 4.3, TSRI hereby grants to Sponsor: 

  a.        an exclusive option (the “Option”) to acquire an exclusive,
worldwide license, including the right to sublicense, under TSRI’s rights in the Patent Rights and/or Biological Materials, to make, have made, use, offer for sale, sell, have sold and import products, processes and Biological Material in the
Field. In the event that a product or process utilizes a Research Tool, such Research Tool shall be made available to Sponsor solely on a non-exclusive basis. 

  b.        a non-exclusive, royalty-free, non-transferable license to make and use Technology solely for Sponsor’s internal research purposes during the performance of the Research Program. Any transfer of materials to Sponsor under this
Section 3.1(b) shall require the execution of a Material Transfer Agreement. The terms of such Material Transfer Agreement shall be materially consistent with the form Material Transfer Agreement attached hereto as Exhibit C. 

3.2      Disclosure of Technology. After Principal Investigator submits an invention disclosure
covering any Technology to TSRI’s Office of Technology Development, TSRI shall disclose such Technology in writing to Sponsor (the “Technology Disclosure”). TSRI shall use reasonable efforts to provide a Technology Disclosure that
contains sufficient detail to (i) enable both parties to determine whether or not the particular Technology is TSRI Technology or Joint Technology; and (ii) enable Sponsor to appreciate the significance of such Technology and to evaluate
the advisability of exercising the option granted hereunder with respect to such Technology. All such Technology Disclosures shall be maintained in confidence by Sponsor. 

3.3      Option. Sponsor shall have a period of [...***...] from receipt of the Technology
Disclosure from TSRI (“Option Period”), within which to exercise its Option with respect to the particular Technology disclosed therein. 

3.4      Exercise of Option. Sponsor shall exercise its Option by delivering to TSRI a written
notice within the Option Period which specifies the particular Technology for which the Option is being exercised. Upon such notification, Sponsor and TSRI shall have a period of [...***...] within which to negotiate a definitive license
agreement. 

3.5                         
                   Patent Filings. TSRI shall direct and control the preparation, filing and prosecution of patent applications and patents within
the Patent Rights. As consideration for the Option, [...***...]. Payment shall be made within [...***...] 

  
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[...***...] after Sponsor receives an invoice therefor. Failure of Sponsor to pay patent fees and expenses as set forth above shall immediately relieve TSRI from its obligation to incur any
further patent fees and expenses. Sponsor’s obligation to [...***...] shall survive the termination or expiration of this Agreement. Both parties hereto agree that TSRI may, at its sole discretion, utilize TSRI’s Office of Patent
Counsel in lieu of or in addition to independent counsel for patent prosecution and maintenance of patent application(s). Sponsor shall have full rights of consultation with the patent attorney so selected on all matters relating to patent
application(s). 
 3.6      Joint Technology. The parties hereby agree that in the event that
the disclosed Technology is Joint Technology and Sponsor neither exercises its Option to such Joint Technology nor has a license to such Joint Technology under the Exclusive License Agreement (i.e., if the Exclusive License Agreement has
terminated), both Parties shall (i) have no further obligations to each other with respect to such Joint Technology and any resulting Patent Rights; and (ii) be free to independently license or otherwise dispose of their rights to such
Joint Technology and any resulting Patent Rights on a worldwide basis without accounting to the other Party. 

4.        INTERESTS AND RIGHTS IN INTELLECTUAL PROPERTY. 

4.1      Title. TSRI shall retain sole ownership and title to TSRI Technology and to all
intellectual property rights related thereto. TSRI shall, in the good faith exercise of its discretion, undertake reasonable efforts to preserve and maintain its ownership and title as TSRI deems appropriate. Ownership of and title to Joint
Technology shall be vested jointly in TSRI and Sponsor, with each owning an undivided interest therein. 

4.2      Governmental Interest. TSRI and Sponsor acknowledge that TSRI has received, and expects
to continue to receive, funding from the United States Government in support of TSRI’s research activities. TSRI and Sponsor acknowledge and agree that their respective rights and obligations pursuant to this Agreement shall be subject to the
rights of the United States Government, existing and as amended, which may arise or result from TSRI’s receipt of research support from the United States Government, including but not limited to, 37 CFR 401, the NIH Grants Policy Statement and
the NIH Guidelines for Obtaining and Disseminating Biomedical Research Resources. 

4.3      Reservation of Rights. TSRI reserves the right to [...***...]. In addition, TSRI
reserves the right to [...***...]. TSRI shall have no obligation to notify or inform Sponsor of such use or licenses. 

  
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 5.        CONFIDENTIALITY AND
PUBLICATION. 
 5.1      Treatment of Confidential Information. The parties agree that
during [...***...] of this Agreement, the receiving party will (a) maintain in confidence all Confidential Information to the same extent the receiving party maintains its own proprietary information; (b) not disclose such
Confidential Information to any third party without the prior written consent of the disclosing party; and (c) not use such Confidential Information for any purpose except those permitted by this Agreement (and, if and to the extent applicable,
the Exclusive License Agreement). 
 If the receiving party is required to disclose Confidential Information by law or court order, the receiving
party shall limit the same to the minimum required to comply with the law or court order; provided that, prior to making such disclosure the receiving party shall notify the disclosing party, not later than [...***...] (or such shorter period
of time as may be reasonably practicable under the circumstances) before the disclosure, and shall, at the disclosing party’s request and expense, cooperate with the Disclosing Party’s efforts to seek confidential treatment of the
Confidential Information to be disclosed and/or to obtain a protective or other order, including extensions of time and the like, with respect to such disclosure. 

5.2      Publications. Sponsor acknowledges that it is the general policy of TSRI to encourage
publication of research results in technical or scientific journals; and Sponsor agrees that TSRI shall have a right to publish in accordance with its general policy. TSRI shall submit to Sponsor copies of proposed publications which describe
Technology and afford Sponsor a period of [...***...] to review the publication to (i) ascertain whether Sponsor’s Confidential Information would be disclosed by the publication; and (ii) ascertain whether or not submission or
presentation of the publication would preclude the parties from obtaining patent rights claiming Technology disclosed therein unless an application is filed with relevant patent authorities. If such publication discloses Sponsor’s Confidential
Information and upon Sponsor’s written request, TSRI shall remove such Confidential Information or delay publication for up to an additional [...***...] to allow Sponsor to protect its Confidential Information by filing a patent
application(s). In the event that Sponsor identifies any potentially patentable Technology with respect to which it wishes to file, or have TSRI file (as applicable), patent application(s), Sponsor shall notify TSRI of such in writing. Upon such
notification, TSRI shall, at its option, either delete the enabling portion of the proposed publication or presentation, or withhold publication or delay presentation for up to an additional [...***...] to allow filing of patent
application(s). Absent receipt by TSRI of any written instruction by Sponsor within the [...***...] period, TSRI shall be free to publish the proposed publication. 

5.3      Publicity. Except as otherwise provided herein or required by law, no party shall
originate any publication, news release or other public announcement, written or oral, whether in the public press, stockholders’ reports, or otherwise, relating to this 

  
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Agreement or to the performance hereunder without the prior written approval of the other party, which approval shall not be unreasonably withheld. Scientific publications published in accordance
with Section 5.2 of this Agreement shall not be construed as publicity governed by this Section 5.3. 

