# EDGAR Filing Document

**Accession Number:** 0001568077
**File Stem:** 0001415889-25-015977
**Filing Date:** 2025-6
**Character Count:** 8691
**Document Hash:** 1d866c4ead9436339dfa929d72ccd311
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001415889-25-015977.hdr.sgml**: 20250606

**ACCESSION NUMBER**: 0001415889-25-015977

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250604

**FILED AS OF DATE**: 20250606

**DATE AS OF CHANGE**: 20250606

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Kariv Tomer
- **CENTRAL INDEX KEY:** 0001568077

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39264
- **FILM NUMBER:** 251030840

**MAIL ADDRESS:**
- **STREET 1:** C/O ARNO THERAPEUTICS, INC.
- **STREET 2:** 200 ROUTE 31 NORTH, SUITE 104
- **CITY:** FLEMINGTON
- **STATE:** NJ
- **ZIP:** 08822
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Keros Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001664710
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 811173868
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 1050 WALTHAM STREET, SUITE 302
- **CITY:** LEXINGTON
- **STATE:** MA
- **ZIP:** 02421
- **BUSINESS PHONE:** 617-314-6297

**MAIL ADDRESS:**
- **STREET 1:** 1050 WALTHAM STREET, SUITE 302
- **CITY:** LEXINGTON
- **STATE:** MA
- **ZIP:** 02421

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] 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**<sup>*</sup><br>Kariv Tomer<br><sub>(Last) (First) (Middle)</sub><br>C/O KEROS THERAPEUTICS, INC.<br>1050 WALTHAM STREET, SUITE 302<br><sub>(Street)</sub><br>LEXINGTON, MA 02421<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-06-04 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Keros Therapeutics, Inc. [ KROS ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2025-06-04 |  | A |  | 5250<sup>(1)</sup> | A | $0 | 5250 | D |  |
| Common Stock |  |  |  |  |  |  |  | 2284612 | I | See footnote<sup>(2)</sup> |
| Common Stock |  |  |  |  |  |  |  | 1121045 | I | See footnote<sup>(3)</sup> |
| Common Stock |  |  |  |  |  |  |  | 1226412 | I | See footnote<sup>(4)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Stock Option (right to buy) | $14.82 | 2025-06-04 |  | A |  | 10500 |  | <sup>(5)</sup> | 2035-06-03 | Common Stock | 10500 | $0 | 10500 | D |  |

---

### Footnotes:

(1) Represents a restricted stock unit ("RSU") award. The RSUs fully vest on the earlier of (A) June 4, 2026 and (B) the date of the Issuer's 2026 annual meeting of stockholders, subject to the Reporting Person continuing to provide service through each such date.

(2) The securities are held by Israel IV. Pontifax Management 4 G.P. (2015) Ltd. ("Management 4") is the ultimate general partner of Israel IV. As a result Management 4 may be deemed to share voting and dispositive power with respect to the shares held by Israel IV. The Reporting Person, a member of the board of directors of the Issuer, is a Managing Partner of Management 4 and, as a result, may be deemed to share voting and investment power with respect to the shares held by Israel IV. Each of Management 4 and the Reporting Person disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest therein, and the inclusion of the shares in this report shall not be deemed to be an admission of beneficial ownership of the reported shares for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise.

(3) The securities are held by Cayman IV. Management 4 is the ultimate general partner of Cayman IV. The Reporting Person, a member of the board of directors of the Issuer, is a Managing Partner of Management 4 and, as a result, may be deemed to share voting and investment power with respect to the shares held by Cayman IV. Each of Management 4 and the Reporting Person disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest therein, and the inclusion of the shares in this report shall not be deemed to be an admission of beneficial ownership of the reported shares for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise.

(4) The securities are held by China IV. Management 4 is the ultimate general partner of China IV. The Reporting Person, a member of the board of directors of the Issuer, is a Managing Partner of Management 4 and, as a result, may be deemed to share voting and investment power with respect to the shares held by China IV. Each of Management 4 and the Reporting Person disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest therein, and the inclusion of the shares in this report shall not be deemed to be an admission of beneficial ownership of the reported shares for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise.

(5) The option shall vest in equal quarterly installments over the 12 months following the date of grant, provided that the grant will in any case be fully vested on the date of Issuer's 2026 annual meeting of stockholders, subject to the Reporting Person continuing to provide service through each such date.

**Signature:** /s/ Keith Regnante, Attorney-in-Fact  
**Date:** 2025-06-06

### Remarks:

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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**