Document:

EX-10.10

 Exhibit 10.10 

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE KEROS THERAPEUTICS, INC. HAS DETERMINED THE
INFORMATION (I) IS NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM TO KEROS THERAPEUTICS, INC. IF PUBLICLY DISCLOSED. 

THE GENERAL HOSPITAL CORPORATION 

EXCLUSIVE PATENT LICENSE AGREEMENT 

MGH Agreement No: [***] 

MGH Case Nos: [***] 
 This
License Agreement (“Agreement”) is made as of the 5th day of April, 2016 (“Effective Date”), by and between Keros
Therapeutics, Inc., a Delaware corporation, having a principal place of business at 3 Lincoln Terrace, Lexington, MA 02421 (“Company”) and The General Hospital Corporation, d/b/a Massachusetts General Hospital, a not-for-profit Massachusetts corporation, with a principal place of business at 55 Fruit Street, Boston, Massachusetts 02114 (“Hospital”), each referred to herein
individually as a “Party” and collectively as the “Parties”. 
 RECITALS 

Hospital, as a center for patient care, research and education, is the co- owner of certain Patent
Rights (defined below) and desires to grant a license of those Patent Rights to Company in order to benefit the public by disseminating the results of its research via the commercial development, manufacture, distribution and use of Products and
Processes (defined below). 
 Hospital has executed Inter Institutional Agreements (“IAAs) with [***], [***], and
[***], (collectively “Co-Owners”), granting Hospital sole agency to license the Patent Rights. 

Company has the capability to commercially develop, manufacture, distribute and use Products and Processes for public use and benefit and
desires to license such Patent Rights. 
 For good and valuable consideration, the sufficiency of which is hereby acknowledged, the Parties
hereby agree as follows: 
 1. CERTAIN DEFINITIONS 

As used in this Agreement, the following terms shall have the following meanings, unless the context requires otherwise. 

1.1 “Affiliate” with respect to either Party shall mean any corporation or other legal entity other than that Party in whatever country
organized, controlling, controlled by or under common control with that Party. The term “control” shall mean (i) in the case of Company, direct or indirect ownership of fifty percent (50%) or more of the voting securities having the
right to elect directors, and (ii) in the case of Hospital or Company, the power, direct or indirect, to elect or appoint fifty percent (50%) or more of the directors or trustees, or to cause direction of management and policies, whether
through the ownership of voting securities, by contract or otherwise. 

  
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 1.2 “Change of Control” shall mean either: (a) a sale of all or substantially all of
the assets of Company, in one or a series of integrated transactions not in the ordinary course of business to a Third Party; or (b) the acquisition of Company by a Third Party by means of any transaction or series of related transactions
(including, any stock acquisition, merger, consolidation or other business combination); in either case, in which transaction or series of transactions the holders of outstanding voting securities of Company immediately prior to such transaction do
not beneficially own, directly or indirectly, at least fifty percent (50%) of the combined outstanding voting power of the acquiring entity (or of Company if it is the surviving entity in such transaction described in subsection (b)), or its direct
or indirect parent entity, immediately after such transaction or series of related transactions. 
 1.3 “Claim” shall mean any pending (but
only if pending for less than [***]) or issued claim of any Patent Right that has not been abandoned, lapsed, permanently revoked, nor expired, held unenforceable or invalid by a decision of a court or other governmental agency of competent
jurisdiction that is unappealable or unappealed in the time allowed for appeal. 
 1.4 “Commercially Reasonable Efforts” means the efforts
and resources reasonably used by [***] with respect to the research, development, manufacture, commercialization, use or other exploitation, as applicable, of its own products at a similar stage in development, taking into account all
“Relevant Factors” in effect at the time such efforts are to be expended. As used herein, “Relevant Factors” shall mean all relevant factors that may affect the development, regulatory approval or commercialization of the
Product, including (as applicable): actual and potential issues of safety, efficacy or stability; product profile (including product modality, category and mechanism of action); stage of development or life cycle status; actual and projected
development, regulatory approval, manufacturing, and commercialization costs; any issues regarding the ability to manufacture or have manufactured the Product; the likelihood of obtaining regulatory approvals (including satisfactory price
approvals); the timing of such approvals; the current guidance and requirements for regulatory approval for the Product and similar products and the current and projected regulatory status; labeling or anticipated labeling; the then-current
competitive environment and the likely competitive environment at the time of projected entry into the market; past performance of the Product or similar products; present and future risk-adjusted market potential; existing or projected
risk-adjusted pricing, sales, reimbursement and profitability; pricing or reimbursement changes in relevant countries; proprietary position, strength and duration of patent protection and anticipated exclusivity; and other relevant scientific,
technical, operational and commercial factors. 
 1.5 “Control” means the Hospital’s ability to grant to Company rights to Patent Rights,
without (a) violating the terms of any agreement or other arrangement with any third party, and (b) violating any law or regulation. 
 16
“Derived Process” shall mean any process, method or service derived from or comprising compounds and processes covered under Patent Rights, the use or performance of which, in whole or in part, and absent the rights granted
under the License would infringe, and/or is covered by and/or dominated by, one or more (1) Valid Claims of the Patent Rights granted in the License and/or (2) [***]; provided, however that any subject matter pertaining to any
process method for deriving a compound which is not within the same chemical series as the compounds claimed or covered by the Patent Rights exclusively licensed to Company herein shall not be included under the scope of this definition.

  
 2 

 
1.6 “Derived Product” shall mean any diagnostic or therapeutic article, device or composition, the manufacture, use, or sale of which, in whole or in part, is derived from or comprises
compounds covered under Patent Rights, and absent the rights granted under the License would infringe, and/or is covered by and/or dominated by, one or more (1) Valid Claims of the Patent Rights granted in the License and/or (2) [***];
provided, however that any subject matter pertaining to any compound which is not in the same chemical series as the compounds claimed or covered by the Patent Rights exclusively licensed to Company herein shall not be included under the scope of
this definition [***]. 
 1.7 “Distributor” shall mean any third party entity to whom Company, a Company Affiliate or a Sublicensee
has granted, express or implied, the right to distribute any Product or Process pursuant to Section 2.1(b)(ii). 
 1.8 “First Commercial
Sale” shall mean the initial Sale anywhere in the applicable License Territory of a Product or Process. 
 1.9 “Follow-On Patent Right” means any patent right that is Controlled by Hospital, individually or collectively with another institution, other than the licensed Patent Rights, to the extent such Follow-On Patent Rights directly relate to [***] products that [***], and (2) is conceived and reduced to practice by personnel directly under the supervision of [***] (or any designated
successor laboratory as may be mutually agreed in writing between the Parties in the event of the departure of [***] from his current role with Hospital) during the period commencing on the Effective Date hereof and ending on the [***]
anniversary thereof, unless extended by the mutual written agreement of the Parties. 
 1.10 “License Field” shall mean all use(s) of
Products and Processes for the treatment, diagnosis (the development, manufacture, use, and/or sale of a kit for use in in-vitro diagnostic (IVD) testing), palliation or prevention of diseases and disorders in
humans and animals, including, without limitation, [***]. The first sub-field expected to be developed is the sub-field of [***]. Additional sub-fields for the prevention or treatment of diseases and disorders in humans may include [***]. 
 For clarity,
the license grant in the diagnostic field of use shall be non-exclusive for any implementation of Laboratory Developed Test, performed in a medical and/or clinical laboratory that is operating in
compliance with the Clinical Laboratory Improvement Amendments of 1988 (“CLIA”), or its foreign equivalent, said test being performed on clinical specimens for the diagnosis, treatment and/or prevention of disease. 

1.11 “License Territory” shall mean worldwide. 

1.12 “Net Sales” shall be calculated as set forth in this Section 1.12. 

 

	 	(a)	 Subject to the conditions set forth below, “Net Sales” shall mean: 

 

	 	(i)	 the gross amount billed or invoiced, or if no such bill or invoice is issued the amount received, whichever is
greatest, by Company and its Affiliates and Sublicensees for or on account of Sales of Products and Processes; 

  
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	 	(ii)	 less the following amounts: 

 

	 	(A)	 [***]: 

  

	 	1.	 [***]; 

  

	 	2.	 [***]; 

  

	 	3.	 [***]; and 

  

	 	4.	 [***]. 

  

	 	(B)	 [***]. 

  

	 	(b)	 [***]. 

  

	 	(c)	 [***]. 

  

	 	(d)	 [***]. 

  

	 	(e)	 [***]. 

  

	 	(f)	 [***]: 

  

	 	(i)	 [***]. 

  

	 	(ii)	 [***]. 

  

	 	(iii)	 [***]. 

1.13 “Patent Rights” shall mean Hospital and Co-Owners’ rights in the U.S. Patent Applications
and patents, as described in the Appendix A and/or the equivalent of such application including any division, continuation (including continuation-in-parts, to
the extent that the claims are entitled to the priority date of the respective parent applications) and/or any foreign patent application and/or Letters Patent, and/or the equivalent thereof issuing thereon, and/or reissue, reexamination and/or
extension thereof. 
 1.14 Phase I Clinical Trial” means a human clinical trial in any country that is intended to initially evaluate the safety
and/or effectiveness of a Licensed Product in subjects or that would otherwise satisfy requirements of 21 CFR 312.21(a), or its foreign equivalent. 
 1.15
“Phase II Clinical Trial” means a human clinical trial in any country that is intended to initially evaluate the effectiveness of a Licensed Product for a particular indication or indications in patients with the disease or
indication under study or that would otherwise satisfy requirements of 21 CFR 312.21(b), or its foreign equivalent. 
 1.16 “Phase III Clinical
Trial” means a pivotal human clinical trial in any country the results of which could be used to establish safety and effectiveness of a Licensed Product as a basis for a NDA (or a BLA, as applicable) or that would otherwise satisfy
requirements of 21 CFR 312.21(c), or its foreign equivalent. 

  
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 1.17 “Process” shall mean any process, method or service the use or performance of which,
in whole or in part: 
  

	 	(a)	 absent the license granted hereunder would infringe, or is covered by, one or more Claims of Patent Rights; or

  

	 	(b)	 employs, is based upon or is derived from Technological Information. 

1.18 “Product” shall mean any article, device or composition, the manufacture, use, or sale of which, in whole or in part: 

 

	 	(a)	 absent the license granted hereunder would infringe, or is covered by, one or more Claims of Patent Rights; or

  

	 	(b)	 employs, is based upon or is derived from Technological Information. 

1.19 “Reporting Period” shall mean each three month period ending March 31, June 30, September 30 and December 31. 

1.20 “Sell” (and “Sale” and “Sold” as the case may be) shall mean to sell or have sold, to lease or have leased, to import
or have imported or otherwise to transfer or have transferred a Product or Process for valuable consideration (in the form of cash or otherwise), and further in the case of a Process to use or perform such Process for the benefit of a third party.

 1.21 “Non-Royalty Income/Sublicense Income” shall mean consideration in any form received by
Company and/or Company’s Affiliate(s) in connection with or otherwise attributable to a grant of an option or sublicense or any other right, license, privilege or immunity (regardless of whether such grantee is a “Sublicensee” as
defined in this Agreement) to make, have made, use, have used, Sell or have Sold Products or Processes, but excluding consideration included within Net Sales. Sublicense Income shall include [***]. 

For clarity, non-royalty income shall exclude: [***]. 

To the extent that other patent rights, other intellectual property rights or other rights or obligations other than Patent Rights are licensed, sublicensed
or granted by Company together with the rights granted under this Agreement, that portion of the consideration received by Company and subject to this clause shall be equitably apportioned by Company between the Patent Rights and those other rights
and obligations, and such apportionment shall be reasonable and in accordance with customary standards in the industry. Such apportionment shall be determined by [***]. 

1.22 “Sublicensee” shall mean any sublicensee of rights granted in accordance with Section 2.1(a)(ii). For purpose of this Agreement, a
Distributor of a Product or Process shall not be included in the definition of Sublicensee unless such Distributor (i) is granted any right to make, have made, use or have used Products or Processes in accordance with Section 2.1(a)(ii),
or (ii) has agreed to pay to Company or its Affiliate(s) royalties on such Distributor’s sales of Products or Processes, in which case such Distributor shall be a Sublicensee for all purposes of this Agreement. 

  
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 1.23 “Technological Information” shall mean [***], as further described in
Appendix B. Company and Hospital each hereby agree to treat each other’s Technological Information in accordance with the provisions of Appendix E. 

2. LICENSE 
 2.1 Grant of License.

  

	 	(a)	 Subject to the terms of this Agreement [***], Hospital hereby grants to Company in the License Field in
the License Territory: 

  

	 	(i)	 an exclusive, royalty-bearing license under its rights in Patent Rights to make, have made, use, have used,
Sell and have Sold Products and Processes; 

  

	 	(ii)	 the right to grant sublicenses under the rights granted in Section 2.1(a)(i) to Sublicensees, provided
that in each case Company shall be responsible for the performance of any obligations of Sublicensees relevant to this Agreement as if such performance were carried out by Company itself, including, without limitation, the payment of any royalties
or other payments provided for hereunder, regardless of whether the terms of any sublicense provide for such amounts to be paid by the Sublicensee directly to Hospital; and 

 

	 	(iii)	 the nonexclusive right and license to use Technological Information disclosed by Hospital to Company hereunder
in accordance with this Agreement. 

  

	 	(b)	 The license granted in Section 2.1(a) above includes: 

 

	 	(i)	 the right to grant to the final purchaser, user or consumer of Products the right to use such purchased
Products in a method coming within the scope of Patent Rights within the License Field and License Territory; and 

  

	 	(ii)	 the right to grant a Distributor the right to Sell (but not to make, have made, use or have used) such Products
and/or Processes for or on behalf of Company, its Affiliates and Sublicensees in a manner consistent with this Agreement. 

  

	 	(c)	 The foregoing license grant shall include the grant of such license to any Affiliate of Company, provided that
such Affiliate shall assume the same obligations as those of Company and be subject to the same terms and conditions hereunder; and further provided that Company shall be responsible for the performance of all of such obligations and for compliance
with all of such terms and conditions by Affiliate. Company shall provide to Hospital a fully signed, non-redacted copy of each agreement with each Affiliate that assumes the aforesaid obligations, including
all exhibits, attachments and related documents and any amendments, within [***] of request by Hospital. 

  
 6 

 2.2 Sublicenses. Each sublicense granted hereunder shall be in writing, consistent with and comply
with all terms of this Agreement, shall incorporate terms and conditions sufficient to enable Company to comply with this Agreement, shall prohibit any further sublicense or assignment by a Sublicensee without prior written notice to Hospital and
the opportunity for review by Hospital solely to confirm compliance with the terms and conditions applicable to all sublicenses hereunder, and shall provide that Hospital is a third party beneficiary thereof. Company will timely notify Hospital of a
contemplated sublicense and Hospital will provide comments and input within [***] of such notice. Company will provide Hospital with a fully signed non-redacted copy of all sublicense agreements and
amendments thereto, including all exhibits, attachments and related documents, within [***] of executing the same. Upon termination of this Agreement or any license granted hereunder for any reason, any sublicenses shall be addressed in
accordance with Section 10.7. Any sublicense which is not in accordance with the forgoing provisions shall be null and void. 
 2.3 Retained Rights:
Requirements. Any and all licenses granted hereunder are subject to: 
 (a) the right of Hospital and Hospital’s Affiliates
academic, government and not-for-profit institutions, to make and to use Patent Rights solely for their own internal academic and educational research purposes and not
for any use with or for the benefit of any for-profit or commercial third party or for any use in the context of any commercially-sponsored research. Any compounds claimed in Patent Rights provided by Hospital
to third parties shall be subject to a Materials Transfer Agreement with terms including, but not limited to the following and that will require that the material: (a) shall not be used in humans, (b) shall be subject to an agreed
statement of work, (c) be used only for non-commercial purposes, (c), shall be subject to invention reporting requirements, and (d) have a defined term. 

(b) 2.3(b) for Patent Rights co-owned or funded by the federal governmentsupported by
federal funding, the rights, conditions and limitations imposed by U.S. law (see 35 U.S.C. § 202 et seq. and regulations pertaining thereto) and by the Hospital-NIH
IIA, as applicable, including without limitation: 
 (i) the NIH’s right to receive Company’s confidential information to
ensure compliance with the teens of the Hospital-NIH IIA Agreement; 
 (ii) the
royalty-free nonexclusive license rights as required to be retained by granted to the U.S. government; and; 
  

	 	(i)	 the requirement that any Products (in final, finished form) used or sold in the United States shall be
manufactured substantially in the United States. 

 2.4 No Additional Rights. It is understood that nothing in this Agreement shall
be construed to grant Company or any of its Affiliates a license, express or implied, under any patent owned solely or jointly by Hospital other than the Patent Rights expressly licensed hereunder. Hospital shall have the right to license any Patent
Rights to any other party for any purpose outside of the License Field or the License Territory. 
 2.5 Disclosure of Technological Information. At
Company’s request prior to execution of this Agreement, Hospital (through [***]) shall use reasonable efforts to disclose in confidence within [***] after execution of this Agreement, the Technological Information licensed
hereunder. [***]. 

  
 7 

 
3. DUE DILIGENCE OBLIGATIONS 
 3.1 Diligence Requirements. Company shall use, and shall
cause its Affiliates and Sublicensees, as applicable, to use, its Commercially Reasonable Efforts to develop and make available to the public Products and Processes throughout the License Territory in the License Field. Such efforts shall be deemed
fully satisfied by achieving or substantially achieving the following objectives within the time periods designated below following the Effective Date, subject to any mutually agreed-upon adjustments to the timing requirements stated below in view
of all Relevant Factors as described in Section 3.2 below: 
  

	 	(a)	 Pre-Sales Requirements. 

 

	 	1.	 Within [***] (of the Effective Date) and [***] thereafter, submit a commercial development plan
to Hospital (the “Development Plan”) including plans as shown in Appendix F, for making/raising investment and hiring management; 

  

	 	2.	 Within [***] of the Effective Date, [***]. 

 

	 	3.	 Within [***], conduct [***] 

 

	 	4.	 Within [***], [***] 

 

	 	5.	 Within [***], Company will [***]; 

 

	 	6.	 Within [***], Company will [***]; 

 

	 	7.	 Within [***], Company will [***]; 

 

	 	8.	 Within [***], Company will [***]; and 

 

	 	9.	 Within [***], Company will [***]. 

 

	 	(b)	 Post-Sales Requirements. 

 

	 	(i)	 Following the First Commercial Sale in any country in the License Territory, Company shall itself or through
its Distributors, Affiliates and/or Sublicensees make continuing Sales in such country without any elapsed time period of [***] or more in which such Sales do not occur. 

 

	 	(ii)	 Company shall itself or through an Affiliate, Distributor or Sublicensee make such First Commercial Sale within
the following countries and regions in the License Territory within [***] after the Effective Date of this Agreement: [***] 

  
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 Achievement of all or substantially all of the foregoing objectives shall be deemed to fully
satisfy Company’s obligations to use Commercially Reasonable Efforts under this Section 3.1. 
 3.2 Diligence Failures. [***]. 

3.3 Diligence Reports. Company shall provide all reports with respect to its obligations under Section 3.1 as set forth in Section 5. 

4. PAYMENTS AND ROYALTIES 
 4.1 License
Issue Fee. Company shall pay Hospital a non-refundable license issue fee in the amount of One Hundred Thousand U.S. Dollars ($100,000) within [***] of the Effective Date of this Agreement. 

4.2 Patent Cost Reimbursement. Company shall reimburse Hospital for all reasonable and documented costs associated with the preparation, filing,
prosecution and maintenance of all Patent Rights (“Patent Costs”). As of the Effective Date, Hospital has incurred approximately two hundred and eighty thousand dollars ($280,000.00) U.S. dollars in Patent Costs, which amount Company shall
pay to Hospital in three semi-annual installments, with the first payment due within [***] of the Effective Date of this Agreement. Company shall pay to Hospital, or at Hospital’s request directly to patent counsel, all other Patent
Costs within [***] of Company’s receipt of an invoice for such Patent Costs either from Hospital or Hospital’s patent counsel. Company agrees to indemnify, defend and hold Hospital harmless from and against any and all liabilities,
damages, costs and expenses arising from the failure of Company to timely pay such invoices and Patent Costs. Hospital shall instruct patent counsel to provide copies to Hospital for Hospital’s administrative files of all invoices detailing
Patent Costs which are sent directly to Company. If Company pays any Patent Costs directly, Company shall advise patent counsel that Hospital is and shall remain patent counsel’s client. 

4.3 Annual License Fee; Annual Minimum Royalty. 
  

	 	(a)	 Before First Commercial Sale. Prior to the First Commercial Sale, Company shall pay to Hospital the
following non-refundable amounts as an annual license fee within [***] after each of the following anniversaries of the Effective Date of the License: The annual license fees shall be credited in full
against any royalties subsequently due on Net Sales during the same calendar year: 

  

	 	(i)	 [***]; 

  

	 	(ii)	 [***]. 

  

	 	(b)	 After First Commercial Sale. Following the First Commercial Sale, Company shall pay Hospital a non-refundable minimum annual royalty in the amount of [***] per year within [***] after each annual anniversary of the Effective Date occurring after the First Commercial Sale. The annual minimum
royalty shall be credited in full against royalties subsequently due on Net Sales made during the same calendar year. 

  
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 4.4 Milestone Payments. In addition to the payments set forth in Sections 4.1 through 4.3 above,
Company shall pay Hospital milestone payments within [***] of the occurrence of the Milestone, as follows: 
 For each of the first
three indications or Products, which shall each be payable a maximum of three times in total under the Agreement regardless of the total number of Products or indications progressed. For clarity, in the event Company [***]: 

 

	 	(a)	 [***] 

  

	 	(b)	 [***] 

  

	 	(c)	 [***] 

  

	 	(d)	 [***] 

  

	 	(e)	 [***] 

  

	 	(f)	 [***] 

  

	 	(g)	 [***] 

  

	 	(h)	 [***] 

  

	 	(i)	 [***] 

  

	 	(j)	 [***]. 

The Company shall be entitled to offset the milestone payments actually paid to Hospital against any amounts that the Company is required to pay to Hospital
on account of non-royalty income that is paid to the Company for achievement of the exact same development milestone for the same Product. 

