Filing Details
- Accession Number:
- 0001213900-25-037931
- Form Type:
- 13D Filing
- Publication Date:
- 2025-04-29 20:00:00
- Filed By:
- Madison Avenue Partners
- Company:
- Acelyrin Inc.
- Filing Date:
- 2025-04-30
- 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 |
|---|---|---|---|---|---|---|
| Madison Avenue International LP | 0 | 5,089,260 | 0 | 5,089,260 | 5,089,260 | 5.1% |
| Madison Avenue Partners, LP | 0 | 5,089,260 | 0 | 5,089,260 | 5,089,260 | 5.1% |
| EMAI Management, LLC | 0 | 5,089,260 | 0 | 5,089,260 | 5,089,260 | 5.1% |
| Madison Avenue GP, LLC | 0 | 5,089,260 | 0 | 5,089,260 | 5,089,260 | 5.1% |
| Caraway Jackson Investments LLC | 0 | 5,089,260 | 0 | 5,089,260 | 5,089,260 | 5.1% |
| Eli Samaha | 0 | 5,089,260 | 0 | 5,089,260 | 5,089,260 | 5.1% |
Filing
|
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549 |
SCHEDULE 13D
Under the Securities Exchange Act of 1934
|
ACELYRIN, Inc. (Name of Issuer) |
Common Stock (Title of Class of Securities) |
00445A100 (CUSIP Number) |
Mark Leeds Pillsbury Winthrop Shaw Pittman LLP, 31 W 52nd St New York, NY, 10019 (212) 858-1000 (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) |
04/29/2025 (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. | 00445A100 |
| 1 |
Name of reporting person
Madison Avenue International LP | ||||||||
| 2 | Check the appropriate box if a member of a Group (See Instructions)
(a)
(b)
| ||||||||
| 3 | SEC use only | ||||||||
| 4 |
Source of funds (See Instructions)
WC | ||||||||
| 5 |
Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)
| ||||||||
| 6 | Citizenship or place of organization
CAYMAN ISLANDS
| ||||||||
| Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
| 11 | Aggregate amount beneficially owned by each reporting person
5,089,260.00 | ||||||||
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
| ||||||||
| 13 | Percent of class represented by amount in Row (11)
5.1 % | ||||||||
| 14 | Type of Reporting Person (See Instructions)
PN |
SCHEDULE 13D
|
| CUSIP No. | 00445A100 |
| 1 |
Name of reporting person
Madison Avenue Partners, LP | ||||||||
| 2 | Check the appropriate box if a member of a Group (See Instructions)
(a)
(b)
| ||||||||
| 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
DELAWARE
| ||||||||
| Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
| 11 | Aggregate amount beneficially owned by each reporting person
5,089,260.00 | ||||||||
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
| ||||||||
| 13 | Percent of class represented by amount in Row (11)
5.1 % | ||||||||
| 14 | Type of Reporting Person (See Instructions)
PN |
SCHEDULE 13D
|
| CUSIP No. | 00445A100 |
| 1 |
Name of reporting person
EMAI Management, LLC | ||||||||
| 2 | Check the appropriate box if a member of a Group (See Instructions)
(a)
(b)
| ||||||||
| 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
DELAWARE
| ||||||||
| Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
| 11 | Aggregate amount beneficially owned by each reporting person
5,089,260.00 | ||||||||
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
| ||||||||
| 13 | Percent of class represented by amount in Row (11)
5.1 % | ||||||||
| 14 | Type of Reporting Person (See Instructions)
OO |
Comment for Type of Reporting Person:
Limited liability company
SCHEDULE 13D
|
| CUSIP No. | 00445A100 |
| 1 |
Name of reporting person
Madison Avenue GP, LLC | ||||||||
| 2 | Check the appropriate box if a member of a Group (See Instructions)
(a)
(b)
| ||||||||
| 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
DELAWARE
| ||||||||
| Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
| 11 | Aggregate amount beneficially owned by each reporting person
5,089,260.00 | ||||||||
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
| ||||||||
| 13 | Percent of class represented by amount in Row (11)
5.1 % | ||||||||
| 14 | Type of Reporting Person (See Instructions)
OO |
Comment for Type of Reporting Person:
Limited liability company
SCHEDULE 13D
|
| CUSIP No. | 00445A100 |
| 1 |
Name of reporting person
Caraway Jackson Investments LLC | ||||||||
| 2 | Check the appropriate box if a member of a Group (See Instructions)
