Document:

EX-10.9

 Exhibit 10.9 

SPONSORED RESEARCH AGREEMENT NO. UTA13-001113 

This Sponsored Research Agreement (“Agreement”) is made between The University of Texas at Austin, Austin, Texas (“University”), an
institution of higher education created by the Constitution and law of the State of Texas under The University of Texas System (“System”) and Aeglea Development Company, Inc., AERase, Inc., AEMase, Inc., AECase, Inc., AE4ase, Inc., AE5ase,
Inc., and AE6ase, Inc., all Delaware C corporations with their principal place of business at 815 A Brazos St., #101, Austin TX 78701 (each a “Sponsor Entity” and collectively, “Sponsor”). Aeglea Development Company, Inc. may be
referred to herein as the “Funding Sponsor” or “Sponsor Entity” as appropriate. 
 RECITALS 

A. Sponsor desires that University perform certain research work hereinafter described and is willing to advance funds to sponsor such
research; 
 B. Sponsor desires to obtain certain rights to patents and technology developed during the course of such research with a view
to profitable commercialization of such patents and technology for the Sponsor’s benefit; and 
 C. University is willing to perform
such research and to grant rights to such patents and technology; 
 NOW THEREFORE, in consideration of the mutual covenants and promises herein contained,
the University and Sponsor agree as follows: 
 1. EFFECTIVE DATE 

This Agreement shall be effective as of December 1, 2013 (the “Effective Date”). 

2. RESEARCH PROGRAM 

2.1 University will use reasonable efforts to conduct the Research Program described in Attachment A (“Research Program”), and will furnish the
facilities necessary to carry out said Research Program. The Research Program will be under the direction of Professor George Georgiou (“Principal Investigator”), or (his or her) successor as mutually agreed to by the parties and
will be conducted by the Principal Investigator at the University. University agrees to use reasonable efforts to perform the Research Program in a manner consistent with its status as an institution of higher education. University shall perform the
Research Program in accordance with (i) established University policies and procedures, including, but not limited to, policies and procedures applicable to research involving human subjects, human tissues or organs, laboratory animals, and
hazardous agents and materials, and (ii) all applicable federal, state, and local laws, rules, regulations and guidelines. 
  

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

 2.2 The Research Program shall be performed during the period from the Effective Date for a period of 12 month
periods thereafter (the “Research Term”). Funding Sponsor shall have the option of extending the Research Program under mutually agreeable support terms. 

2.3 Sponsor understands that University’s primary mission is education and advancement of knowledge, and consequently the Research Program will be
designed to carry out that mission. The manner of performance of the Research Program shall be determined solely by the Principal investigator. University does not guarantee specific results, and the Research Program will be conducted only on a
reasonable efforts basis. 
 2.4 University will keep accurate financial and scientific records relating to the Research Program and will make such records
available to Sponsor or its authorized representative throughout the Term of the Agreement during normal business hours upon reasonable notice. 
 2.5
Sponsor understands that University may be involved in similar research on behalf of itself and others. University shall be free to continue such research provided that it is conducted separately from the Research Program hereinafter defined, and
Sponsor shall not gain any rights via this Agreement to such other research. 
 2.6 University does not guarantee that any patent rights will result from
the Research Program, that the scope of any patent rights obtained will cover Sponsor’s commercial interests, or that any such patent rights will be free of dominance by other patents, including those based upon inventions made by other
inventors in The University of Texas System independent of the Research Program. 
 3. COMPENSATION 

3.1 Sponsor obligations under this Article 3 shall be limited to Funding Sponsor. 

3.2 As consideration for the performance by University of its obligations under this Agreement, Funding Sponsor will pay the University an amount equal to its
reasonable, documented expenditures and reasonable overhead (such overhead to not exceed the rate set forth in University’s indirect rate agreement with the U.S. Federal Government) in conducting the Research Program subject to a maximum
expenditure limitation of $386,252, provided that in any and all events, the amounts charged by University shall not, without Funding Sponsor’s prior written consent, exceed the amount. Payments shall be made as follows (subject to the possible
later return of funds if uncommitted and unexpended, under Section 3.3): 
  

	 	(a)	Upon execution of all parties to the Agreement: $193,126; 

  

	 	(b)	$96,563 by March 31, 2014; and 

  

	 	(c)	$96,563 by June 30, 2014 

 Payments should be made within 30 days of the receipt of an undisputed invoice
sent via mail and email and payable to The University of Texas at Austin, make reference to the Principal Investigator, Agreement number and title of the Research Program funded under this Agreement, and submitted to the address in
Article 3.5. 
  
  

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

  
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 3.3 University shall maintain all Research Program funds in a separate account and shall expend such funds for
wages, supplies, equipment, travel, and other operational expenses in connection with the Research Program. It is understood that funds of the Research Program which are not used in a particular quarter may be used in subsequent quarters, and that
the Principal Investigator may transfer funds within the budget as needed without Funding Sponsor’s approval, as long as such transfers do not effect a change in the scope of work of the Research Program. It is also understood that subject to
Section 10.4, uncommitted and unexpended funds remaining at the termination of the Agreement shall be returned to Funding Sponsor within ninety (90) days of the effective date of termination; provided, however, that the parties agree that
in order to minimize administrative close-out expenses, if funds remaining upon termination or expiration of the Agreement equal $250.00 or less, such funds shall be retained by the University and disposed of in accordance with University policy.

 3.4 University shall retain title to all equipment purchased and/or fabricated by it with funds provided by Funding Sponsor under this Agreement. 

3.5 
  

			
	 Checks shall be made payable to University

and sent to:
		 Invoices shall be mailed and emailed to

Funding Sponsor at:

	 The University of Texas at Austin

Office of Accounting — SPAA
		 Aeglea Development Company

815-A Brazos, Ste_#101

	 P.O. Box 7159
		 Austin TX 78701

	 Austin, Texas 78713-7159
		 Attn: David G. Lowe

	 (512) 471-6231
		 Phone: [phone]

	Tax ID #: 746000203		 Fax: (866) 873-2149

			 E-mail: [email]

 4. CONSULTATION AND REPORTS 

4.1 Sponsor’s designated representative (“Designated Representative”) for consultation and communications with the Principal Investigator shall
be David G. Lowe or such other person as Sponsor may from time to time designate in writing to University and the Principal Investigator. 
 4.2
During the term of the Agreement, Sponsor’s representatives may consult informally with University’s representatives regarding the project, both personally and by telephone. Access to work carried on in University laboratories in the
course of these investigations shall be entirely under the control of University personnel but shall be made available on a reasonable basis. 
 4.3 The
Principal Investigator will make up to one oral report(s) monthly and quarterly written reports accompanied by a presentation describing the results and accomplishments obtained and plans going forward. Changes or amendments to the Research Program
if any, will be discussed at the quarterly meeting and described in a written amendment to the Research 
  

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

  
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Program as requested by Sponsor’s Designated Representative. The Principal Investigator shall also submit a comprehensive final report within ninety (90) days of termination of the
Agreement which shall consist of a report of all activities undertaken and accomplishments achieved through the Research 

5. PUBLICITY 

Neither party shall make reference to the other in a press release or any other written statement in connection with work performed under this Agreement, if
it is intended for use in the public media, except as required by the Texas Public Information Act or other law or regulation. University, however, shall have the right to acknowledge Sponsor’s support of the investigations under this Agreement
in scientific or academic publications and other scientific or academic communications, without Sponsor’s prior approval. In any statements, the scope and nature of participation shall be described accurately and appropriately. 

6. PUBLICATION AND ACADEMIC RIGHTS: CONFIDENTIALITY 

6.1 University and the Principal Investigator have the right to publish or otherwise publicly disclose information gained in the course of this Agreement,
except for Sponsor’s Confidential Information. In order to avoid loss of patent rights as a result of premature public disclosure of patentable information, University will submit (a) any prepublication materials and (b) a copy of any
materials to be publicly disclosed to Sponsor for review and comment thirty (30) days in advance of its planned submission for publication or public disclosure to the extent possible, but in the case of any requests under the Texas Public
Information Act, prior to release of any information to the requestor. Funding Sponsor may request in writing, and University shall agree to, (i) the deletion of any Confidential Information provided by Sponsor, and (iii) a delay of such
proposed publication or public disclosure for an additional period, not to exceed sixty (60) days, in order to protect the potential patentability of any technology described therein. Funding Sponsor shall be entitled to receive in any such
publication or public disclosure an acknowledgment of its sponsorship of the Research Program. University shall have final authority to determine the scope and content of any publications or disclosures provided that in no event shall any
publication or disclosure include Sponsor’s Confidential Information. 
 6.2 It is anticipated that inventions or discoveries arising from the Research
Program (“Inventions”) shall be discussed with Funding Sponsor concurrently with their reduction to practice by the Principal Investigator. It is understood that the University investigators may discuss the research being performed under
this Agreement with other University investigators but shall not reveal Confidential Information to such investigators unless such investigators have signed a nondisclosure agreement. 

6.3 In conjunction with the Research Program, Sponsor may wish to disclose certain of its confidential and/or proprietary information (“Confidential
Information”) to University during the term of this Agreement. Confidential Information will be transmitted in writing and clearly marked “Confidential,” “Proprietary,” or similarly, or if disclosed orally will be reduced to

  
  

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

  
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writing by Disclosing Party, clearly marked “Confidential,” “Proprietary,” or similarly, and transmitted to the Contact Person of Receiving Party within thirty (30) days
after oral disclosure. No license under or title to any invention, patent, trademark, trade name or other intellectual property or other rights or interests in the Confidential Information now or hereafter owned by or controlled by any Party is
granted either expressly, by implication, estoppel or otherwise by the Agreement. All Confidential Information is provided “AS IS” and without warranty, express or implied, of any kind. 

University will use Confidential Information solely for the purpose of conducting the Research Program, and shall use reasonable efforts to
prevent the disclosure of Confidential Information to third parties during the term of this Agreement and for a period of five (5) years after its expiration or termination. If required, University may disclose Confidential Information to a
governmental authority or by order of a court of competent jurisdiction, provided that such disclosure is subject to all applicable governmental or judicial protection available for like information and reasonable advance notice is given to Funding
Sponsor. University’s obligations with respect to Confidential Information shall not apply to information that (a) is already in University’s possession at the time of disclosure; (b) is or later becomes part of the public domain
through no fault of University; (c) is received on a non-confidential basis from a third party having no obligations of confidentiality or nonuse to University’s; or (d) independently developed by University. Notwithstanding the
foregoing, University may retain one archival copy of the Confidential Information received in a secure location to be used solely to determine its obligations under the Agreement. 

The Parties agree that, in the event of breach or threatened breach or intended breach of the Agreement, each Party, in addition to any other
rights and remedies available to it at law or in equity, may seek injunctive or equitable relief without the necessity of posting bond or proving that it has no adequate remedy at law. 

7. PATENTS, COPYRIGHTS AND TECHNOLOGY RIGHTS 

7.1 Title to Inventions conceived and reduced to practice solely by University shall reside in University (“University Inventions”). Title to all
Inventions conceived and reduced to practice solely by Sponsor shall reside in Sponsor (“Sponsor Inventions”). Title to all inventions and discoveries conceived and reduced to practice jointly by Sponsor and University shall reside jointly
in Sponsor and University (“Joint Inventions”). University hereby grants to Sponsor an exclusive first option to negotiate a royalty- bearing exclusive license for any invention or discovery that is conceived or reduced to practice during
the term of this Agreement directly resulting from the performance of research hereunder to the extent that University is able to do so under applicable law. It is contemplated that, in the majority of instances, Sponsor will be asked to determine
whether it will exercise its option prior to the filing of the first patent application. University reserves for itself a royalty-free, irrevocable license to make and use such University Inventions and Joint Inventions for its own research and
educational purposes, but not for commercial purposes during the option period. If a University Invention or Joint Invention arises from the Research Program, the Principal Investigator shall promptly submit an invention 

 
  

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

  
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disclosure (http://www.otc.utexas.edu/InventorForms.jsp) to University’s Office of Technology Commercialization (“OTC”). University will provide to Sponsor a full copy of
such disclosure promptly after such disclosure is received by OTC. Sponsor may review (and University shall provide to Sponsor) any and all patentability and freedom to operate opinions that have been commissioned by the University. A Sponsor Entity
shall then have ninety (90) days from receipt of such disclosure of any University Invention or Joint Invention to notify University of its desire to enter into such a license agreement, and a non-binding term sheet and thereafter a license
agreement shall be negotiated in good faith within a period not to exceed six (6) months (“License Option Period”) from the applicable Sponsor Entity’s notification to University of its desire to enter into a license agreement,
or such period of time as the parties shall mutually agree in writing. The parties agree to negotiate, in good faith, a license agreement with terms and conditions substantially similar to existing license agreements between the parties, to the
extent allowed by current law, University policy, and reasonable updates to financial terms. During the License Option Period, University agrees that it will not offer its rights in University Inventions or Joint Inventions to any third party or
negotiate with third parties with respect to those rights. If the parties fail to enter into a license agreement within the License Option Period under the provisions of this Section 7.1, University rights in University Inventions and Joint
Inventions shall be disposed of in accordance with University policies with no further obligations to Sponsor. 
 7.2 “Background Intellectual
Property” (“BIP”) means intellectual property and the legal rights therein (including, but not limited to, inventions, patent applications, patents, copyrights, and any information embodying proprietary data such as technical data and
computer software) of University developed or created by Principal Investigator(s) before the Effective Date of the Research Program and necessary for the full exercise of all intellectual property which is related to the Research Program.
University BIP is listed in Attachment B of this Agreement. The Parties agree that nothing in this Agreement grants either Party any rights to any background intellectual property of the other Party created before the Effective Date of the
Agreement. 
 7.3 The applicable Sponsor Entity has the right to elect to have patent applications filed on any University Invention or Joint Invention, and
if it does so, then such Sponsor Entity shall reimburse University for all documented, out-of-pocket patent expenses incurred by University, including those for patentability opinions, within thirty (30) days of such Sponsor Entity’s
receipt of an invoice from University. Such patent expenses shall include, but not be limited to, the cost of any prior activities investigating patentability of said invention before exercise of the option, such as search and opinion for
patentability, that may have been performed by University pursuant to its arrival at a judgment of commercially exploitable status. Following expiration of the License Option Period, and in the event that University grants a license to any
University Inventions to a third party (the “Third Party License”), University shall pay to the applicable Sponsor Entity its reasonable costs incurred in connection with the preparation, filing, prosecution and maintenance of the licensed
University Inventions or Joint Inventions paid under the Third Party License with the following priority for payment: i) in one full payment from the fees reimbursed to University by a third party under the executed license; or if necessary, ii) on
a quarterly basis, a royalty (the “Third Party Royalty”) equal to one hundred percent (100%) of 
  