6.        WARRANTIES. 

6.1      Limited Warranty. TSRI hereby represents and warrants that it has full right and power to
enter into this Agreement. TSRI MAKES NO OTHER WARRANTIES CONCERNING PATENT RIGHTS, TECHNOLOGY, RESEARCH TOOLS, BIOLOGICAL MATERIALS OR ANY OTHER MATTER WHATSOEVER, INCLUDING WITHOUT LIMITATION, ANY EXPRESS OR IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT OF THIRD PARTY RIGHTS OR ARISING OUT OF COURSE OF CONDUCT OR TRADE CUSTOM OR USAGE, AND TSRI DISCLAIMS ALL SUCH EXPRESS OR IMPLIED
WARRANTIES. TSRI MAKES NO WARRANTY OR REPRESENTATION AS TO THE VALIDITY OR SCOPE OF PATENT RIGHTS, OR THAT ANY PRODUCT, PROCESS, SERVICE, BIOLOGICAL MATERIAL, OR RESEARCH TOOL WILL BE FREE FROM AN INFRINGEMENT ON PATENTS OR OTHER INTELLECTUAL
PROPERTY RIGHTS OF THIRD PARTIES, OR THAT NO THIRD PARTIES ARE IN ANY WAY INFRINGING UPON ANY PATENT RIGHTS, TECHNOLOGY, RESEARCH TOOLS OR BIOLOGICAL MATERIALS COVERED BY THIS AGREEMENT. FURTHER, TSRI HAS MADE NO INVESTIGATION AND
MAKES NO REPRESENTATION THAT THE PATENT RIGHTS, RESEARCH TOOLS OR BIOLOGICAL MATERIALS ARE SUITABLE FOR SPONSOR’S PURPOSES. 
 IN NO EVENT SHALL
EITHER PARTY BE LIABLE TO THE OTHER PARTY FOR ANY INDIRECT, SPECIAL, INCIDENTAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS OR EXPECTED SAVINGS OR OTHER ECONOMIC LOSSES, OR FOR INJURY TO PERSONS OR
PROPERTY) ARISING OUT OF OR IN CONNECTION WITH THIS AGREEMENT OR ITS SUBJECT MATTER. TSRI’S AGGREGATE LIABILITY, IF ANY, FOR ALL DAMAGES OF ANY KIND RELATING TO THIS AGREEMENT OR ITS SUBJECT MATTER SHALL NOT EXCEED THE AMOUNT PAID BY SPONSOR TO
TSRI UNDER THIS AGREEMENT. THE FOREGOING EXCLUSIONS AND LIMITATIONS SHALL APPLY TO ALL CLAIMS AND ACTIONS OF ANY KIND AND ON ANY THEORY OF LIABILITY, WHETHER BASED ON CONTRACT, TORT (INCLUDING, BUT NOT LIMITED TO NEGLIGENCE OR STRICT LIABILITY), OR
ANY OTHER GROUNDS, AND REGARDLESS OF WHETHER A PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, AND NOTWITHSTANDING ANY FAILURE OF ESSENTIAL PURPOSE OF ANY LIMITED REMEDY. THE PARTIES FURTHER AGREE THAT EACH WARRANTY DISCLAIMER, EXCLUSION
OF DAMAGES OR OTHER LIMITATION OF LIABILITY HEREIN IS INTENDED TO BE SEVERABLE AND INDEPENDENT OF THE OTHER PROVISIONS SINCE THEY EACH REPRESENT SEPARATE ELEMENTS OF RISK ALLOCATION BETWEEN THE PARTIES. 

7.        TERM AND TERMINATION. 

7.1      Term. Unless terminated sooner, the initial term of this Agreement shall commence on the
Effective Date and shall continue until the earlier of (a) the 

  
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 first (1st) anniversary of the Effective
Date, and (b) the completion of the Research Program, unless extended by written mutual agreement of the parties. 

7.2      Termination by Mutual Agreement.     This Agreement may be terminated
at any time upon the mutual written agreement of the parties. In the absence of an agreement to the contrary, no such termination shall have the effect of relieving Sponsor of its monetary obligations to fund the Research Program which shall have
accrued up and to the date of such termination. 
 7.3      Termination Upon Default. Except as
specified in Section 7.4, the failure of a party to perform any obligation required of it to be performed hereunder and the failure to cure within sixty (60) days (or, in the case of any failure by Sponsor to make any payment hereunder
when due, within thirty (30) days) after receipt of notice from the other party specifying in reasonable detail the nature of such default, shall constitute an event of default hereunder. Upon the occurrence of an event of default which is not
cured within the applicable notice period, the non-defaulting party may deliver to the defaulting party written notice of intent to terminate, such termination to be effective upon the date set forth in such
notice. Such termination rights shall be in addition to and not in substitution for any other remedies that may be available to the non-defaulting party serving such notice against the defaulting party.
Termination pursuant to this Section 7.3 shall not relieve the defaulting party of liability and damages to the non-defaulting party for breach of this Agreement. Waiver by any party of a single default
or a succession of defaults shall not deprive such party of any right to terminate this Agreement arising by reason of any subsequent default. 

7.4      Termination Upon Insolvency.     This Agreement may be terminated by a
party upon written notice of termination to the other party (“Insolvent Party”) in the event of the filing of bankruptcy by the Insolvent Party, or the appointment of a receiver of any of the Insolvent Party’s assets, or the making by
the Insolvent Party of any assignment for the benefit of creditors, or the institution of any involuntary bankruptcy proceedings against the Insolvent Party under any bankruptcy law that are not dismissed within sixty (60) days after
institution. Termination shall be effective upon the date specified in this notice. 

7.5      Effect of Expiration or Termination. 

  a.        Termination Upon Default of Sponsor.     Upon
the termination of this Agreement by reason of a default by Sponsor, neither party shall have any further rights or obligations with respect to this Agreement, other than the rights and obligations of the parties that accrued prior to the effective
date of such termination (including, without limitation, the obligation of Sponsor to make any and all final payments accrued prior to the date of termination and the obligation of the parties to make all reports required hereunder), and except as
provided below. Upon such termination of this Agreement, the parties shall continue to abide by their non-disclosure obligations as described in Section 5.1 and each party hereto shall fulfill any other
obligations incurred prior to such termination. Any such termination of this Agreement shall not constitute the termination of any license or any other agreements between the parties which are then in effect (such as, but not limited to, the 

  
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Exclusive License Agreement) except as expressly provided therein. In addition, upon such termination, Sponsor’s Option under Section 3.1 shall be deemed automatically cancelled, and
Sections 4, 6, 7, 8 and 9 shall survive any such termination. 

  b.        Expiration or Termination upon Default of TSRI. Upon the
expiration of this Agreement at its regularly scheduled expiration date, or upon a termination of this Agreement on account of a default by TSRI, then TSRI shall make the disclosures required by Section 3.2 for Technology conceived or reduced
to practice up to the date of said expiration or termination; Sponsor shall have the right to exercise its option with respect to said Technology in accordance with the schedule and procedures specified in Sections 3.3 and 3.4 above; and any non-exclusive licenses that have been granted under Section 3.1 shall survive. Additionally, each party shall perform all other obligations up to the date of said expiration or termination; the parties shall
continue to abide by their non-disclosure obligations described in Section 5.1; and any previously existing license agreements or other agreements between the parties (such as, but not limited to, the
Exclusive License Agreement) shall continue in effect. No such expiration or termination of this Agreement shall affect the rights and obligations of the parties that accrued prior to the effective date of such expiration or termination. In
addition, upon such expiration or termination, Sections 4, 6, 7, 8 and 9 shall survive. 

