# EDGAR Filing Document

**Accession Number:** 0001664710
**File Stem:** 0001104659-25-058955
**Filing Date:** 2025-6
**Character Count:** 12044
**Document Hash:** d52d14d4d4dd9351f0b0e2ba3f1dbedb
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-058955.hdr.sgml**: 20250612

**ACCESSION NUMBER**: 0001104659-25-058955

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250516

**FILED AS OF DATE**: 20250612

**DATE AS OF CHANGE**: 20250612

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Schneeberger Daniel
- **CENTRAL INDEX KEY:** 0001861120

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39264
- **FILM NUMBER:** 251043597

**MAIL ADDRESS:**
- **STREET 1:** C/O ANEBULO PHARMACEUTICALS, INC.
- **STREET 2:** 1415 RANCH ROAD 620 SOUTH, SUITE 201
- **CITY:** LAKEWAY
- **STATE:** TX
- **ZIP:** 78734
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** ADAR1 Partners, LP
- **CENTRAL INDEX KEY:** 0001758866

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39264
- **FILM NUMBER:** 251043599

**BUSINESS ADDRESS:**
- **STREET 1:** 3503 WILD CHERRY DRIVE
- **STREET 2:** BUILDING 9
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78738
- **BUSINESS PHONE:** 512-531-9088

**MAIL ADDRESS:**
- **STREET 1:** 3503 WILD CHERRY DRIVE
- **STREET 2:** BUILDING 9
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78738
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** ADAR1 Capital Management, LLC
- **CENTRAL INDEX KEY:** 0001940272

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** TX
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39264
- **FILM NUMBER:** 251043600

**BUSINESS ADDRESS:**
- **STREET 1:** 3503 WILD CHERRY DRIVE
- **STREET 2:** BUILDING 9
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78738
- **BUSINESS PHONE:** 512-254-3790

**MAIL ADDRESS:**
- **STREET 1:** 3503 WILD CHERRY DRIVE
- **STREET 2:** BUILDING 9
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78738
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** ADAR1 Capital Management GP, LLC
- **CENTRAL INDEX KEY:** 0001940267

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** TX
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39264
- **FILM NUMBER:** 251043598

**BUSINESS ADDRESS:**
- **STREET 1:** 325 RANCH ROAD 620 SOUTH
- **STREET 2:** SUITE 200
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78738
- **BUSINESS PHONE:** 512-531-9088

**MAIL ADDRESS:**
- **STREET 1:** 325 RANCH ROAD 620 SOUTH
- **STREET 2:** SUITE 200
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78738

**FORMER NAME:**
- **FORMER CONFORMED NAME:** fDAR1 Capital Management GP, LLC
- **DATE OF NAME CHANGE:** 20220728
**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>ADAR1 Capital Management, LLC<br><sub>(Last) (First) (Middle)</sub><br>3503 WILD CHERRY DRIVE, BUILDING 9<br><sub>(Street)</sub><br>AUSTIN, TX 78738<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-05-16 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] 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>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>ADAR1 Partners, LP<br><sub>(Last) (First) (Middle)</sub><br>3503 WILD CHERRY DRIVE, BUILDING 9<br><sub>(Street)</sub><br>AUSTIN, TX 78738<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-05-16 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] 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>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>ADAR1 Capital Management GP, LLC<br><sub>(Last) (First) (Middle)</sub><br>3503 WILD CHERRY DRIVE, BUILDING 9<br><sub>(Street)</sub><br>AUSTIN, TX 78738<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-05-16 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] 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>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Schneeberger Daniel<br><sub>(Last) (First) (Middle)</sub><br>3503 WILD CHERRY DRIVE, BUILDING 9<br><sub>(Street)</sub><br>AUSTIN, TX 78738<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-05-16 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] 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>[ ] Form filed by One Reporting Person<br>[X] 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 |
|  |  |  |  |  |  |  |  |  |  |  |

---

## 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 |
| Put Option (obligation to buy) | $10 | 2025-05-16 |  | E |  |  | 300 | 2025-02-27 | 2025-05-16 | Common Stock | 30000 | $0 | 0 | I | By ADAR1 Partners, LP<sup>(1)(2)</sup> |
| Put Option (obligation to buy) | $10 | 2025-05-16 |  | E |  |  | 836 | 2025-04-03 | 2025-05-16 | Common Stock | 83600 | $0 | 0 | I | By ADAR1 Partners, LP<sup>(1)(2)</sup> |
| Put Option (obligation to buy) | $10 | 2025-05-16 |  | E |  |  | 178 | 2025-04-03 | 2025-05-16 | Common Stock | 17800 | $0 | 0 | I | By Spearhead Insurance Solutions IDF, LLC<sup>(1)(2)</sup> |

---

### Footnotes:

(1) As the investment manager of ADAR1 Partners, LP and as the sub-advisor of Spearhead Insurance Solutions IDF, LLC, ADAR1 Capital Management, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Mr. Schneeberger may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC.

(2) For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

**Signature:** ADAR1 Capital Management, LLC, By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger  
**Date:** 2025-06-12

**Signature:** ADAR1 Partners, LP, By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger  
**Date:** 2025-06-12

**Signature:** ADAR1 Capital Management GP, LLC, By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger  
**Date:** 2025-06-12

**Signature:** /s/ Daniel Schneeberger  
**Date:** 2025-06-12

### 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.**