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): July 18, 2025

SONNET BIOTHERAPEUTICS HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (609) 375-2227

N/A

(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 8.01. Other Events.

As previously reported, on May 30, 2025, Sonnet Biotherapeutics Holdings, Inc. (the “Company”) received a deficiency notice from the Listing Qualifications Staff (the “Staff”) of The Nasdaq Stock Market LLC (“Nasdaq”) indicating that the Company was not in compliance with the $2.5 million minimum stockholders’ equity requirement for continued listing of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), on Nasdaq, as set forth in Nasdaq Listing Rule 5550(b)(1) (the “Minimum Stockholders’ Equity Rule”).

On July 15, 2025, the Company closed the private placement offering, as reported on July 14, 2025, for gross proceeds of approximately $5.5 million (the “PIPE Proceeds”). In addition to the PIPE Proceeds, as of the date of this report, the Company has received proceeds of approximately $10.5 million in connection with the exercise of outstanding warrants.

As a result, the Company believes that, as of the date of this report, it has stockholders’ equity in excess of the $2.5 million required pursuant to the Minimum Stockholders’ Equity Rule. The Company must await the Staff’s formal confirmation that it has evidenced compliance with the Minimum Stockholders’ Equity Rule.

As of the date of this report, the Company has 6,264,165 shares of issued and outstanding Common Stock.

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.