8.        ASSIGNMENT; SUCCESSORS. 

8.1      Assignment. Any and all assignments of this Agreement or any rights granted hereunder by
Sponsor without the prior written consent of TSRI are void, except that, without the prior written consent of TSRI, (a) Sponsor may assign this Agreement and its rights and obligations hereunder to an Affiliate of Sponsor; and (b) Sponsor
may assign this Agreement and its rights and obligations hereunder in connection with the transfer or sale of all or substantially all of Sponsor’s business or assets to which this Agreement relates to a third party, whether by merger, sale of
stock, sale of assets or otherwise, subject to Section 8.2 hereof. 
 8.2      Binding Upon
Successors and Assigns.   Subject to the limitations on assignment set forth herein, this Agreement shall be binding upon and inure to the benefit of any successors in interest and assigns of TSRI and Sponsor. Any such successor to or
assignee of a party’s interest shall expressly assume in writing the performance of all the terms and conditions of this Agreement to be performed by such party and such written assumption shall be delivered to the other Party. 

9.        GENERAL PROVISIONS. 

9.1      Independent Contractors.     The relationship between TSRI and
Sponsor is that of independent contractors. TSRI and Sponsor are not joint venturers, partners, principal and agent, master and servant, employer or employee, and have no other relationship other than independent contracting parties. TSRI and
Sponsor shall have no power to bind or obligate each other in any manner, other than as is expressly set forth in this Agreement. 

  
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 9.2      Arbitration. Any controversy or claim
arising out of or relating to this Agreement, or the breach thereof, shall be settled by binding confidential arbitration in accordance with the Commercial Arbitration Rules of the American Arbitration Association (“AAA”), and the
procedures set forth below. In the event of any inconsistency between the Rules of AAA and the procedures set forth below, the procedures set forth below shall control. Judgment upon the award rendered by the arbitrators may be enforced in any court
having jurisdiction thereof. 
   a.        Location.   The
location of the arbitration shall be in the County of San Diego. TSRI and Sponsor hereby irrevocably submit to the exclusive jurisdiction and venue of the American Arbitration Association arbitration panel selected by the parties and located in San
Diego County, California for any dispute regarding this Agreement, and to the exclusive jurisdiction and venue of the federal and state courts located in San Diego County, California for any action or proceeding to enforce an arbitration award or as
otherwise provided in Section 9.2 e below, and waive any right to contest or otherwise object to such jurisdiction or venue. 

  b.        Selection of Arbitrators.       The
arbitration shall be conducted by a panel of three neutral arbitrators who are independent and disinterested with respect to the parties, this Agreement, and the outcome of the arbitration. Each party shall appoint one neutral arbitrator, and these
two arbitrators so selected by the parties shall then select the third arbitrator, and all arbitrators must have at least ten (10) years experience in mediating or arbitrating cases regarding the same or substantially similar subject matter as
the dispute between TSRI and Sponsor. If one party has given written notice to the other party as to the identity of the arbitrator appointed by the party, and the party thereafter makes a written demand on the other party to appoint its designated
arbitrator within the next ten days, and the other party fails to appoint its designated arbitrator within ten days after receiving said written demand, then the arbitrator who has already been designated shall appoint the other two arbitrators.

   c.        Discovery. The arbitrators shall decide any disputes and
shall control the process concerning these pre-hearing discovery matters. Pursuant to the Rules of AAA, the parties may subpoena witnesses and documents for presentation at the hearing. 

  d.        Case Management. Prompt resolution of any dispute is important to
both parties; and the parties agree that the arbitration of any dispute shall be conducted expeditiously. The arbitrators are instructed and directed to assume case management initiative and control over the arbitration process (including scheduling
of events, pre-hearing discovery and activities, and the conduct of the hearing), in order to complete the arbitration as expeditiously as is reasonably practical for obtaining a just resolution of the
dispute. 

e.                         
                                Remedies.     The arbitrators
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 remedies or relief could be granted by a state or federal court, provided however, that no punitive
damages may be awarded. No court action shall be maintained seeking punitive damages. The decision of any two of the three arbitrators appointed shall be binding upon the parties. Notwithstanding anything to the contrary in this Agreement, prior to
or while an arbitration proceeding is pending, either party has the right to seek and obtain injunctive and other equitable relief from a court of competent jurisdiction to enforce that party’s rights hereunder. In addition, no claim, dispute
or controversy that concerns the validity, enforceability, scope or infringement of a patent, trademark or copyright shall be subject to arbitration or any other provision of this Section 9.2. 

  f.        Expenses. The expenses of the arbitration, including the
arbitrators’ fees, expert witness fees, and attorney’s fees, may be awarded to the prevailing party, in the discretion of the arbitrators, or may be apportioned between the parties in any manner deemed appropriate by the arbitrators.
Unless and until the arbitrators decide that one party is to pay for all (or a share) of such expenses, both parties shall share equally in the payment of the arbitrators’ fees as and when billed by the arbitrators. 

  g.        Confidentiality. Except as set forth below and as necessary to
obtain or enforce a judgment upon any arbitration award, the parties shall keep confidential the fact of the arbitration, the dispute being arbitrated, and the decision of the arbitrators. Notwithstanding the foregoing, the parties may disclose
information about the arbitration to persons who have a need to know, such as directors, trustees, management employees, witnesses, experts, investors, attorneys, lenders, insurers, and others who may be directly affected. Additionally, if a party
has stock which is publicly traded, the party may make such disclosures as are required by applicable securities laws, but will use commercially reasonably efforts to seek confidential treatment for such disclosure. 

9.3      Entire Agreement; Modification.     This Agreement and all of the
attached Exhibits set forth the entire agreement and understanding between the parties as to the subject matter hereof, and supersede all prior or contemporaneous written or oral agreements, excluding the Exclusive License Agreement. There shall be
no amendments or modifications to this Agreement, except by a written document which is signed by both parties. 

9.4      California Law.     This Agreement shall be construed and enforced in
accordance with the laws of the State of California notwithstanding any conflicts or choice of laws provisions. 

9.5      No Use of Name.     The use of the name “The Scripps Research
Institute”, “Scripps”, “TSRI” or any variation thereof in connection with the advertising, sale or performance of products, processes, services, Biological Materials or Research Tools is expressly prohibited. 

9.6      Headings.     The headings for each article and section in this
Agreement have been inserted for the convenience of reference only and are not intended to limit or expand on the meaning of the language contained in the particular article or section. 

  
 -13- 













 9.7        Severability.
  Should any one or more of the provisions of this Agreement be held invalid or unenforceable by a court of competent jurisdiction, it shall be considered severed from this Agreement and shall not serve to invalidate the remaining
provisions thereof. The parties shall make a good faith effort to replace any invalid or unenforceable provision with a valid and enforceable one such that the objectives contemplated by them when entering this Agreement may be realized. 