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

  
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University’s net licensing revenue attributable to the Third Party License (including license fees, royalties, revenue sharing, milestone payments and other monetary payments) until such
time as University has paid to such Sponsor Entity aggregate Third Party Royalties equal to such Sponsor Entity’s reasonable costs incurred in connection with the preparation, filing, prosecution and maintenance of the licensed University
Inventions. 
 7.4 At its discretion, University may allow the applicable Sponsor Entity to instruct Prosecution Counsel directly for University Inventions
and Joint Inventions, provided, that prior written approval is obtained and the Prosecution Counsel remains counsel to the University with an appropriate contract (and shall not jointly represent such Sponsor Entity unless requested by such Sponsor
Entity and approved by University, not to be unreasonably denied, and an appropriate engagement letter and conflict, waiver are in effect). If such Sponsor Entity wishes to instruct Prosecution Counsel directly or change Prosecution Counsel, such
Sponsor Entity may request to do so by following the University’s procedures for such. Subject to the terms herein University reserves in its sole discretion the ability to change Prosecution Counsel and to approve or disapprove any requested
changes by such Sponsor Entity. The Parties agree that they share a common legal interest to get valid enforceable patents in strategically important countries and that both Parties will maintain as privileged all information received pursuant to
this Section 7. Each Party agrees to cooperate fully in the preparation, filing, and prosecution of any patent and any joint patent, as described herein. Such cooperation includes without limitation executing all papers and instruments, or requiring
its representatives to execute such papers and instruments, so as to effectuate the ownership of such intellectual property rights. 
 7.5 Notwithstanding
anything to the contrary set forth herein, University hereby grants to Sponsor a perpetual, irrevocable, worldwide, non-exclusive, royalty free right and license, with the right to sublicense to third parties through multiple tiers, to use the Data
and Results for any and all purposes. Data and Results mean all data, information and results arising from the Research Program that are included in the Research Program deliverables but are not inventions and discoveries for which a patent
invention disclosure is made. 
 8. LIABILITY 

8.1 Sponsor agrees to defend (and subject to the statutory duties of the Texas State Attorney General to defend University, if applicable),indemnify and hold
harmless System, University, their Regents, officers, agents and employees from any liability, loss or damage they may suffer as a result of third party claims, demands, costs or judgments against them arising out of the activities to be carried out
pursuant to the obligations of this Agreement, including but not limited to the use by Sponsor of the results obtained from the activities performed by University under this Agreement; provided, however, that the following is excluded from
Sponsor’s obligation to defend, indemnify and hold harmless: 
  

	 	(a)	the negligent failure of University to substantially comply with any applicable FDA or other governmental requirements; or 

  

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

  
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	 	(b)	the negligence or willful malfeasance of any Regent, officer, agent or employee of University or System 

 8.2
To the extent authorized by the constitution and laws of the State of Texas, University agrees to defend, indemnify and hold harmless Sponsor, its officers, agents and employees from any liability, loss or damage they may suffer as a result of third
party claims, demands, costs or judgments against them arising out of (i) the negligence or willful malfeasance of any Regent, officer, agent or employee of University or System or (ii) breach of this Agreement by any Regent, officer,
agent or employee of University or System, provided, however, that University shall not be obligated to hold harmless any Sponsor Indemnitee from claims arising out of the negligence or willful malfeasance of Sponsor. 

8.3 Both parties agree that upon receipt of a notice of claim or action arising out of the activities to be carried out pursuant to the Research Program, the
party receiving such notice will notify the other party promptly. 
 9. INDEPENDENT CONTRACTOR 

For the purposes of this Agreement and all services to be provided hereunder, the parties shall be, and shall be deemed to be, independent contractors and not
agents or employees of the other party. Neither party shall have authority to make any statements, representations or commitments of any kind, or to take any action which shall be binding on the other party, except as may be expressly provided for
herein or authorized in writing. 
 10. TERM AND TERMINATION 

10.1 This Agreement shall commence on the Effective Date and extend until the end of the Research Term, unless sooner terminated in accordance with the
provisions of this Article 10. 
 10.2 This Agreement may be terminated by Sponsor for its convenience upon sixty (60) days prior written notice to
University. 
 10.3 In the event that either party shall be in default of its material obligations under this Agreement and shall fail to remedy such
default within sixty (60) days after receipt of written notice thereof, this Agreement may be terminated at the option of the party not in default upon expiration of the sixty (60) day period. 

10.4 This Agreement shall terminate automatically and immediately if Sponsor becomes bankrupt or insolvent and/or enters receivership or trusteeship, whether
by voluntary act of Sponsor or otherwise. 
 10.5 Termination or cancellation of this Agreement shall not affect the rights and obligations of the parties
accrued prior to termination. Upon termination, (i) Sponsor shall pay University for all reasonable expenses incurred or committed to be expended due pursuant to Section 3 hereof as of the effective termination date, including salaries for
appointees for the remainder of their 
  
  

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

  
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appointment and (ii) University shall return to Sponsor or destroy any Confidential Information in its possession or control, subject to University’s right to keep an archival copy
pursuant to Section 6.3. 
 10.6 Any provisions of this Agreement which by their nature extend beyond termination shall survive such termination
including, without limitation, Sections 6 and 7. 
 10.7 This Agreement will terminate with respect to any individual Sponsor Entity at such time as it is
no longer a wholly owned subsidiary of Aeglea BioTherapeutics Holdings LLC and upon such a termination the respective Sponsor Entity shall be removed as a party to this Agreement. Sponsor will provide prompt written notice of the same to University.

 11. ATTACHMENTS 

Attachments A and B are incorporated and made a part of this Agreement for all purposes. 

12. USE OF HUMAN SUBJECTS (if applicable) 

12.1 University will conduct all research in accordance with Federal Wide Assurance #2030, written protocol, applicable law, and University’s ethical
standards. In the event a research participant has a research related injury neither University nor the Sponsor are responsible for any resulting medical care. 

12.2 If the Sponsor is responsible for monitoring research, then the Sponsor must alert University’s Institutional Review Board (“IRB”) when
research findings: 
  

	 	(a)	Affect the safety of the participants 

  

	 	(b)	Affect the willingness of research participants to continue participation 

  

	 	(c)	Influence the conduct of the study 

  

	 	(d)	Alter the IRB’s approval for the study 

 12.3 In the event research findings indicate that current and
past participants are at increased risk that was not anticipated at the time of the study design, the Principal Investigator, in accordance with both University IRB Policy and Procedures and the informed consent agreement, will immediately inform
research participants of risk alteration. 
 13. GENERAL 

13.1 Neither Party can assign its rights under this Agreement without the prior written consent of the other Party, which consent will not be unreasonably
withheld. Notwithstanding the foregoing, no such consent shall be needed for a assignment by any Sponsor Entity to another Sponsor Entity of part or all of the assigning Sponsor Entity’s interest. After a Party has received 

 
  

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

  
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a written request for consent to assign, the receiving Party will respond in writing within thirty (30) days. If the receiving Party does not respond in writing within thirty (30) days, that
Party’s silence will be deemed to mean that the receiving Party consents to the assignment. Any assignment made without the written or deemed consent of the non-assigning Party will be null and void. Subject to the approval of University, which
may not be unreasonably withheld, Sponsor is permitted to assign this Agreement in connection with a merger or a sale or transfer of substantially all of its assets; provided, however, that such assignee shall have expressly assumed all of the
obligations and liabilities of Sponsor under this Agreement, and provided, further that, University may assign its right to receive payments hereunder. 

13.2 This Agreement constitutes the entire and only agreement between the parties relating to the Research Program, and all prior negotiations,
representations, agreements and understandings are superseded hereby. No agreements altering or supplementing the terms hereof may be made except by means of a written document signed by the duly authorized representatives of University and Funding
Sponsor. Terms and conditions which may be set forth (front, reverse, attached or incorporated) in any purchase order issued by Sponsor in connection with this Agreement shall not apply, except for informational billing purposes; i.e., reference to
purchase order number, address for submission of invoices, or other invoicing items of a similar informational nature. 
 13.3 Any notice required by this
Agreement by Articles 7, 8 or 10 shall be given prepaid, first class, certified mail, return receipt requested, addressed in the case of University to: 

The University of Texas System, O.G.C. 

201 West 7th Street 
 Austin, Texas
78701 
 Attention: Intellectual Property Section 

Phone: (512) 499-4462 
 FAX:
(512) 499-4523 
 Vice President for Research 

The University of Texas at Austin 

P.O. Box 7996, Mail Code G1400 

Austin, Texas 78713 
 Attention:
Technology Licensing Specialist 
 Phone: (512) 471-2995 

FAX: (512) 475-6894 
  

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

  
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 or in the case of the Sponsor to: 

Aeglea Development Company, Inc. 

815-A Brazos St., #101 
 Austin TX
78701 
 Attn: David G. Lowe 

Phone: [phone] 
 FAX:
(866) 873-2149 
 E-Mail: [email] 
 or at
such other addresses as may be given from time to time in accordance with the terms of this notice provision. 
 Notices and other communications regarding
the day-to-day administration and operations of this Agreement shall be mailed (or otherwise delivered), addressed in the case of University to: 

The University of Texas at Austin 

Office of Industry Engagement 

North Office Building-A, Suite 5.2 

Post Office Box 7727, MC A9300 

Austin, Texas 78712-1736 

Attention: Bill Catlett, Director 

Phone: (512) 471-3866 
 FAX:
(512) 471-7839 
 E-mail: industry@austin.utexas.edu 

with a copy to: 
 Dr. George Georgiou 

The University of Texas at Austin 

Department of Chemical Engineering 

Austin, Texas 78712 
 Phone: [phone]

 E-Mail: gg@che.utexas.edu 
 or in the case of
Sponsor to: 
 Aeglea Development Company, Inc. 

815-A Brazos St., #101 
 Austin TX
78701 
 Attn: David G. Lowe 

Phone: [phone] 
 FAX:
(866) 873-2149 
 E-Mail: [email] 
  

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

  
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 13.4 This Agreement shall be governed by, construed, and enforced in accordance with the internal laws of the
State of Texas. 
 13.5 Each Party acknowledges that this Agreement and the performance thereof are subject to compliance with any and all applicable United
States laws, regulations, or orders, including those that may relate to the export of technical data, and each Party agrees to comply with all such laws, regulations and orders, including, if applicable, all requirements of the International Traffic
in Arms Regulations and/or the Export Administration Act, as may be amended. Sponsor further agrees that if the export laws are applicable, it will not disclose or re-export any technical data under this Agreement to any countries for which the
United States government requires an export license or other supporting documentation at the time of export or transfer, unless Sponsor has obtained prior written authorization from the U.S. Office of Export Control or other authority responsible
for such matters. 
 13.6 If any provision contained in this Agreement is held invalid, unenforceable or contrary to laws then the validity of the remaining
provisions of this Agreement shall remain in full force. In such instance, Parties shall use their best efforts to replace the invalid provision(s) with legally valid provisions having an economic effect as close as possible to the original intent
of Parties. 
 IN WITNESS WHEREOF, the parties have caused this Agreement to be executed by their duly authorized representatives. 

 

									
	THE UNIVERSITY OF TEXAS AT AUSTIN				AEGLEA DEVELOPMENT COMPANY, INC.
			
	/s/ Ty Helpinstill				/s/ David G. Lowe
	By: Ty Helpinstill				By: David G Lowe
					
	Title:		Assoc Dir, Office of Industry Engagement				Title:		CEO
					
	Date:		19 December 2013				Date:		12/24/13

  
  

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

  
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	AERASE, INC.				AEMASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
					
	Title:		CEO				Title:		CEO
					
	Date:		12/24/13				Date:		12/24/13

  

									
	AECASE, INC.				AE4ASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
					
	Title:		CEO				Title:		CEO
					
	Date:		12/24/13				Date:		12/24/13

  

									
	AE5ASE, INC.				AE6ASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
					
	Title:		CEO				Title:		CEO
					
	Date:		12/24/13				Date:		12/24/13

  
  

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

  
 13 

 ATTACHMENT A — RESEARCH PROGRAM 

Aeglea LLC will sponsor research in the laboratory of Professor George Georgiou, Depts of Chemical Engineering, Biomedical Engineering and
Molecular Biosciences on the engineering, optimization and initial animal validation of human enzyme therapeutics for the following purposes: 

Specific Aim 1. The systemic depletion of amino acids for cancer therapy, as elaborated below. 

Specific Aim 2. Enzyme replacement for the treatment of patients having inborn metabolic defects, primarily but not limited to diseases
stemming from mutations impacting physiological enzymatic function. 
 It is anticipated that during the 2013-2014 fiscal year, the work to
be carried out at the Georgiou lab will focus primarily, but not exclusively on Specific Aim 1. During this period the Georgiou lab will seek to focus on the engineering and optimization of the following enzymes: 

 

	 	1.1	[***] 

  

	 	1.2	[***] 

  

	 	1.3	[***] 

  

	 	1.4	[***] 

 Studies to be performed under 1.1-1.4 may include: 

 

	 	a)	Engineering enzymes having high catalytic proficiency (kcat/Km) and substrate specificity, as required for human therapeutic purposes. 

 

	 	b)	High thermodynamic stability in vitro and in physiological fluids, namely in human serum 

  

	 	c)	Formulation of the enzymes from 1.1-1.4 for prolonged circulation half-life by conjugation or polyethylene glycol or similar means. 

  

	 	d)	Development of lab scale processes for the preparative production of these enzymes at scale. 

  

	 	e)	In vitro studies to evaluate the effect of the engineered enzymes from 1.1-1.4 on cancer cell lines and, if available on primary tumor cells. 

 

	 	f)	Evaluation of the efficacy of the enzymes from 1.1-1.4 above in xenograft tumor mouse models, as applicable. 

  

	 	g)	Mechanistic studies as might be required to support Investigative New Drug applications (IND) to the FDA specifically addressing the impact of enzymes from 1.1-1.4 on cell cycle arrest, autophagy and apoptotic death of
cancer cells. 

  
  

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

  
 14 

 ATTACHMENT B 

SPONSORED RESEARCH AGREEMENT UTA13-001113 

Identification of Background IP and Restrictions on its Use, Release, 

or Disclosure 
 University’s Principal
Investigator asserts that the following identifies the Background IP (BIP) developed by University researchers performing under the Research Program and restrictions that exist on the rights of the entity owning or controlling the BIP to use,
release, or disclose the BIP. 
 Controlled by George Georgiou and exclusively licensed by Sponsor: 

 

			
	“Arginase formulations and methods”
	Serial No. 13/380,776		United States
	Serial No. PCT/US2010/040205		International
	Serial No. 61/221,396		United States
	Serial No. 10800270.0 (Publication No. EP2449102)		European Patent Office
	Serial No. 12111085.9		Hong Kong
	Serial No. 2012-517824		Japan
	Serial No. 2,766,039		Canada
	“Engineered Enzymes with Methionine-Gamma-Lyase Enzymes and
Pharmacological Preparations Thereof”
	Serial No. 61/301,368		United States
	Serial No. 13/020,268		United States
	Serial No. PCT/US2011/023606		International
	Serial No. 2011212885•		Australia
	Serial No. 2,788,689		Canada
	Serial No. 201180013307.X		China
	Serial No. 11740355		European Patent Office
	Serial No. 2012-552084		Japan
	Serial No. 10-2012-7023176		Republic of Korea .
	“Compositions of Engineered Human Arginases and Methods for Treating
Cancer”
	Serial No. 12/610,685		United States
	Serial No. 61/110,218		United States
	Serial No. PCT/US2009/062969		International
	 Serial No. 09824219.1

(Publication No. EP2350273)
		European Patent Office
	Serial No. 12100429.7		Hong Kong
	Serial No. 2,742,497		Canada
	Serial No. 2011-534855 (Publication No. JP2012507301)		Japan

  
  

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

  
 15 

			
	Background IP * and party owning or controlling that BIP		 Restrictions on BIP**
  

(If restrictions exist, describe nature of restrictions and third party that holds the rights thereto.) (If no restrictions exist, state
“none”)

		
	Owned by The University of Texas at Austin:		Exclusively licensed by Sponsor:
		
	 Engineering of L-Cysteine/L-Cystine degrading enzymes for therapeutic purposes.
		 PLA number PM1400601 (6337 GEO)
  

BIP: 61/871,727 (provisional patent application number)

		
	 Improvement on UTSB 741 “Engineered methionine gammal-lyase enzymes and pharmacological preparations thereof
		 PLA number PM4011501 (6314 GEO)
  

BIP: 61/871,768 (provisional patent application number)

 * “Background II” means any and all patents or patent applications for inventions, discoveries or
technology developed prior to the date hereof which necessarily would be infringed by the making, use or sale of a product the making, use or sale of which would also infringe a claim of a patent or patent application for any invention, discovery or
technology reasonably expected to result from the performance of the Research Program. If the BIP is applicable to multiple items, components, or processes identify both the BIP and each such item, component, or process. 