4.5 Royalties and Sublicense Income. 
  

	 	(A)	 Beginning with the First Commercial Sale by Company, its Affiliates and Sublicensees in the applicable country
in the License Territory, Company shall pay Hospital: 

  

	 	(i)	 During the term of any license granted under Section 2.1(a)(i), a royalty on the Net Sales of all Products
and Processes the manufacture, use or sale of which is claimed or covered by a Valid Claim within the Patent Rights licensed to Company under Section 2.1(a)(i) for as long as such Valid Claim exists at the time of sale and in the applicable
country of sale, as per the scale below: 

 Sales of up to [***] 

Sales above [***] 
 Sales
above [***] 
 And 

  
 10 

	 	(ii)	 On a product-by-product and country-by-country basis, in the absence of a Valid Claim existing within the licensed Patent Rights under Section 2.1(a)(i) which claims or covers the manufacture, use
or sale of the Product or Process at the relevant time and in the applicable country of manufacture, use or sale as described in subpart A(i) above, then, in lieu of the royalty described in subpart A(i) above, and in accordance with
Section 2.1(a)(iii) and Section 10.1, running for a period not to exceed ten (10) years from the date of the First Commercial Sale in the applicable country, a royalty of [***] of the Net Sales of all such Products and
Processes which employ Technological Information; provided, however that such royalty on Technological Information will only be payable if such Technological Information is directed specifically to the composition of matter or the applicable method
of synthesis or use of a lead compound for which an IND was filed by Company. 

 (B) Royalties on annual Net Sales by
Company, its Affiliates, and Sublicensees of Derived Products and/or Derived Processes will be payable at [***] of the rate payable for Products and Processes as applicable under subpart (A)(i) above. For clarity, the royalty rate shall range
from [***] to [***] based on sales volume as in Section 4.5(A)(i). 
  

	 	(C)	 On a product-by product and
country-by-country basis, Company shall be entitled to reduce the royalty rates otherwise applicable under subpart A or B above on account of generic competition from
which Company can demonstrate is of comparable quality and performance and have [***], provided that the applicable royalty rate for generic competition will not be reduced by more than [***] of the royalty due, in any reporting
period. 

 (D) The royalty rate may be reduced by up to 50% for any royalty paid by Company to third parties for their
patent rights wherein Company is required to obtain a license from such third party in order to manufacture, use or sell any Product or Process in any country of the License Territory to avoid infringing or misappropriating the intellectual property
rights of such third party. 
 (E) For the avoidance of doubt, in no event, shall the royalty rate, when aggregated with any other offsets
and credits allowed under this Agreement, be reduced to less than [***] of the royalty otherwise due under Part (A)(i) (A)(ii), C, or D, under this section 4.5, in any reporting period. 

(F) The obligation to pay royalties under this Agreement will be imposed only once with respect to the same unit of product sold by Company,
its Affiliates, or Sublicensees, provided, however, that the highest applicable royalty rate for such product shall apply. 
 (E) Company
shall pay Hospital a percentage of Sublicense Income as follows, depending upon the stage of development of the relevant Product or Process when the Sublicense is granted: 

(i) [***]; 
 (ii)
[***]; or 

  
 11 

 (iii) [***]. 

(F) All payments due to Hospital under this Section 4.5 shall be due and payable by Company within [***] after the end of each
Reporting Period, and shall be accompanied by a report as set forth in Sections 5.3 and 5.4. 
 4.6 Equity. As partial consideration for the rights
granted in this Agreement, upon Hospital’s execution and delivery to Company of a fully-executed copy of a Stock Issuance Agreement in the form prescribed by Company (a “Issuance Agreement”), Company shall issue to Hospital
(a) within [***] of the Effective Date, that number shares of its common stock that equal [***] of Company’s fully-diluted shares on the Effective Date (the “Shares”), and (b) [***]. 

[***]. 
 4.7 Board Seat and Co-Investment. 
  

	 	(a)	 For so long as Hospital holds shares of Company stock and The Partners Innovation Fund (PIF) is not represented
on Company’s Board of Directors, Company shall invite a representative of Hospital to attend all meetings of its Board of Directors in a nonvoting observer capacity; provided, however, that Hospital shall cause such representative to, and prior
to the exercise of the rights contained in this Section 4.7 such representative shall enter into a written agreement with Company providing that such representative will, hold in confidence and trust and to act in a fiduciary manner with
respect to all information so provided; and provided further, that the Company reserves the right to withhold any information and to exclude such representative from any meeting or portion thereof if access to such information or attendance at such
meeting could adversely affect the attorney-client privilege between Company and its counsel or result in disclosure of trade secrets or a conflict of interest. [***] and one or more of his collaborators shall be invited to serve as members
on Company’s Scientific Advisory Board. The terms and conditions of such membership shall be set forth in a definitive written agreement in the form prescribed by Company. 

 

	 	(b)	 [***]. 

4.8 Form of Payment. All payments due under this Agreement shall be drawn on a United States bank and shall be payable in United States dollars. Each
payment shall reference this Agreement and its Agreement Number and identify the obligation under this Agreement that the payment satisfies. Conversion of foreign currency to U.S. dollars shall be made at the conversion rate existing in the United
States, as reported in The Wall Street Journal, on the last working day of the applicable Reporting Period. Such payments shall be without deduction of exchange, collection or other charges, and, specifically, without deduction of withholding or
similar taxes or other government imposed fees or taxes, except as permitted in the definition of Net Sales. 

  
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 Checks for all payments due to the Hospital under this Agreement shall be made payable to the Hospital and
addressed as set forth below: 
 Massachusetts General Hospital 

BOA-Lockbox Services 

PCSR Lockbox #[***] 
 MA5-527-02-07 
 2
Morrissey Blvd 
 Dorchester, MA 02125 

Reference Agreement #: [***] 
 Payments
via wire transfer should be made as follows: 
 ACH Credit: ABA # [***] 

Federal Reserve Wire: [***] 

SWIFT Code: [***] 
 Account
#[***] 
 Massachusetts General Hospital 

Bank of America 
 100 Federal
Street 
 Boston, MA 02110 

Reference Agreement #: [***] 
 4.9
Overdue Payments. The payments due under this Agreement shall, if overdue, bear interest beginning on the first day following the Reporting Period to which such payment was incurred and until payment thereof at a per annum rate equal to
[***] above the prime rate in effect on the due date as reported by The Wall Street Journal, [***], not to exceed the maximum permitted by law. Any such overdue payments when made shall be accompanied by all interest so accrued. Said
interest and the payment and acceptance thereof shall not preclude Hospital from exercising any other rights it may have as a consequence of the lateness of any payment. 

5. REPORTS AND RECORDS 
 5.1 Diligence
Reports. Within [***] after the end of each calendar year, Company shall report in writing to Hospital on progress made toward the objectives set forth in Section 3.1 during such preceding 12 month period, including, without
limitation, progress on research and development, status of applications for regulatory approvals, manufacturing, sublicensing and the number of sublicenses entered into and marketing. 

5.2 Milestone Achievement Notification. Company shall report to Hospital the dates on which it achieves the milestones set forth in Section 4.4
within [***] of each such occurrence. 

  
 13 

 5.3 Sales Reports. Company shall report to Hospital the date of the First Commercial Sale in each
country of the License Territory within [***] of each such occurrence. Following the First Commercial Sale, Company shall deliver reports to Hospital within [***] after the end of each Reporting Period. Each report under this
Section 5.4 shall have substantially the format outlined in Appendix C, shall be certified as correct by an officer of Company and shall contain at least the following information as may be pertinent to a royalty accounting hereunder for
the immediately preceding Reporting Period: 
  

	 	(a)	 the number of Products and Processes Sold by Company, its Affiliates and Sublicensees in each country;

  

	 	(b)	 the amounts billed, invoiced and received by Company, its Affiliates and Sublicensees for each Product and
Process, in each country, and total billings or payments due or made for all Products and Processes; 

  

	 	(c)	 calculation of Net Sales for the applicable Reporting Period in each country, including an itemized listing of
permitted offsets and deductions; 

  

	 	(d)	 total royalties payable on Net Sales in U.S. dollars, together with the exchange rates used for conversion; and

  

	 	(e)	 any other payments due to Hospital under this Agreement. 

If no amounts are due to Hospital for any Reporting Period, the report shall so state. 

5.4 Sublicense Income Reports. Company shall, along with delivering payment as set forth in Section 4.6, report to Hospital within [***] of
receipt the amount of all Sublicense Income received by Company, and Company’s calculation of the amount due and paid to Hospital from such income, including an itemized listing of the source of income comprising such consideration, and the
name and address of each entity making such payments in substantially the format outlined in Appendix D. 
 5.5 Audit Rights. Company shall
maintain, and shall cause each of its Affiliates and Sublicensees to maintain, complete and accurate records relating to the rights and obligations under this Agreement and any amounts payable to Hospital in relation to this Agreement, which records
shall contain sufficient information to permit Hospital and its representatives to confirm the accuracy of any payments and reports delivered to Hospital and compliance in all other respects with this Agreement. Company shall retain and make
available, and shall cause each of its Affiliates and Sublicensees to retain and make available, such records for at least [***] following the end of the calendar year to which they pertain, to Hospital and/or its representatives and upon at
least [***] advance written notice, for inspection during normal business hours, to verify any reports and payments made and/or compliance in other respects under this Agreement. If any examination conducted by Hospital or its representatives
pursuant to the provisions of this Section show an underreporting or underpayment of [***] or more in any payment due to Hospital hereunder, Company shall bear the full cost of such audit and shall remit any amounts due to Hospital (including
interest due in accordance with Section 4.7) within [***] of receiving notice thereof from Hospital. 

  
 14 

 6. PATENT PROSECUTION AND MAINTENANCE 

6.1 Prosecution. Hospital shall be responsible for the preparation, filing, prosecution and maintenance of all patent applications and patents included
in Patent Rights through patent counsel reasonably acceptable Company. Company shall reimburse Hospital for Patent Costs incurred by Hospital prior to the Effective Date relating thereto in accordance with Section 4.2. 

6.2 Copies of Documents. With respect to any Patent Right licensed hereunder, Hospital shall instruct the patent counsel prosecuting such Patent Right
to (i) copy Company on patent prosecution documents that are received from or filed with the United States Patent and Trademark Office and foreign equivalent, as applicable; (ii) provide Company with copies of draft submissions to the
USPTO and foreign equivalent, as applicable, prior to filing; and (iii) give consideration to the comments and requests of Company or its patent counsel. 

6.3 Hospital’s Election Not to Proceed. Hospital, will not, without prior written notice Company, abandon any patent application or patent with the
Patent Rights. In the event Hospital, in its sole discretion, determines not to prepare, file, prosecute or maintain any patent application or patent within the Licensed Patents in any country in the Territory, Hospital will promptly notify Company
thereof, and Company will have the right, at its own expense to prepare, file, prosecute and maintain any patent application or patent in such country in the name of Hospital. If Company fails to assume control of preparation, filing, prosecution
and maintenance of such patent application or patent in Patent Rights or if Company otherwise elects to surrender any patent application or patent in Patent Rights in any country upon [***] prior written notice to Hospital, Hospital shall be
relieved of its obligations regarding such surrendered patent application or patent under Section 6.2 below and Company shall be relieved of the obligation to reimburse Hospital for future patent expenses with respect to such surrendered patent
application or patent; provided, that, Company shall continue to have the obligation to reimburse Hospital for patent expenses incurred in connection with that patent application or patent prior to the expiration of the [***] notice. For
purposes of clarity, in the event Company elects to surrender or abandon any patent application or patent in Patent Rights, such application or patent will be excluded from the definition of Rights Hospital shall be free to license its rights to
that particular U.S. or foreign patent application or patent to any other party on any terms. 
 6.4 Confidentiality of Prosecution and Maintenance
Information. Company and Hospital each hereby agrees to treat all information received from the other related to prosecution and maintenance of Patent Rights as Confidential Information in accordance with the provisions of Appendix E.

 7. THIRD PARTY INFRINGEMENT AND LEGAL ACTIONS 

7.1 Company Right to Prosecute. Company will have the first right, but not the obligation, to protect the Patent Rights from infringement and prosecute
infringers when, in its sole judgment, such action may be reasonably necessary, proper and justified. If Company shall have supplied Hospital with written evidence demonstrating to Hospital’s reasonable satisfaction prima facie infringement of
a claim of a Patent Right in the License Field in the License Territory by a third party which poses a material threat to Company’s rights under this Agreement, Company may by notice request Hospital to cooperate with Company to take steps to
protect such Patent Right. 

  
 15 

 7.2 Hospital Right to Prosecute. In the event Company notifies Hospital that Company does not intend
to prosecute infringement identified under Section 7.1, Hospital may, upon notice to Company, initiate legal proceedings against the infringer at Hospital’s expense with respect to a claim of a Patent Right in the License Field in the
License Territory. Before commencing such action, Hospital and, as applicable, any Affiliate, shall consult with Company , concerning, among other things, Hospital’s standing to bring suit, the advisability of bringing suit, the selection of
counsel and the jurisdiction for such action (provided Hospital must have Company’s prior written consent with respect to selection of jurisdiction for any action in which Company may be joined as a party-plaintiff) and shall use reasonable
efforts to accommodate the views of Company regarding the proposed action, including without limitation with respect to potential effects on the public interest. Hospital shall be responsible for all costs, expenses and liabilities in connection
with any such action and shall indemnify and hold Company harmless therefrom, regardless of whether Company is a party-plaintiff, except for the expense of any independent counsel retained by Company in accordance with Section 7.5 below. 

7.3 Company Joined as Party-Plaintiff. If Hospital elects to commence an action as described in Section 7.2 above, Company shall have, in its sole
discretion, the option to join such action as a party-plaintiff. If Company is required by law to join such action as a party-plaintiff, Company may either, in its sole discretion, permit itself to be joined as a party-plaintiff at the sole expense
of Company. 
 7.4 Notice of Actions; Settlement. Each Party shall promptly inform the other Party of any action or suit relating to Patent Rights and
shall not enter into any settlement, consent judgment or other voluntary final disposition of any action relating to Patent Rights, including but not limited to appeals, without the prior written consent of Company. 

7.5 Cooperation. Each Party agrees to cooperate reasonably in any action under Section 7 which is controlled by the other Party, provided that the
controlling party reimburses the cooperating party for any costs and expenses incurred by the cooperating party in connection with providing such assistance, except for the expense of any independent counsel retained by the cooperating party in
accordance with this Section 7.5.Such controlling party shall keep the cooperating party informed of the progress of such proceedings and shall make its counsel available to the cooperating party. The cooperating party shall also be entitled to
independent counsel in such proceedings but at its own expense, said expense to be offset against any damages received by the Party bringing suit in accordance with Section 7.6. 

7.6 Recovery. Any award paid by third parties as the result of such proceedings (whether by way of settlement or otherwise) shall first be applied to
reimbursement of any legal fees and expenses incurred by either Party and then the remainder shall be divided between the Parties as follows: 
  

	 	(a)	 (i)      [***]; and 

 

	 	(ii)	 [***]; and 

  

	 	(b)	 [***]. 

7.7 Additional IP. [***]. 
 [***]. 

  
 16 

 8. INDEMNIFICATION AND INSURANCE 

8.1 Indemnification. 
  

	 	(a)	 Company shall indemnify, defend and hold harmless Hospital and its Affiliates and their respective trustees,
directors, officers, medical and professional staff, employees, and agents and their respective successors, heirs and assigns (the “Indemnitees”), against any liability, damage, loss or expense (including reasonable attorney’s fees
and expenses of litigation) incurred by or imposed upon the Indemnitees or any one of them in connection with any claims, suits, actions, demands or judgments arising out of any theory of product liability (including, but not limited to, actions in
the farm of contract, tort, warranty, or strict liability) concerning any Product, Process made, used, or sold or performed pursuant to any right or license granted to Company under this Agreement, except to the extent that such liability, damage,
loss or expense result from the gross negligence, wilful misconduct or breach of any of the provisions of this Agreement on the part of any of the Indemnities. 

 

	 	(b)	 Company agrees, at its own expense, to provide attorneys reasonably acceptable to the Hospital to defend
against any actions brought or filed against any party indemnified hereunder with respect to the subject of indemnity contained herein; provided, however, that any Indemnitee shall have the right to retain its own counsel, at the expense of Company,
if representation of such Indemnitee by counsel retained by Company would be inappropriate because of conflict of interests of such Indemnitee and any other party represented by such counsel. Company agrees to keep Hospital informed of the progress
in the defense and disposition of such claim and to consult with Hospital prior to any proposed settlement. 

  

	 	(c)	 This section 8.1 shall survive expiration or termination of this Agreement. 

8.2 Insurance. 
  

	 	(a)	 Beginning at such time as any such Product or Process is being commercially distributed, sold, leased or
otherwise transferred, or performed or used (other than for the purpose of obtaining regulatory approvals), by Company, an Affiliate or Sublicensee, Company shall, at its sole cost and expense, procure and maintain commercial general liability
insurance in amounts not less than $[***] per incident and $[***] annual aggregate and naming the Indemnitees as additional insureds. Such commercial general liability insurance shall provide (i) product liability coverage and
(ii) broad form contractual liability coverage for 

  
 17 

	 	Company’s indemnification under Section 8.1 of this Agreement. If Company elects to self-insure all or part of the limits described above (including deductibles or retentions which are in excess of
$[***] annual aggregate) such self-insurance program must be acceptable to the Hospital and the Risk Management Foundation. The minimum amounts of insurance coverage required under this Section 8.2 shall not be construed to create a
limit of Company’s liability with respect to its indemnification under Section 8.1 of this Agreement. 

  

	 	(b)	 Company shall provide Hospital with written evidence of such insurance upon request of Hospital. Company shall
provide Hospital with written notice at least [***] prior to the cancellation, non-renewal or material change in such insurance; if Company does not obtain replacement insurance providing comparable
coverage prior to the expiration of such [***] period, Hospital shall have the right to terminate this Agreement effective at the end of such [***] period without notice or any additional waiting periods. 

 

	 	(c)	 Company shall maintain such commercial general liability insurance beyond the expiration or termination of this
Agreement during (i) the period that any such Product or Process is being commercially distributed, sold, leased or otherwise transferred, or performed or used (other than for the purpose of obtaining regulatory approvals), by Company or by a
licensee, affiliate or agent of Company and (ii) a reasonable period after the period referred to in (c) (i) above which in no event shall be less than [***]. 

 

	 	(d)	 This section 8.2 shall survive expiration or termination of this Agreement. 

9. DISCLAIMER OF WARRANTIES; LIMITATION OF LIABILITY 

9.1 Title to Patent Rights. Hospital is an owner by assignment from [***] of the Patent Rights and has the sole authority to enter this
Agreement, and to license the Patent Rights to Company hereunder. Hospital hereby represents and warrants to Company that, as between Hospital and the Co-Owners, pursuant to the terms and conditions of the
IAAs, Hospital has exclusive agency to license the Patent Rights and all Co-Owners have agreed that Hospital has the sole legal right and authority to grant licenses under the ownership interests of the Co-Owners in the Patent Rights on behalf of all Co-Owners, and that no Co-Owner (other than Hospital) is permitted to grant to any
third party any license under its rights in the Patent Rights, and that, to the best of Hospital’s knowledge as of the Effective Date, there is no encumbrance, lien or restriction or retained or reserved rights of any Co-Owners (other than the reserved academic rights as set forth in Section 2.3 of this Agreement) or of any third party that would conflict or interfere with the exclusive license rights granted to Company
hereunder. 

  
 18 

 To the best of Hospital’s Innovation Office’s knowledge as of the Effective Date,
(a) Hospital has not received written notice from a third party of any pending or threatened legal action or proceeding asserting that the use of the Patent Rights as contemplated by the License to be granted hereunder does or would infringe or
misappropriate the intellectual property rights of any third party; (b) Hospital has not granted a license in, to or under, or any option or other right to Patent Rights that would conflict or interfere with the rights granted to Company under
the License, and (c) the execution, delivery and performance of the License does not conflict with, or constitute a breach of, any order, judgment or agreement to which Hospital is a party. 

9.2 No Warranties. EXCEPT AS EXPRESSLY SET FORTH IN SECTION 9.1, HOSPITAL MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED,
CONCERNING THE PATENT RIGHTS AND THE RIGHTS GRANTED HEREUNDER, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, VALIDITY OF PATENT RIGHTS CLAIMS, WHETHER ISSUED OR PENDING, AND
THE ABSENCE OF LATENT OR OTHER DEFECTS, WHETHER OR NOT DISCOVERABLE, AND HEREBY DISCLAIMS THE SAME. SPECIFICALLY, AND NOT TO LIMIT THE FOREGOING, HOSPITAL MAKES NO WARRANTY OR REPRESENTATION (i) REGARDING THE VALIDITY OR SCOPE OF ANY OF THE
CLAIM(S), WHETHER ISSUED OR PENDING, OF ANY OF THE PATENT RIGHTS, AND (ii) THAT THE EXPLOITATION OF THE PATENT RIGHTS OR ANY PRODUCT WILL NOT INFRINGE ANY PATENTS OR OTHER INTELLECTUAL PROPERTY RIGHTS OF HOSPITAL OR OF ANY THIRD PARTY. 

9.3 Limitation of Liability. IN NO EVENT SHALL HOSPITAL OR ANY OF ITS AFFILIATES OR ANY OF THEIR RESPECTIVE TRUSTEES, DIRECTORS, OFFICERS, MEDICAL OR
PROFESSIONAL STAFF, EMPLOYEES AND AGENTS BE LIABLE TO LICENSEE OR ANY OF ITS AFFILIATES, SUBLICENSEES OR DISTRIBUTORS FOR INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND ARISING IN ANY WAY OUT OF THIS AGREEMENT OR THE LICENSE OR
RIGHTS GRANTED HEREUNDER, HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, INCLUDING WITHOUT LIMITATION ECONOMIC DAMAGES OR INJURY TO PROPERTY OR LOST PROFITS, REGARDLESS OF WHETHER HOSPITAL SHALL BE ADVISED, SHALL HAVE OTHER REASON TO KNOW, OR IN
FACT SHALL KNOW OF THE POSSIBILITY OF THE FOREGOING. 
 10. TERM AND TERMINATION 

10.1 Term. The term of this Agreement shall commence on the Effective Date and shall remain in effect until the later of: 

 

	 	(a)	 the date on which all issued patents and filed patent applications within the Patent Rights with any Valid
Claim covering the Product or Process have expired or been abandoned, and 

  

	 	(b)	 ten (10) years after the First Commercial Sale of the last Product or Process for which a royalty is due
under Section 4.5(A)(ii); 

  
 19 

 unless this Agreement is terminated earlier in accordance with any of the other provisions of
Section 10. 
 10.2 Termination for Failure to Pay. If Company fails to make any payment due hereunder, Hospital shall have the right to
terminate this Agreement upon [***] written notice, unless Company makes such payments plus any interest due, as set forth in Section 4.7, within said [***] notice period. If payments are not made, Hospital may immediately
terminate this Agreement at the end of said [***] period. Company shall be entitled to only one such cure period in a calendar year; for a second failure to make payment on time, Hospital shall have the right to terminate this Agreement
immediately upon written notice. 
 10.3 Termination for Insurance and Insolvency. 