9.8        No Waiver.   Any delay in enforcing a party’s rights under
this Agreement or any waiver as to a particular default or other matter shall not constitute a waiver of such party’s rights to the future enforcement of its rights under this Agreement, excepting only as to an express written and signed waiver
as to a particular matter for a particular period of time. 
 9.9        Notices. Any
notices required by this Agreement shall be in writing, shall specifically refer to this Agreement and shall be sent by registered or certified airmail, postage prepaid, or by telefax, telex or cable, charges prepaid, or by overnight courier,
postage prepaid, and shall be forwarded to the respective addresses set forth below unless subsequently changed by written notice to the other party: 
  

			
	 FOR TSRI:
	  	 The Scripps Research Institute

		  	 10550 North Torrey Pines Road, TPC-9

		  	 La Jolla, California 92037

		  	 Attn: Vice President, Business Development

		  	 Fax No.: (858) 784-9910

		
	 With a copy to:
	  	 The Scripps Research Institute

		  	 10550 North Torrey Pines Road, TPC-8

		  	 La Jolla, California 92037

		  	 Attention: Chief Business Counsel

		  	 Fax No.: (858) 784-9910

		
	 FOR SPONSOR:
	  	 Synthorx, Inc.

		  	 11099 North Torrey Pines Road, Suite 290

		  	 La Jolla, California 92037

		  	 Attn: President and Chief Executive Officer

		  	 Fax No.: (858) 750-4701


 Notices shall be deemed delivered upon the earlier of (i) when received; (ii) three (3) days after
deposit into the U.S. mail; (iii) the date notice is sent via telefax, telex or cable; or (iv) the day immediately following delivery to an overnight courier guaranteeing next-day delivery (except
Sunday and holidays). 
 9.10    Compliance with U.S. Laws. Nothing contained in this Agreement shall
require or permit TSRI or Sponsor to do any act inconsistent with the requirements of any 

  
 -14- 













 
United States law, regulation or executive order as the same may be in effect from time to time. 

9.11        Indemnity.     Sponsor shall indemnify, defend (by
counsel reasonably acceptable to TSRI) and hold harmless TSRI and any parent, subsidiary or other affiliated entity of TSRI and their trustees, directors, officers, employees, scientists, agents, successors, assigns and other representatives
(collectively, the “Indemnitees”) from and against all claims, suits, actions, damages, liabilities, losses and other expenses, including without limitation reasonable attorney’s fees, expert witness fees and costs incurred by or
asserted against the Indemnitees, whether or not a lawsuit or other proceeding is filed (collectively “Claim”), that arise out of or relate to any third party allegations or suits regarding Sponsor’s use of the Technology or the
exercise of its non-exclusive license rights under Section 3.1.b. Sponsor shall not enter into any settlement of such Claims that imposes any obligation on TSRI, that does not unconditionally release TSRI
from all liability or that would have an adverse effect on TSRI’s reputation or business without TSRI’s prior written consent. In the event an Indemnitee seeks indemnification with respect to a Claim under this Section 9.11, it shall
notify Sponsor in writing of such Claim as soon as reasonably practicable after it receives notice of such Claim, shall permit Sponsor to assume direction and control of the defense of the Claim (including the right to settle the Claim solely for
monetary consideration, subject to the limitations of the preceding sentence) using counsel selected by Sponsor and reasonably acceptable to TSRI, and shall cooperate as reasonably requested (at the expense of Sponsor) in the defense of the Claim.
Notwithstanding the above, Indemnitees, [...***...], shall have the right to retain separate independent counsel to assist in defending any such Claims. In the event Sponsor fails to promptly indemnify and defend such Claims and/or pay
Indemnitees’ expenses as provided above, Indemnitees shall have the right to defend themselves, and in that case, [...***...] of each of Indemnitees’ written requests. This indemnity shall be a direct payment obligation and not
merely a reimbursement obligation of Sponsor to Indemnitees. 

  
 ***Confidential
Treatment Requested 
 -15- 













 IN WITNESS WHEREOF, the parties have executed this Agreement by their duly authorized
representatives as of the date set forth above. 
  

					
	 TSRI:
	 		 	 SPONSOR:

			
	 THE SCRIPPS RESEARCH INSTITUTE
	 		 	 SYNTHORX, INC.

		
	 By: /s/
Scott Forrest                     
	 	 By:  /s/ Court
Turner                          

		
	 Title: VP, Business Development
	 	 Title: President and
CEO                   



  
 -16- 













 EXHIBIT A 

RESEARCH PROGRAM 
 Background

 [...***...] 

  
 ***Confidential
Treatment Requested 













 [...***...] 

Literature Cited 
  

	1.	 DA Malyshev, K Dhami, HT Quach, T Lavergne, P Ordoukhanian, A Torkamani, FE Romesberg. Efficient and
sequence-independent replication of DNA containing a third base pair establishes a functional six-letter genetic alphabet. (2012) Proc Natl Acad Sci USA, 109:12005-12010. PMCID: 3409741.




	2.	 YJ Seo, S Matsuda, FE Romesberg. Transcription of an expanded genetic alphabet. (2009) J Am Chem Soc,
131:5046-5047. PMCID: PMC2728119. 



	3.	 HH Winkler, HE Neuhaus. Non-mitochondrial ATP transport. (1999) Trends
Biochem Sci, 24:64-68. 



	4.	 H Amiri, O Karlberg, SG Andersson. Deep origin of plastid/parasite ATP/ADP translocases. (2003) J Mol Evol, 56:137-150. 



	5.	 TP Hatch, E Al-Hossainy, JA Silverman. Adenine nucleotide and lysine transport
in Chlamydia psittaci. (1982) J Bacteriol, 150:662-670. 



	6.	 HH Winkler. Rickettsial permeability: an ADP-ATP transport system.
(1976) J Biol Chem, 251:389-396. 



	7.	 M Horn, M Wagner. Bacterial endosymbionts of free-living amoebae. (2004) J Eukaryot Microbiol, 5:509-514. 



	8.	 I Haferkamp, S Schmitz-Esser, M Wagner, N Neigel, M Horn, HE Neuhaus. Tapping the nucleotide pool of the host: novel
nucleotide carrier proteins of Protochlamydia amoebophila. (2006) Mol Microbiol, 60:1534-1545. PMCID: 1513512. 



	9.	 B Miroux, JE Walker. Over-production of proteins in Escherichia coli: mutant hosts that allow synthesis of some
membrane proteins and globular proteins at high levels. (1996) J Mol Biol, 260:289-298. 



	10.	 I Haferkamp, N Linka. Functional expression and characterisation of membrane transport proteins. (2012) Plant
Biol, 14:675-690. 



	11.	 M Ast, A Gruber, S Schmitz-Esser, HE Neuhaus, PG Kroth, M Horn, I Haferkamp. Diatom plastids depend on nucleotide
import from the cytosol. (2009) Proc Natl Acad Sci USA, 106:3621-3626. PMCID: 2642474. 



  
 ***Confidential
Treatment Requested 














	12.	 T Lavergne, DA Malyshev, FE Romesberg. Major groove substituents and polymerase recognition of a class of
predominantly hydrophobic unnatural base pairs. (2012) Chem Eur J, 18:1231-1239. PMCID: 3693734. 