**Restrictions on BIP may include licenses granted by the owner of the BIP or industrial sponsorship arrangements that allow the sponsor
rights to review publications or to negotiate a license. Indicate whether development was funded either exclusively or partially by a government or non-government source, and list the source. Enter any reason that owner’s ability to grant
licenses in the BIP could be restricted. Identify basis of restriction (e.g., rights from a pre-existing agreement, rights in data generated under another contract, limited purpose rights under this or a prior contract, or specifically negotiated
licenses). 
  

			
	Printed Name:		George Georgiou
		
	Title:		Professor
		
	Signature		/s/ George Georgiou
		
	Date		 December 6, 2013

  
  

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

  
 16 

 Amendment 1 

To Sponsored Research Agreement UTA13-001113 (“Agreement”) 

Betwee 
 The University of
Texas at Austin (“UT”) 
 And 

Aeglea Development Company, Inc., AERase, Inc., AEMase, Inc., AECase, Inc., AE4ase, Inc., 

AE5ase, Inc., and AE6ase, Inc. (each a “Sponsor Entity” and collectively, “Sponsor”) 

The purpose of this Amendment: 
 To extend
the period of performance and increase the limitation of funding to perform additional research. 
 This Sponsored Research Agreement
is modified by mutual agreement of the Parties 
 as follows: 

 

	1.	Attachment A, Statement of Work, is appended with the Statement of Work included with this Amendment 1 as Attachment A-1, attached hereto. 

 

	2.	Section 2.2 is hereby replaced with the following: “The Research Program shall be performed during the period from the Effective Date through and including January 15, 2016 (the “Research
Term”). Funding Sponsor shall have the option of extending the Research Program under mutually agreeable support terms. 

  

	3.	Section 3.2, first paragraph and payment schedule, are hereby replaced with the following: “As consideration for the performance by University of its obligations under this Agreement, Funding Sponsor will pay
the University an amount equal to its reasonable, documented expenditures and reasonable overhead (such overhead to not exceed the rate set forth in University’s indirect rate agreement with the U.S. Federal Government) in conducting the
Research Program subject to a maximum expenditure limitation of $761,252, an increase of $375,000 over the currently funded amount of $386,252, provided that in any and all events, the amounts charged by University shall not, without Funding
Sponsor’s prior written consent, exceed the amount of the maximum expenditure limitation. Funding Sponsor has paid University $386,252 as consideration for its performance under the Research Program as described in Attachment A. Payments under
the following Attachment A-1 shall be made as follows (subject to the possible later return of funds if uncommitted and unexpended, under Section 3.3): 

  

	 	a)	Upon execution of all parties to the Agreement: $93,750; 

  

	 	b)	$93,750 by March 31, 2015; and 

  

	 	c)	$93,750 by June 30, 2015 

  

	 	d)	$93,750 by Sept 30, 2015” 

  

			
	Effective Date of the Sponsored Research Agreement:		December 1, 2013
	Effective Date of Amendment:		January 15, 2015

  
  

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

  

					
	Sponsor: Aeglea		PI: George Georgiou		SRA Amendment No. 1
	The University of Texas at Austin		Page 1 of 3		Agreement No. UTA13-001113

 All other terms and conditions of this Sponsored Research Agreement remain unchanged. 

 

									
	THE UNIVERSITY OF TEXAS AT AUSTIN				AEGLEA DEVELOPMENT COMPANY, INC.
			
	/s/ Ty Helpinstill				/s/ David G. Lowe
	By: Ty Helpinstill				By: David G Lowe
	Title:		Assoc Dir, Office of Industry Engagement				Title:		CEO
	Date:		28 October 2014				Date:		11/13/14

  

									
	AERASE, INC.				AEMASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
	Title:		CEO				Title:		CEO
	Date:		11/13/14				Date:		11/13/14

  

									
	AECASE, INC.				AE4ASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
	Title:		CEO				Title:		CEO
	Date:		11/13/14				Date:		11/13/14

  

									
	AE5ASE, INC.				AE6ASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
	Title:		CEO				Title:		CEO
	Date:		11/13/14				Date:		11/13/14

  
  

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

  

					
	Sponsor: Aeglea		PI: George Georgiou		SRA Amendment No. 1
	The University of Texas at Austin		Page 2 of 3		Agreement No. UTA13-001113

 Attachment A-1, Statement of Work 

Aeglea LLC will sponsor research in the laboratory of Professor George Georgiou, Departments of Chemical Engineering, Biomedical Engineering
and Molecular Biosciences on the engineering, optimization and initial animal validation of human enzyme therapeutics for the following purposes: 

Specific Aim 1. The systemic depletion of amino acids for cancer therapy. 

Specific Aim 2. Enzyme replacement for the treatment of patients having inborn metabolic defects, primarily but not limited to diseases
stemming from mutations impacting physiological enzymatic function. 
 It is anticipated that during the 2014-2015 fiscal year most of the
work to be carried out at the Georgiou lab will focus primarily, but not exclusively on Specific Aim 1. During this period the Georgiou lab will seek to focus on the engineering and optimization of the following enzymes: 

 

	 	1.1.	[***] 

  

	 	1.2.	[***] 

  

	 	1.3.	[***] 

  

	 	1.4.	[***]: 

  

	 	a)	Engineering enzymes having high catalytic proficiency (kcat/Km) and substrate specificity, as required for human therapeutic purposes. 

 

	 	b)	High thermodynamic stability in vitro and in physiological fluids, namely in human serum 

  

	 	c)	Formulation of the enzymes from 1.1-1.4 for prolonged circulation half-life by conjugation or polyethylene glycol or similar means. 

  

	 	d)	Development of lab scale processes for the preparative production of these enzymes at scale. 

  

	 	e)	In vitro studies to evaluate the effect of the engineered enzymes from 1.1-1.4 on cancer cell lines and, if available on primary tumor cells. 

 

	 	f)	Evaluation of the efficacy of the enzymes from 1.1-1.4 above in xenograft tumor mouse models, as applicable. 

  

	 	g)	Mechanistic studies as might be required to support Investigative New Drug applications (IND) to the FDA specifically addressing the impact of enzymes from 1.1-1.4 on cell cycle arrest, autophagy and apoptotic death of
cancer cells. 

  
  

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

  

					
	Sponsor: Aeglea		PI: George Georgiou		SRA Amendment No. 1
	The University of Texas at Austin		Page 3 of 3		Agreement No. UTA13-001113

 Amendment 01 

To Sponsored Research Agreement UTA13-001113 (“Agreement”) 

This Amendment to the Sponsored Research Agreement (“Agreement”) is made between The University of Texas at Austin, Austin, Texas
(“University”), an institution of higher education created by the Constitution and law of the State of Texas under The University of Texas System (“System”) and Aeglea Development Company, Inc., AERase, Inc., AEMase, Inc.,
AECase, Inc., AE4ase, Inc., AE5ase, Inc., and AE6ase, Inc., all Delaware C corporations with their principal place of business at 815 A Brazos St., #101, Austin TX 78701 (each a “Sponsor Entity” and collectively, “Sponsor”).
Aeglea Development Company, Inc. may be referred to herein as the “Funding Sponsor” or “Sponsor Entity” as appropriate. 

The purpose of this Amendment: 
 Sponsor
and University desire to amend the terms of the Agreement to extend the performance period at no cost as set forth below. 
 This
Agreement is modified by mutual agreement of the Parties as follows: 
 1. Article 2. Research Program, paragraph 2.2 is hereby amended to read: 

The Research Program shall be performed during the period from the Effective Date through and including January 15, 2015. Funding Sponsor
shall have the option of extending the Research Program under mutually agreeable support terms. 
 All other terms and conditions of this
Agreement remain unchanged. 
 IN WITNESS WHEREOF, the parties have caused this Amendment to be executed by their duly authorized representatives. 

 

									
	THE UNIVERSITY OF TEXAS AT AUSTIN				AEGLEA DEVELOPMENT COMPANY, INC.
			
	/s/ Ty Helpinstill				/s/ David G. Lowe
	By: Ty Helpinstill				By: David G Lowe
	Title:		Assoc Dir, Office of Industry Engagement				Title:		CEO
	Date:		24 September 2014				Date:		9/23/14

  

									
	AERASE, INC.				AEMASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
	Title:		CEO				Title:		CEO
	Date:		9/23/14				Date:		9/23/14

  
  

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

									
	AECASE, INC.				AE4ASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
	Title:		CEO				Title:		CEO
	Date:		9/23/14				Date:		9/23/14

  

									
	AE5ASE, INC.				AE6ASE, INC.
			
	/s/ David G. Lowe				/s/ David G. Lowe
	By: David G Lowe				By: David G Lowe
	Title:		CEO				Title:		CEO
	Date:		9/23/14				Date:		9/23/14

  
  

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

 Amendment 3 

To Sponsored Research Agreement UTA13-001113 (“Agreement”) 

Between 
 The University
of Texas at Austin (“UT”) 
 And 

Aeglea Development Company, Inc., AERase, Inc., AEMase, Inc., AECase, Inc., AE4ase, 

Inc., AE5ase, Inc., and AE6ase, Inc. (each a “Sponsor Entity” and collectively, “Sponsor”) 

The purpose of this Amendment: 
 To
correct the numeration of the prior amendment and increase the limitation of funding to perform additional research, and restructure payment terms, 

This Sponsored Research Agreement is modified by mutual agreement of the Parties as follows: 

 

	1.	“Amendment 1” executed between the parties on November 13, 2014, is restated as and shall hereafter be known as “Amendment 2.” 

 

	2.	Attachment A, Research Program, is appended with the statement of work included with this Amendment 3 as Attachment A-2, attached hereto. 

 

	3.	Section 2.2 is hereby replaced with the following: “The Research Program shall be performed during the period from the Effective Dale through and including August 31, 2016 (the “Research Term”).
Funding Sponsor shall have the option of extending the Research Program under mutually agreeable support terms. 

  

	4.	Section 3.2, first paragraph and the payment schedule, are hereby replaced with the following: “As consideration for the performance by University of its obligations under this Agreement, Funding Sponsor will
pay the University an amount equal to its reasonable, documented expenditures and reasonable overhead (such overhead to not exceed the rate set forth in University’s indirect rate agreement with the U.S. Federal Government) in conducting the
Research Program subject to a maximum expenditure limitation of $1,323,752, an increase of $562,500 over the currently funded amount of $761,252, provided that in any and all events, the amounts charged by University shall not, without Funding
Sponsor’s prior written consent, exceed the amount of the maximum expenditure limitation. Payments shall be made as follows (subject to the possible later return of funds if uncommitted and unexpended, under Section 3.3):

  

	 	a)	$573,752 - PAID TO DATE (consisting of $386,252 under the initial Agreement and $187,500 under Amendment 2) 

  

	 	b)	$375,000 due upon execution of this Amendment, which shall include the $93,750 previously due June 30, 2015 under Amendment 2, invoice issued on June 29, 2015 

 

	 	c)	$187,500 due on January 31, 2016, invoice to be issued by December 31, 2015 

  

	 	d)	$187,500 due on April 30, 2016, invoice to be issued by March 31, 2016 

  

					
	 Sponsor: Aeglea
	 	PI: George Georgiou	 	SRA Amendment No. 3
	 The University of Texas at Austin
	 	Page 1 of 5	 	Agreement No. UTA13-001113
	[***] Certain confidential information contained in this document, marked by brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933,
as amended. Confidential treatment has been requested with respect to this information.

	5.	Section 3.5 is hereby amended to change the Sponsor contact information for University invoices to: accounting@aegleabio.com, and for questions: Jo O’Keefe, 512-900-3662, (Alternate contacts: April
Duley, aduley@aegleabio.com, 512-900-3826, and Charles York, cyork@aegleabio.com, 512-394-4188) 

 All other terms and
conditions of this Sponsored Research Agreement remain unchanged. 
  

									
	THE UNIVERSITY OF TEXAS AT AUSTIN	 		 	AEGLEA DEVELOPMENT COMPANY, INC.
			
	 /s/ Ty Helpinstill
	 		 	 /s/ Charles York

	By:	 	Ty Helpinstill	 		 	By:	 	Charles York
	Title:	 	Assoc Dir, Office of Industry Engagement	 		 	Title:	 	Sr. Vice President of Finance + Accounting
	Date:	 	3 Aug 2015	 		 	Date:	 	10 Aug 2015
			
	AERASE, INC.	 		 	AEMASE, INC.
			
	 /s/ Charles York
	 		 	 /s/ Charles York

	By:	 	Charles York	 		 	By:	 	Charles York
	Title:	 	Sr. Vice President of Finance + Accounting	 		 	Title:	 	Sr. Vice President of Finance + Accounting
	Date:	 	10 Aug 2015	 		 	Date:	 	10 Aug 2015
			
	AECASE, INC.	 		 	AE4ASE, INC.
			
	 /s/ Charles York
	 		 	 /s/ Charles York

	By:	 	Charles York	 		 	By:	 	Charles York
	Title:	 	Sr. Vice President of Finance + Accounting	 		 	Title:	 	Sr. Vice President of Finance + Accounting
	Date:	 	10 Aug 2015	 		 	Date:	 	10 Aug 2015
			
	AE5ASE, INC.	 		 	AE6ASE, INC.
			
	 /s/ Charles York
	 		 	 /s/ Charles York

	By:	 	Charles York	 		 	By:	 	Charles York
	Title:	 	Sr. Vice President of Finance + Accounting	 		 	Title:	 	Sr. Vice President of Finance + Accounting
	Date:	 	10 Aug 2015	 		 	Date:	 	10 Aug 2015

  

					
	 Sponsor: Aeglea
	 	PI: George Georgiou	 	SRA Amendment No. 3
	 The University of Texas at Austin
	 	Page 2 of 5	 	Agreement No. UTA13-001113
	[***] Certain confidential information contained in this document, marked by brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933,
as amended. Confidential treatment has been requested with respect to this information.

 Attachment A-2 

Statement of Work 
 Aeglea
LLC will sponsor research in the laboratory of Professor George Georgiou, Departments of Chemical Engineering, Biomedical Engineering and Molecular Biosciences on the engineering, optimization and initial animal validation of human enzyme
therapeutics for the following purposes: 
 Specific Aim 1. The systemic depletion of amino acids for cancer therapy. 