 

	 	(a)	 Insurance. Hospital shall have the right to terminate this Agreement in accordance with
Section 8.2(b) if Company fails to maintain the insurance required by Section 8.2. 

  

	 	(b)	 Insolvency and other Bankruptcy Related Events. Hospital shall have the right to terminate this
Agreement immediately upon written notice to Company with no further notice obligation or opportunity to cure if: (i) Company passes a resolution for voluntary winding up, or a dissolution, winding-up or
liquidation proceeding is initiated against it and not set aside within [***]; (ii) a receiver or liquidator is appointed for the Company and has not been removed within [***]; or (iii) Company makes an assignment for the benefit
of creditors. 

 10.4 Termination for Non-Financial Default. If Company, any of its
Affiliates or any Sublicensee shall default in the performance of any of its other material obligations under this Agreement not otherwise covered by the provisions of Section 10.2 and 10.3, and if such default has not been cured within
[***] after notice by Hospital in writing of such default, or to provide a reasonably acceptable plan to cure such breach, Hospital may immediately terminate this Agreement, and/or any license granted hereunder with respect to the country or
countries in which such default has occurred, at the end of said [***] cure period. Hospital shall also have the right to terminate this Agreement and/or any such license immediately, upon written notice, in the event of repeated defaults,
even if cured within such [***] periods. Hospital shall have no further obligations hereunder. 
 10.5 Challenging Validity. During the term of
this Agreement, Company shall not challenge, and shall restrict Company Affiliates and Sublicensees from challenging, the validity of the Patent Rights and in the event of any breach of this provision Hospital shall have the right to terminate this
Agreement and any license granted hereunder immediately. 
 10.6 Termination by Company. Company shall have the right to terminate this Agreement for
any reason or merely for convenience by giving [***] advance written notice to Hospital and upon such termination shall immediately cease all use and Sales of Products and Processes, except as otherwise expressly set forth under
Section 10.8 or 10.9. 

  
 20 

 10.7 Effect of Termination on Sublicenses. If this Agreement is terminated for any reason, all
outstanding sublicenses not in default will be assigned by Company to Hospital. The assigned sublicenses will remain in full force and effect with the Hospital as the licensor or sublicensor instead of Company; provided, however, that the duties of
the Hospital under the assigned sublicenses will not be greater than the duties of the Hospital under this Agreement, and the rights of the Hospital under the assigned sublicenses will not be less than the rights of the Hospital under this
Agreement, including all rights to receive financial consideration and other rights of the Hospital. 
 10.8 Effects of Termination of Agreement. Upon
termination of this Agreement or any of the licenses hereunder for any reason, (i) final reports in accordance with Section 5 shall be submitted to Hospital and (ii) all royalties and other payments, including without limitation any
unreimbursed Patent Costs, accrued or due to Hospital as of the termination or expiration date shall become immediately due and payable and (iii) all obligations of the parties shall cease, except those that expressly survive termination or
expiration of the License. Company shall cease, and shall cause its Affiliates and Sublicensees to cease under any sublicense granted by Company, all Sales and uses of Products and Processes upon such termination, subject to Section 10.9. The
termination or expiration of this Agreement or any license granted hereunder shall not relieve Company, its Affiliates or Sublicensees of obligations arising before such termination or expiration. 

[***]. 
 10.9 Inventory. Upon early termination of
this Agreement other than for Company default, Company, Company Affiliates and Sublicensees may complete and sell any work-in-progress and inventory of Products that
exist as of the effective date of termination provided that (i) Company pays Hospital the applicable running royalty or other amounts due on such Net Sales in accordance with the terms and conditions of this Agreement, and (ii) Company,
Company Affiliates and Sublicensees shall complete and sell all work-in-progress and inventory of Products within six (6) months after the effective date of
termination. Upon expiration of this Agreement, Company shall pay to Hospital the royalties set forth in Section 4.5(a) for Sales of any Product that was in inventory or was a
work-in-progress on the date of expiration of the Agreement. 

11. COMPLIANCE WITH LAW 
 11.1
Compliance. Company shall have the sole obligation for compliance with, and shall ensure that any Affiliates and Sublicensees comply with, all government statutes and regulations that relate to Products and Processes, including, but not
limited to, those of the Food and Drug Administration and the Export Administration, as amended, and any applicable laws and regulations of any other country in the License Territory. Company agrees that it shall be solely responsible for obtaining
any necessary licenses to export, re-export, or import Products or Processes covered by Patent Rights and/or Confidential Information. Company shall indemnify and hold harmless Hospital for any breach of
Company’s obligations under this Section 11.1. 
 11.2 Patent Numbers. Company shall cause all Products sold in the United States to be
marked with all applicable U.S. Patent Numbers, to the full extent required by United States law. Company shall similarly cause all Products shipped to or sold in any other country to be marked in such a manner as to conform with the patent laws and
legal requirements of such country. 

  
 21 

 12. MISCELLANEOUS 

12.1 Entire Agreement. This Agreement constitutes the entire understanding between the Parties with respect to the subject matter hereof. 

12.2 Notices. Any notices, reports, waivers, correspondences or other communications required under or pertaining to this Agreement shall be in writing
and shall be delivered by hand, or sent by a reputable overnight mail service (e.g., Federal Express), or by first class mail (certified or registered), or by facsimile confirmed by one of the foregoing methods, to the other party. Notices will be
deemed effective (a) three (3) working days after deposit, postage prepaid, if mailed, (b) the next day if sent by overnight mail, or (c) the same day if sent by facsimile and confirmed as set forth above or delivered by hand. Unless
changed in writing in accordance with this Section, the notice address for Hospital shall be as follows: 
 Director, Innovation 

The General Hospital Corporation 

101 Huntington Avenue, 4th Floor 

Boston, MA 02199 
 Fax No.
[***] 
 12.3 Amendment; Waiver. This Agreement may be amended and any of its terms or conditions may be waived only by a written instrument
executed by an authorized signatory of the Parties or, in the case of a waiver, by the Party waiving compliance. The failure of either Party at any time or times to require performance of any provision hereof shall in no manner affect its rights at
a later time to enforce the same. No waiver by either Party of any condition or term shall be deemed as a further or continuing waiver of such condition or term or of any other condition or term. 

12.4 Binding Effect. This Agreement shall be binding upon and inure to the benefit of and be enforceable by the Parties hereto and their respective
permitted successors and assigns. 
 12.5 Assignment. Company shall not assign this Agreement or any of its rights or obligations under this Agreement
without the prior written consent of Hospital; provided, however, that if Company has fulfilled its diligence obligations as set forth in Section 3, no such consent will be required to assign this Agreement to an Affiliate of Company or to a
successor of the Company’s business or assets to which this Agreement pertains or to a purchaser of substantially all of the Company’s assets related to this Agreement, so long as such successor or purchaser shall agree in writing to be
bound by all of the terms and conditions hereof prior to such assignment. Company shall notify Hospital in writing of any such assignment and provide a copy of all assignment documents and related agreements to Hospital within [***] of such
assignment. Failure of an assignee to agree to be bound by the terms hereof or failure of Company to notify Hospital and provide copies of assignment documentation shall be grounds for termination of this Agreement for default. Further, neither any
rights granted under this Agreement, nor any sublicense, may be assigned by any Sublicensee without the prior written consent of Hospital, such consent not to be unreasonably withheld by Hospital. 

  
 22 

 12.6 Force Majeure. Neither Party shall be responsible for delays resulting from causes beyond the
reasonable control of such Party, including without limitation fire, explosion, flood, war, sabotage, strike or riot, provided that the nonperforming Party uses commercially reasonable efforts to avoid or remove such causes of nonperformance and
continues performance under this Agreement with reasonable dispatch whenever such causes are removed. 
 12.7 Use of Name. Unless required by law,
applicable regulation or court order, neither Party shall use the name of the other Party or of any trustee, director, officer, staff member, employee, student or agent of the other Party or any adaptation thereof in any advertising, promotional or
sales literature, publicity or in any document employed to obtain funds or financing without the prior written approval of the Party or individual whose name is to be used. For Hospital, such approval shall be obtained from Hospital’s VP of
Public Affairs. 
 12.8 Governing Law. This Agreement shall be governed by and construed and interpreted in accordance with the laws of a United
States jurisdiction, to be determined by the mutual agreement of the Parties as may be appropriate given the contacts with the relevant jurisdictions and the involvement of any rights of other Co-Owners,
excluding with respect to conflict of laws, except that questions affecting the construction and effect of any patent shall be determined by the law of the country in which the patent shall have been granted. 

12.9 Hospital Policies. Company acknowledges that Hospital’s employees and medical and professional staff members and the employees and staff
members of Hospital’s Affiliates are subject to the applicable policies of Hospital and such Affiliates, including, without limitation, policies regarding conflicts of interest, intellectual property and other matters. Company shall provide
Hospital with any agreement it proposes to enter into with any employee or staff member of Hospital or any of Hospital’s Affiliates for Hospital’s prior review and shall not enter into any oral or written agreement with such employee or
staff member which conflicts with any such policy. Hospital shall provide Company, at Company’s request, with copies of any such policies applicable to any such employee or staff member. 

12.10 Severability. If any provision(s) of this Agreement are or become invalid, are ruled illegal by any court of competent jurisdiction or are deemed
unenforceable under then current applicable law from time to time in effect during the term hereof, it is the intention of the parties that the remainder of this Agreement shall not be effected thereby. It is further the intention of the parties
that in lieu of each such provision which is invalid, illegal or unenforceable, there be substituted or added as part of this Agreement a provision which shall be as similar as possible in economic and business objectives as intended by the parties
to such invalid, illegal or enforceable provision, but shall be valid, legal and enforceable. 
 12.11 Survival. In addition to any specific survival
references in this Agreement, Sections 1, 2.4, 4.2, 4.6, 4.7, 5.3, 5.4, 5.5, 6.4, 8.1, 8.2, 9.2, 9.3, 10.7, 10.8, 10.9, 12.1, 12.2, 12.3, 12.4, 12.7, 12.8, 12.9, 12.10, 12.11, 12.12 and 12.13 shall survive termination or expiration of this
Agreement. Any other rights, responsibilities, obligations, covenants and warranties which by their nature should survive this Agreement shall similarly survive and remain in effect. 

  
 23 

 12.12 Interpretation. The parties hereto are sophisticated, have had the opportunity to consult legal
counsel with respect to this transaction and hereby waive any presumptions of any statutory or common law rule relating to the interpretation of contracts against the drafter. 

12.13 Headings. All headings are for convenience only and shall not affect the meaning of any provision of this Agreement. 

[Remainder of page intentionally left blank] 

  
 24 

 IN WITNESS WHEREOF, the Parties have caused this Agreement to be executed by their duly
authorized representatives as of the Effective Date first written above. 
  

							
	 KEROS THERAPEUTICS,
INC.
	 	 MASSACHUSETTS GENERAL
HOSPITAL

				
	 BY:
	 	 /s/ Jasbir
Seehra            Ran Nussbaum
	 	 BY:
	 	 /s/ [***]

		 	Name: Jasbir Seehra      Ran Nussbaum	 		 	Name: [***]
	 TITLE:
	 	
CEO                   
            Director
	 	 TITLE:
	 	 Director, Innovation

	 DATE:
	 	     April 5th,
2016
	 	 DATE:
	 	     April 5th,
2016

  
 25 

 Appendix A 

DESCRIPTION OF PATENT RIGHTS 
 [***]

 Remainder of page intentionally left blank 

  
 26 

 Appendix B 

DESCRIPTION OF TECHNOLOGICAL INFORMATION 

  
 27 

 Appendix C 

SALES REPORTS 
  

			
	AGREEMENT INCOME REPORT	 	Royalty Income
		
	 MGH Agreement # -
	 	 
		
	 Licensee -
	 	 
		
	 Sub-Licensee -
	 	 
		
	 Separate reports must be filed for:
	 	
		
	 1.  Each Product sold.
	 	
	
	 2.  Each country of sale, if different
deductions or royalty rates apply.

			
	
	
Product Name:               
                                         
                                         
                                         
                                         
                                     

	
	 Report Time
Period:

			
		
	 From
	    	mm/dd/yyyy                                   
                                         
                                         
                                         
                                         
     
		
	 To
	    	mm/dd/yyyy                                   
                                         
                                         
                                         
                                         
     

  

	
	 

  

							
	 Country of Sale
	 	                                   
     	 	                                   
     	 	                                   
     
				
	 Quantity Sold
	 	                                   
     	 	                                   
     	 	                                   
     
				
	 Gross Sales (USD)
	 	$                                   
     	 	$                                   
     	 	$                                  
      
				
	 Exchange Rate
	 	                                   
     	 	                                   
     	 	                                   
     

 Deductions (Itemize) 

Please list each deduction separately. Use same definition as appears in Agreement and include the contract paragraph as a reference (Std
Section 1.17(a)(ii) line item deductions listed below). 
  

							
	 A1.
	 	                                   
     	 	                                   
     	 	                                   
     
				
	 A2.
	 	                                   
     	 	                                   
     	 	                                   
     
				
	 A3.
	 	                                   
     	 	                                   
     	 	                                  
      
				
	 A4.
	 	                                   
     	 	                                   
     	 	                                   
     
				
	 B.
	 	                                   
     	 	                                   
     	 	                                   
     

  

							
	 Total Deductions
	 	(                                   
     )	 	(                                   
     )	 	(                                   
     )
				
	 Net Sales
	 	                                   
       	 	                                   
       	 	                                   
       
				
	 Royalty Percentage
	 	                                   
       	 	                                   
       	 	                                   
       
				
	 Credits (itemize)
	 	(                                   
     )	 	(                                   
     )	 	(                                   
     )
				
	 Royalties Due
	 	$                                   
     	 	$                                   
     	 	$                                   
     

  

					
	 

 PLEASE ATTACH DETAIL SALES REPORTS AS REQUIRED 

  
 28 

 Appendix D 
  

			
	AGREEMENT INCOME REPORT	 	Sublicense Income
		
	 MGH Agreement # -
	 	 
		
	 Licensee -
	 	 
		
	 Sub-Licensee -
	 	 
	
	 Separate reports must be filed for Payments associated with
each Product:

			
	
	
Product Name:               
                                         
                                         
                                         
                                         
                                       

	
	 Report Time
Period:

			
		
	 From
	  	mm/dd/yyyy                                   
                                         
                                         
                                         
                                         
     
		
	 To
	  	mm/dd/yyyy                                   
                                         
                                         
                                         
                                         
     

  

	
	 

 Detailed Explanation of Payment 

Required for “Other Payment” 
  

					
	 Annual Fees/Minimum Royalties
	  	$                            	  	  

			
	 Milestone Payments
	  	$                            	  	  

			
	 Sublicense Fees and Royalties
	  	$                            	  	  

			
	 Other Payment
	  	$                            	  	  

			
	 Other Payment
	  	$                            	  	  

			
	 Other Payment
	  	$                            	  	  

			
	 TOTAL
	  	$                            	  	  

  

	
	 

 PLEASE ATTACH DETAIL AS REQUIRED 

  
 29 

 Appendix E 

CONFIDENTIALITY TERMS AND CONDITIONS 
 1.
Definition of Confidential Information. “Confidential Information” shall mean any information, including but not limited to data, techniques, protocols or results, or business, financial, commercial or technical information,
disclosed by one Party ( each a “Discloser” as applicable) to the other Party (each a “Recipient” as applicable) in connection with the terms of that certain Exclusive License Agreement dated ____________________ (the
“License Agreement”) and identified as confidential at the time of disclosure (the “Purpose”). Hospital’s Confidential Information shall also include all information disclosed by Hospital to Company in connection with the
Patent Rights. Capitalized terms used in this Appendix that are not otherwise defined herein have the meanings ascribed in the License Agreement to which this Appendix is attached and made a part thereof 

2. Exclusions. “Confidential Information” under this Agreement shall not include any information that (i) is or becomes publicly
available through no wrongful act of Recipient; (ii) was known by Recipient prior to disclosure by Discloser, as evidenced by tangible records; (iii) becomes known to Recipient after disclosure from a third party having an apparent bona
fide right to disclose it; (iv) is independently developed or discovered by Recipient without use of Discloser’s Confidential Information, as evidenced by tangible records; or (v) is disclosed to another party by Discloser without
restriction on further disclosure. The obligations of confidentiality and non-use set forth in this Agreement shall not apply with respect to any information that Recipient is required to disclose or produce
pursuant to applicable law, court order or other valid legal process provided that Recipient promptly notifies Discloser prior to such required disclosure, discloses such information only to the extent so required and cooperates reasonably with
Discloser’s efforts to contest or limit the scope of such disclosure. 
 3. Permitted Purpose. Recipient shall have the right to, and agrees that
it will, use Discloser’s Confidential Information solely for the Purpose as described in the License Agreement, except as may be otherwise specified in a separate definitive written agreement negotiated and executed between the parties. 

4. Restrictions. For the term of the License Agreement and a period of seven (7) years thereafter (and indefinitely with respect to any
individually identifiable health information disclosed by Hospital to Company, if any), each Recipient agrees that: (i) it will not use such Confidential Information for any purpose other than as specified herein, including without limitation
for its own benefit or the benefit of any other person or entity; and (ii) it will use reasonable efforts (but no less than the efforts used to protect its own confidential and/or proprietary information of a similar nature) not to disclose
such Confidential Information to any other person or entity except as expressly permitted hereunder. Recipient may, however, disclose Discloser’s Confidential Information only on a
need-to-know basis to its and its Affiliates employees, staff members and agents (“Receiving Individuals”) who are directly participating in the Purpose and
who are informed of the confidential nature of such information, provided Recipient shall be responsible for compliance by Receiving Individuals with the terms 

  
 30 

 of this Agreement and any breach thereof. Each party further agrees not to use the name of the other party
or any of its Affiliates or any of their respective trustees, directors, officers, staff members, employees, students or agents in any advertising, promotional or sales literature, publicity or in any document employed to obtain funds or financing
without the prior written approval of the party or individual whose name is to be used, in the case of Hospital such approval to be given by the Public Affairs Department. This Section 4 shall survive termination or expiration of this
Agreement. 
 5. Right to Disclose. Discloser represents that to the best of its knowledge it has the right to disclose to each Recipient all of
Discloser’s Confidential Information that will be disclosed hereunder. 
 6. Ownership. All Confidential Information disclosed pursuant to this
Agreement, including without limitation all written and tangible forms thereof, shall be and remain the property of the Discloser. Upon termination of this Agreement, if requested by Discloser, Recipient shall return or destroy at Discloser’s
discretion all of Discloser’s Confidential Information, provided that Recipient shall be entitled to keep one copy of such Confidential Information in a secure location solely for the purpose of determining Recipient’s legal obligations
hereunder. 
 7. No License. Nothing in this Agreement shall be construed as granting or conferring, expressly or impliedly, any rights by license or
otherwise, under any patent, copyright, or other intellectual property rights owned or controlled by Discloser relating to Confidential Information, except as specifically set forth in the License Agreement. 

8. Remedies. Each party acknowledges that any breach of this Agreement by it may cause irreparable harm to the other party and that each party is
entitled to seek injunctive relief and any other remedy available at law or in equity. 
 9. General. These Confidentiality Terms and Conditions,
along with the License Agreement, contain the entire understanding of the parties with respect to the subject matter hereof, and supersede any prior oral or written understandings between the parties relating to confidential treatment of
information. Sections 1, 2, 4, 6, 8 and 9 of these Confidentiality Terms and Conditions shall survive any expiration or termination of the License Agreement. 

  
 31 

 Appendix F 

Brief Financing and Commercial Development Plans 

[***] 
 Remainder of page intentionally
left blank 

  
 32 

 [***] 

Remainder of page intentionally left blank 

  
 33 

 CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE
KEROS THERAPEUTICS, INC. HAS DETERMINED THE INFORMATION (I) IS NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM TO KEROS THERAPEUTICS, INC. IF PUBLICLY DISCLOSED. 

AMENDMENT #1 
 This
Amendment (“Amendment #1”) is entered into as May 12, 2017 (the “Amendment #1 Effective Date”) by and between Keros Therapeutics, Inc., a Delaware corporation, having a principal place of business at 3
Lincoln Te1rnce, Lexington, MA 02421 (“Company”), and The Brigham and Women’s Hospital, Inc., a not-for-profit Massachusetts corporation,
located at 75 Francis Street, Boston, MA 02115 (“Hospital”), each referred to herein individually as a “Party” and collectively as the “Parties”. 

RECITALS 
 WHEREAS,
Company and Hospital are parties to that certain Amended and Restated Exclusive Patent License Agreement, effective as of April 6, 2016, as amended by that Consent and Amendment entered into as of May 12, 2017 (such agreement as so
amended, the “Agreement #1”); 
 WHEREAS, in accordance with Section 12.3 of the Agreement, the
Parties with to clarify the list of Patent Rights; 
 NOW THEREFORE, in consideration of the mutual covenants and agreements contained
herein, the Parties agree as follows: 
 AGREEMENT 
  

	1.	 All capitalized terms used, but not defined, in this Amendment shall have the meaning set forth in the
Agreement. 

  

	2.	 Appendix A to the Agreement is hereby replaced with Appendix A attached to this Amendment.

  

	3.	 Except as amended by this Amendment, the Agreement shall remain in full force and effect. After the
Amendment Effective Date, every reference in the Agreement to the “Agreement #1” shall mean the Agreement as amended by this Amendment. 

