Filing Details
- Accession Number:
- 0001104659-25-040354
- Form Type:
- 13D Filing
- Publication Date:
- 2025-04-27 20:00:00
- Filed By:
- ADAR1 Capital Management
- Company:
- Keros Therapeutics Inc. (NASDAQ:KROS)
- Filing Date:
- 2025-04-28
- SEC Url:
- 13D Filing
Ownership Summary
Please notice the below summary table is generated without human intervention and may contain errors. Please refer to the complete filing displayed below for exact figures.
Name | Sole Voting Power | Shared Voting Power | Sole Dispositive Power | Shared Dispositive Power | Aggregate Amount Owned Power | Percent of Class |
---|---|---|---|---|---|---|
ADAR1 Capital Management, LLC | 5,390,964 | 0 | 5,390,964 | 0 | 5,390,964 | 13.29% |
ADAR1 Capital Management GP, LLC | 4,647,406 | 0 | 4,647,406 | 0 | 4,647,406 | 11.46% |
Daniel Schneeberger | 5,390,964 | 0 | 5,390,964 | 0 | 5,390,964 | 13.29% |
Filing
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549 |
SCHEDULE 13D
Under the Securities Exchange Act of 1934
(Amendment No. 1)
|
Keros Therapeutics, Inc. (Name of Issuer) |
Common Stock, $0.0001 par value per share (Title of Class of Securities) |
492327101 (CUSIP Number) |
Daniel Schneeberger 3503 Wild Cherry Drive, Building 9 Austin, TX, 78738 (512) 254-3790 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) |
04/24/2025 (Date of Event Which Requires Filing of This Statement) |
If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.


The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the
Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other
provisions of the Act (however, see the Notes).
SCHEDULE 13D
|
CUSIP No. | 492327101 |
1 |
Name of reporting person
ADAR1 Capital Management, LLC | ||||||||
2 | Check the appropriate box if a member of a Group (See Instructions)
![]() ![]() | ||||||||
3 | SEC use only | ||||||||
4 |
Source of funds (See Instructions)
AF | ||||||||
5 |
Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)
![]() | ||||||||
6 | Citizenship or place of organization
TEXAS
| ||||||||
Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
11 | Aggregate amount beneficially owned by each reporting person
5,390,964.00 | ||||||||
12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
![]() | ||||||||
13 | Percent of class represented by amount in Row (11)
13.29 % | ||||||||
14 | Type of Reporting Person (See Instructions)
OO |
Comment for Type of Reporting Person:
The amounts reported in boxes 7, 9 and 11 include (i) 4,392,737 shares of common stock, par value $0.0001 per share ("Common Stock") held by ADAR1 Partners, LP, (ii) 743,558 shares of Common Stock held by Spearhead Insurance Solutions IDF, LLC and (iii) 254,669 shares of Common Stock held by ADAR1 SPV I, LP as of April 11, 2025. As the investment manager of ADAR1 Partners, LP and ADAR1 SPV I, 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, ADAR1 SPV I, LP and Spearhead Insurance Solutions IDF, LLC. Amounts reported do not include shares underlying certain put options and swap arrangements as disclosed in this Schedule 13D.
The percentage in box 13 is based on 40,562,047 shares of Common Stock of Keros Therapeutics, Inc. (the "Issuer") outstanding as of February 20, 2025 reported in the Issuer's Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 26, 2025.
SCHEDULE 13D
|
CUSIP No. | 492327101 |
1 |
Name of reporting person
ADAR1 Capital Management GP, LLC | ||||||||
2 | Check the appropriate box if a member of a Group (See Instructions)
![]() ![]() | ||||||||
3 | SEC use only | ||||||||
4 |
Source of funds (See Instructions)
AF | ||||||||
5 |
Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)
![]() | ||||||||
6 | Citizenship or place of organization
TEXAS
| ||||||||
Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
11 | Aggregate amount beneficially owned by each reporting person
4,647,406.00 | ||||||||
12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
![]() | ||||||||
13 | Percent of class represented by amount in Row (11)
11.46 % | ||||||||
14 | Type of Reporting Person (See Instructions)
OO |
Comment for Type of Reporting Person:
The amounts reported in boxes 7, 9 and 11 include (i) 4,392,737 shares of Common Stock held by ADAR1 Partners, LP and (ii) 254,669 shares of Common Stock held by ADAR1 SPV I, LP as of April 11, 2025. As the general partner of ADAR1 Partners, LP and ADAR1 SPV I, LP, ADAR1 Capital Management GP, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and ADAR1 SPV I, LP. Amounts reported do not include shares underlying certain put options and swap arrangements as disclosed in this Schedule 13D.
