Filed Pursuant to Rule 424(b)(3)
Registration No. 333-284263
PROSPECTUS SUPPLEMENT
To Prospectus dated February 7, 2025
Up to 73,333 Shares of Common Stock
Up to 31,145,319 Shares of Common Stock Issuable
Upon Conversion of Notes
Up to 600,000 Shares of Common Stock Issuable
Upon Exercise of Warrants
Adagio Medical Holdings, Inc.
This prospectus supplement
updates and supplements the information contained in the prospectus dated February 7, 2025 (as may be supplemented or amended from time
to time, the “Prospectus”), which forms part of our registration statement on Form S-1 (File No. 333-284263) with the information
contained in our Current Report on Form 8-K that was filed with the Securities and Exchange Commission on October 24, 2025 (the “Current
Report”). Accordingly, we have attached the Current Report to this prospectus supplement.
The Prospectus and this prospectus
supplement relate to the offer, sale or other disposition from time to time of up to 31,818,652 shares of our common stock, $0.0001 par
value per share (the “Common Stock”), by the selling stockholders named in this prospectus or their permitted transferees
(the “selling stockholders”), consisting of (i) 73,333 shares of Common Stock (the “Registration Delay Shares”)
issued pursuant to the terms of the Convert Waivers (as defined below), (ii) up to 31,145,319 shares of Common Stock (excluding the shares
of Common Stock underlying the Warrants (as defined below)) (the “Convertible Note Shares”) issuable upon the conversion of
those certain 13% senior secured convertible notes, with a conversion price of $10.00 per share, subject to adjustment (the “Convertible
Notes”) issuable pursuant to that certain securities purchase agreement, dated February 13, 2024, by and among us and those certain
investors (the “Convert Investors”), and any assignment thereunder (the “Convertible Security Subscription Agreement”),
and that certain note purchase agreement, dated February 13, 2024, by and among us, Adagio Medical, Inc., a Delaware corporation, and
that certain investor party thereto, and (iii) up to 600,000 shares of Common Stock (the “Warrant Shares”) issuable upon exercise
of those warrants to purchase shares of Common Stock, with an exercise price of $24.00 per share (the “Warrants”), issued
pursuant to the Convertible Security Subscription Agreement.
You should read this prospectus
supplement in conjunction with the Prospectus. This prospectus supplement is qualified by reference to the Prospectus except to the extent
that the information in this prospectus supplement supersedes the information contained in the Prospectus. This prospectus supplement
is not complete without, and may not be delivered or utilized except in connection with, the Prospectus. If there is any inconsistency
between the information in the Prospectus and this prospectus supplement, you should rely on the information in this prospectus supplement.
Terms used in this prospectus supplement but not defined herein shall have the meanings given to such terms in the Prospectus.
Our Common Stock is listed
on The Nasdaq Capital Market under the symbol “ADGM”. On October 23, 2025, the last reported sales price of our Common Stock
was $1.31 per share.
We are an “emerging
growth company” as defined under U.S. federal securities laws and, as such, have elected to comply with reduced public company reporting
requirements. This prospectus complies with the requirements that apply to an issuer that is an emerging growth company.
Investing in our securities
involves a high degree of risk. You should review carefully the risks and uncertainties described in the section titled “Risk Factors”
beginning on page 10 of the prospectus, and under similar headings in any amendments or supplements to the prospectus.
Neither the Securities
and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or passed upon the accuracy
or adequacy of the prospectus. Any representation to the contrary is a criminal offense.
The date of this prospectus supplement is October
24, 2025.
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d) of
the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported):
October 23, 2025
ADAGIO MEDICAL HOLDINGS, INC.
(Exact name of registrant as specified in its
charter)
| Delaware |
001-42199 |
99-1151466 |
| (State or other jurisdiction of incorporation) |
(Commission File Number) |
(I.R.S. Employer Identification No.) |
|
26051 Merit Circle, Suite 102
Laguna Hills, CA |
|
92653 |
| (Address of principal executive offices) |
|
(Zip Code) |
(949) 348-1188
(Registrant’s telephone number, including
area code)
Not Applicable
(Former name or former address, if changed since
last report)
Check the appropriate box below if the Form 8-K
filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:
| ¨ |
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) |
| |
|
| ¨ |
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) |
| |
|
| ¨ |
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) |
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| ¨ |
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) |
Securities registered pursuant to Section 12(b) of
the Act:
| Title of each class |
Trading
Symbol(s) |
Name of each exchange
on which registered |
| Common Stock, par value $0.0001 per share |
ADGM |
The Nasdaq Stock Market LLC |
Indicate by check mark whether the registrant
is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 or Rule 12b-2 of the Securities Exchange
Act of 1934.
Emerging growth
company x
If an emerging growth
company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or
revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
Item 5.08 Shareholder Director Nominations
On October 23, 2025, the Board of Directors of
Adagio Medical Holdings, Inc. (the “Company”) established December 15, 2025 as the date of the Company’s 2025 Annual
Meeting of Stockholders (the “2025 Annual Meeting”). The time and location of the 2025 Annual Meeting will be set forth in
the Company’s definitive proxy statement for the 2025 Annual Meeting to be filed with the Securities and Exchange Commission (the
“SEC”). The record date for determining stockholders entitled to notice of, and to vote at, the 2025 Annual Meeting will be
the close of business on October 31, 2025.
Because the Company did not hold a 2024 Annual
Meeting of Stockholders, the Company is filing this Current Report on Form 8-K to inform stockholders of the date of the 2025 Annual Meeting
and to provide the due date for the submission of any qualified stockholder proposals or qualified stockholder director nominations.
Stockholders who intend to present proposals for
inclusion in the Company’s proxy materials for the 2025 Annual Meeting pursuant to Rule 14a-8 (“Rule 14a-8”) promulgated
under the Securities and Exchange Act of 1934, as amended (the “Exchange Act”), must ensure that such proposals are delivered
to or mailed and received by the Company’s Secretary at Adagio Medical Holdings, Inc., 26051 Merit Circle, Suite 102 Laguna Hills,
CA, no later than November 3, 2025, which the Company has determined to be a reasonable time before it expects to begin to deliver and
make available its proxy materials for the 2025 Annual Meeting, and must furthermore comply with all applicable requirements of Rule 14a-8.
Pursuant to the Company’s amended and restated
bylaws (“Bylaws”), for stockholder director nominations or other proposals to be considered at an annual meeting, the stockholder
must give timely notice thereof in writing to the Company’s Secretary at Adagio Medical Holdings, Inc., 26051 Merit Circle, Suite
102 Laguna Hills, CA, no later than November 3, 2025. To be timely for the 2025 Annual Meeting, a stockholder’s notice must be delivered
to or mailed and received by the Company’s Secretary at the Company’s principal executive offices not later than November
3, 2025, the tenth calendar day following the date of this Current Report on Form 8-K publicly announcing the date of the 2025 Annual
Meeting. A stockholder’s notice to the Secretary must also set forth the information required by the Bylaws.
In addition to satisfying the foregoing requirements
under the Bylaws, to comply with the SEC’s universal proxy rules, stockholders who intend to solicit proxies in support of director
nominees other than the Company’s nominees must provide notice to the Company that sets forth the information required by Rule 14a-19
under the Exchange Act no later than November 3, 2025.
SIGNATURE
Pursuant to the requirements
of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto
duly authorized.
Dated: October 24, 2025
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Adagio Medical Holdings, Inc. |
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|
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By: |
/s/ Deborah Kaster |
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Name: |
Deborah Kaster |
| |
Title: |
Chief Financial Officer |