	13.	 L Li, M Degardin, T Lavergne, D Malyshev, K Dhami, P Ordoukhanian, FE Romesberg. Natural-like replication of an
unnatural base pair for the expansion of the genetic alphabet and biotechnology applications. (2014) J Am Chem Soc, 136:826-829. 



	14.	 H Hashimoto, JE Pais, X Zhang, L Saleh, Z-Q Fu, N Dai, IR Correa, Y Zheng, X
Cheng. Structure of a Naegleria Tet-like dioxygenase in complex with 5-methylcytosine DNA. (2014) Nature, 506:391-395.




	15.	 YJ Seo, DA Malyshev, T Lavergne, P Ordoukhanian, FE Romesberg. Site-specific labeling of DNA and RNA using an
efficiently replicated and transcribed class of unnatural base pairs. (2011) J Am Chem Soc, 133:19878-19888. 



	16.	 DA Malyshev, YJ Seo, P Ordoukhanian, FE Romesberg. PCR with an expanded genetic alphabet. (2009) J Am Chem Soc,
131:14620-14621. PMCID: 2978235. 



	17.	 I Hirao, M Kimoto, T Mitsui, T Fujiwara, R Kawai, A Sato, Y Harada, S Yokoyama. An unnatural hydrophobic base pair
system: site-specific incorporation of nucleotide analogs into DNA and RNA. (2006) Nat Methods, 3:729-735. 



	18.	 MF Goodman. Error-prone repair DNA polymerases in prokaryotes and eukaryotes. (2002) Annu Rev Biochem, 71:17-50. 



	19.	 J Samuelson. Bacterial Systems. In: AS Robinson, editor. Production of Membrane Proteins: Strategies for Expression
and Isolation: Wiley-VCH; 2011. p. 11-35. 



	20.	 MJ Giacalone, AM Gentile, BT Lovitt, NL Berkley, CW Gunderson, MW Surber. Toxic protein expression in Escherichia coli
using a rhamnose-based tightly regulated and tunable promoter system. (2006) Biotechniques, 40:355-364. 



	21.	 ST Cardona, CL Mueller, MA Valvano. Identification of essential operons with a rhamnose-inducible promoter in
Burkholderia cenocepacia. (2006) Appl Environ Microbiol, 72:2547-2555. PMCID: 1448982. 



	22.	 H Dong, W Tao, Y Zhang, Y Li. Development of an anhydrotetracycline-inducible gene expression system for
solvent-producing Clostridium acetobutylicum: A useful tool for strain engineering. (2012) Metab Eng, 14:59-67. 



	23.	 A Chatterjee, SB Sun, JL Furman, H Xiao, PG Schultz. A versatile platform for single- and multiple-unnatural amino
acid mutagenesis in Escherichia coli. (2013) Biochemistry, 52:1828-1837. PMCID: 3855549. 



	24.	 A Berlec, B Štrukelj. Current state and recent advances in biopharmaceutical production in Escherichia coli,
yeasts and mammalian cells. (2013) J Ind Microbiol Biotechnol, 40:257-274. 



	25.	 S Shao, RS Hegde. Membrane Protein Insertion at the Endoplasmic Reticulum. (2011) Annual Review of Cell and
Developmental Biology, 27:25-56. 



	26.	 A Idiris, H Tohda, H Kumagai, K Takegawa. Engineering of protein secretion in yeast: strategies and impact on protein
production. (2010) Appl Microbiol Biotechnol, 86:403-417. 



	27.	 P Malkus, F Jiang, R Schekman. Concentrative sorting of secretory cargo proteins into COPII-coated vesicles.
(2002) J Cell Biol, 159:915-921. PMCID: 2173974. 



	28.	 HB Parmar, C Barry, F Kai, R Duncan. Golgi complex-plasma membrane trafficking directed by an autonomous, tribasic
Golgi export signal. (2014) Mol Biol Cell, 25:866-878. PMCID: 3952855. 















	29.	 A Graf, M Dragosits, B Gasser, D Mattanovich. Yeast systems biotechnology for the production of heterologous proteins.
(2009) FEMS Yeast Res, 9:335-348. 



	30.	 M Delic, M Valli, AB Graf, M Pfeffer, D Mattanovich, B Gasser. The secretory pathway: exploring yeast diversity.
(2013) FEMS Microbiol Rev, 37:872-914. 



	31.	 C Da-Re, E Franzolin, A Biscontin, A Piazzesi, B Pacchioni, MC Gagliani, G
Mazzotta, C Tacchetti, MA Zordan, M Zeviani, P Bernardi, V Bianchi, C De Pitta, R Costa. Functional Characterization of drim2, the Drosophila melanogaster Homolog of the Yeast Mitochondrial Deoxynucleotide Transporter. (2014) J Biol Chem,
289:7448-7459. PMCID: 3953259. 














 EXHIBIT B 

BUDGET 
  

											
	 Principal Investigator/Program Director (Last, First, Middle):

 
	  	 Romesberg, Floyd
  
	 
	 
	 BUDGET

 
	  



	 	 	 
	
PERSONNEL (Applicant organization only)
	  	 %

 
	  	 	YEAR 1	 
	 NAME
	  	ROLE ON
PROJECT	  	 EFFORT  

ON  
 PROJ.  
	  	 
	        SALARY/
FRINGE	
 
	 Romesberg, Floyd
	  	
Principal
Investigator
  
	  	[...***...]	  	 	[...***...]	 
	 	 	 	 
	
Chin, Jodie
  
	  	 Research Scientist

 
	  	 [...***...]

 
	  	 	[...***...]	 
	 	 	 	 
	
Technician, TBN
  
	  	 Technician

 
	  	 [...***...]

 
	  	 	[...***...]	 
	
SUBTOTAL                




	  	 	[...***...]	 
	  EQUIPMENT 
(Itemize)
  
	  	 	 	 
	
 SUPPLIES  (Itemize by category)
	  	 	 	 
	
Bio/chemicals, molecular biology kits, enzymes, disposable plasticware (tubes, trays, pipette tips), bacterial and yeast growth media components

 
	  	 	[...***...]	 
	  TRAVEL

 
	  	 	 	 
	
 OTHER EXPENSES  (Itemize by category)
	  	 	 	 
	
DNA synthesis; DNA sequencing; Access fees for NMR and MS characterizations

 
	  	 	[...***...]	 
	 	 
	
 DIRECT COSTS
  
	  	$	[...***...]	 
	 	 
	
 INDIRECT COSTS @ [...***...]%

 
	  	$	[...***...]	 
	
 TOTAL COSTS  



 
  
	  	$	[...***...]	 