Specific Aim 2. Enzyme replacement for the treatment of patients having inborn metabolic defects, primarily but not limited to diseases
stemming from mutations impacting physiological enzymatic function. 
 During the 2014-2015 fiscal year the Georgiou lab has been focusing on Specific Aim
1; the engineering and optimization of the following enzymes: 
  

	 	1.1.	[***] 

	 	1.2.	[***] 

	 	1.3.	[***] 

	 	1.4.	[***] 

 It is anticipated that during the 2015-2016 fiscal year most of the work to be
carried out at the Georgiou lab will focus primarily on Specific Aim 1 but also Specific Aim 2. During this period the Georgiou lab will seek to focus on the engineering and optimization of the following enzyme programs: 

1.1. [***] 
 1.2. [***] 

1.3. [***] 
 2.1. Specific Aim 1 

2.2. Specific Aim 2 
 2.4. Specific Aim 3 

Studies to be performed under 1.1-2.4 may include: 
  

	•	 	Recombination (DNA shuffling) and screening of variants identified from pfunkel library: 

  

	 	–	[***] 

  

	 	–	[***] 

  

	 	–	[***] 

  

	•	 	Biophysical studies aimed at [***] 

  

					
	 Sponsor: Aeglea
	 	PI: George Georgiou	 	SRA Amendment No. 3
	 The University of Texas at Austin
	 	Page 3 of 5	 	Agreement No. UTA13-001113
	[***] Certain confidential information contained in this document, marked by brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933,
as amended. Confidential treatment has been requested with respect to this information.

	 	–	Excipients: survey of buffer, pH, excipient conditions for effect on activity, aggregation etc. 

  

	 	–	Preliminary stress tests 

  

	 	•	 	Develop assays for transsulfuration enzyme expression 

  

	 	•	 	Proof of concept experiments in triple negative breast cancer 

  

	1.2	[***] program 

  

	 	•	 	[***] 

  

	1.3.	[***] 

  

	 	•	 	1.3.1 Proof of concept studies for immune-oncology studies. 

  

	 	•	 	[***] 

  

	 	•	 	1.3.2. [***] 

  

	 	•	 	1.3.3. [***] 

  

	 	•	 	1.3.4. [***] 

 2. SRA expansion 

The purpose of the SRA expansion is to further support activities outlined in the initial 2015-2016 scope of work and to provide expanded research for: 

 

	 	a)	the treatment of patients having inborn metabolic defects, primarily but not limited to diseases stemming from mutations impacting physiological enzymatic function 

 

	 	b)	the treatment of patients with solid or hematologic malignancies 

 Specific Aim 1: [***] 

Specific Aim 2: [***] 
 Specific Aim 3.
[***] 
 2.1 Specific Aim 1: 
 Recombination (DNA
shuffling) and screening of variants identified from a scanning saturation library of [***] 
  

	 	–	[***] 

  

					
	 Sponsor: Aeglea
	 	PI: George Georgiou	 	SRA Amendment No. 3
	 The University of Texas at Austin
	 	Page 4 of 5	 	Agreement No. UTA13-001113
	[***] Certain confidential information contained in this document, marked by brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933,
as amended. Confidential treatment has been requested with respect to this information.

	 	–	Tertiary screening for expression, kinetics and stability (purified protein) 

  

	 	•	 	Biophysical studies of selected variants 

  

	 	•	 	[***] 

  

	 	•	 	PD study in mice to evaluate Cystine & Cysteine levels following single dose administration 

 2.2
Specific Aim 2: 
  

	 	•	 	Method development to support analysis of [***] in animal models (see below) 

  

	 	•	 	Evaluation of [***] 

  

	 	•	 	[***] 

  

	 	•	 	[***]. 

 2.3 Specific Aim 3: 
  

	 	•	 	[***] 

  

	 	•	 	[***] 

  

	 	•	 	Other scaffold TBD 

  

					
	 Sponsor: Aeglea
	 	PI: George Georgiou	 	SRA Amendment No. 3
	 The University of Texas at Austin
	 	Page 5 of 5	 	Agreement No. UTA13-001113
	[***] Certain confidential information contained in this document, marked by brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933,
as amended. Confidential treatment has been requested with respect to this information.EX-10.10

 Exhibit 10.10 
  

 
 Master Services Agreement 

This Master Services Agreement (this “Agreement”) dated December 24, 2013 (the “Effective
Date”), between Aeglea Development Company, Inc., having a place of business at 815-A Brazos St. #101, Austin, TX 78701 (“Client”) and KBI Biopharma, Inc., having a place of business at 1101 Hamlin Road,
Durham, North Carolina 27704 (“KBI Biopharma”) (Client and KBI Biopharma, each a “Party”, and collectively, the “Parties”). 

Whereas, Client is engaged in the discovery and development of new biological therapeutics; 

Whereas, KBI Biopharma is in the business of providing biological development and clinical manufacturing services; and 

Whereas, Client desires KBI Biopharma to perform certain services in accordance with the terms of this Agreement and KBI Biopharma desires to perform such
services. 
 Now, therefore, in consideration of the above statements, which form part of this Agreement, and other good and valuable consideration, the
sufficiency and receipt of which are hereby acknowledged, the Parties hereto agree as follows: 
  

	1.	Services to be Performed 

  

	1.1	Scope. KBI Biopharma shall use reasonable commercial efforts to perform the services (the “Services”) detailed in the proposals, which have been executed by the Parties, listed on
Attachment One, and incorporated herein by reference (proposals listed on Attachment One and subsequent proposals agreed to by the Parties are each hereinafter referred to as a “Propose”). Any deliverables to be
provided to Client as a result of the performance by KBI Biopharma of the Services shall be set forth in the Proposal (the “Deliverables”). In the event that Client requests KBI Biopharma to perform services beyond the scope
of services specifically stated in the Proposal, KBI Biopharma shall have no obligation to perform such supplemental services unless and until a Change Order is executed in accordance with Article 8 below, or unless the Parties agree in writing
on a proposal for additional services to be performed under this Agreement. 

  

	1.2	Additional Services. The Parties may agree upon additional Services to be performed under the terms of this Agreement, as may be described in purchase orders or Proposals to be mutually agreed upon by the Parties
in writing. 

  
  

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

	1.3	Compliance with Laws. As applicable to the Services, KBI Biopharma shall perform the Services in all material aspects in compliance with current cGMP and other rules, regulations and guidelines of the U.S. Food
and Drug Administration (“FDA”), as then in effect, applicable to the performance of the Services, including without limitation, those governing the manufacture, testing and quality control of investigational drugs. For
purposes of the foregoing, “cGMP” means the current Good Manufacturing Practices as promulgated under each of the following as in effect on the date of this Agreement and as amended or revised after the date of this Agreement
and in effect at the time of the performance of the Services: (a) the U.S. Food, Drug & Cosmetics Act (21 U.S.C. § 301 et seq.) and related U.S. regulations, including 21 Code of Federal Regulations
(Chapters 210 and 211) and (b) the ICH guide Q7 “ICH Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients” as applied to investigational drugs (Section 19). Client shall have responsibility for determining
regulatory strategy and for all regulatory decisions except for those matters that KBI Biopharma, in its reasonable discretion deems contrary to regulatory requirements or commitments made by KBI Biopharma to regulatory authorities, of which matters
KBI Biopharma shall promptly notify Client in writing. Should the U.S. government regulatory requirements change, KBI Biopharma will use reasonable best efforts to satisfy the new requirements. Notwithstanding the foregoing, in the event that
compliance with such new U.S. regulatory requirements necessitates a change in the scope or nature of the Services to be completed, KBI Biopharma will submit to Client a Change Order in accordance with Article 8. 

 

	2.	Client Obligations 

  

	2.1	General. Unless otherwise agreed to by the Parties in writing, in each case in accordance with the Proposal, Client is solely responsible for, and performance hereunder by KBI Biopharma is contingent upon:
(a) to the extent Client is required to provide data under a Proposal regarding the product which is the subject of the Proposal (the “Product”) Client shall provide such data, which shall be complete and accurate;
(b) to the extent Client is required pursuant to a Proposal to transfer its methods to KBI Biopharma, provision of all information necessary to effect the reliable transfer of such methods to KBI Biopharma; (c) provision of specific
reagents, reference standards or other materials (“Client Materials”) to the extent it is required pursuant to a Proposal and necessary for execution of Services; (d) to the extent the Proposal requires Client’s
review and approval of in-process and/or finished product test results to ensure conformity of such results with required Product specifications Client shall not unreasonably withhold or delay such approval; (e) preparation of all submissions
to regulatory authorities; and (f) performance of all other obligations of Client set forth in the Proposal. Client shall perform its obligations as set forth in this Agreement, and reasonably cooperate with the execution of the Services and
shall not engage in any act or omission, which may reasonably be expected to prevent or delay the successful execution of the Services. Such support and cooperation shall include, but not be limited to, reasonably informing KBI Biopharma of global
regulatory strategy for development and approval of the Product (to the extent such strategy is reasonably necessary to perform the Services), 

  

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

	 	
review and approval or rejection of documents requiring Client’s signature without unreasonable delay, timely delivery of methods and materials (to the extent delivery of such methods and
materials is contemplated by the Scope and reasonably necessary for KBI Biopharma to perform the Services) and response to other similar issues without unreasonable delay. 

 

	2.2	Provision of Regulatory Submissions. Prior to making any submission for regulatory approval of the Product, upon the request of KBI Biopharma, Client shall provide copies of the portions of regulatory submissions
that solely relate to KBI Biopharma’s manufacturing procedures (if applicable to the Services) to KBI Biopharma for review and opportunity to comment. 

  

	2.3	Information Regarding Hazardous Materials. Client shall provide to KBI Biopharma, on an on-going basis throughout the Term (as defined below), any applicable safe handling instructions for any Client Materials as
soon as is commercially practicable prior to delivery of any such Client Materials to KBI Biopharma. Where appropriate or required by law, Client shall provide a Material Safety Data Sheet and instructions for proper storage for all Client-provided
materials, finished product and reference standards. Client shall notify KBI Biopharma in writing of the possibility of cross contamination of any products being manufactured or stored by KBI Biopharma. KBI Biopharma shall safely store and handle
Client Materials in accordance with information provided to it by Client. KBI Biopharma shall be solely responsible for implementing and maintaining health and safety procedures for the Client Materials, taking into account the information provided
to KBI Biopharma. 

  

	2.4	Client Materials. All property rights in the Client Materials supplied to KBI Biopharma shall remain vested in Client. KBI Biopharma shall at all times use reasonable efforts to keep the Client Materials secure
and safe from loss or damage. Subject to the limitations of liability set forth in Section 11, KBI Biopharma shall be liable for loss or damage to Client Materials resulting from its negligence or intentional misconduct. Client grants KBI
Biopharma the right to use the Client Materials solely to the extent required to perform the Services. KBI Biopharma shall use the Client Materials only for the purpose of performing the Services and shall not subject the Client Materials to any
analysis or use inconsistent with the Services. In no event shall KBI Biopharma use Client Materials for its own benefit or in connection with the performance of services for third parties. 

 

	3.	Performance 

  

	3.1	Schedule. Due to the unpredictable nature of biological processes, the timelines and schedules for the performance of the Services (including without limitation the dates for production and delivery of Product)
and the yield or quantity of Product as set out in the Proposal are estimates only, provided, that in any and all events KBI Biopharma shall (i) use commercially reasonable efforts to meet the timelines, schedules, yields and quantities, and
(ii) use commercially reasonable efforts to mitigate the adverse effects of 

  

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

	 	
any failure to meet the timelines, schedules, yields and quantities. KBI Biopharma shall keep Client regularly informed in writing of any such changes that are necessary to the Proposal, and
agrees that such changes will be made to the minimum extent reasonably necessary. 

  

	3.2	Technical Difficulties. 

  

	    	If it becomes apparent to either KBI Biopharma or Client at any stage in the provision of any Services that, as a result of scientific or technical reasons out of the reasonable control of either Party, it will not be
possible to complete the Services in the manner described in this Agreement or the Proposal or any Change Order thereto, the Parties will (a) identify the problem, (b) submit the problem in writing to senior management of each Party, and
(c) negotiate in good faith for a sixty (60) day period from the date senior management of the Parties first convene regarding how to resolve such problem in a commercially reasonable manner. 

 

	3.3	Quality Agreement. Contemporaneously with the execution of this Agreement, or as soon as practicable after the execution hereof, in the event that the Proposal specifically enumerates Services that include the
performance of activities that are subject to cGMP, the Parties shall develop and agree upon a quality agreement describing the regulatory and compliance roles and responsibilities of each Party, including without limitation, procedures for handling
Product recalls and non-conforming Product, the format and content of which shall be agreed upon by the Parties (the “Quality Agreement”). Upon execution by both Parties, the Quality Agreement shall be incorporated herein and
attached hereto as Attachment Two. 

  

	3.4	Non-Conforming Services. Within thirty (30) days of delivery of any deliverable in connection with the Services (“Deliverable”), Client shall inform KBI Biopharma of any material
non-conformity with (i) the specifications (the “Specifications”) set forth in the Proposal, the Quality Agreement or otherwise mutually agreed upon in writing and (ii) the requirements of this Agreement ((i) and
(ii) are collectively, the “Product Requirements”). Any failure of a Deliverable to meet the Product Requirements due to causes which are reasonably within KBI Biopharma’s control shall be deemed a
“Defective Deliverable”). As Client’s sole and exclusive remedy for a Defective Deliverable, KBI Biopharma shall, subject to Client providing the replacement active pharmaceutical ingredient or other source materials, as
applicable, promptly re-perform such non-conforming Services and deliver a replacement Deliverable that meets the Product Requirements with no additional fees to Client. A Deliverable shall be deemed “Accepted” upon the earlier of
(a) Client delivering written notice to KBI Biopharma that the Deliverable meets the applicable Specifications and Product Requirements or (b) Client failing to notify KBI Biopharma of a Defective Deliverable within the applicable thirty
(30) day period specified in this Section 3.4. 

  

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

	4.	Work Output 

  

	    	All reports specified in the Proposal and other applicable cGMP documentation (“Work Output”) will be prepared using KBI Biopharma’s standard format(s) (which shall be commercially
reasonable) unless otherwise specified in the Proposal or this Agreement. Client will be supplied with copies of Work Output generated as a result of the Services as set forth in the Proposal or Quality Agreement Unless otherwise required by law,
KBI Biopharma shall maintain records related to each Proposal, including, but not limited to the Services, accounting records, time sheets, written policies and procedures, test results, reports, correspondence, memoranda and any other documentation
relating to the performance of its obligations under to this Agreement (“Records”). KBI Biopharma shall, during normal working hours, and with reasonable advance notice, permit Client or its authorized agents to inspect,
audit and/or reproduce Records (i) to the extent necessary to adequately evaluate invoices submitted to Client by KBI Biopharma hereunder, (ii) as required by governmental authorities or (iii) as desired by Client for any other valid
business purpose related to this Agreement. Vendor shall make appropriate personnel or other representatives available to Client and its agents to discuss Records and to resolve any questions or issues relating thereto. Such audits shall not be
conducted more frequently than once per year. 

  

	    	KBI Biopharma shall maintain all information and data generated by it in the course of providing the Services, including all Work Output, computerized records and files, in a secure area reasonably protected from fire,
theft and destruction. To the extent not delivered prior to the expiration or termination of this Agreement, at the expiration or termination of this Agreement and upon the written request of Client, all Records, data, information and tangible
property obtained or generated by KBI Biopharma in the course of providing the Services or arising out of the use of Client’s Confidential Information (collectively, “Results”) shall, at Client’s option, be (a) delivered to
Client at any address as Client may specify in such request, or (b) retained by KBI Biopharma for a period of five (5) years from the completion of the Services or such longer period required by applicable laws and regulations. Client
shall reimburse KBI Biopharma for the reasonable, documented cost of deliveries to Client under this Section 4. In no event shall KBI Biopharma dispose of any Results without first giving Client sixty (60) days’ prior written notice
of its intent to do so. 

