PLUS THERAPEUTICS Inc. filed SEC Form 8-K: Material Modification to Rights of Security Holders, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Other Events, Financial Statements and Exhibits

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

PLUS THERAPEUTICS, INC.

(Exact name of Registrant as Specified in Its Charter)

(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 3.03 Material Modification to Rights of Security Holders.

To the extent required by Item 3.03 of Form 8-K, the information regarding the Reverse Stock Split (as defined herein) contained in Item 5.03 of this Current Report on Form 8-K is incorporated by reference herein.

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

At the Annual Meeting of Stockholders of Plus Therapeutics, Inc. (the “Company”) held on August 7, 2025 (the “Annual Meeting”), the stockholders of the Company approved an amendment to the Company’s Amended and Restated Certificate of Incorporation (the “Charter”) to implement a reverse stock split of the Company’s common stock, par value $0.001 per share, with the ratio to be determined by the Board of Directors (the “Board”) of the Company, within a range of not less than 1-for-2 and not greater than 1-for-250. Subsequently, on March 20, 2026, the Board determined to fix the ratio for the reverse stock split at 1-for-25. Thereafter, on April 1, 2026, the Company filed a certificate of amendment to its Charter (the “Certificate of Amendment”) with the Secretary of State of the State of Delaware, to implement the 1-for-25 reverse split of its common stock (the “Reverse Stock Split”). The Reverse Stock Split became effective as of 12:01 a.m. (Eastern time) on April 2, 2026, and the Company’s common stock began trading on The Nasdaq Capital Market on a post-split basis at the open of business on April 2, 2026.

As a result of the Reverse Stock Split, every twenty-five (25) shares of the Company’s issued and outstanding common stock, par value $0.001, were converted into one (1) share of common stock, par value $0.001, reducing the number of issued and outstanding shares of the Company’s common stock from approximately 171,550,698 shares to approximately 6,862,027 shares. The Company’s transfer agent Broadridge Financial Services, Inc. (“Broadridge”), will provide instructions to stockholders of record regarding the process of exchanging shares.

Because the Certificate of Amendment did not reduce the number of authorized shares of the Company’s common stock, the effect of the Certificate of Amendment and the Reverse Stock Split is to increase the number of shares of common stock available for issuance relative to the number of shares issued and outstanding. The Reverse Stock Split did not alter the par value of the Company’s common stock or modify any voting rights or other terms of the common stock.

No fractional shares will be issued in connection with the Reverse Stock Split. Stockholders who otherwise would be entitled to receive fractional shares because they hold a number of pre-Reverse Stock Split shares of the Company’s common stock not evenly divisible by twenty-five (25) will, in lieu of a fractional share, be entitled, upon surrender to the exchange agent of certificate(s) representing their pre-split shares or upon conversion of their shares held in book-entry, to receive a cash payment equal to the fraction to which the stockholder would otherwise be entitled multiplied by the fair market value of a share of the Company’s common stock.

Broadridge will be issuing all of the post-split shares through their paperless Direct Registration System, also known as “book-entry form”. Broadridge will hold the shares in an account set up for the stockholder. All book-entry or other electronic positions representing issued and outstanding shares of the Company’s common stock will be automatically adjusted. Those stockholders holding common stock in “street name” will receive instructions from their brokers.

In addition, pursuant to their terms, a proportionate adjustment will be made to the per share exercise price and number of shares issuable under all of the Company’s outstanding equity awards and warrants to purchase shares of common stock, and the number of shares authorized and reserved for issuance pursuant to the Company’s equity incentive plan will be reduced proportionately.

After the Reverse Stock Split, the trading symbol for the Company’s common stock will continue to be “PSTV.” The new CUSIP number for the Company’s common stock is 72941H806.

The above description of the Certificate of Amendment and the Reverse Stock Split is a summary of the material terms thereof and is qualified in its entirety by reference to the Certificate of Amendment, a copy of which is attached hereto as Exhibit 3.1, as filed with the Secretary of State of the State of Delaware on April 1, 2026.

Item 8.01 Other Events.

On March 31, 2026, the Company issued a press release relating to the matters described in Item 5.03 above. A copy of the press release is attached as Exhibit 99.1 to this report and is incorporated herein by reference.

Item 9.01 Financial Statements and 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.