  
 ***Confidential
Treatment Requested 













 EXHIBIT C 

FORM OF MATERIAL TRANSFER AGREEMENT 
 THE
SCRIPPS RESEARCH INSTITUTE 
 MATERIAL TRANSFER AGREEMENT 

[Date] 
 [Contact’s Name] 

[Sponsor’s name] 
 [Sponsor’s Address] 

Dear Dr. [Contact’s Name]: 
 This is to
acknowledge your request for the [Materials Requested] to be provided by [Principal Investigator] at The Scripps Research Institute (TSRI) pursuant to Section 3.1.b of the Research Funding and Option Agreement between TSRI and [Sponsor’s
name] dated                                 . This material and all modifications
and derivatives of this material are referred to herein as “Materials”. 
 TSRI is pleased to cooperate with your use of these Materials at
[Sponsor’s name] for your scientific research. However, before forwarding them to you, TSRI needs [Sponsor’s name] to agree to the following terms and conditions: 

(1)    that TSRI hereby grants Sponsor a nonexclusive, royalty-free,
non-transferable license to make and use the Materials solely for your internal research purposes; 

(2)    that the Materials shall be received by [Sponsor’s name] only for use in scientific research in
[Sponsor’s name]’s laboratories and that all applicable guidelines set forth by the National Institutes of Health (NIH), U.S. Department of Agriculture (USDA) or other government agencies regarding the use of these Materials shall be
followed; 
 (3)    these Materials are provided as a service to the research community. THE MATERIALS ARE BEING
SUPPLIED TO YOU WITH NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTY OF MERCHANTABILITY OF ANY KIND, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT OF THIRD PARTY RIGHTS
ARISING OUT OF COURSE OF CONDUCT OR TRADE CUSTOM OR USAGE, ALL OF WHICH ARE DISCLAIMED BY TSRI 












 (4)    that [Sponsor’s name] shall bear all risk to
[Sponsor’s name] and/or any others resulting from any use, directly or indirectly, to which [Sponsor’s name] puts the Materials or any other materials that could not have been made but for these Materials; 

(5)    that [Sponsor’s name] hereby defends, indemnifies, and holds harmless TSRI, its affiliates, its
trustees, officers, employees and agents from any loss, claim, damage, or liability, of any kind whatsoever, including without limitation reasonable attorney’s fees, expert witness fees and costs, whether or not a lawsuit or other proceeding is
filed, which may arise from [Sponsor’s name]’s use, storage or disposal of the Materials or any other material that could not have been made but for the Materials, except to the extent such arise due to the gross negligence or willful
misconduct of TSRI; 
 (6)    that you provide us with your Federal Express account number or an account number
for another courier service, so that we may ship the Materials to you. 
 The Materials are to be used with caution and prudence in any experimental
work, since all of their characteristics are not known. Moreover, they are not to be used for testing in or treatment of humans. 
 If you agree to
accept these Materials under the above conditions, please sign the enclosed duplicate copy of this letter, have it signed by an authorized representative of [Sponsor’s name] and return one original to me. Upon receipt of that confirmation I
will forward the Materials to you. 
 THE SCRIPPS RESEARCH INSTITUTE 

 

	
	
	 Scott Forrest

	 Senior Director, Technology Development

	 [Date]


 ACCEPTED: 
  

					
	 Recipient’s Signature
	 		    	 Authorized Institutional Rep. Signature

			
		 		    	
	 Recipient’s Printed Name and Title
	 		    	 Authorized Rep. Printed Name and Title

			
		 		    	
	 Date
	 		    	 Date














 FIRST AMENDMENT to 

RESEARCH FUNDING AND OPTION AGREEMENT 

This First Amendment (“Amendment”) is entered into effective as of the last date set forth below and is made to RESEARCH FUNDING AND
OPTION AGREEMENT dated July 31, 2014 (the “Agreement”) by and between THE SCRIPPS RESEARCH INSTITUTE, a California nonprofit public benefit corporation (“TSRI”), and SYNTHORX, INC., a Delaware corporation
(“Sponsor”). Capitalized terms used but not defined herein shall have the same meanings set forth in the Agreement. 

WHEREAS, the Parties desire to make certain amendments to the Agreement under the terms and conditions contained herein; 

NOW, THEREFORE, the Parties agree to amend the Agreement as follows: 

 

	1	 Sponsor and TSRI agree Section 2.4 (a) of the Agreement shall be revised to add the following payments
to the payment schedule: 



							
		 	 5th payment:
	 	due: [...***...]	  	amount (USD): $[...***...]
		 	 6th payment:
	 	due: [...***...]	  	amount (USD): $[...***...]
		 	 7th payment:
	 	due: [...***...]	  	amount (USD): $[...***...]
		 	 8th payment:
	 	due: [...***...]	  	amount (USD): $[...***...]

  

	2.	 Exhibit B-2 below shall be added to Exhibit B and is hereby
incorporated by reference. 


  

	3.	 Section 7.1 shall be deleted in its entirety and replaces as follows:  



Term.       Unless terminated sooner, the initial term of this Agreement
shallcommence on the Effective Date and shall continue until the earlier of (a) thesecond (2nd) anniversary of the Effective Date, and (b) the completion of theResearch Program, unless
extended by written mutual agreement of the parties. 
  

	4.	 The Research Program in Exhibit A of the Agreement shall be expanded by the research described in Exhibit A-1 below. 


 Except as expressly set forth herein, all of the terms and provisions of
the Agreement shall remain in full force and effect. 
 IN WITNESS WHEREOF, the Parties have executed this Amendment by their duly
authorized representatives as of the last date set forth below. 
  

									
	 TSRI:    
	 		 	Sponsor:                
	  
 THE SCRIPPS
RESEARCH INSTITUTE
	 		 	  
 SYNTHORX, INC.

			
		 		 	
	 By: /s/ Scott
Forrest                            
	 		 	By: /s/ Court
Turner                        
	             Scott
Forrest
	 		 	       Court Turner

			
	 Title: VP, Business Development
	 		 	Title: Chief Executive Officer
					
		 		 		 		 	
	 Date:
9/2/2015                                     
	 		 	Date:
9/2/2015                                


  
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 Exhibit A-1 

[...***...] 

  
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 Exhibit B-2 

Synthorx 
 Principal
Investigator/Program Director (Last, First, Middle): Romesberg, Floyd 

 
  

BUDGET 
  

									
	 	 	 
	
PERSONNEL (Applicant organization only)
	  	 %

 
 EFFORT

 
 ON

 
	  	 	YEAR 2	 
	  

NAME
	  	 ROLE ON

 
 PROJECT
	  	   


	
            SALARY/             

FRINGE
	   

 

	 	 	 	 
	 Romesberg,
Floyd
	  	Principal	  	[...***...]	  	 	[...***...]	 
	 	 	 	 
	 Chin,
Jodie
	  	Research Scientist	  	[...***...]	  	 	[...***...]	 
	 	 	 	 
	 Technician,
TBN
	  	Technician	  	[...***...]	  	 	[...***...]	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 
	
SUBTOTAL   




	  	 	[...***...]	 
		 
	 EQUIPMENT (Itemize)

 
	  	 	 	 
		 
	 SUPPLIES (itemize by category)

 
 Bio/chemicals, molecular biology kits, enzymes, disposable plasticware (tubes,
trays, pipette tips), bacterial and yeast growth media components
  
	  	 


	


[...***...]	


 
		 
	 TRAVEL

 
	  	 	 	 
		 
	 OTHER EXPENSES (itemize by category)

 
 DNA synthesis; DNA sequencing; access fees for NMR and MS characterizations

 
	  	 



	



[...***...]	



 
				 
	 TOTAL COSTS   




  
	  	 	  	 	  	$	              [...***...]	 