  

	4.	 This Amendment may be executed in one or more counterparts, each of which shall be deemed an original,
but all of which together shall constitute one and the same instrument. Signatures provided by facsimile transmission or in AdobeTM Portable Document Format (PDF) sent by electronic mail shall be
deemed to be original signatures. 

 [SIGNATURE PAGE FOLLOWS] 

  
 1. 

 IN WITNESS WHEREOF, the Parties have caused this Amendment to be executed by their duly
authorized representatives as of the Amendment Effective Date first written above. 
  

							
	 THE BRIGHAM AND
WOMEN’S HOSPITAL, INC.
	  	 KEROS THERAPEUTICS, INC.

				
	 By:
	  	/S/ [***]	  	By:	  	/S/ Jasbir. S. Seehra
	 Title:
	  	Associate Director	  	Title:	  	 CEO

	 Name:
	  	[***]	  	Name:	  	Jasbir S. Seehra

  
 Signature Page to the
Consent and Amendment 

 Appendix A 

DESCRIPTION OF PATENT RIGHTS 
 [***] 

  

 CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE
KEROS THERAPEUTICS, INC. HAS DETERMINED THE INFORMATION (I) IS NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM TO KEROS THERAPEUTICS, INC. IF PUBLICLY DISCLOSED. 

AMENDMENT #2 
 MGH
Agreement No: [***] 
 This Amendment (“Amendment #2”) is entered into as of February 23, 2018 (the “Amendment #2
Effective Date”) by and between Keros Therapeutics, Inc., a Delaware corporation, having a principal place of business at 99 Hayden Avenue, Suite 120, Building E,. Lexington, MA 02421 (“Company”), and The General
Hospital Corporation, d/b/a Massachusetts General Hospital, a not-for-profit Massachusetts corporation, having a principal place of business at 55 Fruit St., Boston,
MA 02114 (“Hospital”), each referred to herein individually as a “Party” and collectively as the “Parties”. 

RECITALS 
 WHEREAS, Company and Hospital
are Parties to that certain Amended and Restated Exclusive Patent License Agreement, .effective as of April 6, 2016, as amended by that Consent and Amendment (Amendment #1) entered into as of May 12, 2017 (such agreement as so amended, the
“Agreement”); 
 WHEREAS, in accordance with Section 12.3 of the Agreement, the Parties wish to clarify the list of Patent Rights; 

WHEREAS, in accordance with Section 6.3 of the Agreement, Company elected to surrender a subset of patent applications or patents (“Abandoned Patent
Rights” in Appendix B) and such patent applications or patents shall no longer be included as part of the Patent Rights under Amendment #2 effective as of February 23, 2018, provided, that, Company shall continue to have the obligation to
reimburse Hospital for patent expenses incurred in connection with Abandoned Patent Rights prior to the expiration of the sixty (60) day notice, effective up to April 24, 2018. 

NOW THEREFORE, in consideration of the mutual covenants and agreements contained herein, the Parties agree as follows: 

AGREEMENT 
  

	 	1.	 All capitalized terms used, but not defined, in this Amendment #2 shall have the meaning set forth in the
Agreement. 

  

	 	2.	 Appendix A to the Agreement is hereby replaced with Appendix A attached to this Amendment #2.

  

	 	3.	 Except as amended by this Amendment #2, the Agreement shall remain in full force and effect. After the
Amendment #2 Effective date, every reference in the Agreement shall mean the Agreement as amended by this Amendment. 

  

	 	4.	 This Amendment may be executed in one or more counterparts, each of which shall be deemed an original, but all
of which together shall constitute one and the same instrument. Signatures provided by facsimile transmission or in AdobeTM Portable Document Format (PDF) sent by electronic mail shall be deemed
to be original signatures. 

  

	 	5.	 IN WITNESS WHEREOF, the Parties have caused this Amendment #2 to be executed by their duly authorized
representatives as of the Amendment #2 Effective Date. 

  
 1 

							
	THE GENERAL HOSPITAL CORPORATION, INC.	 	KEROS THERAPEUTICS, INC.
				
	By:	 	/s/ [***]	 	By:	 	/s/ Jasbir. S. Seehra
	Name:	 	[***]	 	Name:	 	Jasbir S. Seehra, Ph.D.
	Title:	 	Director	 	Title:	 	President and CEO
	Date:	 	June 13, 2018	 	Date:	 	June 6, 2018

  
 2 

 Appendix A 

Description of Patent Rights 
 [***]

  
 3 

 Appendix A (Continued) 

Description of Patent Rights 
 [***]

  
 4 

 Appendix B 

Description of Abandoned Patent Rights 

[***] 

  
 5EX-10.11

 Exhibit 10.11 

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE KEROS THERAPEUTICS, INC. HAS DETERMINED THE
INFORMATION (I) IS NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM TO KEROS THERAPEUTICS, INC. IF PUBLICLY DISCLOSED. 

EXECUTION VERSION 

RESEARCH COLLABORATION AND EXCLUSIVE LICENSE 

AGREEMENT 

BETWEEN 

KEROS THERAPEUTICS, INC. 

AND 

NOVO NORDISK A/S 
  

 EXECUTION VERSION 

 

			
	Exhibits	  	 
		
	Exhibit A	  	Existing Ligand Traps
		
	Exhibit B	  	Keros Background Patents
		
	Exhibit C	  	Research Plan
		
	Exhibit D	  	New Ligand Traps Information Package
		
	Exhibit E	  	Novo Nordisk Policy for Use of Animals
		
	Exhibit F	  	Novo Nordisk A/S’ Invoicing Instructions

 EXECUTION VERSION 

RESEARCH COLLABORATION AND EXCLUSIVE LICENSE AGREEMENT 

This Research Collaboration and Exclusive License Agreement (“Agreement”) is made and entered into, effective as of
December 14, 2017 (“Effective Date”), by and between Keros Therapeutics, Inc., a Delaware corporation, having a principal place of business at Suite 120, Building E, 99 Hayden Avenue, Lexington, MA 02421, USA
(“Keros”) and Novo Nordisk A/S, a company organized and existing under the laws of Denmark, having a principal place of business at Novo Allé, DK-2880 Bagsværd, Denmark
(“Novo Nordisk”). Keros and Novo Nordisk are each referred to herein individually as a “Party” and collectively as the “Parties”. 

Recitals 
 A. Keros is a
biotechnology company founded in 2016 employing its proprietary Ligand Trap platform, a discovery platform which enables the identification of Ligand Traps. 

B. Novo Nordisk is a leading global healthcare company engaged in the research, development and commercialization of pharmaceutical products
within diabetes and obesity and possesses extensive know-how within these fields. 
 C. The Parties
desire to establish a Research Collaboration which shall generally cover development of Ligand Traps in order to facilitate that Novo Nordisk can exploit and commercialize certain Ligand Traps within the Novo Nordisk Field in pharmaceutical products
on the terms and conditions set forth in this Agreement. The Research Collaboration will include (i) an Existing Ligand Trap of Keros and (ii) certain New Ligand Traps which Keros will use its Ligand Trap platform to identify. 

Agreement 
 Now,
therefore, for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, Novo Nordisk and Keros agree as follows: 

ARTICLE 1 
 Definitions

 Capitalized terms used in this Agreement shall have the meanings set forth below. 

1.1 “Affiliate” means any Person which controls, is controlled by, or is under common control with a Party, as the case
may be. For the purpose of this definition, “control” of an entity means the ownership, directly or indirectly, of more than fifty percent (50%) of the outstanding voting securities or capital stock of such entity, or the legal power to
direct or cause the direction of the general management and policies of the entity in question. For purposes of this definition, Novo Holdings A/S and its affiliates (other than Novo Nordisk and its subsidiaries) are not considered Affiliates of
Novo Nordisk. 
 1.2 “Alliance Managers” is defined in Section 2.9. 

1.3 “Bankruptcy Code” is defined in Section 5.4. 

  
 1. 

 EXECUTION VERSION 

 

 1.4 “Business Day” means a day, other than a Saturday, Sunday or day
on which commercial banks located in Boston, Massachusetts or Copenhagen, Denmark are generally closed. 
 1.5 “Cardiovascular
Indication” or “CVD Indication” means, with respect to any pharmaceutical product, an indication for which Regulatory Approval has been granted, or is intended to be sought, for the treatment or prevention of any
cardiovascular disease or condition that are not associated with diabetes or obesity. 
 1.6 “Chronic Kidney Disease
Indication” or “CKD Indication” means, with respect to any pharmaceutical product, an indication for which Regulatory Approval has been granted, or is intended to be sought, for the treatment or prevention of any disease,
condition or complication (including anemia and bone loss) arising from or associated with chronic kidney disease or the gradual loss or deterioration of kidney function, other than CKD associated with diabetes or obesity. 

1.7 “Collaboration Invention” means any invention, discovery, creation, materials,
Know-How or other intellectual property, whether or not patentable, that (a) is first generated or developed by a Party or its Affiliates or Third Party contractors, (b) is not either Keros New
Ligand Trap Inventions or Novo Nordisk Inventions, and (c) is directly related to and arising from the Research Collaboration during the Collaboration Term, whether generated or developed solely or jointly by employees of Keros and/or Novo
Nordisk or their respective Affiliates or Third Party contractors. 
 1.8 “Collaboration IP” means Collaboration
Inventions and Collaboration Patents. 
 1.9 “Collaboration Patent” means a Patent that Covers a Collaboration
Invention. 
 1.10 “Collaboration Term” is defined in Section 2.5. 

1.11 “Collaboration Year” means a one-year period during the Collaboration Term
commencing on the Effective Date or an anniversary of the Effective Date and continuing thereafter until the next anniversary of the Effective Date or the end of the Collaboration Term. 

1.12 “Commercialization” or “Commercialize” means any activities directed to manufacturing, marketing,
distributing, offering for sale, selling, using, importing or exporting a product. 
 1.13 “Commercially Reasonable
Efforts” means such application of effort and resources by the applicable Party as would be consistent with [***] in respect of a molecule controlled by such Party, which is at a similar stage in its development, taking into account,
without limitation, with respect to a product, issues of safety and efficacy, product profile, the proprietary position of the product, the then current competitive environment for the product and the likely timing of the product’s entry into
the market, the regulatory environment of the product, and other relevant scientific, technical and commercial factors, [***]. [***]. 

  
 2. 

 EXECUTION VERSION 

 

 1.14 “Confidential Information” means, with respect to a Party, any
and all confidential or proprietary information disclosed or otherwise made available by such Party to the other Party in any form under this Agreement or the Existing CDA, including but not limited to, technical processes, specifications,
instrumentation, formulae, assays, manufacturing techniques, biological, chemical or physical samples and materials, research and development plans and efforts, business plans, finances, and competitive position. The terms and conditions of this
Agreement shall be Confidential Information of both Parties. Subject to Article 6, Confidential or proprietary information arising from the Research Collaboration or the Research Plan shall be treated as Confidential Information of both Parties for
so long as both Parties retain rights to the applicable Ligand Trap pursuant to this Agreement or such Ligand Trap remains subject to the exclusivity provisions set forth in Section 2.7 (i.e., excluding Declined Ligand Traps), and thereafter
such information shall be the Confidential Information of only the Disclosing Party. 
 1.15 “Conserved Carrier”
means any part of the Ligand Trap excluding the Ligand Binder and/or Novo Nordisk Proprietary Molecule. 
 1.16 “Controlled
by” or “Control,” or the like, means the possession by a Party of, (a) with respect to any particular item, materials or information, the right (other than solely pursuant to a license granted under this Agreement) to
physical possession of those items, with the right to provide them to the other Party as provided for in this Agreement, or (b) with respect to intellectual property rights, the right (other than solely pursuant to a license granted under this
Agreement) to grant the other Party a license, sublicense or other right to exploit as provided for in this Agreement, in the case of either (a) or (b), without violating the terms of any agreement or other arrangement with a Third Party. 

1.17 “Covered by” or “Covers” means, with respect to a Patent, that the research, development, sale,
offer for sale, manufacture, having manufactured, use, export, or import of a composition of matter or other material or practice of a claimed method would, but for ownership of, or a license granted in this Agreement under, the relevant Patent,
infringe an issued Valid Claim, or a pending Valid Claim if a Patent containing such pending Valid Claim were to issue, of such Patent. 

1.18 “CVD/CKD License” is defined in Section 2.7(c). 

1.19 “Declined Ligand Trap” means any Ligand Trap which is not a Selected Ligand Trap and is further defined in
Section 2.3(a). 
 1.20 “Declined Ligand Traps-Specific Patents” is defined in Section 6.2(a)(i). 

1.21 “Development” or “Develop” means research, discovery and preclinical and clinical drug
development activities, including without limitation test method development and stability testing, toxicology, formulation, quality assurance/quality control development, statistical analysis, clinical studies, regulatory affairs, product approval
and registration. 
 1.22 “Disclosing Party” is defined in Section 8.1. 

  
 3. 

 EXECUTION VERSION 

 

 1.23 “Dispute” or the like, means any controversy, claim or legal
proceeding arising out of or relating to this Agreement, or the breach, termination or invalidity thereof. 
 1.24 “Effective
Date” is defined in the Preamble. 
 1.25 “EMA” means the European Medicines Authority, or any successor
entity thereto performing similar functions. 
 1.26 “Executive” means, with respect to a Party, an executive officer
of such Party having greater seniority than such Party’s JSC representatives, which executive officer such Party designates for the escalation of deadlocked JSC decisions pursuant to Section 2.8(e) and Disputes pursuant to
Section 13.1. For the avoidance of doubt, the Chief Executive Officer of Keros (or his or her designee) may serve both as a JSC representative and as the designated Executive for Keros, provided the Chief Executive Officer of Keros was not part
of the deadlocked JSC decision. 
 1.27 “Existing CDA” means the Confidentiality Agreement effective as of
April 20, 2017 by and between Novo Nordisk and Keros. 
 1.28 “Existing Ligand Traps” means Ligand Traps set
forth in Exhibit A. 
 1.29 “FDA” means the United States Food and Drug Administration, or any successor entity
thereto performing similar functions. 
 1.30 “First Commercial Sale” means with respect to a Licensed Product in any
country, on a Licensed Product-by-Licensed Product and country-by-country basis, the
first commercial transfer or disposition for value of such Licensed Product for end use in such country to a Third Party (not being a sublicensee for the relevant Licensed Product) by Novo Nordisk or any of its Affiliates or sublicensees after such
Licensed Product has been granted Regulatory Approval by a Regulatory Authority having jurisdiction for such country. The following sales shall not constitute a “First Commercial Sale”: (i) sales for clinical studies, [***] as well as
(ii) sales between Novo Nordisk and/or its Affiliates and/or sublicensees which do not constitute a commercial launch of a Licensed Product in the market. 

1.31 “FTE” shall mean the equivalent of a full-time employee or consultant at Keros. 

1.32 “Indication” means a separate and distinct disease, disorder or medical condition, in humans, including the
diagnosis and symptoms thereof, that a Licensed Product is intended to treat, prevent and/or ameliorate. For the avoidance of doubt, the treatment of [***] shall be deemed to be the same Indication. 

1.33 “Infringement” is defined in Section 7.1. 

1.34 “Joint Steering Committee” or “JSC” is defined in Section 2.8(a). 

1.35 “JSC Co-Chair” is defined in Section 2.8(b). 

  
 4. 

 EXECUTION VERSION 

 

 1.36 “Keros Background IP” means Keros Background Patents and Keros
Background Know-How. 
 1.37 “Keros Background
Know-How” means Know-How Controlled by Keros as of the Effective Date specifically relating to Ligand Traps. 

1.38 “Keros Background Patents” means Patents Controlled by Keros as of the Effective Date that Cover Ligand Traps. The
Keros Background Patents in existence as of the Effective Date are set forth on Exhibit B. 
 1.39 “Keros New Ligand Trap
Invention” means any invention, discovery, creation, materials, Know-How or other intellectual property, whether or not patentable, that is first generated or developed by a Party or its Affiliates or
Third Party contractors, which is specifically related to Ligand Traps and directly related to and arising from the Research Collaboration during the Collaboration Term, whether generated or developed solely or jointly by employees of Keros and/or
Novo Nordisk or their respective Affiliates or Third Party contractors. For the avoidance of doubt, no Conserved Carrier will be included in the Keros New Ligand Trap Invention. 

1.40 “Keros New Ligand Trap IP” means Keros New Ligand Trap Inventions and Keros New Ligand Trap Patents. 

1.41 “Keros New Ligand Trap Patent” means a Patent that Covers Keros New Ligand Trap Inventions, whether such Patent
names, as inventor(s), employee(s) of Keros and/or Novo Nordisk or their respective Affiliates or Third Party contractor. For the avoidance of doubt, no Conserved Carrier other than those Conserved Carriers as set forth in Keros Background Patents
will be included in the Keros New Ligand Trap Patent. 
 1.42 “Keros Patents” means Keros Background Patents and
Keros New Ligand Trap Patents. 
 1.43 “Know-How” means all information,
ideas, concepts, discoveries, technology, inventions, improvements, practices, formula, trade secrets, techniques, methods, procedures, knowledge, results, test data (including pharmacological, toxicological, pharmacokinetic and pre-clinical and clinical information and test data, related reports, structure-activity relationship data and statistical analysis), analytical and quality control data, protocols, processes, specifications,
models, designs, and other information regarding discovery, development, regulatory approval, marketing, pricing, distribution, cost, sales and manufacturing and other similar information, in any tangible or intangible form whatsoever, that is not
in the public domain or otherwise publicly known. Know-How shall not include any Patents. 
 1.44
“Licensed Combination Product” means any pharmaceutical product for human use in the Territory within the Novo Nordisk Field which contains a Novo Nordisk Proprietary Molecule fused to a Selected Ligand Trap into a single
molecule or a co-formulation of a Novo Nordisk Proprietary Molecule and a Selected Ligand Trap. 

  
 5. 

 EXECUTION VERSION 

 

 1.45 “Licensed Product” means any pharmaceutical product for human
use in the Territory within the Novo Nordisk Field which contains a Selected Ligand Trap whether alone or as a Licensed Combination Product. 

1.46 “Ligand Binder” means the extracellular portion of the [***]. 

1.47 “Ligand Trap” means a fusion molecule consisting of a Ligand Binder present as part of a larger molecule having
additional domains (defined as Conserved Carrier) excluding a Licensed Combination Product. The Ligand Trap consists of a Ligand Binder fused to a Conserved Carrier. 

1.48 “[***] Approval” means the development stage in Novo Nordisk’s [***]. 

1.49 “Net Sales” shall [***]: 

(a) [***]; 
 (b) [***]; 

(c) [***]; 
 (d) [***]; and 

(e) [***]. 
 [***]. 

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

1.50 “New Ligand Traps Information Package” is defined in Section 2.2(a). 

1.51 “New Ligand Traps” means the Ligand Traps having Ligand Binder [***] which differ from Existing Ligand Traps and
are developed during the Collaboration Term. 
 1.52 “No-Shop Period” is
defined in Section 2.7(c). 
 1.53 “Novo Nordisk Field” means: (a) any and all uses of any Licensed Product
for the treatment of diabetes (including diabetes-related complications of cardiovascular disease (CVD) and chronic kidney disease (CKD)), obesity (including obesity-related complications of cardiovascular disease (CVD), chronic kidney disease (CKD)
and sarcopenic obesity), nonalcoholic steatohepatitis (NASH) and cachexia; and (b) solely with respect to Licensed Combination Products, any and all uses in Cardiovascular Indications or CKD Indications. For clarity, the Novo Nordisk Field does
not include use of a Licensed Product that is not a Licensed Combination Product for use in the treatment of Cardiovascular Indications or CKD Indications. 

  
 6. 

 EXECUTION VERSION 

 

 1.54 “Novo Nordisk Invention” means any invention, discovery,
creation, materials, Know-How or other intellectual property, whether or not patentable, that (a) is first generated or developed by a Party or its Affiliates or Third Party contractors directly related
to and arising from the Research Collaboration during the term of this Agreement, and (b) which is specifically related to (i) a Novo Nordisk Proprietary Molecule, (ii) a Conserved Carrier and/or (iii) a Licensed Product to the
extent not solely a Keros New Ligand Trap Invention, whether generated or developed solely or jointly by employees of Keros and/or Novo Nordisk or their respective Affiliates or Third Party contractors. For the avoidance of doubt, any formulation
intellectual property, including any Know-How related to methods or processes for making formulations or for optimizing pharmacokinetic properties of Ligand Traps (by optimizing Conserved Carrier), Conserved
Carriers or a Licensed Combination Product, as well as all data and results from clinical trials related to the Selected Ligand Traps or a Licensed Combination Product shall be deemed to be Novo Nordisk Inventions. 

1.55 “Novo Nordisk Background IP” means those Patents and Know-How (to the
extent such Know-How is actually disclosed to Keros) Controlled by Novo Nordisk as of the Effective Date that are necessary for the Development or Commercialization of Licensed Products. 

1.56 “Novo Nordisk IP” means Novo Nordisk Inventions and Novo Nordisk Patents. 

1.57 “Novo Nordisk Patent” means a Patent that Covers a Novo Nordisk Invention, whether such Patent names, as
inventor(s), employee(s) of Keros and/or Novo Nordisk or their respective Affiliates or Third Party contractors. For the avoidance of doubt, subject to Keros’ ownership of Keros New Ligand Trap Patents, a Patent that Covers the combination of
(i) Selected Ligand Traps(s) and (ii) Novo Nordisk Invention(s) shall be a Novo Nordisk Patent and not a Keros New Ligand Trap Patent. 

1.58 “Novo Nordisk Proprietary Molecule” means a molecule owned or controlled (other than solely pursuant to a license
granted under this Agreement) by Novo Nordisk. 
 1.59 “Patents” means all patents, provisional and non-provisional patent applications, invention certificates, in any country, including any reissues, extensions, patent term extensions, supplementary protection certificates, registrations, divisionals,
continuations, continuations-in-part, reexaminations, substitutions or renewals thereof including any and all foreign counterparts thereof. The singular term
“Patent” has the same meaning. 
 1.60 “Person” means any person or entity, including any
individual, trustee, corporation, partnership, trust, unincorporated organization, company, business association, firm, joint venture or governmental agency or authority. 