(a)
(b)
| ||||||||
| 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
DELAWARE
| ||||||||
| Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
| 11 | Aggregate amount beneficially owned by each reporting person
5,089,260.00 | ||||||||
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
| ||||||||
| 13 | Percent of class represented by amount in Row (11)
5.1 % | ||||||||
| 14 | Type of Reporting Person (See Instructions)
OO |
Comment for Type of Reporting Person:
Limited liability company
SCHEDULE 13D
|
| CUSIP No. | 00445A100 |
| 1 |
Name of reporting person
Eli Samaha | ||||||||
| 2 | Check the appropriate box if a member of a Group (See Instructions)
(a)
(b)
| ||||||||
| 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
UNITED STATES
| ||||||||
| Number of Shares Beneficially Owned by Each Reporting Person With: |
| ||||||||
| 11 | Aggregate amount beneficially owned by each reporting person
5,089,260.00 | ||||||||
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
| ||||||||
| 13 | Percent of class represented by amount in Row (11)
5.1 % | ||||||||
| 14 | Type of Reporting Person (See Instructions)
IN |
SCHEDULE 13D
|
| Item 1. | Security and Issuer |
| (a) | Title of Class of Securities:
Common Stock |
| (b) | Name of Issuer:
ACELYRIN, Inc. |
| (c) | Address of Issuer's Principal Executive Offices:
4149 LIBERTY CANYON ROAD, AGOURA HILLS,
CALIFORNIA
, 91301. |
| Item 2. | Identity and Background |
| (a) | This Schedule 13D is being filed by (i) Madison Avenue International LP, a Cayman Islands exempted limited partnership ("International"), (ii) Madison Avenue Partners, LP, a Delaware limited partnership ("Partners"), (iii) EMAI Management, LLC, a Delaware limited liability company ("Management"), (iv) Madison Avenue GP, LLC, a Delaware limited liability company ("GP"), (v) Caraway Jackson Investments LLC, a Delaware limited liability company ("Caraway"), and (vi) Eli Samaha, a citizen of the United States of America ("Mr. Samaha" and, together with International, Partners, EMAI Management, GP and Caraway, the "Reporting Persons"). |
| (b) | The principal business address for each of the Reporting Persons is 150 East 58th St, 14th Fl, New York, NY 10155. |
| (c) | International holds the shares of Common Stock of ACELYRIN, Inc. (the "Company") that are the subject of this statement. The principal business of International is to invest in securities. The principal business of Partners is to serve as an investment manager, including as the investment manager of International. The principal business of GP is to serve as the general partner of International. The principal business of Management is to serve as the general partner of Partners. The principal business of Caraway is owning GP. Mr. Samaha's principal occupation is investing, and directing the investment of assets, including by serving as the non-member manager of GP and as the managing member of Management. As a result of the foregoing relationships, (i) each of Partners and GP may be deemed to beneficially own the Shares held by International, (ii) Management may be deemed to beneficially own the Shares held by Partners, (iii) Caraway may be deemed to beneficially own the Shares held by GP, and (iv) Mr. Samaha may be deemed to beneficially own the Shares held by each of Management, GP and Caraway. |
| (d) | None |
| (e) | None |
| (f) | International is a Cayman Islands exempted limited partnership. Partners is a Delaware limited partnership. Each of Management, GP and Caraway are Delaware limited liability companies. Mr. Samaha is a citizen of the United States of America. |
| Item 3. | Source and Amount of Funds or Other Consideration |
All of the Common Stock to which this statement relates were purchased on behalf of the Reporting Persons using the investment capital of the respective Reporting Person. The aggregate amount of funds used for the purchase of the securities held by the Reporting Persons was approximately $12,767,883, including commissions. | |
| Item 4. | Purpose of Transaction |
The Reporting Persons purchased the shares of Common Stock for investment purposes.