  

	5.	Facility Visits and Audits 

  

	5.1	Scope of Visit. Client shall have the right upon no less than fifteen (15) business days’ prior written notice to KBI Biopharma and during regular business hours, to visit KBI Biopharma (i.e., person in
the plant) to observe the progress of the Services and to inspect related records and data for the purpose of making quality control inspections so as to assure compliance with this Agreement. The form, participants, duration and procedures of all
visits shall be subject to KBI Biopharma’s approval, which approval shall not be unreasonably withheld and shall be provided by KBI Biopharma within five (5) business days of Client’s notice of the visit. 

 
  

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

	5.2	Client Obligations. It shall be the duty of Client to provide for the safety of, and prevention of accident or injury to, Client, its employees, agents, representatives, and guests of any of them while in, on or
about KBI Biopharma’s premises. KBI Biopharma also wants to ensure that all visits are conducted in a manner reasonably required to protect the confidentiality of KBI Biopharma Confidential Information and the confidential information of other
clients. As such, Client agrees that it and its subcontractors, employees, agents, representatives, and guests of any of them shall: (a) be subject to a nondisclosure obligation comparable in scope to Article 13, (b) follow
commercially reasonable security and facility access procedures as are designated by KBI Biopharma, (c) be accompanied by a KBI Biopharma representative, (d) not enter areas of any KBI Biopharma facility at times when any third
party’s products are being manufactured to assure protection of KBI Biopharma’s or third party’s confidential information (provided that to the extent Client’s products or deliverables hereunder are manufactured in such areas,
Client may schedule another visit at a time when the area where such products or deliverables are manufactured is accessible), (e) stay within the confines of KBI Biopharma’s facilities and shall not visit areas of the facility other than
those areas necessary for the performance of the facility visit provided for herein without KBI Biopharma’s prior written permission, and (f) use good faith efforts to avoid disrupting KBI Biopharma’s operations. All information
learned, observed or obtained by Client during any visit to KBI Biopharma’s facilities, excluding information regarding Client’s products, Client Materials and Results, shall be deemed “Confidential Information” of KBI Biopharma
under Article 13, regardless of whether such information is marked “Confidential” or subsequently summarized in writing. Client warrants that it, and to its knowledge, its subcontractors, employees, agents, representatives, and any
personnel acting on behalf of Client hereunder who visit the KBI Biopharma facility are not debarred, under subsections 306(a) or (b) of the Generic Drug Enforcement Act of 1992, as each may be amended from time to time,. 

 

	5.3	Costs. Client may conduct one (1) such quality assurance facility visit per calendar year at no cost to Client. Additional audits will be invoiced separately on a time and materials basis at the then current
rate for such services, provided, however, that if any visit by Client reveals noncompliance with the terms of this Agreement or the Quality Agreement, Client may conduct additional audits during such year at no cost. 

 

	6.	Regulatory Inspections 

  

	6.1	General. KBI Biopharma will promptly notify Client of any regulatory inspections directly relating to the Services, in accordance with the terms of the Quality Agreement (if applicable). KBI Biopharma shall
promptly rectify any deficiencies discovered during such inspections, audits and investigations of which KBI Biopharma is notified. KBI Biopharma agrees to reasonably cooperate with all regulatory authorities and submit to reasonable inspections by
such authorities. 

  
  

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

	6.2	Costs. Client shall be responsible for, and shall (i) promptly pay, all documented costs charged by a regulatory authority for inspections that arise solely out of Client’s product to be manufactured
under the Proposal and (ii) reimburse KBI Biopharma for its reasonable, documented out-of-pocket costs incurred by it in connection with such regulatory inspection. For the avoidance of doubt, Client shall not be responsible for costs
associated with inspections relating to KBI Biopharma’s or any third parties’ products, facilities, policies, procedures or manufacturing processes. 

  

	7.	Compensation 

  

	7.1	Fees. In consideration for KBI Biopharma performing the Services, Client shall pay to KBI Biopharma such amounts as described in the Price and Payment Terms section of the Proposal and as otherwise described in
this Agreement. The Parties agree and acknowledge that the Proposals will incorporate compensation terms generally consistent with the terms outline (the “Terms Outline”) attached to this Agreement as Attachment Three, as
applicable. It is further agreed by the Parties that references in the Terms Outline to a Program 1 shall apply to Aeglea’s Arginase program, and that references in the Terms Outline to a Program 2 shall apply to Aeglea’s
Cystinase program. To the extent there is any conflict between this Agreement and the Terms Outline, this Agreement shall govern. 

  

	7.2	Equity Component of Service Fees. Certain portions of the service fees (the “Equity Component”) under the applicable Proposals will be paid for in the form of the issuance of shares of Aeglea
BioTherapeutics Holdings, LLC (“Aeglea Holdings”) as described below. The Equity Component will be paid as follows: 

  

	    	7.2.1 For Stage 1 of Program 1 (corresponding to enabling Phase I studies for Arginase) and Stage 1 of Program 2 (corresponding to process development for Cystinase), a number of Preferred A
Shares of Aeglea Holdings shall be issued to KBI Biopharma calculated as set forth in the table below, provided further that all shares of Aeglea Holdings issued to KBI Biopharma shall be subject to the Share Return Right in Section 7.2.7
below. 

  

			
	Program 1, Stage 1		
	Service Fees Under Current Proposals		$[***]
	Service Fees Discount Percentage Under Current Proposals		[***]%
	Percentage of Cash Component		[***]%
	Percentage of Equity Component		[***]%
	Value of Shares to Be Issued		$[***]
	 Number of Preferred A Shares to Be Issued @

$[***] per share
		[***] Preferred A Shares
		
	Program 2, Stage 1		

  
  

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

			
	Service Fees Under Current Proposals	  	$[***]
	Service Fees Discount Percentage Under Current Proposals	  	[***]%
	Percentage of Cash Component	  	[***]%
	Percentage of Equity Component	  	[***]%
	Value of Shares to Be Issued	  	$[***]
	 Number of Preferred A Shares to Be Issued @

$[***] per share
	  	[***] Preferred A Shares
		
	Total Value of Preferred A Shares to be Issued for Program 1, Stage 1 and Program 2, Stage 1	  	$[***]
		
	Total Preferred A Shares to be Issued (at a purchase price of $[***] per share)	  	[***] Preferred A Shares

 For Program 1 Stage 1, the Preferred A Shares shall be issued as follows: 

 

					
	 Percentage of Shares
	  	Event	 
	 [***]
	  	 	[***]	  
	 [***]
	  	 	[***]	  
		  	 	[***]	  
	 [***]
	  	 	[***]	  

 The value of the equity payment shall be credited against invoiced amounts. 

For Program 2 Stage 1, the Preferred A Shares shall be issued as follows: 
  

					
	 Percentage of Shares
	  	Event:	 
	 [***]
	  	 	[***]	  
	 [***]
	  	 	[***]	  

 The $[***] in services value of the first equity payment for Program 2 shall be credited against invoiced
amounts. The next $[***] in invoiced amounts shall be paid in cash. The $[***] in services value of the second equity payment shall be next credited against invoiced amounts. In the event that Aeglea Holdings issues a new series of preferred shares
other than Preferred A Shares prior to the issuance of any Preferred A Shares as required above (“New Round Securities”), then in lieu of Preferred A Shares, KBI shall be issued a number of New Round Securities equal to the corresponding
equity value set forth above with respect to such Preferred A Shares (determined by reference to the Preferred A Share original purchase price of $[***] per share) divided by the price per share of the New Round Securities. 

7.2.2 For all other Services for which the Parties have agreed to compensation which includes an Equity Component, the applicable amount of the
Equity Component shall be 
  
  

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

 
issued to KBI Biopharma for each stage (including Program 1, Stage 2; Program 2, Stage 2; and optional Program 3, Stages 1 and 2) (each a
“Stage”), pursuant to the applicable Proposal or other written agreement of the Parties. All such shares of Aeglea Holdings issued to KBI Biopharma shall be subject to the Share Return Right in Section 7.2.7 below. 

7.2.3 Each portion of the Equity Component not issued pursuant to Section 7.2.1 above shall be compensated by issuance to KBI Biopharma
of the agreed value of shares in the then current series and valuation of preferred shares of Aeglea Holdings in a manner agreed upon by KBI Biopharma and Client. The Parties acknowledge that, depending on the date of initiation of KBI
Biopharma’s Services for subsequent Stages, this may result in KBI Biopharma receiving a subsequently created, authorized and issued class of preferred shares for such subsequent Stage. 

7.2.4 Client shall ensure that Aeglea Holdings allocates [***] shares of Preferred A Shares to be potentially issued to KBI Biopharma pursuant
to Section 7.2.1 in order to satisfy the anticipated amounts of the Equity Component under Section 7.2.1 (the “KBI Allocated Shares”). 

7.2.5 In the event that the Parties agree on Modifications to the Services, pursuant to Article 8 hereunder, that would require payment
of an additional amount of Equity Component, such additional amount of Equity Component shall be paid by either (a) issuance to KBI Biopharma of the agreed value of shares in the then current series and valuation of preferred shares of Aeglea
Holdings, if KBI Allocated Shares remain available for issuance; or (b) payment to KBI Biopharma of the agreed amount in cash if all applicable KBI Allocated Shares have been previously issued to KBI. 

7.2.6 Upon the issuance of the first installment of any Equity Component, KBI Biopharma shall execute a signature page to and become party to
and bound by the Aeglea Holdings Limited Liability Company Agreement, as amended and restated from time to time (the “Aeglea LLC Agreement”) with respect to the issued shares. The shares received for the Equity Component by
KBI Biopharma shall have the same respective rights, preferences and privileges, and subject to same obligations, pursuant to the Aeglea LLC Agreement as the other preferred shares issued to investors; provided that KBI Biopharma shall not have any
rights to elect members to the Aeglea Holdings Board of Directors (but KBI Biopharma shall have the right to appoint an observer to the Board meetings. All shares issued to KBI BioPharma as part of the Equity Component shall be issued pursuant to a
form of subscription agreement in the form of agreement attached hereto as Attachment Four. 
 7.2.7 In the event that Client terminates
this Agreement or a Proposal pursuant to Section 25.3 or Section 25.4, the portion of any shares of Aeglea Holdings which was issued to KBI Biopharma for Services which were either not performed or were performed in a manner which gave
rise to Client’s right to terminate for breach shall be 
  

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

 
automatically cancelled and KBI Biopharma shall return the share certificate for such cancelled shares to Client and upon Client’s receipt of the share certificate for such cancelled shares
Aeglea Holdings shall issue a new share certificate to KBI Biopharma for any shares not cancelled(hereinafter, the “Share Return Right”). 
  

	7.3	Payment of Cash Component of Service Fees and Materials. Certain portions of the service fees under the applicable Proposals, other than the Equity Component, and the cost of materials will be paid for by Client
in cash (the “Cash Component”). The Cash Component shall be invoiced and paid as set forth below. 

  

	7.4	Invoices for Cash Component. Following payment of any initial fee as provided in Section 7.5 subject to Section 7.2.1 for Proposals related to Program 1, Stage 1 and Program 2,
Stage 2, the remainder of the service fees for the Cash Component will be billed by KBI Biopharma in semi-monthly invoices based on a billing schedule derived from the project schedule. Payments are due thirty (30) days from date of the
undisputed invoice, except as specifically provided in this Agreement. Invoices shall not be dated earlier than the date sent to Client. If KBI is required to purchase material on behalf of client, such material shall be deemed “Client
Materials” and charges for materials will be invoiced to Client and are payable at the time that KBI Biopharma orders such materials for Client’s project. Client agrees to pay to KBI Biopharma the cost for such Client Materials specified
in the Proposal, including any handling fees which may be agreed upon by the Parties in the Proposal. Undisputed late payments are subject to an interest charge of one and one percent (1%) per month or, if less, the maximum legal interest rate
per month. Failure to bill for interest due shall not be a waiver of KBI Biopharma’s right to charge interest. All payments are non-refundable. If paid by wire transfer, any applicable wire transfer fees must be included in the payment issued
to KBI Biopharma. Unless within thirty (30) days of the date of invoice, Client has advised KBI Biopharma, in good faith and in writing the specific basis for disputing an invoice, Client’s failure to promptly pay an invoice may, at KBI
Biopharma’s election, and notwithstanding the provisions of Section 25.3, constitute a material breach of this Agreement. 

  

	7.5	Start-up Payment. For Proposals without an Equity Component, KBI Biopharma requires payment of an initial fee of one third of the Cash Component portion of the service fees specified in the Proposal, prior to
commencement of Services, to account for facilities preparation costs and resource allocation commitments with respect to Client’s project(s). Initial fees are due upon execution of this Agreement or the applicable Proposal, whichever occurs
later. The initial fee shall be applied on a one-third pro rata basis to the invoices in the order received. As an example, a charge of $3,000 would be satisfied by application of $1,000 from the existing initial fee balance and an additional
payment by Client of $2,000. Upon termination of a Proposal or this Agreement, any remaining portion of the initial fee shall be applied to any outstanding amounts due from Client under the applicable Proposal. Unless otherwise provided in this
Agreement or the applicable Proposal, initial fees are non-creditable, nonrefundable, non-transferable to apply to any Services other than under the applicable Proposal. 

 
  

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

	7.6	Client Delays. KBI Biopharma has allocated resources to the Services that may be difficult or impractical to reallocate to other programs in the event of a delay attributable to Client’s material failure to
comply with its obligations under this Agreement or Client’s written request for delay. In recognition of this, in the event that KBI Biopharma is unable to reasonably reallocate such resources, the Parties shall negotiate in good faith
regarding how to address the delay in a commercially reasonable manner. 

  

	7.7	Taxes. Any federal, state, county or municipal sales or use tax, excise tax, customs charges, duties or similar charge, or any other tax assessment (other than that assessed against KBI Biopharma’s income),
license, fee or other charge lawfully assessed or charged on the manufacture, sale or transportation of Product sold or Services performed pursuant to this Agreement, and all government license filing fees and, if applicable, Prescription API User
(PDUFA) annual establishment fees with respect to all Products and Services shall be paid by Client. 

  

	8.	Change Orders 

  

	8.1	Change Orders. The assumptions relating to the completion of the Services are set forth in the Proposal (“Proposal Assumptions”). KBI Biopharma also assumes that Client will perform its
obligations under this Agreement and the Proposal as set forth herein, that no Force Majeure Event will occur, and that there are no changes to any applicable laws, rules or regulations relating to and materially affecting the performance of the
Services (the foregoing assumptions together with the Proposal Assumptions, collectively, the “Assumptions”). In the event of a material failure of any of the Assumptions that directly and adversely affects KBI
Biopharma’s ability to perform the Services, then the scope of services to be performed shall be amended as provided in this Article 8 (a “Modification”). Modifications shall also arise in the event Client
(i) revises KBI Biopharma’s responsibilities, the specifications, the Proposal instructions, procedures, Assumptions, processes, test protocols, test methods, or analytical requirements or (ii) requests changes to the Proposal.