1.61 “Phase I Clinical Trial” means a study in humans, conducted by or on behalf of Novo Nordisk or its Affiliates or
sublicensees, the principal purpose of which is a preliminary determination of the safety and/or pharmacokinetics of a pharmaceutical product in healthy individuals or patients, as further described in 21 CFR § 312.21(a) (as may be amended), or
a similar human clinical study in a country other than the United States. 

  
 7. 

 EXECUTION VERSION 

 

 1.62 “Phase 2 Clinical Trial” means any human clinical trial of a
product that would satisfy the requirements of 21 CFR § 312.21(b) or its non-United States equivalents. 

1.63 “Phase 3 Clinical Trial” means any human clinical trial of a product that would satisfy the requirements of 21 CFR
§ 312.21(c) or its non-United States equivalents. 
 1.64 “Prosecution and
Maintenance” or “Prosecute and Maintain” means, with regard to a given Patent, the preparation, filing, prosecution and maintenance of such Patent, as well as re-examinations, post
grant reviews, reissues, inter partes reviews, applications for patent term extensions and the like with respect to such Patent, together with the conduct of interferences and derivation proceedings, the defense of oppositions and other similar
proceedings with respect to such Patent. 
 1.65 “R&D Collaboration Budget Funding” is defined in
Section 3.2(a). 
 1.66 “Regulatory Approval” means the approvals, licenses, registrations or authorizations of
the applicable Regulatory Authority necessary for the Commercialization of a product in a country or territory. 
 1.67
“Research Collaboration” is defined in Section 2.1(a). 
 1.68 “Research Plan” means the
written research and development plan attached as Exhibit C as may be adopted and updated from time-to-time in accordance with Section 2.6. 

1.69 “Receiving Party” is defined in Section 8.1. 

1.70 “Regulatory Authority” means (a) the FDA; (b) the EMA; or (c) any regulatory body performing
similar functions in any jurisdiction other than the United States and the European Union. 
 1.71 “Selected Existing Ligand
Trap” means an Existing Ligand Trap which is selected by Novo Nordisk prior to or as of the Effective Date. [***]. 
 1.72
“Selected Ligand Trap” means a Selected Existing Ligand Trap and/or Selected New Ligand Trap(s). [***]. 
 1.73
“Selected Ligand Traps-Specific Patents” is defined in Section 6.2(a)(i). 
 1.74 “Selected New
Ligand Trap(s)” means one (1) or two (2) New Ligand Traps which are selected by Novo Nordisk during the Collaboration Term. For the avoidance of doubt, the unique Ligand Binder of a Selected New Ligand Trap coupled with various
Conserved Carriers shall be deemed a “Selected New Ligand Trap”. 
 1.75 “Technology Transfer” is
defined in Section 2.12. 
 1.76 “Territory” means all countries of the world. 

  
 8. 

 EXECUTION VERSION 

 

 1.77 “Third Party” means any Person other than a Party or an
Affiliate of a Party. 
 1.78 “Third Party R&D Rights” means intellectual property rights to Selected Ligand
Traps that are held by Third Parties. 
 1.79 “Valid Claim” means a claim of a Patent that is (a) issued and not
expired or lapsed, which claim has not been (i) cancelled, withdrawn, abandoned, dedicated to the public, admitted to be invalid or unenforceable or (ii) formally revoked or held invalid, unpatentable or unenforceable by a patent office,
tribunal, court or other governmental agency of competent jurisdiction in a final and non-appealable judgment (or judgment from which no appeal was taken within the allowable time period) or (b) in a
pending patent application, which application (i) has not been pending for more than [***] and (ii) has not been (A) rejected, cancelled, withdrawn, or abandoned, without the possibility of continued prosecution or (B) finally
determined to be unallowable in a decision from which an appeal has not and can no longer be taken. 
 ARTICLE 2 

Research Collaboration 

2.1 Research Collaboration Overview; Diligence. 

(a) The Parties shall conduct a research collaboration (the “Research Collaboration”) under which they will work
together during the Collaboration Term for the discovery and development of Ligand Traps pursuant to the Research Plan. The primary goal of the Research Collaboration is for Keros to generate New Ligand Traps and for Novo Nordisk to further develop
certain New Ligand Traps that it selects as Selected Ligand Traps. If Keros during this Research Collaboration successfully identifies and optimises one or more New Ligand Trap(s) in accordance with the Research Plan, Novo Nordisk has the right in
its discretion to select such New Ligand Trap(s) pursuant to Section 2.2(b) and be responsible for the further development of such Selected New Ligand Trap(s) and Commercialization of Licensed Products. 

(b) On a Ligand Trap-by-Ligand Trap basis, during the
Collaboration Term, each Party shall use Commercially Reasonable Efforts to conduct research and development of New Ligand Traps in accordance with the Research Plan. 

2.2 New Ligand Traps. 

(a) During the Collaboration Term, Keros shall present to the JSC New Ligand Traps and all scientific data supporting New Ligand Traps
as set forth in Exhibit D prior to Keros’ commencement of validation activities (each, a “New Ligand Traps Information Package”). 

(b) Novo Nordisk shall have the right to select [***] New Ligand Traps (based on the applicable New Ligand Traps Information Package)
proposed by Keros to the JSC and include the Selected New Ligand Traps under the license set forth in Section 5.1 by notifying Keros of such election within [***] after (i) Keros provides the applicable New Ligand Traps Information Package
to the JSC; or (ii) the end of the Collaboration Term. [***]. 

  
 9. 

 EXECUTION VERSION 

 

 (c) Novo Nordisk shall have the right to modify any part of the Conserved Carrier of
any Selected New Ligand Trap(s) but may not modify the Ligand Binder of the Selected New Ligand Trap(s). 
 2.3 Declined Ligand Traps.

 (a) As of the Effective Date, the Existing Ligand Trap not selected by Novo Nordisk, is deemed a “Declined Ligand
Trap”. Furthermore, any New Ligand Trap(s) proposed by Keros to the JSC which are not selected by Novo Nordisk under Section 2.2(b) as Selected New Ligand Trap(s) are also deemed a “Declined Ligand Trap”. 

(b) For the avoidance of doubt, Novo Nordisk shall have the right to propose to the JSC that any New Ligand Traps for which a New Ligand
Traps Information Package has not been completed and/or which have not been already been presented to the JSC per 2.2(b) be given a low priority with regard to ongoing Research Collaboration research efforts (e.g., FTE allocation and utilization of
funds), and such priority proposal shall not be construed as Novo Nordisk declining such New Ligand Traps (i.e., such Ligand Trap shall not as a consequence of such prioritization proposal be designated a Declined Ligand Trap). 

(c) Declined Ligand Traps shall be excluded from the Research Collaboration and, subject to Keros’ exclusivity obligations as
described in Section 2.7 with respect to any Declined Ligand Traps, Keros shall have the right to license to a Third Party or otherwise transfer the rights to Declined Ligand Traps. If Keros licenses or otherwise transfers any such Declined
Ligand Traps to a Third Party, then such Third Party terms may not conflict with or limit Novo Nordisk’s rights under this Agreement. Any license granted to a Third Party in connection with such license or transfer to a Third Party of a
Declined Ligand Trap may not include a license or access to Keros Background IP and Keros New Ligand Trap IP beyond that reasonably related to the applicable Declined Ligand Traps. 

(d) If Keros expends Keros resources to research and/or develop a Declined Ligand Trap after the date on which such Ligand Trap became a
Declined Ligand Trap pursuant to Section 2.3(a), Keros’ fully burdened costs, including overhead costs and Third Party license payments, expended to research and/or develop such Declined Ligand Traps after such time shall be borne by
Keros. For the avoidance of doubt, after the designation of a Ligand Trap as a Declined Ligand Trap, payments made by Novo Nordisk as set forth in Section 3.2 shall only be used for the Research Collaboration and not for work on Declined Ligand
Traps and the personnel costs attributable to efforts spent by Keros personnel on Declined Ligand Traps shall not be allocated against the R&D Collaboration Budget Funding. 

2.4 Third Party R&D Rights. During the Collaboration Term, Keros shall notify the JSC if Keros believes a license to any Third Party
R&D Rights would be useful to advance research and development activities under this Agreement, and Keros shall submit to the JSC a written proposal detailing the value and potential license terms for such Third Party R&D Rights.

  
 10. 

 EXECUTION VERSION 

 

 
Thereafter, the JSC shall evaluate Keros’ proposal and, if the JSC unanimously approves such proposal, Keros may license or otherwise acquire Control of such Third Party R&D Rights on
the terms and conditions specified in Keros’ written proposal to the JSC within [***] after JSC’s approval thereof; provided that, Novo Nordisk shall have the right to approve Third Parties performing in vivo animal studies in order
to ensure compliance with Novo Nordisk Principles for the Use of Animals set forth in Exhibit E. Novo Nordisk shall require that its JSC representatives not unreasonably withhold, delay or condition their approval of any such proposal, provided that
Novo Nordisk’s JSC representatives shall have the right to decline a license to any Third Party R&D Rights based on the financial obligations that would be owned to a Third Party by Novo Nordisk. [***] responsible for payment of any license
fees, royalties and other expenses owing for exploitation of such Third Party R&D Rights. 
 2.5 Collaboration Term. The term of
the Research Collaboration (the “Collaboration Term”) shall commence on the Effective Date and continue until (a) the second anniversary of the Effective Date or, if Novo Nordisk elects to extend the term of the Research
Collaboration to a third Collaboration Year as set forth in this Section 2.5, the third anniversary of the Effective Date, or (b) such earlier time as this Agreement is terminated pursuant to Article 10. Novo Nordisk shall have the
right to extend the Collaboration Term to a third Collaboration Year on the same terms and conditions applicable for the two (2) first Collaboration Years, subject to mutual written agreement of the Parties on research scope and research
funding for such third Collaboration Year, if the Collaboration Term has not otherwise terminated and Novo Nordisk provides written notice to Keros at least [***] prior to the end of the second Collaboration Year that Novo Nordisk elects to extend
the Collaboration Term to a third Collaboration Year. 
 2.6 Research Plan. 

(a) Research Plan for Ligand Traps. The purpose of this Agreement is for the Parties to perform the activities as described in the
Research Plan attached hereto as Exhibit C, as such Research Plan may be amended as set forth in Sections 2.6(b) and 2.8(c)(iii). Unless otherwise agreed by the Parties, the Research Plan shall allocate responsibilities between the Parties as
described in Section 2.1. As part of the Research Collaboration, Novo Nordisk would produce New Ligand Traps reasonably needed for further testing as agreed under the Research Collaboration. The Parties agree that failure to produce such New
Ligand Traps shall not be deemed to be a material breach of Novo Nordisk. Keros would evaluate New Ligand Traps –including providing a mechanism for selection of New Ligand Traps. The characterization of New Ligand Traps will be set forth in
the Research Plan. 
 (b) Review and Updating of Research Plan. The JSC shall review and update the Research Plan on regular basis in
accordance with Section 2.8. In furtherance of the JSC’s efforts to review and update the Research Plan during the Collaboration Term, Keros shall keep the JSC informed and updated regarding research and development activities for each New
Ligand Trap. 

  
 11. 

 EXECUTION VERSION 

 

 (c) Responsibilities; Conduct. The evaluation and characterization of each New Ligand
Trap will be carried out by the Parties in accordance with the Research Plan. Each Party will be responsible for conducting the activities allocated to such Party under the Research Plan. Each Party shall use Commercially Reasonable Efforts to
perform its responsibilities under the Research Plan. Each Party’s performance of such responsibilities shall, subject to Section 3.2, be at such Party’s own cost and expense. All work conducted for each New Ligand Trap shall be
documented in a format capable of tangible reproduction sufficient to enable such documented work to be offered as evidence, such as in a laboratory notebook, signed and dated, or other acceptable form. 

2.7 Exclusivity. 
 (a)
Keros and its Affiliates shall not, during the term of this Agreement, save for the Research Collaboration activities contemplated to be performed under the Agreement, research, Develop, Commercialize or enter into any license, sublicense, sale,
assignment or collaboration with, or otherwise grant rights or other form of transfer to or assist, any Third Party with respect to the Development or Commercialization of any Ligand Traps or Ligand Binders for use within the Novo Nordisk
Field; provided, however, that nothing, save for Section 2.7(c), in this Section 2.7 shall restrict Keros and its Affiliates, directly or in collaboration with Third Parties, from engaging in Development or Commercialization of Declined
Ligand Traps in the Cardiovascular Indications and CKD Indications. Furthermore, Keros shall not, during the term of this Agreement, save for the Research Collaboration activities contemplated to be performed under the Agreement, Develop,
Commercialize or enter into any license, sublicense, sale, assignment or collaboration with, or otherwise grant rights or other form of transfer to or assist, any Third Party with respect to the Development or Commercialization of any Selected
Ligand Traps for uses outside the Novo Nordisk Field. For clarity, notwithstanding the foregoing, a Keros Affiliate may, directly or through its Affiliates (other than Keros), Develop and Commercialize in all fields—without the use or reference
to Keros Background IP, Collaboration IP or Keros New Ligand Trap IP—those Ligand Traps or Ligand Binders that were being Developed by a Third Party as of the date such Third Party becomes a Keros Affiliate—as the Third Party and/or Keros
can by written documentation demonstrate—pursuant to Section 14.3(b). 
 (b) The restrictions set forth in
Section 2.7(a) shall not restrict or limit Keros from engaging Third Parties to perform tasks in furtherance of the Research Collaboration; provided that, Novo Nordisk shall have the right to approve Third Parties performing in vivo
animal studies in order to ensure compliance with Novo Nordisk Principles for the Use of Animals set forth in Exhibit E and provided that, Keros enters into a written agreement with such Third Parties ensuring they are bound by
confidentiality obligations that are consistent with those set forth in the Agreement and are obligated to assign to Keros any Patents and Know-How developed by the Third Party in its performance of tasks in
furtherance of the Research Collaboration. 
 (c) [***]. 

  
 12. 

 EXECUTION VERSION 

 

 2.8 Joint Steering Committee. 

(a) Establishment of the JSC. Promptly following the Effective Date, the Parties shall establish a joint steering committee
(“Joint Steering Committee” or “JSC”), which shall be responsible for the management and conduct of the Research Collaboration, including (i) overseeing progress in and prioritization amongst New Ligand Traps
and the allocation of resources thereto, and (ii) resolving disputes between the Parties with respect to the conduct of the Research Collaboration. The JSC shall consist of [***] representatives of each Party. A Party may replace any or all of
its representatives at any time upon prior written notice (including by email) to the other Party. The representatives shall be appropriate (in terms of their seniority, availability, function in their respective organizations, training and
experience) to oversee the activities under the Research Collaboration that will be performed and make decisions as to such activities. 

(b) JSC Co-Chairs. Each Party shall designate one of its representatives as co-chairman of the JSC meetings (such Party’s “JSC Co-Chair”). The chairmanship of JSC meetings shall alternate between each Party’s JSC Co-Chair. A Party may replace its designated JSC Co-Chair at any time upon prior written notice (including by email) to the other Party. Either JSC Co-Chair may call an emergency JSC meeting for good cause by written request to the other Party. 
 (c)
Responsibilities of the JSC. The Joint Steering Committee shall be responsible for performing the following functions: 
 (i)
exchange information concerning the overall strategy and timelines for the New Ligand Traps including prioritization and coordination of New Ligand Traps; 

(ii) evaluating and managing potential Ligand Traps for designation as, and designating, New Ligand Traps; 

(iii) adopting, reviewing and amending the Research Plan and documenting the same; 

(iv) evaluating New Ligand Traps; 

(v) discussing issues identified in the preliminary
freedom-to-operate assessments specified in Exhibit D as well as freedom-to-operate
issues subsequently identified by the Parties relating to New Ligand Traps; 
 (vi) evaluating the progress of the Research
Collaboration, as compared with the objectives set forth in this Agreement and the Research Plan; 
 (vii) coordinating, as the
primary conduit for, the transfer of information and materials, including the Technology Transfer, between the Parties during the Collaboration Term; 

  
 13. 

 EXECUTION VERSION 

 

 (viii) performing such other functions referred to the JSC in the Research Plan as
appropriate to further the purposes of the Research Collaboration by mutual agreement of the Parties, or as otherwise specified in this Agreement or agreed to by the Parties; and 

(ix) serving as a forum for informal dispute resolution of issues that may arise in relation to operational or technical activities
engaged in pursuant to this Agreement. 
 (d) Areas Outside the JSC’s Authority. The JSC shall have no authority other than that
expressly set forth in this Agreement and, specifically, shall have no authority: (a) to amend, or interpret any ambiguous provision of, this Agreement, (b) to require either Party to perform any activities other than as specified in the
then current Research Plan, (c) to determine whether or not a Party has met its diligence or other obligations under the Agreement, (d) to determine whether or not a breach of this Agreement has occurred, (e) to waive compliance with
any provisions of this Agreement, (f) subject to Section 2.12, to make any decision with respect to the Selected Existing Ligand Trap, or (g) to make any decision that is expressly stated by this Agreement to require the approval of
one or the other Party or the approval of both Parties. 
 (e) Decision Making Authority. With respect to the responsibilities of the
Joint Steering Committee, each Party shall have one (1) collective vote in all decisions, and the Parties shall attempt to make decisions by unanimous vote. If the JSC cannot reach agreement within [***] of an issue being brought to a vote,
then the matter will be referred to the Executives of the Parties. The Executives will use reasonable efforts to resolve matters referred to them. 

(f) Meetings; Attendees. Once established, the Joint Steering Committee shall meet at least once each calendar quarter during the
Collaboration Term unless otherwise agreed by the Parties. The first meeting of the JSC shall be held as soon as practicable after the Effective Date. The JSC may meet in person at a mutually agreed location or via teleconference, video conference
or the like, provided that, unless otherwise agreed by the Parties, [***]. Each Party shall bear the expense of its respective representatives’ participation in JSC meetings. The JSC forms a quorum when [***] are present. If any of a
Party’s representatives is unable to attend a given meeting, such Party may designate a knowledgeable alternate to attend such meeting and perform the functions of such representative, provided that notice hereof is given in writing to the
other Party in advance of the meeting. Each Alliance Manager may attend JSC meetings as a non-voting observer. Each Party may invite a reasonable number of non-voting
employees, consultants or scientific advisors to attend JSC meetings as deemed necessary or desirable by such Party, subject to the prior consent of the other Party, not to be unreasonably withheld, and provided that such invitees are bound
in writing by confidentiality obligations that are consistent with those set forth in the Agreement. 
 (g) Minutes; Other Documentation
of Decisions. The Joint Steering Committee shall keep minutes of its meetings that record in writing all decisions made, action items assigned and completed and other appropriate matters. Novo Nordisk’s Alliance Manager shall be responsible
for drafting meeting minutes and such draft minutes shall be sent to Keros 

  
 14. 

 EXECUTION VERSION 

 

 
promptly after a meeting for review, comment and approval by both Parties. A decision that may be made at a JSC meeting may also be made without a meeting if such decision is agreed to in writing
(including by email) by each Party’s JSC Co-Chair (or its designee), provided that each Party’s JSC Co-Chair’s (or its designee’s) written
communication clearly indicates that such decision is a formal decision on behalf of such Party’s JSC representatives. Any modifications to the Research Plan that are approved by the JSC shall constitute an amendment to the Research Plan. 

(h) Control of Intellectual Property. The Joint Steering Committee shall have the right to propose that any New Ligand Trap be given a
low priority with regard to ongoing Research Collaboration research efforts (e.g., personnel allocation and utilization of funds), if Keros does not Control the Know-How and Patents with respect to such New
Ligand Trap. 
 (i) Term of JSC Operation. The Joint Steering Committee shall meet during the Collaboration Term. Thereafter, the JSC
shall cease operations and perform no further functions under this Agreement. 
 2.9 Alliance Manager. Promptly following the
Effective Date, each Party shall appoint a representative of such Party as the primary contact for matters related to this Agreement, unless another contact is expressly specified in the Agreement or designated by the JSC for a particular purpose
(the “Alliance Managers”). During the Collaboration Term, both Alliance Managers shall jointly be responsible for and shall collaborate in scheduling Joint Steering Committee meetings and setting meeting agendas after consulting the
JSC Co-Chairs. The Alliance Managers shall facilitate open and transparent communication and collaboration between the Parties and shall seek to facilitate resolution of potential and pending issues and
potential disputes to enable the JSC to reach consensus and avert escalation of such issues or potential disputes. Either Party may replace its Alliance Manager at any time upon prior written notification (including by email) to the other Party.

 2.10 Records and Reports. 

(a) Records. Each Party shall use commercially reasonable efforts to maintain complete, current and accurate records of all research and
development activities conducted by it in the conduct of the Research Collaboration, and all data and other Know-How resulting from such activities. 

(b) Reports. At least once quarterly during the Collaboration Term, each Party shall provide to the JSC a written summary of its
Research Collaboration research and Development and results, remaining activities and updates on new Know-How and Patents relating to New Ligand Traps (excluding Declined Ligand Traps). Novo Nordisk shall
incorporate the information provided by both Parties into a consolidated quarterly summary that reflects both Parties’ Research Collaboration research and development and results, which Novo Nordisk shall provide to the JSC. Within [***] after
the expiration or earlier termination of the Collaboration Term, Keros shall provide to Novo Nordisk a final written report directed to any additional data and results generated by Keros subsequent to the last quarterly summary during

  
 15. 

 EXECUTION VERSION 

 

 
the Collaboration Term as well as listing all New Ligand Traps and Keros New Ligand Trap IP (excluding any Keros New Ligand Trap IP specifically related to Declined Ligand Traps) and any
inventions developed or conceived during the Collaboration Term that specifically related to Selected Ligand Traps on which patents have not yet been filed. 

(c) Prioritization and Resource Allocation Planning. [***] following the first JSC meeting and at least every [***] thereafter, Keros
will present to the JSC for approval a proposed project prioritization for the next [***] period, including a suggested allocation of R&D Collaboration Budget Funding to each New Ligand Trap and to activities directed to identifying potential
New Ligand Traps. Keros shall provide to Novo Nordisk a draft of the above project prioritization at least [***] in advance of the JSC meeting at which such project prioritization is to be discussed. 