  
 ***Confidential
Treatment Requested 













 SECOND AMENDMENT to 

RESEARCH FUNDING AND OPTION AGREEMENT 

This Second Amendment (“Amendment”) is entered into effective as of the last date set forth below and is made to RESEARCH FUNDING AND
OPTION AGREEMENT dated July 31, 2014 (the “Agreement”) by and between THE SCRIPPS RESEARCH INSTITUTE, a California nonprofit public benefit corporation (“TSRI”), and SYNTHORX, INC., a Delaware
corporation(“Sponsor”). Capitalized terms used but not defined herein shall have the same meanings set forth in the Agreement. 

WHEREAS, the Parties desire to make certain amendments to the Agreement (as amended) under the terms and conditions contained herein; 

NOW, THEREFORE, the Parties agree to amend the Agreement as follows: 
  

	1.	 Sponsor and TSRI agree Section 2.4 (a) of the Agreement shall be revised to add the following payments
to the payment schedule: 


  

							
		 	 9th payment:
	 	 due: [...***...]
	  	amount (USD): $[...***...]
		 	 10th payment:
	 	 due: [...***...]
	  	amount (USD): $[...***...]
		 	 11th payment:
	 	 due: [...***...]
	  	amount (USD): $[...***...]
		 	 12th payment:
	 	 due: [...***...]
	  	amount (USD): $[...***...]

  

	2.	 Exhibit B-2 below shall be added to Exhibit B and is hereby
incorporated by reference. 


  

	3.	 Section 7.1 shall be deleted in its entirety and replaces as follows: 



Term. Unless terminated sooner, the initial term of this Agreement shall commence on the Effective Date
and shall continue until the earlier of (a) the third (3rd) anniversary of the Effective Date, and (b) the completion of the Research Program, unless extended by written mutual agreement
of the parties. 
  

	4.	 The Research Program in Exhibit A of the Agreement shall be expanded by theresearch described in Exhibit A-1 below. 


 Except as expressly set forth herein, all of the terms and provisions of
the Agreement shall remain in full force and effect. 
 IN WITNESS WHEREOF, the Parties have executed this Amendment by their duly authorized
representatives as of the last date set forth below. 
  

					
	 TSRI:
	 		  	 Sponsor.

			
	 THE SCRIPPS RESEARCH INSTITUTE
	 		  	 SYNTHORX, INC.

			
	 By: /s/ Julia
Roufer                                        
  
	 		  	 By: /s/ Court R.
Turner                                

		 		  	             Court R. Turner

	 Title:    Executive Director
	 		  	
	              Business Development
	 		  	 Title:  Chief Executive Officer

			
	
Date:    9/9/16                
                                    
	 		  	 Date:  
9/9/16                                        
       



  
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 Exhibit A-1 

[...***...] 

  
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 Exhibit B-2 

Synthorx 
 Principal
Investigator/Program Director (Last, First, Middle): Romesberg, Floyd 

 
  

BUDGET 
  

									
	 	 	 
	 PERSONNEL (Applicant organization only)
	  	 %

 
 EFFORT

 
 ON

 
	  	 	YEAR 2	 
	  

NAME
	  	  

ROLE ON
  

PROJECT
  
	  	 
 
	            SALARY/         
   
 FRINGE
	 

 

	
Romesberg, Floyd
	  	Principal	  	[...***...]	  	 	[...***...]	 
	 	 	 	 
	 Chin,
Jodie
	  	Research Scientist	  	[...***...]	  	 	[...***...]	 
	 	 	 	 
	 Technician,
TBN
	  	Technician	  	[...***...]	  	 	[...***...]	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 
	
SUBTOTAL  




	  	 	[...***...]	 
		 
	 EQUIPMENT (Itemize)

 
	  	 	 	 
		 
	 SUPPLIES (Itemize by category)

 
 Bio/chemicals, molecular biology kits, enzymes, disposable plasticware (tubes,
trays, pipette tips), bacterial and yeast growth media components
  
	  	 	[...***...]	 
		 
	 TRAVEL

 
	  	 	 	 
		 
	 OTHER EXPENSES (Itemize by category)

 
 DNA synthesis; DNA sequencing; access fees for NMR and MS
characterizations
  
  
	  	 	[...***...]	 
				 
	   TOTAL COSTS  




	  	 	  	 	  	 	$[...***...]	 


  
 ***Confidential
Treatment Requested 














 CONFIDENTIAL 
  

 THIRD AMENDMENT to 

RESEARCH FUNDING AND OPTION AGREEMENT 

This third Amendment (“Third Amendment”), entered into and made effective as of the last dated signature below, is made to RESEARCH
FUNDING AND OPTION AGREEMENT dated July 31st, 2014 (the “Agreement”) by and between THE SCRIPPS RESEARCH INSTITUTE, a California nonprofit public benefit corporation (“TSRI”), and SYNTHORX, INC., a Delaware corporation
(“Sponsor”). Capitalized terms used but not defined herein shall have the same meanings set forth in the Agreement. 
 WHEREAS,
the Parties desire to make certain amendments to the Agreement (as amended) under the terms and conditions contained herein; 
 NOW,
THEREFORE, the Parties agree to amend the Agreement as follows: 
  

	1	 Section 1.2 of the Agreement shall be deleted in its entirety and replaced as follows:



  

	 	1.2	 Agreement Number. The original Agreement has been assigned TSRI agreement number 2014-0475, the first
amendment has been assigned TSRI agreement number 2015-0949, the second amendment has been assigned TSRI agreement number 2016-0927, and this Third Amendment has been assigned TSRI agreement number 2017-0685. 



 

	2.	 In accordance with Exhibit B-1 and with the preceding amendments
referenced above, Section 2.4 (a) of the Agreement shall be revised to add the following payments to the payment schedule: 


  

							
		 	 13th payment:
	  	due: [...***...]	  	amount (USD): $[...***...]
		 	 14th payment:
	  	due: [...***...]	  	amount (USD): $[...***...]
		 	 15th payment:
	  	due: [...***...]	  	amount (USD): $[...***...]
		 	 16th payment:
	  	due: [...***...]	  	amount (USD): $[...***...]

  

	3.	 Exhibit B-2 below shall be added to Exhibit B and is hereby
incorporated by reference. 


  

	4.	 Section 7.1 shall be deleted in its entirety and replaced as follows: 



 

	 	7.1	 Term. Unless terminated sooner, the initial term of this Agreement shall commence on the Effective
Date and shall continue until the earlier of (a) the fourth (4th) anniversary of the Effective Date, and (b) the completion of the Research Program, unless extended by written mutual agreement of the parties. 



 

	5.	 The Research Program in Exhibit A of the Agreement shall be expanded by the research described in Exhibit A-1 below. 


 Except as expressly set forth herein, all of the terms and provisions of
the Agreement shall remain in full force and effect. 
 IN WITNESS WHEREOF, the Parties have executed this Third Amendment by their duly
authorized representatives as of the last date set forth below. 

  
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 CONFIDENTIAL 
  


									
	 TSRI:
	 		 	Sponsor:                
			
	 THE SCRIPPS RESEARCH INSTITUTE
	 		 	SYNTHORX, INC.
			