  

	8.2	Change Order Process. In the event a Modification is required pursuant to Section 8.1 and requested by Client or by KBI Biopharma, KBI Biopharma shall provide Client with a change order containing an
estimate of the required Modifications to the budget, activities and/or duration specified in the Proposal (“Change Order”). Client and KBI Biopharma shall negotiate in good faith for a period of ten (10) business days
following receipt of such Change Order by Client (the “Change Order Negotiation Period”) to agree on a Change Order that is mutually acceptable. If practicable, and agreed to by Client, KBI Biopharma shall continue work on
the Services during any such negotiations, but shall have no obligation to commence work with respect to any Change Order unless authorized in writing by Client. In the event the Parties are unable to agree upon such Change Order with respect to a
Modification within the Change Order Negotiation Period, KBI Biopharma or Client may elect to terminate this Agreement, or if reasonably possible, to perform the Services without regard to the unresolved Change Order; 

 
  

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

	 	
provided, however, that the estimated timelines shall be adjusted to reflect any delay during the Change Order Negotiation Period. In the event that this Agreement is so terminated, the
provisions with respect to the effect of termination set forth in Section 25.5 shall apply. Any disputes arising from this Section 8.2 shall be resolved in accordance with the dispute resolution procedures set forth in Article 23.

  

	8.3	Regulatory Changes. Notwithstanding the foregoing, with respect to any changes or modifications to the Proposal, Services or Product specifications dictated by the FDA or other applicable law or authority, Client
shall be responsible for the costs of making such changes (including without limitation capital costs), validating the manufacturing process after any such change is made, and any increases in the cost of manufacturing the Product or provision of
Services as a result of such change. With respect to any such changes dictated by the FDA or other applicable law or authority, the Parties will promptly meet to discuss the actions necessary to comply with such changes and the costs associated
therewith. 

  

	9.	Shipment 

  

	9.1	General. Unless otherwise agreed in writing by the Parties, all Deliverables, products, raw materials, samples components or other materials provided hereunder by KBI Biopharma shall be made available for
shipment Ex Works (INCOTERMS 2010) KBI Biopharma’s facilities. For purposes of clarification, Ex Works means that carriage of goods shall be arranged by Client, and the cost of such carriage and risk of loss shall transfer to Client when the
goods have been made available for shipment at KBI Biopharma’s facilities. KBI Biopharma shall package for shipment such product, raw materials, samples, components or other materials at Client’s expense (including insurance) and in
accordance with Client’s complete written and reasonable instructions. 

  

	9.2	Shipping Charges. Client shall pay to KBI Biopharma, in addition to actual shipping costs, a handling fee of either (i) One Hundred Dollars ($100) for each standard shipment, or (ii) One Thousand
Dollars ($1,000) for each expedited shipment (i.e., shipment made available in less than forty-eight (48) hours from request by Client). 

  

	10.	Notices 

 Any notice required to be given pursuant to the terms and provisions hereof shall be in writing
and shall be sent by certified or registered mail, postage prepaid with return receipt requested, or by nationally recognized overnight courier, postage prepaid with return receipt requested, or by confirmed facsimile (with printed confirmation of
receipt), to the other Party at the following address: 
 If to Client: 

Aeglea Development Company, Inc. 815-A Brazos St #101 

Austin, TX 78701 
 Attention:
David G. Lowe 
  
  

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

 If to KBI Biopharma: 

KBI Biopharma, Inc. 
 1101 Hamlin
Road 
 Durham, North Carolina 27704 

Attention: George Elston, Senior Vice President and CFO 

with a copy to the Vice President and General Counsel, at the same address. 

Each notice shall be deemed sufficiently given, served, sent, or received for all purposes at such time as it is delivered to the addressee or at such time as
delivery is refused by the addressee upon presentation. 
  

	11.	Limitations of Liability 

 Notwithstanding anything herein to the contrary, except as set forth below,
each Party’s total liability for any loss suffered by the other Party resulting from this Agreement, shall be limited to the payment of damages which shall not exceed the price for Services payable by Client to KBI Biopharma under the Proposal.
The foregoing limitation shall not apply to breaches of Section 13, and shall not limit either Party’s obligations under Section 15. 

EXCEPT AS PROVIDED BELOW IN THIS PARAGRAPH, NEITHER PARTY SHALL BE LIABLE TO THE OTHER PARTY FOR ANY INCIDENTAL, INDIRECT, PUNITIVE, CONSEQUENTIAL
(INCLUDING WITHOUT LIMITATION, LOST PROFITS), EXEMPLARY OR SPECIAL DAMAGES OF ANY TYPE, ARISING IN CONNECTION WITH THIS AGREEMENT, THE PROPOSAL, THE QUALITY AGREEMENT OR ANY ATTACHMENTS OR DOCUMENTS RELATED THERETO, WHETHER OR NOT FORESEEABLE AND
WHETHER SUCH DAMAGES ARISE IN TORT, CONTRACT, EQUITY, STRICT LIABILITY, OR OTHERWISE, EVEN IF THE PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. The foregoing limitation shall not apply to breaches of Section 13, and shall not
limit either Party’s obligations under Section 15 
  

	12.	Warranties 

  

	12.1	Warranties of KBI Biopharma. 

  

	    	12.1.1 As of the Effective Date, KBI Biopharma represents and warrants to Client that it has all requisite corporate power and authority to enter into and perform all of its obligations under this Agreement. The
execution and delivery of this Agreement and the consummation of the transactions contemplated hereby have been duly and validly authorized by all necessary corporate action in respect thereof on the part of KBI 

 
  

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

	 	
Biopharma. Neither the execution and delivery of this Agreement nor the performance of the transactions contemplated hereby, nor compliance by KBI Biopharma with the provisions hereof, shall
conflict with any obligations or agreements of KBI Biopharma to any person, contractual or otherwise. 

 12.1.2 KBI Biopharma
warrants to Client that it will render the Services with due care, consistent with industry standards for work of a similar nature. 

12.1.3 KBI Biopharma represents, warrants and covenants to Client that, except to the extent provided in the Proposal, KBI Biopharma will not,
to its knowledge, use the property of any third party in performing the Services. KBI Biopharma represents, warrants and covenants that Client will receive good title to Results without any liens or encumbrances. KBI Biopharma represents and
warrants to Client that to KBI Biopharma’s knowledge, KBI Biopharma’s performance of the Services will not violate or infringe on the patents, trademarks, service marks, copyrights, or intellectual property of any nature of any third
party. 
 12.1.4 KBI Biopharma represents and warrants to Client that it will hold, use and/or dispose of Client Materials in accordance
with all applicable laws, rules and regulations. 
 12.1.5 KBI Biopharma represents to Client that it is not debarred, and warrants to
Client that it will not knowingly use in any capacity the services of any person debarred, under subsections 306(a) or (b) of the Generic Drug Enforcement Act of 1992, as each may be amended from time to time. 

12.1.6 EXCEPT AS EXPRESSLY WARRANTED IN THIS SECTION 12.1, KBI BIOPHARMA MAKES NO REPRESENTATION OR WARRANTY WITH RESPECT TO THE SERVICES OR
PRODUCT, EXPRESS OR IMPLIED, IN ANY MANNER AND EITHER IN FACT OR BY OPERATION OF LAW, AND SPECIFICALLY DISCLAIMS ANY AND ALL IMPLIED OR STATUTORY WARRANTIES, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE, COURSE OF DEALING, COURSE OF PERFORMANCE, USAGE OF TRADE OR NONINFRINGEMENT. KBI BIOPHARMA MAKES NO WARRANTIES THAT THE EXECUTION OF THE SERVICES WILL RESULT IN ANY SPECIFIC QUANTITY OR AMOUNT OF PRODUCT. 

 

	12.2	Warranties of Client. 

 12.2.1 As of the Effective Date, Client represents and warrants
to KBI Biopharma that it has all requisite corporate power and authority to enter into and perform all of its obligations under this Agreement. The execution and delivery of this Agreement and the consummation of the transactions contemplated hereby
have been duly and validly authorized by all necessary corporate action in respect thereof on the part of Client. 
  

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

 
Neither the execution and delivery of this Agreement nor the performance of the transactions contemplated hereby, nor compliance by Client with the provisions hereof, shall conflict with any
obligations or agreements of Client to any person, contractual or otherwise. 
 12.2.2 Client represents and warrants to KBI Biopharma that
it holds legal title to, or is fully entitled to provide, the materials, methods, plans, processes and other intellectual property necessary to conduct the Services and that, to Client’s knowledge, KBI Biopharma’s performance of the
Services will not violate or infringe on the patents, trademarks, service marks, copyrights, or intellectual property of any nature of any third party. 

12.2.3 Client represents and warrants to KBI Biopharma that, to its knowledge, the materials provided by Client for use in the performance of
the Services are free of material defects and contaminants. 
 12.2.4 Client represents and warrants to KBI Biopharma that it will hold, use
and/or dispose of Product delivered to it hereunder and all materials provided by KBI Biopharma in accordance with all applicable laws, rules and regulations. 
  

	13.	Confidentiality 

  

	13.1	Confidential Information. During the Term and for a period of five (5) years thereafter, each Party shall maintain in confidence all information and materials of the other Party disclosed or provided to it
(the “Recipient”) by the other Party (the “Disclosing Party”) including the terms and conditions (but not the existence) of this Agreement (together with all embodiments thereof, the
“Confidential Information”); provided, however, (a) information need not be labeled or marked “confidential” to be deemed Confidential Information hereunder, if under the circumstances it is, or should be,
understood to be confidential; and (b) in accordance with Section 5.2, information learned, observed or obtained by Client during any visit to KBI Biopharma’s facilities shall to the extent provided in Section 5.2 hereof, be
deemed “Confidential Information” of KBI Biopharma hereunder, regardless of whether such information is marked “confidential” or subsequently summarized in writing. Notwithstanding anything to the contrary herein, Results and
information regarding Client Materials, Client Inventions (as defined in Section 14.1), and Client’s business, scientific, research, and development plans shall be deemed Client’s Confidential Information regardless of whether such
information is marked “confidential” or subsequently summarized in writing, with respect to which, Client shall be the Disclosing Party and KBI Biopharma the Recipient. 

 
  

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

	13.2	Exceptions. Notwithstanding the foregoing, Confidential Information shall not include that portion of information or materials that the Recipient can demonstrate by contemporaneous written records was:

  

	 	(i)	known to the general public at the time of its disclosure to the Recipient, or thereafter became generally known to the general public, other than as a result of actions or omissions of the Recipient in violation of
this Agreement; 

  

	 	(ii)	disclosed to the Recipient on an unrestricted basis from a source unrelated to the Disclosing Party and not known by the Recipient to be under a duty of confidentiality to the Disclosing Party, as evidenced by competent
written proof; or 

  

	 	(iii)	independently developed by the Recipient, or known by the Recipient prior the date of disclosure by the Recipient, without the use of Confidential Information of the Disclosing Party, as evidenced by competent written
proof. 

  

	13.3	Additional Protections. Each Party shall take all reasonable steps to maintain the confidentiality of the Confidential Information of the other Party, which steps shall be no less protective than those that such
Party takes to protect its own information and materials of a similar nature, but in no event less than a reasonable degree of care. Neither Party shall use or permit the use of any Confidential Information of the other Party except for the purposes
of carrying out its obligations or exercising its rights under this Agreement. All Confidential Information of a Party, including all copies and derivations thereof, is and shall remain the sole and exclusive property of the Disclosing Party and
subject to the restrictions provided for herein. Neither Party shall disclose any Confidential Information of the other Party other than to those of its directors, officers, employees, licensors, independent contractors, assignees, agents and
external advisors directly concerned with the carrying out of this Agreement, on a strictly applied “need to know” basis, provided that any such disclosure is made subject to obligations of confidentiality no less stringent than the
obligations provided herein. 

  

	13.4	Permitted Disclosures. The obligations set forth in this Article 13 shall not apply to the extent that Recipient is required to disclose information by law, judicial order by a court of competent jurisdiction, or
the rules of a securities exchange or requirement of a governmental agency for purposes of obtaining approval to test or market Product, or disclosures of information to a patent office for the purposes of filing a patent application as permitted in
this Agreement; provided, however, that the Recipient shall provide prior written notice thereof to the Disclosing Party and sufficient opportunity for the Disclosing Party to review and comment on such required disclosure and request confidential
treatment thereof or a protective order therefore. Any disclosure permitted pursuant to this Section 13.4 shall not be considered an exception under Section 13.2. 

 

	13.5	Injunctive Relief. The Parties acknowledge that either Party’s breach of this Article 13 may cause the other Party irreparable injury for which it may not have an adequate remedy at law. In the event of a
breach, the non-breaching Party shall be entitled to seek injunctive relief in addition to any other remedies it may have at law or in equity, in accordance with Article 23. 

 
  

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

	14.	Inventions 

  

	14.1	Inventions. Client shall own (i) any and all Results, (ii) all ideas, developments, inventions, methods, technology, know-how, improvements, techniques generated or created by KBI Biopharma or its
employees, directors, officers, subcontractors, consultants, agents and representatives (“Representatives”) in the performance of the Services or as a result of access to or use of Client Materials or Client’s
Confidential Information whether independently or jointly with one or more employees of Client or others and (iii) all intellectual property rights associated with the foregoing items (i) and (ii), including, without limitation,
copyrights, trade secrets, inventions, whether patentable or not, ((i), (ii) and (iii) are collectively, “Client Inventions”). KBI Biopharma hereby assigns to Client all right, title and interest in and to Client
Inventions without any lien, claim or encumbrance. Notwithstanding the foregoing, KBI Biopharma shall retain all rights to any data, ideas, information, developments, inventions, or know- how relating to general manufacturing and analytical methods
and processes developed, conceived or reduced to practice in connection with the Services that (i) can be generally applied to the production of biologics other than the Product and (ii) are not derived from and do not contain or reference
Client’s Confidential Information (“Process Invention”). If Client requests and at Client’s expense, KBI Biopharma will execute any and all applications, assignments or other instruments and give testimony which
shall be necessary to apply for and obtain letters of patent of the US or of any foreign country with respect to the Client Invention and Client shall compensate KBI Biopharma for the time devoted to such activities (at commercially reasonable
rates) and reimburse it for reasonable, documented out-of-pocket expenses incurred. For Client Inventions assigned pursuant to this section, Client shall provide KBI Biopharma a royalty-free license to use such Client Inventions to the extent
necessary to perform the Services. KBI Biopharma shall not incorporate any intellectual property, inventions, technology, processes, methods or other property of KBI Biopharma into Client Inventions and Results (“Non-Client
Property”). To the extent KBI Biopharma does incorporate Non-Client Property into Client Inventions or Results, KBI Biopharma hereby grants Client a non-exclusive, perpetual, irrevocable, royalty-free, world-wide and transferable
license, with the right to sublicense, to use and exercise all such Non-Client Property and all associated patent rights, trade secret rights and other intellectual property rights for any purpose relating to Client’s and its sublicensee’s
use of the Client Inventions, Deliverables, Products, Results and derivatives thereof. No license fee shall be payable by Client for this license either during or after the term of this Agreement. 

 

	14.2	Process Inventions. KBI Biopharma hereby grants to Client a perpetual, irrevocable, fully-paid, royalty-free, world-wide and transferable non-exclusive license (with the right to sublicense through multiple tiers
of sublicensees) to use Process Inventions and exercise all associated patent rights, trade secret rights and other intellectual property 

  

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

	 	
rights, to the extent necessary to make, have made, sell, offer for sale, use, import and otherwise commercially exploit Product, Deliverables, Client Inventions, Results and derivatives thereof.
If KBI Biopharma reasonably requests, and at KBI Biopharma’s expense, Client will execute any and all applications, assignments or other instruments and give testimony which shall be necessary to apply for and obtain letters of patent of the US
or of any foreign country with respect to the Process Inventions and KBI Biopharma shall compensate Client for the time devoted to such activities and reimburse it for expenses incurred. 