The percentage in box 13 is based on 40,562,047 shares of Common Stock of the Issuer outstanding as of February 20, 2025 reported in the Issuer's Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 26, 2025.
SCHEDULE 13D
|
CUSIP No. | 492327101 |
1 |
Name of reporting person
Daniel Schneeberger | ||||||||
2 | Check the appropriate box if a member of a Group (See Instructions)
![]() ![]() | ||||||||
3 | SEC use only | ||||||||
4 |
Source of funds (See Instructions)
AF | ||||||||
5 |
Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)
![]() | ||||||||
6 | Citizenship or place of organization
TEXAS
| ||||||||
Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
11 | Aggregate amount beneficially owned by each reporting person
5,390,964.00 | ||||||||
12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
![]() | ||||||||
13 | Percent of class represented by amount in Row (11)
13.29 % | ||||||||
14 | Type of Reporting Person (See Instructions)
IN |
Comment for Type of Reporting Person:
The amounts reported in boxes 7, 9 and 11 include (i) 5,390,964 shares of Common Stock held by ADAR1 Partners, LP, (ii) 743,558 shares of Common Stock held by Spearhead Insurance Solutions IDF, LLC and (iii) 254,669 shares of Common Stock held by ADAR1 SPV I, LP as of April 11, 2025. 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, Spearhead Insurance Solutions IDF, LLC, and ADAR1 SPV I, LP. Amounts reported do not include shares underlying certain put options and swap arrangements as disclosed in this Schedule 13D.
The percentage in box 13 is based on 40,562,047 shares of Common Stock of the Issuer outstanding as of February 20, 2025 reported in the Issuer's Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 26, 2025.
SCHEDULE 13D
|
Item 1. | Security and Issuer | |
(a) | Title of Class of Securities:
Common Stock, $0.0001 par value per share | |
(b) | Name of Issuer:
Keros Therapeutics, Inc. | |
(c) | Address of Issuer's Principal Executive Offices:
1050 Waltham Street, Suite 302, Lexington,
MASSACHUSETTS
, 02421. | |
Item 1 Comment:
This Amendment No. 1 ("Amendment No. 1") amends and supplements the statement on Schedule 13D (the "Initial Schedule 13D") filed with the Securities and Exchange Commission on April 11, 2025 to disclose a letter sent by the Reporting Persons to the Board of Directors (the "Board") of Keros Therapeutics, Inc., a Delaware corporation (the "Issuer"). This Amendment No. 1 relates to common stock, par value $0.0001 per share ("Common Stock"), of the Issuer. Except as otherwise stated, the Initial Schedule 13D remains unchanged. | ||
Item 4. | Purpose of Transaction | |
Item 4 of the Initial Schedule 13D is hereby amended and supplemented by the addition of the following:
On April 24, 2025, counsel to ADAR1 Capital Management, LLC sent a letter (the "Letter") to the Board outlining concerns that the Board has taken actions in breach of its fiduciary duties and demanding that that the Board take immediate action to waive or amend the deadline for the Issuer's stockholders to nominate candidates for election to the Board at the annual meeting of the Issuer's stockholders (the "Annual Meeting") scheduled to take place on June 4, 2025.
The foregoing description of the Letter does not purport to be complete and is qualified in its entirety by reference to the full text of the Letter, which is attached hereto as Exhibit C and is incorporated herein by reference.
The Reporting Persons intend to have discussions with the Board and management of the Issuer regarding corporate governance, including the composition of the Board, and may seek representation on the Board. The Reporting Persons may communicate with other shareholders and/or third parties regarding the Issuer and any or all of the foregoing, and may conduct a solicitation of proxies in connection with any matters to be considered at the Annual Meeting. | ||
Item 7. | Material to be Filed as Exhibits. | |
Item 7 of the Initial Schedule 13D is hereby amended and supplemented by the addition of the following:
Exhibit C: Letter to the Board dated as of April 24, 2025 |
SIGNATURE | |
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
|
|
|
|
|
|
|
Comments accompanying signature:
N/A |