2.11 Resource Allocation. 

(a) During the Collaboration Term, Keros agrees that it will assign to the New Ligand Traps, and to activities directed to identifying
potential New Ligand Traps, appropriate personnel resources comprising skills and levels of experience consistent with such R&D Collaboration Budget Funding. [***], provided that resources expended by Keros on the Declined Ligand Traps after
such Ligand Traps have been declined shall not be included. [***]. 
 2.12 Technology Transfer. 

(a) Promptly following the Effective Date, the Parties shall agree on a plan to transfer to Novo Nordisk all material data and any other
information Controlled by Keros as of the Effective Date, including Keros Background Know-How, with respect to the Selected Existing Ligand Trap (the “Technology Transfer”), which transfer
shall proceed in accordance with the Research Plan and subject to JSC oversight. Keros shall provide Novo Nordisk with reasonable assistance to enable Novo Nordisk to implement the Keros Background Know-How
for [***] following the Effective Date. 
 (b) If Novo Nordisk selects Selected New Ligand Traps under Section 2.2(b), then the
Parties shall agree on a plan to promptly transfer to Novo Nordisk all material data and any other information Controlled by Keros as of such transfer date, including Keros Background Know-How, Keros New
Ligand Trap IP and Keros’ interest in the Collaboration IP, with respect to such Selected New Ligand Trap (this transfer shall be deemed part of the “Technology Transfer”), which transfer shall proceed in accordance with the
Research Plan and subject to JSC oversight. Keros shall provide Novo Nordisk with reasonable assistance to enable Novo Nordisk to implement the Keros Background Know-How, Keros New Ligand Trap IP and
Keros’ interest in the Collaboration IP for [***] days following such transfer date. 

  
 16. 

 EXECUTION VERSION 

 

 ARTICLE 3 

Payments 
 3.1 Upfront
Payment. In consideration for Keros entering into this Agreement and conducting the Research Collaboration activities assigned to Keros hereunder and under the Research Plan, Keros shall invoice Novo Nordisk on the Effective Date for an upfront
payment of Sixteen Million U.S. Dollars (US$16,000,000). Novo Nordisk shall make such payment to Keros within [***] of the date of Keros’ invoice. 

3.2 Research Collaboration Budget Funding Payments. 

(a) In consideration for Keros entering into this Agreement and conducting the Research Collaboration activities assigned to Keros
hereunder and under the Research Plan, Novo Nordisk shall provide Keros with funding of US$2,000,000 per Collaboration Year (i.e., US$4,000,000 in total for the two Collaboration Years) (the “R&D Collaboration Budget Funding”).
The R&D Collaboration Budget Funding amount shall constitute non-refundable [***]. 
 (b)
Keros shall invoice Novo Nordisk on the Effective Date for the R&D Collaboration Budget Funding payment (i.e. US$4,000,000) in accordance with the Novo Nordisk Invoicing Instructions set forth in Exhibit F. Novo Nordisk shall make such
payment to Keros within [***] of the date of Keros’ invoice. 
 (c) Within [***] of the end of each Collaboration Year, Keros
shall prepare and deliver to Novo Nordisk a calculation of the costs and expenses, including direct costs and expenses, including for FTEs, incurred in the performance of the Research Collaboration activities as well as reasonable general and
administrative and CAPEX/outsourcing costs and expenses allocated to the Research Collaboration activities, and reasonable supporting documentation. 

3.3 Development Milestone Payments for the First Licensed Product. 

(a) Novo Nordisk shall make each of the following milestone payments within [***] after the achievement of each of the following
respective milestone events with respect to the first Licensed Product by Novo Nordisk, its Affiliates or its sublicensees: 
  

					
	 Development Milestone Event
	  	Milestone Payment
(US Dollars)	 
	 (i) [***]
	  	US$	[***	] 
	 (i) [***]
	  	US$	[***	] 
	 (ii) [***]
	  	US$	[***	] 
	 (iii) [***]
	  	US$	[***	] 
	 (iv) [***]
	  	US$	[***	] 
	 (v) [***]
	  	US$	[***	] 
		  	  
	  
	 
	 Total Milestones
	  	US$	96,000,000	 
		  	  
	  
	 

  
 17. 

 EXECUTION VERSION 

 

 (b) The development milestone payments payable under Sections 3.3(a)(i) and 3.3(a)(ii)
shall only be payable one time (i.e., for the first event by the first Licensed Product regardless of the repeated achievement of the milestone event by the same Licensed Product or other Licensed Product(s)), irrespective of how many Indications
for which the first Licensed Product is Developed or Commercialized by Novo Nordisk, its Affiliates or its sublicensees. Any second or third Indication with the same first Licensed Product shall trigger fifty (50) % of the development milestones
under Sections 3.3(a)(iii), (iv), (v) and (vi) as they occur for such second or third Indication of the first Licensed Product (i.e. no retriggering of development milestones (i) and (ii)). Any fourth Indication for the same first Licensed
Product shall have no milestone payments. 
 (c) Subject to Section 3.3(b), the achievement of any milestone event set forth in
this Section 3.3 shall cause all milestone payments associated with all earlier listed milestone events that have not yet become due and payable to become due and payable as of the date of achievement of such milestone event; provided, however,
that achievement of the milestone event “[***]” shall not cause the milestone payment associated with the milestone event “[***]” to become due and payable, and vice versa. 

3.4 Development Milestone Payments for the Second or Third Licensed Product. 

(a) Novo Nordisk shall make each of the following milestone payments within [***] after the achievement of each of the following
respective milestone events with respect to a second or third Licensed Product by Novo Nordisk, its Affiliates or its sublicensees: 
  

					
	 Development Milestone Event
	  	Milestone Payment
(US Dollars)	 
	 (i) [***]
	  	US$	[***	] 
	 (ii) [***]
	  	US$	[***	] 
	 (iii) [***]
	  	US$	[***	] 
	 (iv) [***]
	  	US$	[***	] 
	 (v) [***]
	  	US$	[***	] 
	 (vi) [***]
	  	US$	[***	] 
		  	  
	  
	 
	 Total Milestones
	  	US$	80,000,000	 
		  	  
	  
	 

  
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 EXECUTION VERSION 

 

 (b) The development milestone payments payable under Sections 3.4 (a)(i) and 3.4
(a)(ii) shall only be payable one time (i.e., for the first event by the second or third Licensed Product regardless of the repeated achievement of the milestone event by the same second or third Licensed Product or other Licensed Product(s)),
irrespective of how many Indications for which a second or third Licensed Product is Developed or Commercialized by Novo Nordisk, its Affiliates or its sublicensees. Any second or third Indication with the same second or third Licensed Product shall
trigger fifty (50) % of the development milestones under Sections 3.43.3(iii), (iv), (v) and (vi) as they occur for such second or third Indication of the second or third Licensed Product (i.e. no retriggering of development milestones
(i) and (ii)). Any fourth Indication for the same second or third Licensed Product shall have no milestone payments. 
 (c) If a
second or third Licensed Product is Developed for same Indication for which a development milestone already has been paid for the first Licensed Product under Section 3.3(a) for which the Development has subsequently been terminated with such
first Licensed Product for such same Indication, then such already paid development milestone shall not be triggered/paid for under Section 3.4. 

(d) Subject to Sections 3.4 (b)-(c), the achievement of any milestone event set forth in this Section 3.4 shall cause all milestone
payments associated with all earlier listed milestone events that have not yet become due and payable to become due and payable as of the date of achievement of such milestone event; provided, however, that achievement of the milestone event
“[***]” shall not cause the milestone payment associated with the milestone event “[***]” to become due and payable, and vice versa. 

3.5 Sales Milestone Payments. 

(a) Novo Nordisk shall provide Keros with written notice of the anticipated first occurrence of each of the events set forth below with
respect to Licensed Product at least [***] prior to such occurrence, and shall provide Keros with written notice of the actual first occurrence of each sales milestone set forth below with respect to Licensed Product within [***]s after such
occurrence. Within [***] of the first occurrence of each of the events set forth below with respect to Licensed Product whether by Novo Nordisk, its Affiliate or any of their respective sublicensees, Novo Nordisk shall pay to Keros the applicable
payment set forth below: 
  

					
	 Sales Milestone Event
	  	Milestone Payment
(US Dollars)	 
	 [***]
	  	US$	[***	] 
	 [***]
	  	US$	[***	] 
		  	  
	  
	 
	 Total Milestones
	  	US$	70,000,000	 
		  	  
	  
	 

  
 19. 

 EXECUTION VERSION 

 

 (b) The sales milestone payments set forth in Section 3.5 shall be triggered by
the achievement of the specified sales for all Licensed Product (including, for purposes of this calculation, aggregate worldwide Net Sales of all Licensed Product for any and all Indications, and including all formulations, generations and/or
refinements thereof) in an annual period, and shall be payable only once despite potential repeated achievement of the specified sales by the same Licensed Product or other Licensed Products. For purposes of clarity, more than one of the foregoing
sales milestone payments may be earned and become payable with respect to Licensed Product in the same annual period based on aggregate worldwide Net Sales of Licensed Product during such annual period. All payments made to Keros pursuant to
Section 3.5 are non-refundable and may not be credited against any other payments payable by Novo Nordisk to Keros under this Agreement. 

3.6 Royalties. 
 (a)
Patent Royalties. During the Royalty Term (as defined in Section 3.6(c)), Novo Nordisk shall pay to Keros a patent royalty of [***] on a country-by-country and
Licensed Product-by-Licensed Product basis in the Territory of annual Net Sales of Licensed Products Covered by a Valid Claim of a Keros Patent, a Novo Nordisk Patent
(provided an employee of Keros or an Affiliate or Third Party contractor thereof is a joint inventor or the sole inventor named on such Novo Nordisk Patent) or a Collaboration Patent. 

(b) Know-How Royalties. In the event that prior to the expiration of the Royalty Term a Licensed
Product is not Covered by a Valid Claim of a Keros Patent, a Novo Nordisk Patent (provided an employee of Keros or an Affiliate or Third Party contractor thereof is a joint inventor or the sole inventor named on such Novo Nordisk Patent) or a
Collaboration Patent, then Novo Nordisk shall pay Keros a Know-How royalty of [***] on a country-by-country and Licensed Product-by-Licensed Product basis in the Territory of annual Net Sales of Licensed Products. 

(c) Royalty Term. Novo Nordisk’s royalty obligations under Section 3.6 shall commence on a country-by-country basis and Licensed Product-by-Licensed Product basis on the date of First Commercial Sale of Licensed Product
by Novo Nordisk, its Affiliates or sublicensees in the relevant country, and shall expire on a country-by-country basis upon the later of (i) expiration of the last
to expire Valid Claim of a Keros Patent, a Novo Nordisk Patent (provided an employee of Keros or an Affiliate or Third Party contractor thereof is a joint inventor or the sole inventor named on such Novo Nordisk Patent) or a Collaboration Patent
Covering the manufacture or sale of the Licensed Product in such country, or (ii) [***] years following First Commercial Sale of Licensed Product after Regulatory Approval in such country (the “Royalty Term”). 

(d) Royalty Reduction. In the event that a Third Party Controls a Patent that Covers the Ligand Binder that in the reasonable written
opinion of a Novo Nordisk patent counsel will be infringed by the Commercialization of Licensed Product, then Novo Nordisk shall have the right (but not the obligation) to obtain a license to such Third Party Patent. The [***] which Novo Nordisk
actually pays to such Third Party for a license to such Patent in a country during a calendar quarter may be credited against up to [***] of royalties otherwise payable by Novo Nordisk to Keros for such Licensed Product in such country in such
calendar quarter; provided, however, that in no event shall the foregoing deduction reduce the amount of royalties payable hereunder with respect to Net Sales of such Licensed Product in such country in a calendar quarter by more than [***] of the
amounts that would otherwise be due hereunder with respect to Net Sales of such Licensed Product in such country in such calendar quarter. Novo Nordisk shall promptly inform Keros if it has executed a license agreement to such Third Party Patent.

  
 20. 

 EXECUTION VERSION 

 

 (e) Royalty Reports; Payments. After the First Commercial Sale of the first Licensed
Product and until expiration of the last Royalty Term, Novo Nordisk shall prepare and deliver to Keros royalty reports of the sale of Licensed Products for each calendar quarter within [***] of the end of each such calendar quarter specifying,
[***]: (a) total gross invoiced amounts for Licensed Products sold; (b) amounts deducted by category in accordance with Section 1.49 (“Net Sales”) from gross invoiced amounts to calculate Net Sales; (c) Net Sales; and
(d) royalties payable. Novo Nordisk shall accompany such report with payment to Keros of all amounts payable to Keros under Section 3.6 on Net Sales of Licensed Products for such calendar quarter. 

(f) Records and Audits. Novo Nordisk will keep complete and accurate records relating to the calculations of Net Sales generated in the
then current calendar year and payments required under this Agreement, and during the preceding [***]. Keros will have the right during the term of this Agreement and for a period of three years thereafter, once annually at its own expense, to have
an internationally recognized, independent, certified public accounting firm, currently one of the following: PWC, E&Y, KPMG or Deloitte (the “Auditor”), selected by it, review any such records of Novo Nordisk and its Affiliates
and sublicensees (the “Audited Party”) in the location(s) where such records are maintained by the Audited Party subject to the following terms: 

(i) Keros shall give Novo Nordisk at least [***] prior written notice of when its Auditor shall visit the Audited Party; 

(ii) At least [***] prior to inspecting any records, the Auditor must enter into a confidentiality agreement with the Audited Party
that is reasonably satisfactory to the Audited Party; 
 (iii) Novo Nordisk shall make their books and records available for review
by the Auditor solely to verify the accuracy of its Net Sales report and payments under this Agreement; 
 (iv) Novo Nordisk shall
give access to the Auditor during regular business hours at the place or places where the books and records are usually kept. While inspecting such accounts and records, the Auditor must abide by all of Novo Nordisk’s standard rules and
regulations; 
 (v) The Auditor shall prepare and deliver to each Party a report setting out its findings no later than [***] after
the audit has been completed. [***]; 
 (vi) Any report by the Auditor under this Section (f) shall be deemed Confidential
Information of Novo Nordisk and Keros shall keep such report and any other information received or learnt in connection with the audit confidential; 

  
 21. 

 EXECUTION VERSION 

 

 (vii) No calendar year will be subject to audit under this Section (f) more than
once; and 
 (viii) Should such inspection lead to the discovery of a discrepancy to Keros’s detriment, Novo Nordisk will,
within [***] after receipt of such report from the accounting firm, pay any undisputed amount of the discrepancy. Keros will pay the full cost of the review unless the underpayment of amounts due to Keros is greater than [***] of the amount due for
the entire period being examined, in which case Novo Nordisk will pay the cost charged by such accounting firm for such review. Should the audit lead to the discovery of a discrepancy to Novo Nordisk’s detriment, Novo Nordisk may credit the
amount of the discrepancy against future payments payable to Keros under this Agreement, and if there are no such payments payable, then Keros shall pay to Novo Nordisk the amount of the discrepancy within [***] of Keros’ receipt of the report.
Any such payments made in connection with such discrepancy shall be subject to Section 4.3. 
 ARTICLE 4 

Payment-Related Provisions 

4.1 Mode of Payment. All payments under this Agreement shall be made in immediately available funds by wire transfer to a United States
based account to be identified by Keros. 
 4.2 Currency of Payments. All payments under this Agreement shall be made in United States
dollars, unless otherwise expressly provided in this Agreement. 
 4.3 Late Payments. To the extent that any payments under this
Agreement are not paid within the specified time period, such outstanding payments shall accrue interest from the date due, at the one year USD LIBOR rate on the last Business Day of the applicable calendar quarter prior to the date on which such
payment was due, plus [***], calculated on the basis of a 360-day year, or, if lower, the maximum rate permitted by law. 

4.4 Novo Nordisk Invoicing Instructions. Any payment payable by Novo Nordisk under this Agreement, including payments under Sections
2.2(b), 3.1, 3.2, 3.3, 3.4, 3.5, 3.6 and 6.2(a)(iii), is subject to receipt by Novo Nordisk of an invoice herefore prepared in accordance with the Novo Nordisk Invoicing Instructions set forth in Exhibit F. 

4.5 Taxes. [***]. 

  
 22. 

 EXECUTION VERSION 

 

 ARTICLE 5 

License Grants 
 5.1
License Grants. 
 (a) Keros hereby grants to Novo Nordisk and its Affiliates an exclusive (even as to Keros), worldwide,
royalty-bearing license, with the right to grant sublicenses, (with Keros retaining the right to perform its activities under the Research Collaboration) under the Keros Background IP, the Keros New Ligand Trap IP and Keros’ interest in the
Collaboration IP, solely to Develop and Commercialize Licensed Products, in all cases in the Novo Nordisk Field and in the Territory. Such license excludes any rights to modify the Ligand Binder, but includes the right to modify any part of the
Conserved Carrier of a Selected Ligand Trap. Such license shall not grant Novo Nordisk any right or license with respect to Declined Ligand Traps, nor to Develop or Commercialize Licensed Products that are not Licensed Combination Products for
Cardiovascular Indications or CVD Indications. 
 (b) Novo Nordisk hereby grants to Keros a nonexclusive, worldwide license under the
Novo Nordisk Background IP, Novo Nordisk IP and Novo Nordisk’s interest in the Collaboration IP, solely for Keros to perform its activities under the Research Collaboration. For the avoidance of doubt, said license does not apply with respect
to Declined Ligand Traps. 
 5.2 Sublicenses. Subject to the terms and conditions herein, Novo Nordisk shall have the right to
sublicense the rights granted to Novo Nordisk by Keros under Section 5.1, provided, however, that: (i) each sublicense shall contain obligations of the sublicensee equivalent or similar to the obligations of Novo Nordisk hereunder; and
(ii) Novo Nordisk shall provide to Keros a redacted copy of each sublicense agreement (and any future amendments or terminations thereof) within [***] after the execution thereof. 

5.3 No Implied Licenses. Except as otherwise expressly provided, this Agreement does not grant any right or license to either Party
under any of the other Party’s intellectual property rights, and no other right or license is to be implied or inferred from any provision of this Agreement or by the conduct of the Parties. 

5.4 Section 365(n) of the Bankruptcy Code. All rights and licenses granted pursuant to any Section of this Agreement
are, and shall be deemed to be, rights and licenses to “intellectual property” (as defined in Section 101(35A) of title 11 of the United States Code and of any similar provisions of applicable Laws under any other jurisdiction (the
“Bankruptcy Code”)). Each Party agrees that the other Party, as a licensee of rights and licenses under this Agreement, shall retain and may fully exercise all of its rights and elections under the Bankruptcy Code. 

ARTICLE 6 
 Intellectual
Property 
 6.1 Ownership of IP. 

(a) Keros Background IP. Subject to the licenses granted under Section 5.1, as between the Parties, Keros shall solely own all
right, title and interest in and to the Keros Background IP. 
 (b) Novo Nordisk Background IP. Subject to the licenses granted under
Section 5.1, as between the Parties, Novo Nordisk shall solely own all right, title and interest in and to the Novo Nordisk Background IP. It is not the Parties’ intent that Novo Nordisk discloses to Keros any Novo Nordisk Background IP.

  
 23. 

 EXECUTION VERSION 

 

 (c) Keros New Ligand Trap IP. Subject to the licenses granted under Section 5.1,
as between the Parties, Keros shall own all right, title and interest in Keros New Ligand Trap IP. 
 (d) Novo Nordisk IP. Subject to
the licenses granted under Section 5.1, as between the Parties, Novo Nordisk shall own all right, title and interest in Novo Nordisk IP. 

(e) Collaboration IP. Subject to the licenses granted under Section 5.1, as between the Parties, all right, title and interest in
Collaboration shall be owned jointly by the Parties. It is not the Parties’ intent that Collaboration IP will be generated. 
 (f)
Further Assurances. The Parties shall reasonably cooperate with each other, and shall cause any employees, agents or consultants of the Party, to effectuate ownership of any intellectual property rights as set forth in this Agreement, including,
but not limited to, by executing and recording assignment documents. On a jurisdiction by jurisdiction basis, the Parties shall also reasonably cooperate with each other and negotiate in good faith any necessary transfer of rights, such as with an
assignment of a Patent, should the law in such jurisdiction require such transfer in order to obtain patentability or maintain validity and/or enforce of such Patent. 

6.2 Patent Prosecution and Maintenance. 

(a) Keros Background IP and Keros New Ligand Trap Patents. 

(i) The Parties acknowledge that Keros Background Patents that exist as of the Effective Date Cover both Declined Ligand Traps as well
as Selected Ligand Traps, and that the Declined Ligand Traps are not subject to Novo Nordisk’s license set forth in Section 5.1(a). Furthermore, the Parties acknowledge that Keros New Ligand Trap Patents potentially will Cover both
Declined Ligand Traps as well as Selected Ligand Traps, and that the Declined Ligand Traps are not subject to Novo Nordisk’s license set forth in Section 5.1(a).The Parties further acknowledge that it is their intent, where reasonably
practicable, to file divisional and/or continuation patent applications (including, if appropriate, continuation-in-part patent applications) claiming priority to such
Keros Background Patents, and/or new patent applications, such as one or more Keros New Ligand Trap Patents, that solely Cover the composition, manufacture or use of the Selected Ligand Traps (such patent applications and any patents issuing
therefrom, defined as the “Selected Ligand Traps-Specific Patents”) without claiming any subject matter related to the Declined Ligand Traps (such patent applications and any patents issuing therefrom, defined as the
“Declined Ligand Traps-Specific Patents”). 
 (ii) To coordinate the efficient Prosecution and Maintenance of the
Selected Ligand Traps-Specific Patents and Declined Ligand Traps-Specific Patents in accordance with the foregoing principles, the Parties shall appoint one senior patent counsel representing each Party to oversee the Prosecution and Maintenance of
the Selected Ligand Traps-Specific Patents and Declined Ligand Traps-Specific Patents pursuant to this Section 6.2. The patent counsels shall meet by telephone or videoconference at least twice per year, and more frequently as its members may
agree. Keros’ patent counsel shall provide an update to Novo Nordisk’s patent counsel with respect to Prosecution and Maintenance of the Keros Background Patents at least [***] prior to a JSC meeting. 

  
 24. 