 

	14.3	KBI Biopharma Process Technology. Client acknowledges that KBI Biopharma, and KBI Biopharma’s personnel, possess and continuously update proprietary inventions, tools, templates, models, methodologies,
processes, know-how, trade secrets, improvements, and other intellectual properties and other assets, including but not limited to analytical methods, procedures and techniques, computer technical expertise and software, and business practices,
related to the development and commercialization of biopharmaceuticals, as well as other areas, which have been independently developed by KBI Biopharma and its personnel (collectively, “KBI Biopharma Process Technology”).
KBI Biopharma, and KBI Biopharma’s personnel, shall retain exclusive right, title and interest in and to all KBI Biopharma Process Technology and improvements thereto. 

 

	15.	Indemnification 

  

	15.1	Indemnification by KBI Biopharma. KBI Biopharma will indemnify, defend and hold harmless Client and its shareholders, directors, officers, employees and agents (each, a “Client
lndemnitee”) from and against all costs, losses, expenses (including reasonable attorneys’ fees) and direct damages (collectively, “Losses”) resulting from all lawsuits, claims, demands, actions and other
proceedings by or on behalf of any third party (collectively “Claims”) to the extent arising out of or resulting from: (i) K61 Biopharma’s material breach of any of its covenants, obligations or warranties
hereunder, or a failure of any material representation made hereunder by KBI Biopharma; or (ii) KBI Biopharma’s gross negligence or intentional misconduct, except in each case to the extent such Claims or Losses arise from negligence or
intentional misconduct on the part of a Client Indemnitee or a breach of this Agreement by Client. 

  

	15.2	Indemnification by Client. Client will indemnify, defend and hold harmless KBI Biopharma and its shareholders, directors, officers, employees and agents (each, a “KBI Biopharma
Indemnitee”) from and against all Losses resulting from all Claims to the extent arising out of or resulting from: (i) Client’s material breach of any of its covenants, obligations or warranties hereunder, or a failure of any
material representation made hereunder by Client; (ii) the development (including the conduct of clinical trials in humans), handling, manufacturing, testing, storage, transportation, disposal, marketing, commercialization (including any
recalls, field corrections or market withdrawals), distribution, promotion, sale or use by Client of the Product or of the results or performance of the Services (including without limitation as a result of any illness, injury 

 
  

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

	 	
or death to persons, including employees, agents or contractors of Client or damage to property); or (iii) Client’s gross negligence or intentional misconduct; except in each case to
the extent such Claims or Losses arise from negligence or intentional misconduct on the part of a KBI Biopharma Indemnitee or a breach of this Agreement by KBI Biopharma. 

 

	15.3	Indemnification Procedure. If any Claim covered by Article 15 is brought: 

 15.3.1
the indemnified Party shall promptly notify the indemnifying Party in writing of such Claim, provided, however, the failure to provide such notice within a reasonable period of time shall not relieve the indemnifying Party of any of its obligations
hereunder except to the extent the indemnifying Party is prejudiced by such failure or delay; 
 15.3.2 the indemnifying Party shall assume,
at its cost and expense, the sole defense of such Claim through counsel selected by the indemnifying Party and reasonably acceptable to the other Party, except that those indemnified may at their option and expense select and be represented by
separate counsel; 
 15.3.3 the indemnifying Party shall maintain control of such defense and/or the settlement of such Claim; 

15.3.4 the indemnified Party may, at its option and expense, participate in such defense, and if it so participates, the indemnifying Party
and the indemnified Party shall cooperate with one another in such defense; 
 15.3.5 the indemnifying Party will have authority to consent
to the entry of any settlement or otherwise to dispose of such Claim (provided and only to the extent that an indemnified Party does not have to admit liability and such judgment does not involve equitable relief), and an indemnified Party may not
consent to the entry of any judgment, enter into any settlement or otherwise to dispose of such Claim without the prior written consent of the indemnifying Party (not to be unreasonably withheld or delayed); and 

15.3.6 the indemnifying Party shall pay the full amount of any judgment, award or settlement with respect to such Claim and all other costs,
fees and expenses related to the resolution thereof; provided, however, that such other costs, fees and expenses have been incurred or agreed, as the case may be, by the indemnifying Party in its defense or settlement of the Claim. 

 

	16.	Force Majeure 

 Except for each Party’s payment, confidentiality and indemnity obligations, the
obligations of either Party under this Agreement shall be excused during each period of delay directly caused by matters such as acts of God, strikes, power failure, government orders, sufferance of acts of government or governmental regulation
(including without limitation, acts of the FDA or an applicable foreign equivalent), or acts of war or terrorism, which are reasonably beyond the 
  

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

 
control of the Party obligated to perform (each, a “Force Majeure Event’). A Force Majeure Event shall not include a lack of funds, bankruptcy or other financial cause or
disadvantage. Nothing contained in this Agreement shall affect either Party’s ability or discretion regarding any strike and all such strikes shall be deemed to be beyond the control of such Party. A Force Majeure Event shall be deemed to
continue only so long as the affected Party shall be using its commercially reasonable effort to overcome such condition. If either Party shall be affected by a Force Majeure Event, such Party shall use commercially reasonable efforts to mitigate
the effects of the Force Majeure Event and shall give the other Party prompt notice thereof, which notice shall contain the affected Party’s estimate of the duration of such condition and a description of the steps being taken or proposed to be
taken to overcome such Force Majeure Event. If a Force Majeure Event continues for more than ninety (90) days, the Party whose performance is not affected by the Force Majeure Event shall have the right to terminate this Agreement, effective
upon notice to the other party. Any delay, or invalidity in the results delivered, in the performance of the Services occasioned by any such cause shall not constitute a default under this Agreement, and the obligations of the Parties shall be
suspended during the period of delay so occasioned. During any period of any Force Majeure Event, the Party that is not directly affected by such Force Majeure Event may take any reasonable action necessary to mitigate the effects of such Force
Majeure Event. If any part of the Services is invalid as a result of such disability, KBI Biopharma will, upon written request from Client, but at Client’s sole cost and expense, repeat that part of the Services affected by the Force Majeure
Event. 
  

	17.	Insurance 

  

	17.1	KBI Biopharma Insurance. KBI Biopharma shall secure and maintain in full force and effect throughout the Term policies of insurance for (a) workers’ compensation in accordance with applicable statutory
requirements, employer’s liability in an amount not less than $1,000,000, and automobile liability in an amount not less than $1,000,000, (b) commercial general liability in an amount not less than $2,000,000 per occurrence and $2,000,000
in the aggregate, and (c) products liability in an amount not less than $2,000,000 per occurrence and $2,000,000 in the aggregate. 

  

	17.2	Client Insurance. Client shall secure and maintain in full force and effect throughout the Term, and for a period of three (3) years after completion of any clinical trials in which any Product provided
under this Agreement is used, policies of insurance for (a) workers’ compensation in accordance with applicable statutory requirements, employer’s liability in an amount not less than $1,000,000, and automobile liability in an amount
not less than $1,000,000 and (b) primary and noncontributory commercial general liability in an amount not less than $1,000,000 per occurrence and $2,000,000 in the aggregate 

 

	18.	Independent Contractor; Non-Solicitation 

  

	18.1	Independent Contractor. KBI Biopharma shall perform the Services as an independent contractor of the Client. The relationship between the Parties shall not constitute a partnership, joint venture or agency nor
constitute either Party as the agent, employee or legal representative of the other. The Parties agree that neither shall have power or right to bind or obligate the other, nor shall either hold itself out as having such authority.

  
  

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

	18.2	Non-Solicitation. During the Term of this Agreement and for one (1) year thereafter, each Party agrees not to directly or indirectly solicit to hire or hire (in any capacity) any person who is an employee,
contractor, consultant or representative of the other Party; provided that newspaper, internet or other advertisements to fill job openings shall not be deemed to be “solicitation” hereunder. Any exceptions to this provision must be in
writing and signed by each Party and, for each person that is hired in such manner, the hiring Party shall compensate the other Party at the rate of 30% of such person’s annualized base salary. 

 

	19.	Publicity 

 The Parties may agree in writing to issue press releases or public disclosures describing the
general nature of the Services provided hereunder. The use of the name, trademark, logo, or other identifying materials of either Party or its employees in any publicity, advertising or promotional material shall require the other Party’s
express prior written consent. 
  

	20.	Use of Intellectual Property Rights 

 Except as expressly stated in this Agreement, no intellectual
property rights of any kind or nature are conveyed by this Agreement and neither Party shall have any right, title or interest in or to the other Party’s intellectual property rights for any purpose whatsoever without such other Party’s
prior written consent. 
  

	21.	Entire Agreement, Amendment, Construction, Precedence 

 This Agreement, the Proposal, and any applicable
Quality Agreement constitute the entire agreement between the Parties and supersede all prior and contemporaneous negotiations, representations, commitments, agreements and understandings between the Parties (whether written or oral) relating to the
subject matter hereof. This Agreement may not be amended or modified without the mutual written consent of both Parties. Each Party has had the opportunity to consult with counsel in connection with the review, drafting and negotiation of this
Agreement. Accordingly, the rule of construction that any ambiguity in this Agreement shall be construed against the drafting Party shall not apply. In the event of any conflict among the components of this Agreement, the following order of
precedence shall apply: (i) the terms and conditions of the Agreement, (ii) the Quality Agreement (if existing), and (iii) the Proposal. If Client chooses to issue a purchase order for the delivery of the Services or any component
thereof, such purchase order should reference this Agreement and shall be issued solely for the convenience of Client and to provide subject matter description; however, any legal terms and conditions contained therein shall be of no effect. 

 
  

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

	22.	Choice of Law 

 This Agreement shall be construed and enforced in accordance with the laws of and in the
venue of the State of North Carolina, without regard to its, or any other jurisdiction’s, rules regarding conflicts or choice of laws. The Parties agree to and submit to the sole and exclusive jurisdiction of the North Carolina courts, both
state and federal. The Parties waive application of the provisions of the 1980 U.N. Convention on Contracts for the International Sale of Goods, as amended. 
  

	23.	Dispute Resolution 

  

	23.1	Initial Attempts to Resolve Disputes. If a dispute arises between the Parties in connection with this Agreement, the respective presidents or senior executives of KB’ Biopharma and Client shall first meet as
promptly as practicable and attempt to resolve in good faith such dispute. If such parties cannot resolve the dispute within thirty (30) days after written notice given by one Party to the other specifically invoking this stage in the dispute
resolution procedure, either Party may by written notice to the other commence the arbitration process set forth in Section 23.2 below. 

  

	23.2	Arbitration. If a dispute has not been resolved by negotiation as provided in Section 23.1 above, then, except as otherwise provided in this Section 23.2, the dispute will be finally settled by binding
arbitration in accordance with the Commercial Arbitration Rules of the AAA then in effect, by three (3) arbitrators, one of whom will be designated by each Party and the third of whom will be designated by the two so designated. The
arbitration, it shall be conducted in English and held in Durham, North Carolina. The arbitrators will render their award in writing and, unless all Parties agree otherwise, will include an explanation in reasonable detail of the reasons for their
award. Judgment upon the award rendered by the arbitrators may be entered in any court having jurisdiction thereof. The Parties expressly waive any putative right they may otherwise have to seek an award arising out of any dispute hereunder of
punitive damages or any other damages limited or excluded by this Agreement. The arbitrator will have the authority to grant injunctive relief and other specific performance. The arbitrator will, in rendering its decision, apply the substantive law
of the State of North Carolina, without regard to its conflict of laws provisions. The decision and/or award rendered by the arbitrator will be final and non- appealable (except for an alleged act of corruption or fraud on the part of the
arbitrator). 

  

	23.3	Expenses. All expenses and fees of the arbitrators and expenses for hearing facilities and other expenses of the arbitration will be borne equally by the Parties unless the Parties agree otherwise or unless the
arbitrators in the award assess such expenses against one of the Parties or allocate such expenses other than equally between the Parties. Each of the Parties will bear its own counsel fees and the expenses of its witnesses except (i) to the
extent otherwise provided in this Agreement or by applicable law or (ii) to the extent the arbitrators in their discretion determine for any reason to allocate such fees and expenses among the Parties in a different manner. Any attorney or
retired judge who serves as an arbitrator will be compensated at a rate equal to his or her current regular hourly billing rate unless otherwise mutually agreed upon by the Parties and the arbitrator. 

 
  

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

	23.4	Interlocutory Relief. Compliance with this Article 23 is a condition precedent to seeking relief in any court or tribunal in respect of a dispute, but nothing in this Article 23 will prevent a Party
from seeking interlocutory relief in the courts of appropriate jurisdiction provided in Article 22, pending the arbitrator’s determination of the merits of the controversy, if applicable to protect the Confidential Information, property or
other rights of that Party. 

  

	24.	Assignment and Delegation 

  

	24.1	Assignment. This Agreement between the Parties shall not be assigned in whole or in part by either Party without the prior written consent of the other, which consent shall not be unreasonably withheld or
delayed; provided, however, either Party may assign this Agreement in its entirety without the other Party’s consent, upon written notice to the other Party, as part of: (a) the sale of all or substantially all of the assets or the entire
business to which this Agreement relates, or (b) a merger, consolidation, reorganization or other combination with or into another person or entity, in each case, pursuant to which the surviving entity or assignee assumes in writing the
assigning or merging Party’s obligations hereunder. Any attempt to assign, or purported assignment of, this Agreement in contravention to this Section 24.1 shall be void ab initio and of no effect. This Agreement shall be binding
upon and inure to the benefit of the Parties hereto and their respective successors and permitted assigns. 

  

	24.2	Delegation. KBI Biopharma shall not delegate the performance of its obligations under this Agreement; however, performance of the Services hereunder may be delegated or subcontracted by KBI Biopharma with the
written consent of Client, which consent shall not be unreasonably withheld. In the event KBI Biopharma subcontracts its obligations hereunder, KBI Biopharma shall require the subcontractor to be bound by the terms of this Agreement, and KBI
Biopharma shall be liable for the act, omissions and breaches of this Agreement by such subcontractors such that any breach of this Agreement by such subcontractors shall be deemed a breach hereof by KBI Biopharma. 

 

	25.	Term and Termination 

  

	25.1	Term. The term of this Agreement (the “Term”) shall be from the Effective Date until the third anniversary thereof, unless extended or earlier terminated as provided herein. If the
Services have not been completed at the end of the initial term, the Term will thereafter be extended for successive one year periods until the Services have been completed. Additionally, the Agreement may be terminated sooner as provided in
Section 25.2 or 25.3, or the Term may be extended by written agreement of the Parties. 

  

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

	25.2	Termination without Breach. Client may terminate this Agreement or a Proposal prior to completion of the Proposal by providing sixty (60) days written notice to KBI Biopharma, subject to the conditions of
this Section 25.2. Upon receipt of such notice of termination, KBI Biopharma will promptly scale down the affected portion of the Proposal and use reasonable commercial efforts to avoid (or minimize, where non-cancellable) additional expenses.

  

	25.3	Termination for Breach. In the event of a material breach of this Agreement by a Party that is not cured within thirty (30) days of written notice of such breach by the non- breaching Party, the
non-breaching Party may terminate this Agreement or a Proposal immediately upon written notice. Upon such termination, KBI Biopharma will promptly scale down the affected portion of the Proposal and use its reasonable commercial efforts to avoid (or
minimize, where non-cancellable) additional expenses. 