	 By: /s/ Matt Tremblay
                                    
	 		 	By: /s/ Tighe
Reardon                                
	
                   
       Matt Tremblay
	 		 	
                      Tighe
Reardon

			
	 Title: VP, Business Development
	 		 	Title: Chief Financial Officer
		 		 		 		 	
	 Date: October 16, 2017
                                         
 
	 		 	Date: October 6, 2017
                                    


  
 Page 2 of 6 














 CONFIDENTIAL 
  

 Exhibit A-1 

[...***...] 

  
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 CONFIDENTIAL 
  

 Exhibit B-1 

Synthorx 
 Principal
Investigator/Program Director (Last, First, Middle): Romesberg, Floyd 

 
  

BUDGET 
  

									
	 	 	 
	
PERSONNEL (Applicant organization only)
	  	 %

 
 EFFORT

 
 ON

 
	  	 	YEAR 2	 
	  

NAME
	  	 ROLE ON

 
 PROJECT
	  	   


	 SALARY/ 

FRINGE
	   

 

	
Romesberg, Floyd
	  	  

Principal
	  	[...***...]	  	 	[...***...]	 
	
Chin, Jodie
	  	  

Research Scientist
	  	[...***...]	  	 	[...***...]	 
	
Technician, TBN
	  	  

Technician
	  	[...***...]	  	 	[...***...]	 
	 	  	 	  	 	  	 	 	 
	 	  	 	  	 	  	 	 	 
	 	  	 	  	 	  	 	 	 
	 	  	 	  	 	  	 	 	 
	 	 
	
      SUBTOTAL   




	  	   
	 [...***...] 
	   

		 
	 EQUIPMENT (Itemize)

 
	  	 	 	 
		 
	 SUPPLIES (itemize by category)

 
 Bio/chemicals, molecular biology kits, enzymes, disposable plasticware
(tubes, trays, pipette tips), bacterial and yeast growth media components
	  	 


  
	


 [...***...] 
	


   

		 
	 TRAVEL

 
	  	 	 	 
	 	 
	 OTHER EXPENSES (itemize by category)

 
 DNA synthesis; DNA sequencing; access fees for NMR and MS characterizations

 
	  	 



	



[...***...]	



 
				 
	  DIRECT COSTS

 
	  	 	  	 	  	 	$        [...***...]	 
				 
	  INDIRECT COSTS @ [...***...] %

 
	  	 	  	 	  	 	$        [...***...]	 
				 
	  TOTAL COSTS  




  
	  	 	  	 	  	 	$        [...***...]	 


  
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 FOURTH AMENDMENT 

to 
 RESEARCH FUNDING AND OPTION
AGREEMENT 
 This Fourth Amendment (“Fourth Amendment”), entered into and made effective as of the last dated signature below, is made to RESEARCH
FUNDING AND OPTION AGREEMENT dated July 31st, 2014 (the “Agreement”) by and between THE SCRIPPS RESEARCH INSTITUTE, a California nonprofit public benefit corporation (“TSRI”), and SYNTHORX, INC., a Delaware corporation
(“Sponsor”). Capitalized terms used but not defined herein shall have the same meanings set forth in the Agreement. 
 WHEREAS, the Parties desire
to make certain amendments to the Agreement (as amended) under the terms and conditions contained herein; 
 NOW, THEREFORE, the Parties agree to amend the
Agreement as follows: 
  

	1.	 Section 1.2 of the Agreement shall be deleted in its entirety and replaced as follows: 



 

	 	1.2	 Agreement Number. The original Agreement has been assigned TSRI agreement number 2014-0475, the first amendment
has been assigned TSRI agreement number 2015-0949, the second amendment has been assigned TSRI agreement number 2016-0927, the Third Amendment has been assigned TSRI agreement number 2017-0685, and this Fourth Amendment has been assigned TSRI
agreement number 2018-0769. 


  

	2.	 In accordance with Exhibit B-1 and with the preceding amendments
referenced above, Section 2.4 (a) of the Agreement shall be revised to add the following payments to the payment schedule: 


  

							
		 	 17th payment:
	  	 due: [...***...]
	  	 amount (USD): $[...***...]

				
		 	 18th payment:
	  	 due: [...***...]
	  	 amount (USD): $[...***...]

				
		 	 19th payment:
	  	 due: [...***...]
	  	 amount (USD): $[...***...]

				
		 	 20th payment:
	  	 due: [...***...]
	  	 amount (USD): $[...***...]


  

	3.	 Exhibit B-1 below shall be added to Exhibit B and is hereby
incorporated by reference. 


  

	4.	 Section 7.1 shall be deleted in its entirety and replaced as follows: 



 

	 	7.1	 Term. Unless terminated sooner, the initial term of this Agreement shall commence on the Effective Date and
shall continue until the earlier of (a) the fifth (5th) anniversary of the Effective Date, and (b) the completion of the Research Program, unless extended by written mutual agreement of the parties. 



 

	5.	 The Research Program in Exhibit A of the Agreement shall be expanded by the research described in Exhibit A-1 below. 



  
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 Except as expressly set forth herein, all of the terms and provisions of the Agreement shall remain in full
force and effect. 
 In WITNESS WHEREOF, the Parties have executed this Fourth Amendment by their duly authorized representatives as of the last date set
forth below. 
  

			
	 TSRI:
	  	 Sponsor:

	 THE SCRIPPS RESEARCH INSTITUTE
	  	 SYNTHORX, INC.

		
	 By: /s/ Daniel
Catron                                        
 
	  	 By: /s/ Laura Shawver,
Ph.D.            

		
	 Name: Daniel Catron
	  	 Name: Laura Shawver, Ph.D.            

		
	 Title: Director, Office of Technology Development
	  	 Title: Chief Executive Officer           

		
	 Date:
8/16/2018                                        
         
	  	 Date:
8/16/2018                                 














 Exhibit A-1 

[...***...] 

  
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 Exhibit B-1 

Synthorx 
 Principal
Investigator/Program Director (Last, First, Middle):         Romesberg, Floyd 
  
  

BUDGET 
  

							
	 	 	 
	  

PERSONNEL (Applicant organization only)
	  	 %

 
 EFFORT
ON
PROJ.
	 	YEAR 1
	
NAME
	  	  
 ROLE
ON
PROJECT
	 	
            SALARY/            

FRINGE

	 Romesberg, Floyd
	  	Principal
Investigator	  	[...***...]	 	[...***...]
	 Chin, Jodie

 
	  	Research Scientist	  	[...***...]	 	[...***...]
	 Technician, TBN

 
	  	Technician	  	[...***...]	 	[...***...]
	  

SUBTOTAL  




  
	 	[...***...]
	  EQUIPMENT (Itemize)

 
	 	 
	
 SUPPLIES (Itemize by category)
	 	 
	
Bio/chemicals, molecular biology kits, enzymes, disposable plasticware (tubes, trays, pipette tips), bacterial and yeast growth media components

 
	 	[...***...]
	  TRAVEL

 
	 	 
	
 OTHER EXPENSES (Itemize by category)
	 	 
	
DNA synthesis, DNA sequencing, access fees for NMR and MS characterizations

 
	 	[...***...]
	  

 DIRECT COSTS
  
	 	$            
[...***...]
	  

 INDIRECT COSTS @ [...***...] %

 
	 	$           
 [...***...]
	  

 TOTAL COSTS  




  
	 	$           
 [...***...]


  
 ***Confidential Treatment
Requested