 EXECUTION VERSION 

 

 (iii) As between the Parties, Keros shall have the sole right, at its sole
discretion, to Prosecute and Maintain and determine the strategy of prosecution of the (A) Keros Background Patents and (B) Keros New Ligand Trap Patents including those Covering Selected Ligand Traps and Declined Ligand Traps. As of the
Effective Date, Novo Nordisk shall be responsible for all reasonable prosecution costs of Keros Background Patents (other than Declined Ligand Traps-Specific Patents) and Keros New Ligand Trap Patents (other than Declined Ligand Traps-Specific
Patents), and shall reimburse Keros for such expenses within [***] after invoice thereof from Keros. 
 (iv) Keros shall, at least
[***] and at minimum intervals of [***], during the term of this Agreement, provide Novo Nordisk with a list of Keros Background Patents (other than Declined Ligand Traps-Specific Patents) and Keros New Ligand Trap Patents (other than Declined
Ligand Traps-Specific Patents), providing relevant filing and status information, beginning on the date that is [***] following the Effective Date. 

(v) Keros shall provide Novo Nordisk with timely notification regarding any information it discovers during the term of this Agreement
that Keros reasonably considers to materially affect the enforceability or adversely affect the term of any Keros Background Patent Covering Selected Ligand Traps or Keros New Ligand Trap Patents Covering Selected Ligand Traps. 

(vi) If requested by Novo Nordisk, Keros shall timely provide Novo Nordisk with copies of all material correspondence from any patent
authority regarding Keros Background Patents and Keros New Ligand Trap Patents Covering Selected Ligand Traps. 
 (vii) If requested
by Novo Nordisk, Keros shall provide Novo Nordisk with a copy of any proposed material filing with any patent authority in connection with proceedings before any patent authority in the Selected Ligand Traps-Specific Patents and, if requested by
Novo Nordisk, shall provide to Novo Nordisk a reasonable opportunity (at least [***], if reasonably practicable) to comment on any such proposed material filing with respect to such Selected Ligand Traps-Specific Patents, which comments Keros shall
consider in good faith. 
 (viii) If Keros elects to discontinue Prosecution or Maintenance of any Keros Background Patent (excluding
Declined Ligand Traps-Specific Patents) or Keros New Ligand Trap Patents (excluding Declined Ligand Traps-Specific Patents) without filing a continuation or substitute patent application, Keros shall so advise Novo Nordisk in writing at least [***]
in advance of such discontinuance and, if requested by Novo Nordisk, shall discuss with Novo Nordisk Keros’ reasons for such discontinuance. If requested by Novo Nordisk and at Novo Nordisk’s sole cost, Keros will take action to prevent
such abandonment of such Patent, unless Keros has a material business or legal reason for not taking such action. For purposes of clarity, as between Keros and Novo Nordisk, Keros shall retain ownership of the Keros Background Patents and Keros New
Ligand Trap Patents Covering Selected Ligand Traps. 

  
 25. 

 EXECUTION VERSION 

 

 (b) Novo Nordisk Background Patents and Novo Nordisk Patents. As between the Parties,
Novo Nordisk shall have the sole right, at its sole discretion and expense, to Prosecute and Maintain and determine the strategy of Prosecution of all Patents comprising the Novo Nordisk Background IP as well as Novo Nordisk Patents. 

(c) Keros New Ligand Trap Patents Covering Declined Ligand Traps. During the term of this Agreement, Keros shall at its own costs have
the sole right, at its sole discretion and expense, to Prosecute and Maintain and determine the strategy for the Prosecution and Maintenance of any Keros New Ligand Trap Patent solely Covering the Declined Ligand Traps (i.e. Declined Ligand
Traps-Specific Patents), including deciding on (A) the scope and content of the Patent; (B) the countries in which Prosecution and Maintenance should be conducted; and (C) whether to retain outside patent counsel to conduct all or
particular Prosecution and Maintenance activities. 
 (d) Collaboration Patents. During the term of this Agreement, the Parties shall
jointly decide if and how to Prosecute and Maintain and determine the strategy for the Prosecution and Maintenance of any Collaboration Patent and how costs and expenses will be allocated between the Parties, including deciding on (A) the scope
and content of the Patent; (B) the countries in which Prosecution and Maintenance should be conducted; and (C) whether to retain outside patent counsel to conduct all or particular Prosecution and Maintenance activities. It is not the
Parties’ intent that Collaboration IP will be generated. 
 (e) Cooperation. Each Party shall reasonably cooperate with and
assist the other Party in the Prosecution and Maintenance of any Keros New Ligand Trap Patent, Novo Nordisk Patent or Collaboration Patent, including by (A) consulting with the other Party as it may reasonably request, and (B) making its
relevant and necessary scientists and scientific records reasonably available. In addition, either Party shall sign and deliver, or use reasonable efforts to have signed and delivered, at no charge to the other Party, all documents necessary in
connection with such Prosecution and Maintenance. 
 (f) Patent Term Extensions. Novo Nordisk shall have the sole right to apply for
patent term extension on a Keros Background Patent (excluding any Declined Ligand Traps-Specific Patents), Keros New Ligand Trap Patents (excluding any Declined Ligand Traps-Specific Patents), Novo Nordisk Patent or Collaboration Patent that Covers
Licensed Product, as may be available under the provisions of the Drug Price Competition and Patent Term Restoration Act of 1984 or comparable laws outside the United States of America (including obtaining a supplementary protection certificate
(SPC), such as those available to Member States of the European Union, and other similar measures in any other country), on a country-by-country basis. Keros shall
cooperate and to provide reasonable assistance (including executing any documents as may reasonably be required) to Novo Nordisk in seeking and obtaining such patent term extension(s). 

  
 26. 

 EXECUTION VERSION 

 

 ARTICLE 7 

Enforcement and Defense of Patents 

7.1 Notice. With respect to intellectual property that is within the scope of any Keros Background IP, Keros New Ligand Trap IP, Novo
Nordisk IP or Collaboration IP, each Party shall promptly notify the other Party in writing upon learning of any (a) actual or suspected infringement and/or misappropriation by a Third Party (collectively, an “Infringement”) of
the Keros Background IP, the Keros New Ligand Trap IP, the Novo Nordisk IP or the Collaboration IP or (b) claim by a Third Party of invalidity, unenforceability and/or non-infringement of a Keros Patent,
Novo Nordisk Patent or the Collaboration Patent. 
 7.2 Enforcement and Defense of Keros Background IP and Keros New Ligand Trap IP.

 (a) Keros shall at its own costs have the sole right (but not the obligation) to file suit against any Third Party for Infringement
of the Keros Background Patents and Keros New Ligand Trap Patents (other than the Selected Ligand Traps-Specific Patents) or to otherwise seek to abate any Infringement thereof by such Third Party and to defend such Declined Ligand Traps-Specific
Patents against a Third Party claim of invalidity, unenforceability or non-infringement. If Keros fails or decides not to institute any such enforcement action of the Keros Background Patents and Keros New
Ligand Trap IP (other than the Declined Ligand Traps-Specific Patents) relevant for the Novo Nordisk Field within [***] of becoming first aware of any such infringement, misappropriation, or misuse, Novo Nordisk shall have the right, but not the
obligation, to institute, at its sole cost and expense, such an enforcement action. Keros shall notify Novo Nordisk as soon as possible if it decides not to institute any such enforcement action. If Keros does institute such enforcement action but
desires at any point in such enforcement action to cease to continue with such enforcement action, then Keros will provide a reasonable written notice to Novo Nordisk prior to discontinuing such enforcement action and Novo Nordisk shall then have
the right, but not the obligation, to continue such enforcement action. The Parties shall reasonably cooperate and shall provide each other with any information or assistance that either reasonably requests. The
non-enforcing Party shall have the right to join, at its own expense, any such legal action and to be represented in such action by its own counsel. If the non-enforcing
Party is required under any law to join any such legal action initiated by the enforcing Party or if the failure of the non-enforcing Party to be a Party to such suit, action, or proceeding would in the
opinion of counsel to the enforcing Party risk dismissal thereof, the non-enforcing Party shall execute all papers and perform such other acts as may be reasonably required to permit the litigation to be
initiated or conducted, and the enforcing Party shall reimburse the non-enforcing Party for its reasonable expenses relating to its joining thereto and participation therein. For the avoidance of doubt, Novo
Nordisk shall have no right to take action against infringement with respect to (a) Declined Ligand Traps-Specific Patents and/or Declined Ligand Traps, or (b) after the end of the Collaboration Term, any Keros Patent (other than Selected
Ligand Traps-Specific Patents as set forth in subsection (b) below) with respect to Cardiovascular Indications or CKD Indications. 

  
 27. 

 EXECUTION VERSION 

 

 (b) Novo Nordisk shall at its own costs have the sole right (but not the obligation)
to file suit against any Third Party for Infringement of the Selected Ligand Traps-Specific Patents or to otherwise seek to abate any Infringement thereof by such Third Party and to defend such Selected Ligand Traps-Specific Patents against a Third
Party claim of invalidity, unenforceability or non-infringement. If requested to do so by Novo Nordisk, Keros shall reasonably cooperate with Novo Nordisk to enforce and defend such rights in relation to the
Novo Nordisk Field. Keros will join such suit if the relevant court, tribunal or patent authority would lack jurisdiction if Keros were absent from such suit, and Keros will execute such legal papers and cooperate in the prosecution of such suit as
may be reasonably requested by Novo Nordisk; provided, that Novo Nordisk will promptly reimburse all out-of-pocket expenses (including reasonable attorneys’ fees
and expenses) incurred by Keros in connection with joining such suit and providing such other requested cooperation. 
 (c) Enforcement
and Defense of Novo Nordisk IP and Novo Nordisk Background Patents. Novo Nordisk shall at its own costs have the sole right (but not the obligation) to file suit against any Third Party for Infringement of the Novo Nordisk Patents and/or Patents
included in the Novo Nordisk Background Patents or to otherwise seek to abate any Infringement thereof by such Third Party and to defend such Novo Nordisk Patents and/or Patents included in the Novo Nordisk Background Patents against a Third Party
claim of invalidity, unenforceability or non-infringement. If requested to do so by Novo Nordisk, Keros shall reasonably cooperate with Novo Nordisk to enforce and defend such rights in relation to the Novo
Nordisk Field. Keros will join such suit if the relevant court, tribunal or patent authority would lack jurisdiction if Keros were absent from such suit, and Keros will execute such legal papers and cooperate in the prosecution of such suit as may
be reasonably requested by Novo Nordisk; provided, that Novo Nordisk will promptly reimburse all out-of-pocket expenses (including reasonable attorneys’ fees and
expenses) incurred by Keros in connection with joining such suit and providing such other requested cooperation. 
 (d) Enforcement and
Defense of Collaboration IP. The Parties shall jointly decide if and how to enforce or otherwise seek to abate any Infringement of Collaboration IP and to defend such Collaboration Patents against a Third Party claim of invalidity,
unenforceability or non-infringement and how costs and expenses will be allocated between the Parties for any such actions or defense. If requested to do so by a Party, the other Party shall reasonably
cooperate with the first Party to enforce and defend such rights. Each Party will join such suit if the relevant court, tribunal or patent authority would lack jurisdiction if a Party were absent from such suit, and each Party will execute such
legal papers and cooperate in the prosecution of such suit as may be reasonably requested by the other Party; provided, that the other Party will promptly reimburse all
out-of-pocket expenses (including reasonable attorneys’ fees and expenses) incurred by the Party in connection with joining such suit and providing such other
requested cooperation. 
 7.3 Recovery. Except as otherwise provided, the costs and expenses of the Party bringing suit against a
Third Party shall be borne by such Party, and any damages, settlements or other monetary awards recovered shall be shared as follows: [***]. The Parties shall agree in good faith the value of any non-monetary
benefits. 

  
 28. 

 EXECUTION VERSION 

 

 ARTICLE 8 

Confidentiality 
 8.1
Disclosure and Use of Confidential Information. Except to the extent expressly authorized by this Agreement, each Party (the “Receiving Party”) in possession of the Confidential Information of the other Party (the
“Disclosing Party”) agrees to: (a) hold in confidence and not disclose or transfer the Disclosing Party’s Confidential Information to any Third Party and (b) use the Disclosing Party’s Confidential Information
only for purposes of this Agreement. 
 8.2 Exceptions. The obligations of the Receiving Party set forth in Section 8.1 shall not
apply to the Disclosing Party’s Confidential Information to the extent that such Confidential Information: 
 (a) was approved in
writing by the Disclosing Party for release or use by the Receiving Party without restriction; 
 (b) is part of the public domain at
the time of disclosure to the Receiving Party or becomes part of the public domain through no wrongful act of the Receiving Party; 
 (c)
is in the Receiving Party’s possession at the time of disclosure, as the Receiving Party can by written documentation demonstrate, other than as a result of any prior confidential disclosure by the Disclosing Party; 

(d) was disclosed to the Receiving Party by a Third Party having no duty of confidentiality to the Disclosing Party with respect to such
Confidential Information and having the legal right to disclose such Confidential Information; or 
 (e) is independently developed,
as the Receiving Party can by written documentation demonstrate, by its employees or consultants without use of or reference to the Confidential Information of the Disclosing Party. 

8.3 Authorized Disclosures. 

(a) Legal Compliance. A Party may disclose the other Party’s Confidential Information if such disclosure is required by law, rule,
regulation or legal process (including to comply with the order of a court or valid discovery request in connection with a legal or administrative proceeding or to comply with governmental regulations or regulations of any nationally recognized
securities exchange), but only to the extent such disclosure is necessary for such compliance; provided, however, except for disclosures otherwise permitted under this Article 8, or as otherwise required or necessitated by law, such
Party shall provide prompt notice of such disclosure requirement to the other Party and provide reasonable assistance requested by the other Party to enable such other Party to seek a protective order or otherwise prevent such disclosure. 

(b) Regulatory Authorities. A Party may disclose the other Party’s Confidential Information to a Regulatory Authority to the extent
such disclosure is required to comply with applicable governmental regulations or to conduct preclinical or clinical studies related to Ligand Traps. 

  
 29. 

 EXECUTION VERSION 

 

 (c) Patent Prosecution. A Party may disclose the other Party’s Confidential
Information to the extent such disclosure is necessary for the Prosecution and Maintenance of any patent application or patent on Novo Nordisk Inventions, Keros New Ligand Trap Inventions or Collaboration Inventions, subject to the provisions of
Section 6.2. 
 (d) Permitted Third Parties. Subject to all the terms and conditions of this Agreement, the Receiving Party may
disclose and grant use of particular Confidential Information of the Disclosing Party to the Receiving Party’s and its Affiliates’ employees, consultants and contractors. Any such disclosure in any form is permitted only on a need to know
basis and only on the condition that such Third Party is bound to the receiving Party by confidentiality obligations no less stringent than those of this Agreement. 

8.4 Continuing Obligation. This Article 8 shall survive the expiration or termination of this Agreement for a period of [***] after any
termination or expiration of this Agreement. 
 8.5 Protection Measures. Each Party agrees that it shall take reasonable measures to
protect the secrecy of and avoid disclosure and unauthorized use of the Confidential Information disclosed to it by the other Party. Without limiting the foregoing, each Party shall take at least those measures that it takes to protect its own
confidential information of a similar nature. 
 8.6 Confidential Information Proprietary to Disclosing Party; Return of Confidential
Information. The Parties understand and agree that (a) the Confidential Information is and shall remain at all times the sole property of the Disclosing Party; (b) the Receiving Party shall not obtain any proprietary interest in any
Confidential Information; and (c) all copies of the Confidential Information shall be returned promptly to the Disclosing Party in their entirety after expiry or termination, apart from one copy to be retained in the legal files of the
receiving Party for the sole purpose of determining the scope of obligations incurred under this Agreement or as otherwise required by law. 

8.7 Breaches of Confidentiality; Assistance in Respect of Same. The Receiving Party shall promptly notify the Disclosing Party if the
Receiving Party becomes aware of any breach of confidence by any person to whom the Receiving Party has disclosed any Confidential Information. The Receiving Party shall give the Disclosing Party all reasonable assistance in connection with any
action, demand, claim or proceeding that the Disclosing Party may institute against any such person in respect of such disclosure. 

  
 30. 

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 ARTICLE 9 

Public Disclosures; Use of Names 

9.1 Press Releases and Other Public Disclosures. 

(a) Press Release. Neither Party will issue a press release, statement or public announcement relating to the terms of this Agreement
without the prior written approval of the other Party, which approval shall not be unreasonably withheld or delayed 
 (b) Disclosures
Regarding Declined Ligand Traps. Disclosures by Keros related to Declined Ligand Traps shall not be subject to either review or approval by Novo Nordisk provided that said disclosure shall not contain any Confidential Information of Novo Nordisk
or of both Parties. 
 (c) Disclosures Required by Law. If one Party reasonably concludes that a public disclosure is required by law,
rule or regulation (including the disclosure requirements of the United States Securities and Exchange Commission or the securities exchange or other stock market on which such Party’s securities are traded), the Party seeking to make such
disclosure shall have the right to make such disclosure, but shall limit such disclosure to that reasonably necessary to comply with the applicable law, rule or regulation. Each Party agrees that it shall obtain its own legal advice with regard to
its compliance with securities and other laws, rules and regulations, and will not rely on any statements made by the other Party relating to such laws, rules and regulations. 

9.2 Use of Names. Except as otherwise expressly provided in this Agreement, no right, express or implied, is granted by the Agreement to
use in any manner the name of “Keros,” “Novo Nordisk” or any other trade name or trademark of the other Party in connection with the performance of this Agreement. 

ARTICLE 10 
 Term;
Termination 
 10.1 Term. The term of the Agreement shall commence on the Effective Date and continue until expiration of the
Royalty Term. After expiration of the Royalty Term, Novo Nordisk shall have a perpetual, fully paid up, non-exclusive license to the Keros Background IP and Keros New Ligand Trap IP related to the Selected
Ligand Trap to Commercialize the Licensed Products, in each case within the Novo Nordisk Field and Territory. 
 10.2 Termination for
Material Breach. Either Party may terminate this Agreement by written notice to the other Party, for any material breach of this Agreement by the other Party, if such breach is not cured within [***] ([***] in the case of a payment breach) after
the breaching Party receives notice from the terminating Party specifying such breach. 
 10.3 Early Termination by Novo Nordisk. Novo
Nordisk may terminate this Agreement and the Collaboration Term at any time and for any reason on [***] prior written notice to Keros. For the avoidance of doubt, Keros shall not be obligated to return the R&D Collaboration Budget Funding to
Novo Nordisk as stipulated in Section 3.2. 
 10.4 Termination upon Bankruptcy. Either Party may terminate this Agreement if, at
any time, the other Party will file in any court, country or jurisdiction, a petition in bankruptcy or insolvency or for reorganization or for an arrangement or for the appointment of a receiver or trustee of that Party or of its assets, or if the
other Party proposes a written agreement of composition or extension of its debts, or if the other Party will be served with an involuntary petition against it, filed in any insolvency proceeding, and such petition will not be dismissed within [***]
after the filing thereof, or if the other Party will propose or be a Party to any dissolution or liquidation, or if the other Party will make an assignment for the benefit of its creditors. 

  
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 10.5 Termination for Patent Challenge. To the extent permitted by law, Keros may
terminate this Agreement either in part or in its entirety upon [***] prior written notice to Novo Nordisk in the event that Novo Nordisk or any of its Affiliates or sublicensees commences any legal or administrative proceeding challenging the
patentability, enforceability or validity of any claim of a Patent within the Keros Background IP, Keros New Ligand Trap IP, or Keros’ interest in the Collaboration IP; provided that Keros will not have the right to terminate this Agreement
under this Section 10.5 for any such challenge by any sublicensee if, within [***] of Keros’ notice to Novo Nordisk under this Section 10.5, (i) such challenge is dismissed or withdrawn and not thereafter continued, or (ii) the
sublicense to such sublicensee is terminated. 
 10.6 Effects of Expiration or Termination. 

(a) Articles 1, 4, 8, 12, 13 and 14, together with Sections 3.3 through 3.6 (with respect to any payments accruing prior to the date of
any such termination or expiration), 6.1 and 10.6 shall survive any termination or expiration of this Agreement; and 
 (b) Upon any
termination of this Agreement by Keros pursuant to Section 10.2, by Novo Nordisk pursuant to Section 10.3 or by either Party pursuant to Section 10.4: 

(i) the license granted by Keros to Novo Nordisk under Section 5.1 shall automatically terminate; 

(ii) the Parties shall be relieved of all its future obligations under the Agreement (other than those set forth in
Section 10.6(a) above). 
 (c) Effect of Certain Terminations. [***]. 

(d) Except as otherwise expressly provided in this Agreement, expiration or termination of this Agreement shall not affect the rights
and obligations of the Parties that accrued prior to the effective date of such expiration or termination. Any right that a Party has to terminate this Agreement, and any rights that such Party has under this Article 10, shall be in addition to and
not in lieu of all other rights or remedies that such Party may have at law or in equity or otherwise. 
 ARTICLE 11 

Representations and Warranties; Keros Covenants 

11.1 Mutual Representations and Warranties. Each Party represents and warrants to the other Party that as of the Effective Date: 

(a) it is validly organized and existing under the laws of its jurisdiction of formation; 

  
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 (b) the execution, delivery and performance of this Agreement, including the Exhibits
hereto have been duly authorized by all necessary corporate action on its part; 
 (c) when executed and delivered, this Agreement
will constitute a legal, valid and binding obligation of such Party enforceable against it in accordance with its terms except (i) as limited by applicable bankruptcy, insolvency, reorganization, moratorium and other laws of general application
affecting enforcement of creditors rights generally, and (ii) as limited by laws relating to the availability of specific performance, injunctive relief or other equitable remedies; 

(d) it has the legal right and power to enter into this Agreement and to fully perform its obligations hereunder and thereunder; 

(e) the performance of its obligations will not conflict with such Party’s charter documents or any agreement, contract or other
arrangement to which such Party is a party; 
 (f) its employees who are or will be involved in the Research Plan have executed an
agreement or has an existing obligation under law requiring assignment to such Party of all intellectual property made during the course of and as the result of his, her or its association with such Party, including in relation to Keros Background
Patents in Exhibit B that such Patents have been assigned by all inventors to Keros, and obligating such employee to maintain the confidentiality of Confidential Information to the extent required under Article 8; and 

(g) it has obtained all necessary consents, approvals and authorizations of all governmental authorities and other persons or entities
required to be obtained by it in connection with this Agreement (as of the Effective Date) and the execution and delivery of this Agreement by it, the performance by it of its obligations hereunder and the consummation of the transactions
contemplated hereby have been duly authorized by all requisite action on the part of the board of directors and stockholders of it, and no other action on the part of it or its board of directors or stockholders is necessary to authorize the
execution and delivery of this Agreement by it or the consummation by it of the transactions contemplated hereby other than such actions which have been taken on or prior to the date hereof. 