  

	25.4	Bankruptcy. This Agreement may be terminated upon written notice by a Party in the event: (i) the other Party voluntarily enters into bankruptcy proceedings; (ii) the other Party makes an assignment for
the benefit of creditors; (iii) a petition is filed against the other Party under a bankruptcy law, a corporate reorganization law, or any other law for relief of debtors or similar law analogous in purpose or effect, which petition is not
stayed or dismissed within thirty (30) days of filing thereof; or (iv) the other Party enters into liquidation or dissolution proceedings or a receiver is appointed with respect to any assets of the other Party, which appointment is not
vacated within one hundred and twenty (120) days. 

  

	25.5	Effects of Termination. Upon termination of this Agreement for any reason, each Party shall, as soon as practicable, but in any event within ten (10) business days of the effective date of termination,
return to the other all Confidential Information which it possesses that belongs to the other Party, except that each may retain a copy in its law department for record keeping purposes. Upon termination of this Agreement, KBI Biopharma will furnish
to Client a complete inventory of all work in progress and an inventory of all Product processed pursuant to the Proposal. Upon termination of this Agreement, neither Party shall use or exploit in any manner whatsoever any intellectual property
rights or Confidential Information of the other Party, excepted as may be specifically provided in this Agreement. With respect to the liquidated damages set forth in Section 25.2 and Section 25.3, the Parties acknowledge and agree that
(i) actual damages would be difficult or impracticable to ascertain, (ii) the amounts set forth in Section 25.2 or Section 25.3, as applicable, represent the Parties reasonable estimate of such damages, and (iii) the amounts
set forth in this Section 25.2 or Section 25.3, as applicable, are not unreasonable under the circumstances existing at the time this Agreement was entered. 

 
  

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

	26.	Survival 

 Articles 4, 6, 10, 11, 13, 14, 15, 19, 20, 21, 22, 23, 26, and Sections 7.2.7, 7.4,
12.2.4, 17.2, 25.2, 25.3 and 25.5 hereof shall survive termination or expiration of this Agreement. Expiration or termination shall not extinguish the rights and remedies of either Party with respect to any ,antecedent breach of any of the
provisions of this Agreement or payments due or earned under this Agreement. 
  

	27.	Severability 

 In the event that any one or more of the provisions of this Agreement should be held for
any reason by any court or authority having final jurisdiction over this Agreement, or over any of the Parties to this Agreement, to be invalid, illegal, or unenforceable, such provision or provisions shall be reformed to approximate as nearly as
possible the intent of the Parties, and if not reformable, shall be divisible and deleted in such jurisdictions; elsewhere, this Agreement shall not be affected. 
  

	28.	Waiver and Remedies 

 The delay or waiver (or single or partial exercise) by either Party hereto of any
right, power, or privilege hereunder, or of any failure of the other Party to perform, or of any breach by the other Party, shall not be deemed a waiver of any other right, power, or privilege hereunder or of any other breach by or failure of such
other Party, whether of a similar nature or otherwise. Any such waiver must be made in writing. Except as may otherwise be specifically set forth in this Agreement, no remedy referred to in this Agreement is intended to be exclusive, but each shall
be cumulative and in addition to any other remedy referred to in this Agreement or otherwise available under law or equity. No Party shall have any right of set off with respect to amounts it has an obligation to pay hereunder. No provision of this
Agreement shall in any way inure to the benefit of any third person so as to constitute to any such person a third-party beneficiary of this Agreement or otherwise give rise to any cause of action in any person not a Party hereto. 

 

	29.	Counterparts 

 This Agreement, the Quality Agreement(s), the Proposal and any other attachment may be
executed in counterparts, each of which will be deemed an original but all of which together will constitute a single instrument. A facsimile or electronic transmission of the above referenced documents, or a counterpart, shall be legal and binding
on the Parties. 
  

	30.	Headings 

 All article and section titles or headings contained in this Agreement, the Quality Agreement
and the Proposal are for convenience only, will not be deemed a part hereof or thereof, and will not affect the meaning or interpretation of this Agreement. 

[Signature Page Follows.] 
  

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

 In Witness Whereof, the Parties by their authorized representatives execute this Agreement as of the Effective
Date. 
  

									
	KBI BIOPHARMA, INC.				AEGLEA DEVELOPMENT COMPANY, INC.
					
	By:		/s/ Andrew B. Cohen				By:		/s/ David G. Lowe
					
	Name:		Andrew B. Cohen				Name:		David G. Lowe
					
	Title:		VP & General Counsel				Title:		President and Chief Executive Officer
					
	Date:		12/24/2013				Date:		12/24/2013

  
  

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

 EXECUTION COPY 

FIRST AMENDMENT 
 TO

 MASTER SERVICES AGREEMENT 

THIS FIRST AMENDMENT TO MASTER SERVICES AGREEMENT (this “Amendment”) is entered into on this 30th day of June, 2015
(the “Amendment Effective Date”), by and between Aeglea Development Company, Inc., a Delaware corporation having a place of business at 815-A Brazos St. #101, Austin, TX 78701 (“Client”) and KBI
Biopharma, Inc., having a place of business at 1101 Hamlin Road, Durham, North Carolina 27704 (“KBI Biopharma”) (Client and KBI Biopharma, each a “Party”, and collectively, the
“Parties”). 
 RECITALS 

A. The Parties entered into that certain Master Services Agreement (the “Agreement”), dated December 24, 2013
(the “Effective Date”). 
 B. The Parties now desire to enter into this Amendment for the purpose of amending
certain terms and conditions of the Agreement as of the Amendment Effective Date. 
 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing recitals and other good and valuable consideration, the
receipt and adequacy of which is hereby acknowledged, and intending to be legally bound, the Parties agree as follows: 
 1. Definitions. Capitalized
terms used but not defined in this Amendment shall have the meanings given to them in the Agreement. 
 2. Amendment to Section 7.1.
Section 7.1 of the Agreement is hereby deleted in its entirety and replaced by the following: 
  

	 	7.1	Fees. In consideration for KBI Biopharma performing the Services, Client shall pay to KBI Biopharma such amounts as described in the Price and Payment Terms section of the Proposal and as otherwise described in
this Agreement. 

 3. Amendment to Section 7.2. Section 7.2 of the Agreement is hereby deleted in its
entirety and replaced by the following: 
  

	 	7.2	Equity Component of Service Fees. Certain portions of the service fees (the “Equity Component”) under the applicable Proposals will be paid for in the form of the issuance of Shares (as
defined in Section 7.2.1) of Aeglea BioTherapeutics Holdings, LLC (“Aeglea Holdings”) or Aeglea BioTherapeutics, Inc. (“Aeglea”) as described in this Section 7.2. The Equity Component will be
paid as follows: 

 7.2.1 “Shares” means: (i) before March 10, 2015, Preferred A Shares of
Aeglea Holdings at a price of $[***] per share, (ii) on or after March 10, 2015, shares of Series B Preferred Stock of Aeglea at a price of $[***] per share or (iii) New Round Securities in Aeglea. In the event that Aeglea issues a
new series of preferred shares other than Series B Preferred prior to the issuance of any Shares as required above (“New Round Securities”), then in lieu of Series B Preferred shares, KBI Biopharma shall be issued a number of
New Round Securities equal to the corresponding equity value set forth above divided by the price per share of the New Round Securities. 
  

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

 7.2.2 Notwithstanding anything to the contrary in this Agreement, with effect from the closing of
a sale of common stock of Aeglea to the public in an underwritten public offering pursuant to an effective registration statement under the Securities Act of 1933, as amended, then all fees for Services under this Agreement (including any previously
agreed Equity Component) will be paid, when due and payable, in cash (and not Shares). 
 7.2.3 For Stage 1 of Program 1 (corresponding to
enabling Phase I studies for Arginase) and Stage 1 of Program 2 (corresponding to process development for Cystinase), a number of Shares shall be issued to KBI Biopharma calculated as set forth in the table immediately below, provided further that
all Shares of Aeglea Holdings or Aeglea issued to KBI Biopharma shall be subject to the Share Return Right in Section 7.2.9. 
  

					
	 Stage 1 of Program 1
	  			
	 Total Service Fees Under Current Proposals
	  	$	[***]	  
	 Service Fees Discount Percentage Under Current Proposals
	  	 	[***]	% 
	 Percentage of Cash Component of Total
	  	 	[***]	% 
	 Percentage of Equity Component of Total
	  	 	[***]	% 
	 Total Value of Shares to Be Issued
	  	$	[***]	  
		
	 Stage 1 of Program 2
	  			
	 Total Service Fees Under Current Proposals
	  	$	[***]	  
	 Service Fees Discount Under Current Proposals
	  	$	[***]	  
	 Cash Payments Before Completion of Proposals
	  	$	[***]	  
	 Value of Shares Previously Issued
	  	$	[***]	  
	 Cash Payment Upon Completion of Proposals
	  	$	[***]	  

 For Stage 1 of Program 1, the parties acknowledge and agree that 100% of the Shares to be issued with respect
to events 1 and 2 in the table immediately below have been issued. The Shares to be issued with respect to event 3 in the table immediately below shall be issued upon achievement of event 3 as described in the table immediately below: 

 

			
	 Percentage
of Shares
	  	 Event

	[***]%	  	 1.      Initiation of Services

	[***]%	  	 2.      Acceptance by Client of Process Development Demonstration Run (as defined in Section
3.4)

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

  
 2 

			
	 Percentage
of Shares
	  	 Event

	[***]%	  	 3.      Acceptance by Client of Delivery of cGMP Material (as defined in Section 3.4) and in
accordance with Section 4.4 of the Quality Agreement between the Parties dated December 24, 2014. For the avoidance of doubt, this event 3 shall be deemed to have occurred upon the delivery of the following to Client by KBI
Biopharma:

		  	  

•    KBI Biopharma-approved enzymatic activity assay method qualification report;

 
 •    all KBI
Biopharma-approved deviations associated with batches 149A14-01 and 149A15-02; and
  

•    all KBI Biopharma-approved batch records for batches 149A14-01 and
149A15-02.

 The value of the equity payment (as set forth above) shall be credited against invoiced amounts. 

For Stage 1 of Program 2, the parties acknowledge and agree that 100% of the Shares to be issued with respect thereto have been issued. The
$[***] in services value of such equity payment for Stage 1 of Program 2 shall be credited against invoiced amounts. All remaining amounts for Stage 1 of Program 2 shall be paid in cash. 

7.2.4 For all other Services for which the Parties have agreed to compensation which includes an Equity Component, the applicable amount of the
Equity Component shall be issued to KBI Biopharma for each stage (including Program 1, Stage 2; Program 2, Stage 2; and optional Program 3, Stages 1 and 2) (each a “Stage”), pursuant to the applicable Proposal or other
written agreement of the Parties. All such Shares issued to KBI Biopharma shall be subject to the Share Return Right in Section 7.2.9. 

7.2.5 Subject to Section 7.2.2, each portion of the Equity Component not issued pursuant to Section 7.2.3 shall be compensated by
issuance to KBI Biopharma of the agreed value of Shares in a manner agreed upon by KBI Biopharma and Client. The Parties acknowledge that, depending on the date of initiation of KBI Biopharma’s Services for subsequent Stages, this may result in
KBI Biopharma receiving New Round Securities or cash. 
 7.2.6 Client shall ensure that Aeglea Holdings or Aeglea allocates sufficient Shares
to be potentially issued to KBI Biopharma pursuant to Section 7.2.3 in order to satisfy the anticipated amounts of the Equity Component under Section 7.2.3 (the “KBI Allocated Shares”). 

7.2.7 In the event that the Parties agree on Modifications to the Services, pursuant to Article 8, that would require payment of an additional
amount of Equity Component, such additional amount of Equity Component shall (subject to Section 7.2.2) be paid by either (a) Shares, if Shares remain available for issuance, or (b) payment to KBI Biopharma of the agreed amount in
cash if all applicable KBI Allocated Shares have been previously issued to KBI Biopharma or if no Shares otherwise remain available for issuance. 

7.2.8 Upon the issuance of the first installment of any Equity Component, KBI Biopharma shall execute a signature page to and become party to
and bound by: (i) the Investors Rights Agreement, dated March 10, 2015, between Aeglea and certain investors, (ii) the Voting Agreement, dated March 10, 2015, between Aeglea and certain investors, and (iii) the Right of
First Refusal and Cosale Agreement, dated 
  
 [***] Certain confidential information
contained in this document, marked by brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Rule 406 of the Securities Act of 1933, as amended. Confidential treatment has been requested with respect
to this information. 

  
 3 

 
March10, 2015, between the Aeglea and certain investors (collectively, the “Aeglea Investment Agreements”). Any Shares received for the Equity Component by KBI Biopharma
shall have the same respective rights, preferences and privileges, and subject to same obligations, pursuant to the Aeglea Investment Agreements, as the other preferred shares issued to investors; provided that KBI Biopharma shall not have any
rights to elect members to the Aeglea Board of Directors (but KBI Biopharma shall have the right to appoint an observer to the Board meetings). All Shares issued to KBI Biopharma as part of the Equity Component shall be issued pursuant to a form of
subscription agreement in the form of agreement attached hereto as Attachment Four. 
 7.2.9 In the event that Client terminates this
Agreement or a Proposal pursuant to Section 25.3 or Section 25.4, the portion of any Shares which were issued to KBI Biopharma for Services which were either not performed or were performed in a manner which gave rise to Client’s
right to terminate for breach shall be automatically cancelled and KBI Biopharma shall return the share certificate for such cancelled Shares to Client and upon Client’s receipt of the share certificate for such cancelled Shares Aeglea Holdings
or Aeglea (as the case may be) shall issue a new share certificate to KBI Biopharma for any Shares not so cancelled (hereinafter, the “Share Return Right”). 

4. Effect of Amendment. All of the terms and conditions of the Agreement shall continue in full force and effect except as modified by the terms of
this Amendment. In the event of any inconsistency between the terms and conditions of this Amendment and the terms and conditions of the Agreement, the terms and conditions of this Amendment shall control and govern. 

5. Integration. This Amendment and the Agreement together represent the entire agreement about their subject matter and supersede all prior
negotiations or agreements. All prior agreements, understandings, representations, warranties, and negotiations between the parties about the subject matter of this Amendment and the Agreement merge into this Amendment and the Agreement. 

6. Counterparts. This Amendment may be executed in any number of counterparts and all of such counterparts taken together shall be deemed to constitute
one and the same instrument. 
 [Signature Page Follows] 
  

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

  
 4 

 IN WITNESS WHEREOF, the Parties have caused this Amendment to
be duly executed and delivered as of the Amendment Effective Date. 
  

									
	AEGLEA DEVELOPMENT COMPANY, INC.	 		 	KBI BIOPHARMA, INC.
					
	By:	 	 /s/ David G. Lowe
	 		 	By:	 	 /s/ Andrew B. Cohen

	Name:	 	David G Lowe	 		 	Name:	 	Andrew B. Cohen
	Title:	 	CEO	 		 	Title:	 	VP & General Counsel
				
	AEGLEA BIOTHERAPEUTICS, INC.	 		 		 	
					
	By:	 	 /s/ David G. Lowe
	 		 		 	
	Name:	 	David G Lowe	 		 		 	
	Title:	 	CEO	 		 		 	

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

  
 5

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