[Form 4] Keros Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Keros Therapeutics, Inc. director reported share dispositions tied to the company’s cash tender offer. On 11/21/2025, the reporting person tendered 191,527 shares of common stock at $17.75 per share and separately tendered 130,494 shares at $17.75 per share, as noted in footnote (1) describing an issuer cash tender offer that began on October 20, 2025 and whose final results were announced on November 20, 2025. Following these transactions, the director beneficially owns 150,047 shares indirectly through Partners Innovation Fund, LLC, 102,233 shares indirectly through Partners Innovation Fund II, L.P., and 6,441 shares directly.

Insider Trade Summary

3 transactions reported

Mixed 3 txns

Insider Knowles Julius

Role Director

Type	Security	Shares	Price	Value
Disposition	Common Stock	191,527	$17.75	$3.40M
Disposition	Common Stock	130,494	$17.75	$2.32M
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 150,047 shares (Indirect, See footnote); Common Stock — 6,441 shares (Direct)

Footnotes (1)

1. Represents shares tendered and accepted for purchase by the Issuer in a cash tender offer commenced by the Issuer on October 20, 2025. The Issuer announced the final results of the tender offer on November 20, 2025. The securities are held by Partners Innovation Fund, LLC ("PIF I"). Partners Innovation Fund, LLC ("Partners GP I") is the ultimate general partner of PIF I. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP I and as a result, may be deemed to share voting and investment power with respect to the shares held by PIF I. The securities are held by Partners Innovation Fund II, L.P. ("PIF II"). Partners Innovation Fund II, LLC ("Partners GP II") is the ultimate general partner of PIF II. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP II and as a result, may be deemed to share voting and investment power with respect to the shares held by PIF II.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Knowles Julius

(Last) (First) (Middle)

C/O KEROS THERAPEUTICS, INC.

1050 WALTHAM STREET, SUITE 302

(Street)

LEXINGTON MA 02421

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Keros Therapeutics, Inc. [ KROS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
11/21/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	11/21/2025		D(1)		191,527	D	$17.75	150,047	I	See footnote(2)
Common Stock	11/21/2025		D(1)		130,494	D	$17.75	102,233	I	See footnote(3)
Common Stock								6,441	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents shares tendered and accepted for purchase by the Issuer in a cash tender offer commenced by the Issuer on October 20, 2025. The Issuer announced the final results of the tender offer on November 20, 2025.

2. The securities are held by Partners Innovation Fund, LLC ("PIF I"). Partners Innovation Fund, LLC ("Partners GP I") is the ultimate general partner of PIF I. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP I and as a result, may be deemed to share voting and investment power with respect to the shares held by PIF I.

3. The securities are held by Partners Innovation Fund II, L.P. ("PIF II"). Partners Innovation Fund II, LLC ("Partners GP II") is the ultimate general partner of PIF II. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP II and as a result, may be deemed to share voting and investment power with respect to the shares held by PIF II.

	/s/ Keith Regnante, Attorney-in-Fact	12/18/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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