The Reporting Persons believe their investment in the Company may appreciate in value in the event the Company does not consummate its proposed merger with Alumis Inc. (the "Proposed Merger"). The Reporting Persons believe the Proposed Merger is financially unsound and will likely deliver less value to shareholders than potential alternatives. In addition, the Reporting Persons believe that the Company's stockholder rights plan (the "Rights Plan"), is not in the best interests of the Company's shareholders and, based on disclosures contained in the Company's proxy statement filed on April 23, 2025, may have been adopted due to the influence of Alumis Inc.'s Chief Executive Officer over the Company. Consequently, the Reporting Persons intend to vote against the Proposed Merger and may seek to have the Rights Plan rescinded.
The Reporting Persons may have conversations, meetings and other communications with the management of the Company, shareholders and other persons, in each case to discuss the Proposed Merger, the Rights Plan, the Company's business, operations, strategy, governance and related matters.
Except as set forth herein or such as would occur upon completion of any of the actions discussed herein, the Reporting Persons have no present plan or proposal that would relate to or result in any of the matters set forth in subparagraphs (a)-(j) of Item 4 of Schedule 13D. The Reporting Persons intend to review their investment in the Company on a continuing basis. Depending on various factors including, without limitation, the Company's financial position and strategic direction, actions taken by the Company's board, price levels of the Common Stock, other investment opportunities available to the Reporting Persons, conditions in the securities market and general economic and industry conditions, the Reporting Persons may in the future take such actions with respect to their investment in the Company as they deem appropriate including, without limitation, purchasing additional shares of Common Stock and/or other securities of the Company (collectively, "Securities"), disposing of any or all of their Securities, in the open market or otherwise, at any time and from time to time, and engaging in any hedging or similar transactions with respect to the Securities. The Reporting Persons reserve the right to change their intention with respect to any and all matters referred to in this Item 4 of this Schedule 13D. | |
| Item 5. | Interest in Securities of the Issuer |
| (a) | The aggregate number is 5,089,260 shares of Common Stock. This represents approximately 5.1% of the outstanding Common Stock, assuming 100,709,853 shares outstanding as of March 14, 2025, based on the Company's 10-K filed on March 19, 2025. |
| (b) | 5,089,260 |
| (c) | The Reporting Persons have not entered into any transactions in the Common Stock during the past sixty days, except as set forth below:
Buy/Sell Trade Price Quantity Trade Date
Buy $2.69 198,262 3/3/25
Buy $2.47 1,000,000 3/4/25
Buy $2.55 250,000 3/5/25
Buy $2.64 350,000 3/6/25
Buy $2.68 250,000 3/7/25
Buy $2.59 225,000 3/10/25
Buy $2.66 310,631 3/11/25
Buy $2.73 9,648 3/12/25
Buy $2.71 160,000 3/13/25
Buy $2.73 28,083 3/14/25
Buy $2.73 15,852 3/17/25
Buy $2.74 16,409 3/18/25
Buy $2.51 153,367 3/26/25
Buy $2.62 20,254 3/27/25
Sell $2.57 40,923 4/4/25
Sell $2.57 77,999 4/4/25
Sell $2.41 1,700 4/7/25
Buy $2.18 198,422 4/14/25
Buy $2.20 144,670 4/15/25
Buy $2.21 173,190 4/16/25
Buy $2.21 300,000 4/17/25
Buy $2.20 32,876 4/17/25
Buy $2.29 2,513 4/22/25
Buy $2.16 64,899 4/24/25
Buy $2.15 17,662 4/25/25
Buy $2.10 45,394 4/25/25
Buy $2.18 42,423 4/28/25
Buy $2.26 35,043 4/29/25
Buy $2.42 10,150 4/30/25 |
| (d) | N/A |
| (e) | N/A |
| Item 6. | Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer |
N/A | |
| Item 7. | Material to be Filed as Exhibits. |
99.1 - Joint Filing Agreement |
| 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.
|
|
|
|
|
|
|
|
|
|
|
|
|