(h) It has not been debarred and in not subject to debarment, and it will not knowingly use in any capacity, in connection with any
activities under this Agreement, the services of any Affiliate or Third Party who has been debarred pursuant to Section 306 of the United States Federal Food, Drug and Cosmetic Act, or who is the subject of a conviction described in such
Section. Each Party agrees to inform the other Party promptly in writing if it or any Affiliate or Third Party who is performing services hereunder is debarred or is the subject of a conviction described in Section 306, or if any action, suit,
claim, investigation or legal or administrative proceeding is pending, or to such Party’s or its Affiliates’ knowledge, is threatened, relating to debarment or conviction of such Party, or any Affiliate or Third Party performing services
hereunder for the benefit of such Party. 

  
 33. 

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 11.2 Keros’ Representations and Warranties. Keros represents and warrants to Novo
Nordisk that as of the Effective Date: 
 (a) it Controls the Keros Patents listed on Exhibit B and has the right to grant licenses
under such Keros Patents (as are in existence as of the Effective Date) to Novo Nordisk as contemplated under this Agreement; 
 (b)
the Keros Background IP that is in existence as of the Effective Date is free of any mortgages, pledges, charges, liens, security interests or other encumbrances of any kind, including but not limited to mortgages, pledges, charges, liens,
security interests or other encumbrances provided by Keros to a creditor in connection with a loan, line of credit or other indebtedness; 

(c) there are no adverse proceedings, claims or actions pending, or, to Keros’ knowledge, threatened, with respect to the Keros
Background IP that would prevent Keros’ performance of its obligations under this Agreement; 
 (d) Keros does not Control Ligand
Traps other than the Existing Ligand Traps and those Ligand Trap variants (as Keros can by written documentation demonstrate) that have been disclosed to Novo Nordisk prior to the Effective Date; 

(e) the rights granted to Novo Nordisk and its Affiliates hereunder do not conflict with, and are not inconsistent with any rights
granted by Keros to any Third Party; 
 (f) to the knowledge of Keros, except as otherwise noted in Exhibit B, each of the Keros
Patents has been duly prosecuted and/or maintained and each of the issued Keros Patents is valid and enforceable; and 
 (g) to the
knowledge of Keros, none of the Keros Patents set forth in Exhibit B is (i) subject to a pending interference action, opposition action, re-examination proceeding, inter partes review, litigation or other
similar action by a Third Party challenging such Keros Patents, other than actions by patent authorities in connection with the prosecution of patent applications, or (ii) except as otherwise noted in Exhibit B, has been abandoned, or has been
asserted to be invalid or unenforceable in a communication to Keros or is subject to any inventorship proceeding or dispute. 
 11.3
Keros’ Covenants. Keros hereby covenants: 
 (a) Keros will not during the term of this Agreement enter into any mortgages,
pledges, charges, liens, security interests or other encumbrances of any kind with respect to Selected Ligand Traps-Specific Patents and Collaboration IP in which Keros has an ownership interest; 

(b) Keros shall, during the term of this Agreement, disclose to Novo Nordisk any such material adverse proceedings, claims or actions
that arise with respect to the Keros Background IP, Keros New Ligand Trap IP or Collaboration IP in which Keros has an ownership interest; and 

  
 34. 

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 (c) Keros will not, after the Effective Date, enter into any written or oral
contractual obligation with a Third Party that would conflict with its obligations under this Agreement or that deprive Novo Nordisk of the benefits of or rights granted under this Agreement. 

11.4 Novo Nordisk’ Covenants. Novo Nordisk hereby covenants: 

(a) Novo Nordisk will not during the term of this Agreement enter into any mortgages, pledges, charges, liens, security interests or
other encumbrances of any kind with respect to Collaboration IP in which Novo Nordisk has an ownership interest; 
 (b) Novo Nordisk
shall, during the term of this Agreement, disclose to Keros any such material adverse proceedings, claims or actions that arise with respect to the Keros New Ligand Trap IP or Collaboration IP in which Novo Nordisk has an ownership interest; and

 (c) Novo Nordisk will not, after the Effective Date, enter into any written or oral contractual obligation with a Third Party that
would conflict with its obligations under this Agreement or that is intended to deprive Keros of the benefits of or rights granted under this Agreement. 

11.5 Disclaimers. EXCEPT AS OTHERWISE EXPRESSLY PROVIDED IN THIS AGREEMENT NEITHER PARTY MAKES ANY REPRESENTATION OR WARRANTY OF ANY
KIND WITH RESPECT TO MATERIALS OR INFORMATION SUPPLIED BY IT TO THE OTHER PARTY HEREUNDER, AND EXPRESSLY DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NON-INFRINGEMENT. 
 ARTICLE 12 

Indemnification; Limitation on Liability; Insurance 

12.1 Indemnification. 

(a) Definitions. The following definitions are for purposes of Section 12.1: 

(i) “Claims” means claims, suits, actions, demands or other proceedings by any Third Party. 

(ii) “Indemnitee” means, as applicable, a Keros Indemnitee (as defined in Section 12.1(b) or a Novo Nordisk
Indemnitee (as defined in Section 12.1 (c)). 
 (iii) “Losses” means any and all liabilities, damages,
settlements, penalties, fines, costs or expenses (including, reasonable attorneys’ fees and other expenses of litigation). 

  
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 (b) Indemnification by Novo Nordisk. Novo Nordisk hereby agrees to indemnify, defend
and hold harmless each of Keros and its officers, directors, employees and agents (for purposes of Section 12.1, each, a “Keros Indemnitee”) from and against Losses resulting directly from Claims arising out of (i) Novo
Nordisk’s breach of its representations or warranties under Section 11 of this Agreement; or (ii) the negligence or willful misconduct in performing the activities to be performed by Novo Nordisk under this Agreement, including the
manufacture, storage, use, Development or Commercialization of Ligands Traps or Licensed Product (including product liability claims), in each case by Novo Nordisk or its Affiliates or its contractors. Novo Nordisk’s obligations under this
Section 12.1 (b) shall not apply to the extent that any such Losses are attributable to (A) Keros’ material breach of this Agreement, including breach of its representations or warranties under this Agreement or (B) the gross
negligence or willful misconduct of any Keros Indemnitee. 
 (c) Indemnification by Keros. Keros hereby agrees to indemnify, defend
and hold harmless each of Novo Nordisk and its officers, directors, employees and agents (for purposes of Section 12.1, each, a “Novo Nordisk Indemnitee”) from and against Losses resulting directly from Claims arising out of
(i) Keros’ breach of its representations or warranties under Section 11 of this Agreement; or (ii) the negligence or willful misconduct in performing the activities to be performed by Keros under this Agreement, including the
manufacture, storage, use, Development or Commercialization of Ligands Traps or Licensed Product (including product liability claims), in each case by Keros or its Affiliates or its contractors. Keros’ obligations under this Section 12.1
(c) shall not apply to the extent that any such Losses are attributable to (A) Novo Nordisk’s material breach of this Agreement, including breach of its representations or warranties under this Agreement or (B) the gross negligence or
willful misconduct of any Novo Nordisk Indemnitee. 
 (d) Indemnification Procedures. The Indemnitee shall (i) notify the
indemnifying Party (the “Indemnitor”) of any Claim for which it seeks to exercise its rights under Section 12.1 (b) or (c) promptly after it receives notice of such Claim; (ii) permit the Indemnitor to assume the sole
control of the defense thereof, including the right to settle or conclude such defense (so long as such settlement does not, without the Indemnitee’s consent, admit liability or impose any obligation on the part of the Indemnitee), with counsel
mutually satisfactory to the Parties; (iii) cooperate as reasonably requested (at the expense of Indemnitor) in the defense of such Claim; and (iv) not settle such Claim without the express, prior written consent of the Indemnitor. 

(e) Limitations. The failure of an Indemnitee to deliver notice to the Indemnitor promptly after the commencement of any Claim for which
such Indemnitee seeks to exercise its rights under Section 12.1, to the extent prejudicial to the Indemnitor’s ability to defend such Claim, shall relieve the Indemnitor of its obligation to the Indemnitees under Section 12.1. The
Parties agree that only Keros or Novo Nordisk may seek to exercise the rights under Section 12.1 (on its own behalf or on behalf of its Indemnitees), and other Indemnitees may not directly seek to exercise such rights. 

12.2 Exclusion of Consequential Damages. IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER PARTY FOR ANY CONSEQUENTIAL, INDIRECT,
INCIDENTAL OR PUNITIVE DAMAGES, INCLUDING LOST PROFITS, HOWEVER CAUSED, ARISING FROM OR RELATING TO THIS AGREEMENT OR ANY BREACH OF THIS AGREEMENT OR ANY CLAIM ARISING HEREUNDER, PROVIDED, HOWEVER, THAT NOTHING IN THIS SECTION 12.2 IS
INTENDED TO LIMIT THE RIGHTS OR OBLIGATIONS OF EITHER PARTY UNDER SECTION 12.1. 

  
 36. 

 EXECUTION VERSION 

 

 ARTICLE 13 

Dispute Resolution 

13.1 Internal Resolution. Except as otherwise expressly provided in this Agreement, any Dispute shall be first referred to an Executive
of each Party for resolution, prior to proceeding under the other provisions of this Article 13. A Dispute shall be referred to such Executives upon one Party providing the other Party with written notice that such Dispute exists, and such
Executives shall attempt to resolve such Dispute through good faith discussions. In the event that such Dispute is not resolved within [***] of such other Party’s receipt of such notice, either Party may initiate by written notice to the other
the Dispute resolution provisions in Section 13.2. The Parties agree that any discussions between such Executives regarding such Dispute will not constitute settlement discussions, unless the Parties agree otherwise in writing. 

13.2 Arbitration. 
 (a)
Rules. Except as otherwise expressly provided in this Agreement, the Parties agree that any Dispute not resolved internally by the Parties pursuant to Section 13.1 shall be resolved through binding arbitration under the Rules of Arbitration
of the International Chamber of Commerce (for purposes of Article 13, the “Rules”) by a single arbitrator appointed in accordance with the said Rules, applying the substantive law specified in Section 14.2. The demand for
arbitration and counterclaim shall each include a statement setting forth the issues in dispute that are being presented for resolution through binding arbitration. In no event shall a demand for arbitration be made after the date when institution
of a legal or equitable proceeding based upon such Dispute would be barred by the applicable statute of limitations as determined from the date such Dispute was referred to the arbitrator in accordance with this Section 13.2. 

(b) Arbitrator; Location. Unless otherwise agreed by the Parties, the arbitrator shall be appointed in accordance with the Rules. The
arbitration proceedings shall be conducted in New York, New York, USA. The Parties shall take all reasonable actions to commence the proceeding under this Section 13.2 as promptly as possible but in no event later than [***] after the
initiation of any Dispute under this Section 13.2. 
 (c) Procedures; Awards. Each Party agrees to use reasonable efforts to make
all of its current employees available, if reasonably needed, and agrees that the arbitrator may deem any party as “necessary.” Following the request by either Party, the arbitrator shall make a determination regarding reasonable
production by the Parties of documents relevant to the Dispute. The arbitrator shall be instructed and required to render a written, binding, non-appealable resolution and award on each issue that clearly
states the basis upon which such resolution and award is made. The written resolution and award shall be delivered to the Parties as expeditiously as possible, but in no event more than [***] after conclusion of the hearing, unless otherwise agreed
by the Parties. Judgment upon such award may be entered in any competent court or application may be made to any competent court for judicial acceptance of such an award and order for enforcement. Each Party agrees that, notwithstanding any
provision of applicable law or of this Agreement, it will not request, and the arbitrator shall have no authority to award, punitive or exemplary damages against any Party. 

  
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 (d) Costs. [***]. 

(e) Interim Equitable Relief. Notwithstanding anything to the contrary in this Section 13.2, in the event that a Party reasonably
requires relief on a more expedited basis than would be possible pursuant to the procedure set forth in this Article 13, such Party may seek a temporary injunction or other interim equitable relief or bring an action in aid of arbitration in a court
of competent jurisdiction pending the opportunity of the arbitrator to review the decision under this Section 13.2. Such court shall have no jurisdiction or ability to resolve Disputes beyond the specific issue of temporary injunction or other
interim equitable relief. 
 (f) Protective Orders; Arbitrability. At the request of either Party, the arbitrator shall enter an
appropriate protective order to maintain the confidentiality of information produced or exchanged in the course of the arbitration proceedings. The arbitrator shall have the power to decide all questions of arbitrability. 

(g) Internation Arbitration Treaty. The Parties intend that each award by an arbitrator in an arbitration pursuant to this
Section 13.2 shall be rendered in accordance with the United Nations Convention on the Recognition and Enforcement of Arbitral Awards and shall be enforceable in accordance therewith. 

ARTICLE 14 

Miscellaneous 
 14.1
Notices. Except as otherwise expressly provided in this Agreement, any notice required under this Agreement shall be in writing, shall specifically refer to this Agreement and shall be sent in accordance with the provisions of this
Section 14.1. Notices shall be sent via one of the following means and will be effective (a) on the date of delivery, if delivered in person; or (b) on the date of receipt, if sent by private express courier or by first class
certified mail, return receipt requested (or its equivalent). Notices shall be sent to the other Party at the addresses set forth below. Either Party may change its addresses for purposes of this Section 14.1 by sending written notice to the
other Party in accordance with this Section 14.1. 
 If to Keros: 

Keros Therapeutics, Inc. 
 99
Hayden Avenue, Building E, Suite 120 
 Lexington, Massachusetts 02142 USA 

Attn: CEO 
 cc: Alliance Manager

  
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 with a required copy to: 

Faber Daeufer & Itrato PC 

890 Winter Street 
 Suite 315 

Waltham, MA 02451 USA 
 [***] 

[***] 
 Attn: [***] 

If to Novo Nordisk: 
 Novo Nordisk A/S

 Novo Allé 
 DK-2880 Bagsværd 
 Denmark 

Attn: Head of Business Development 
 with a
required copy to: 
 Novo Nordisk A/S 

Novo Alle 
 DK-2880 Bagsværd 
 Denmark 

Attn: General Counsel 
 14.2
Governing Law. This Agreement shall be governed by and construed under the laws of the State of New York, USA, without regard to conflict of laws principles. The Parties hereby exclude from this Agreement the application of the United Nations
Convention on Contracts for the International Sale of Goods. 
 14.3 Assignment. Neither Party shall be allowed to assign or transfer
any of its rights and/or obligations arising out of this Agreement, either in full or in part, to any Third Party without prior written consent of the other Party, provided however, that each Party may assign this Agreement (a) to an Affiliate,
or (b) to a Third Party that acquires, by merger, sale of assets or otherwise, all or substantially all of the equity of Keros or all or substantially all of the assets or business of Keros to which the subject matter of this Agreement relates.
This Agreement shall also be binding upon the legal successors of the Parties. No assignment and transfer shall be valid and effective unless and until the assignee/transferee shall agree in writing to be bound by the provisions of this Agreement.

 14.4 Force Majeure. Neither Party shall be deemed to have breached this Agreement for failure to perform its obligations under this
Agreement to the extent such failure results from causes beyond the reasonable control of the affected Party, such causes including acts of God, earthquakes, fires, floods, embargoes, wars, acts of terrorism, insurrections, riots, civil commotions,
omissions or delays in action by any governmental authority, acts of a government 

  
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or agency thereof and judicial orders or decrees. If a force majeure event occurs, the Party unable to perform shall promptly notify the other Party of the occurrence of such event, and the
Parties shall meet (in person or telephonically) promptly thereafter to discuss the circumstances relating thereto. The Party unable to perform shall (a) provide reasonable status updates to the other Party from time to time; (b) use
commercially reasonable efforts to mitigate any adverse consequences arising out of its failure to perform; and (c) resume performance as promptly as possible. 

14.5 Animal Welfare. 

(a) Keros certifies that it is regularly engaged in conducting tests in vitro and in vivo. Further, Keros certifies that
in the Research Collaboration, the Ligand Traps will be used by it only for tests in vitro and in vivo in laboratory research animals pursuant to the Research Plan and will not be administered to humans. The Parties agree to ensure
high welfare standards for experimental animals. Keros acknowledges that it has read and understood the Novo Nordisk Principles for the Use of Animals attached hereto as Exhibit E and agrees to adhere to and comply with these obligations. Keros must
promptly notify Novo Nordisk in the event of any unexpected issues in relation to animal welfare or bioethical concerns that occur under the Research Collaboration during the Collaboration Term. The Parties agree to collaborate to address any such
issues and concerns. 
 (b) Novo Nordisk i) will review the Research Plan and ii) may require an
on-site animal welfare inspection prior to approval of the Research Plan. In the event that Novo Nordisk wishes to perform an animal welfare inspection during the Collaboration Term, Keros must give Novo
Nordisk access to its site upon reasonable notice of no less than [***]. 
 14.6 Relationship of the Parties. The Parties are
independent contractors, and nothing contained in this Agreement shall be deemed or construed to create a partnership, joint venture, employment, franchise, agency or fiduciary relationship between the Parties. 

14.7 Amendment; Waiver. Except as otherwise expressly provided in this Agreement, no amendment to this Agreement shall be effective
unless made in writing and executed by an authorized representative of each Party. A Party’s failure to exercise, or delay in exercising, any right, power, privilege or remedy under this Agreement shall not (a) operate as a waiver thereof
or (b) operate as a waiver of any other right, power, privilege or remedy. A waiver will be effective only upon the written consent of the Party granting such waiver. 

14.8 Severability. If any of the provisions of this Agreement are held to be illegal, invalid or unenforceable, such illegal, invalid or
unenforceable provisions shall be replaced by legal, valid and enforceable provisions that will achieve to the maximum extent possible the intent of the Parties, and the other provisions of this Agreement shall remain in full force and effect. 

  
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 14.9 Entire Agreement. This Agreement contains the entire understanding between the
Parties with respect to the subject matter hereof and supersede and terminate all prior agreements, understandings and arrangements between the Parties with respect to such subject matter, whether written or oral. 

14.10 Counterparts. This Agreement may be executed in two (2) or more counterparts, each of which will be deemed an original, but
all of which together will constitute one and the same instrument. A pdf file contained in an email, of this Agreement, including the signature pages hereto, will be deemed to be an original. 

[Signature page follows] 

  
 41. 

 EXECUTION VERSION 

 

 In witness whereof, the Parties have caused this Agreement to be executed by their
respective duly authorized representatives as set forth below. 
  

									
	Keros Therapeutics, Inc.	 	        	  	Novo Nordisk A/S
					
	Signed:	 	 /s/ Jasbir S. Seehra
	 		  	Signed:	  	 /s/ Mads Krogsgaard Thomsen

	Name:	 	Jasbir S. Seehra	 	        	  	Name:	  	Mads Krogsgaard Thomsen
	Title:	 	CEO	 	        	  	Title:	  	Chief Science Officer
		 		 	        	  		  	Novo Nordisk NS
					
		 		 	        	  	Signed:	  	 /s/ Lars Fruergaard Jørgensen

		 		 	        	  	Name:	  	Lars Fruergaard Jørgensen
		 		 	        	  	Title:	  	President & CEO
		 		 	        	  		  	Novo Nordisk NS

  
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 EXHIBIT A: EXISTING LIGAND TRAPS 

Existing Ligand Traps are the following: 
 [***] 

[***] 

  

 EXECUTION VERSION 

 

 EXHIBIT B: KEROS BACKGROUND PATENTS 

 

							
	 Title
	  	 Serial No. / Publication No. / Patent No.
	  	 Territory
	  	 Status

	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]
	[***]	  	[***]	  	[***]	  	[***]

  

 EXECUTION VERSION 

 

 Exhibit C 

Research Plan 
 [***] 

  

 EXECUTION VERSION 

 

 Exhibit D 

New Ligand Traps Information package 

[***] 

  

 EXECUTION VERSION 

 

 EXHIBIT E: NOVO NORDISK POLICY FOR USE OF ANIMALS 

Novo Nordisk considers the use of animals to be essential for the discovery, development and production of pharmaceutical and medical products. 

Ethical considerations and animal welfare are given high priority at Novo Nordisk. As an integral part of our approach to animal testing, we are constantly
looking for new ways to replace, reduce and refine the use of animals for testing. 
 Animals will be used only where no available and acceptable
alternatives exist. 
 To ensure uniform standards, the following principles must be adhered to throughout Novo Nordisk and all our external collaborators
including contract laboratories, research laboratories, partners and suppliers: 
  

	 	•	 	 All activities involving animals must be conducted strictly in accordance with present legislation

  

	 	•	 	 Alternatives to animal experiments must be used whenever possible 

 

	 	•	 	 Transgenic animals may be used for testing and experiments when this model is justified 

 

	 	•	 	 Animals bred specifically for experimental purposes must be used unless special conditions are in evidence

  

	 	•	 	 Housing, husbandry and transportation of animals must as a minimum comply with internationally approved standards

  

	 	•	 	 Housing conditions must take into consideration the special needs of the animal species in question

  

	 	•	 	 Housing, husbandry and care of animals must be undertaken by personnel having received adequate and relevant
education. The level of education must be documented 

  

	 	•	 	 Health control should be supervised by a veterinary officer experienced in regard to laboratory animals

  

	 	•	 	 Transportation of animals must be as lenient as possible, taking into consideration the special needs of the
animal species in question 

  

	 	•	 	 All precautions must be taken to reduce suffering and distress 

 

	 	•	 	 Procedures for monitoring and evaluation of the well-being of the animals as well as treatment must be
implemented 

 At Novo Nordisk records are kept updated on the type of experiment, animal species and number of animals used in accordance
with the authorities’ and the requirements of Novo Nordisk. The number of animals used internally as well as at facilities run by external collaborators will be published in the Annual Novo Nordisk Sustainability Report. 

  

 EXECUTION VERSION 

 

 EXHIBIT F: NOVO NORDISK A/S’ INVOICING INSTRUCTIONS 

[***]

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