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 31, 2025

CACTUS ACQUISITION CORP. 1 LIMITED

(Exact name of registrant as specified in its charter)

4B Cedar Brook Drive

Cranbury, New Jersey 08512

(Address of principal executive offices, including zip code)

(609) 495-2222

(Registrant’s telephone number, including area code)

(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:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

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 5.07. Submission of Matters to a Vote of Security Holders.

Cactus Acquisition Corp. 1 Limited, a Cayman Islands exempted company (“Cactus” or the “Company”) held an extraordinary general meeting in lieu of an annual general meeting of the Company (the “Meeting”) on October 31, 2025 at 9:00 a.m. Eastern Time at the offices of Loeb & Loeb LLP, 345 Park Ave, New York, New York, 10154, and via live webcast.

There were 3,926,061 Class A ordinary shares par value $0.0001 per share and 1 Class B ordinary Share par value $0.0001 per share (together, the “Ordinary Shares”) for a total of 3,926,062 Ordinary Shares issued and outstanding on the record date, September 12, 2025. There were 3,902,546 Ordinary Shares present at said meeting in person or represented by proxy, which is 99.40% of the total outstanding shares, thereby constituting a quorum. Summarized below are the results of the matters voted on at the Meeting.

Articles Amendment

Shareholders approved the proposal to approve, by way of special resolution, an amendment (the “Amendment”) to the Company’s amended and restated memorandum and articles of association, to extend the date by which the Company would be permitted to consummate an initial business combination from November 2, 2025 to November 2, 2026, as well as to permit the Company’s board of directors, in its sole discretion, to elect to wind up the Company’s operations on an earlier date.

Adoption of the Articles Extension Proposal required approval of a majority of at least two-thirds of Cactus’ shareholders as, being entitled to do so, vote in person or by proxy at the Meeting. The voting results were as follows:

The Company has filed the Amendment with the Registrar of Companies of the Cayman Islands. A copy of the Amendment is attached hereto as Exhibit 3.1.

Item 8.01. Other Events.

In connection with the shareholders’ vote at the Meeting, 711,333 Ordinary Shares were tendered for redemption. As a result, approximately $8,660,805.78 (approximately $12.18 per share) will be removed from the Company’s trust account to pay such holders, without taking into account additional allocation of payments to cover any tax obligation of the Company, such as franchise taxes, but not including any excise tax, since that date. Following redemptions, the Company will have 52,239 public Ordinary Shares outstanding, and approximately $636,033.80 will remain in the Company’s trust account.

Item 9.01. Financial Statements and Exhibits

(c) Exhibits:

SIGNATURES

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: November 6, 2025