# EDGAR Filing Document

**Accession Number:** 0001095981
**File Stem:** 0001193125-26-140267
**Filing Date:** 2026-4
**Character Count:** 19508
**Document Hash:** c3a7bd5b86821a1b6acc22dcf6ce1f6b
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-140267.hdr.sgml**: 20260402

**ACCESSION NUMBER**: 0001193125-26-140267

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 12

**CONFORMED PERIOD OF REPORT**: 20260401

**ITEM INFORMATION**: Material Modifications to Rights of Security Holders

**ITEM INFORMATION**: Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260402

**DATE AS OF CHANGE**: 20260402

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** PLUS THERAPEUTICS, INC.
- **CENTRAL INDEX KEY:** 0001095981
- **STANDARD INDUSTRIAL CLASSIFICATION:** SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 330827593
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-34375
- **FILM NUMBER:** 26834219

**BUSINESS ADDRESS:**
- **STREET 1:** 4200 MARATHON BLVD.
- **STREET 2:** SUITE 200
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78756
- **BUSINESS PHONE:** 737.255.7194

**MAIL ADDRESS:**
- **STREET 1:** 4200 MARATHON BLVD.
- **STREET 2:** SUITE 200
- **CITY:** AUSTIN
- **STATE:** TX
- **ZIP:** 78756

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** CYTORI THERAPEUTICS, INC.
- **DATE OF NAME CHANGE:** 20050712

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MACROPORE INC
- **DATE OF NAME CHANGE:** 20010320

?xml version='1.0' encoding='ASCII'? 8-K

**UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549**

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## FORM 8-K

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**CURRENT REPORT**

**Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934**

**Date of Report (Date of earliest event reported):** April 1, 2026<br>

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PLUS THERAPEUTICS, INC.

**(Exact name of Registrant as Specified in Its Charter)**

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| | | |
|:---|:---|:---|
| Delaware | 001-34375 | 33-0827593 |
| **(State or Other Jurisdiction<br>of Incorporation)** | **(Commission File Number)** | **(IRS Employer<br>Identification No.)** |
| 6420 LEVIT GREEN BOULEVARD<br>Suite 310 |  |  |
| Houston**,** Texas |  | 77021 |
| **(Address of Principal Executive Offices)** |  | **(Zip Code)** |

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**Registrant's Telephone Number, Including Area Code:** (737) 255-7194<br>

**(Former Name or Former Address, if Changed Since Last Report)**

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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))

☐ 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:**

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| | | |
|:---|:---|:---|
| **<br>Title of each class** | **Trading<br>Symbol(s)** | **<br>Name of each exchange on which registered** |
| Common Stock, par value $0.001 per share | PSTV | The Nasdaq Capital Market |

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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. ☐

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## 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.

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## Item 9.01 Financial Statements and Exhibits.

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| | |
|:---|:---|
| **(d) Exhibits.**<br>**Exhibit<br>Number** | <br>**Description** |
| [<u>3.1</u>](pstv-ex3_1.htm) | [<u>Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Plus Therapeutics, Inc., filed with the Delaware Secretary of State on April 1, 2026</u>](pstv-ex3_1.htm) |
| [<u>99.1</u>](pstv-ex99_1.htm) | [<u>Press Release dated March 31, 2026</u>](pstv-ex99_1.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document) |

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**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.

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| | | | |
|:---|:---|:---|:---|
|  |  |  | **PLUS THERAPEUTICS, INC.**  |
| Date: | April 2, 2026 | By:  | /s/ Marc H. Hedrick, M.D.  |
|  |  |  | Marc H. Hedrick, M.D.<br>President and Chief Executive Officer  |

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## Exhibit 3.1

**Exhibit 3.1**

**CERTIFICATE OF AMENDMENT**

**OF AMENDED AND RESTATED CERTIFICATE OF INCORPORATION** 

**OF**

**PLUS THERAPEUTICS, INC.** 

Plus Therapeutics, Inc., a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware, does hereby certify:

FIRST: The name of the corporation is Plus Therapeutics, Inc. (the "Corporation").

SECOND: On July 25, 2025, the Board of Directors of the Corporation duly adopted resolutions approving the following amendment of the Amended and Restated Certificate of Incorporation, as amended (the "Certificate of Incorporation"), declaring said amendment to be advisable and providing for such consideration of such amendment at the Corporation's 2025 annual meeting of the Corporation's stockholders (the "2025 Annual Meeting").

THIRD: On August 7, 2025, the 2025 Annual Meeting was duly called and held, upon notice in accordance with Section 222 of the General Corporation Law of the State of Delaware, at which meeting the necessary number of shares as required by statute were voted in favor of the amendment.

FOURTH: On March 20, 2026, the Board of Directors of the Corporation duly adopted resolutions approving the following amendment of the Certificate of Incorporation.

FIFTH: Article IV.A of the Certificate of Incorporation, of the Corporation be hereby amended and restated to read in its entirety as follows:

"(a) Authorized Shares. The total number of shares of stock which the Corporation shall have authority to issue is 205,000,000 shares, consisting of 200,000,000 shares of Common Stock, par value $0.001 per share ("Common Stock") and 5,000,000 shares of Preferred Stock, par value $0.001 per share ("Preferred Stock"). At 12:01 a.m. Eastern Standard Time on April 2, 2026 (the "Effective Time"), each twenty-five (25) whole number of shares, as determined by the Board, of Common Stock issued and outstanding at such time shall, automatically and without any further action on the part of the Corporation or the holder thereof, be combined into one (1) validly issued, fully paid and non-assessable share of Common Stock (the "Reverse Stock Split"). The par value of the Common Stock following the Reverse Stock Split shall remain $0.001 per share. No fractional shares shall be issued, and, in lieu thereof, the Corporation shall pay cash equal to such fraction multiplied by the fair market value of a share of Common Stock, as determined by the Board of Directors. Each certificate that immediately prior to the Effective Time represented shares of Common Stock (an "Old Certificate") shall thereafter represent that number of shares of Common Stock into which the shares of Common Stock represented by the Old Certificate shall have been combined, subject to the elimination of fractional share interests as described above."

SIXTH: This amendment to the Corporation's Certificate of Incorporation was duly adopted in accordance with the provisions of Section 242 of the General Corporation Law of the State of Delaware and shall be effective on and as of the date of filing of this Certificate of Amendment with the Secretary of State of the State of Delaware.

IN WITNESS WHEREOF, Plus Therapeutics, Inc. has caused this Certificate of Amendment to be signed by the undersigned, thereunto duly appointed, this 2<sup>nd</sup> day of April, 2026.

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| | |
|:---|:---|
| PLUS THERAPEUTICS, INC. | PLUS THERAPEUTICS, INC. |
| By: | */s/ Marc H. Hedrick, M.D.* |
| Name:  | Marc H. Hedrick, M.D. |
| Title: | Chief Executive Officer |

---

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## Exhibit 99.1

**Exhibit 99.1**

![img7200896_0.jpg](img7200896_0.jpg)

**Plus Therapeutics Announces Reverse Stock Split** 

HOUSTON, Texas, March 31, 2026 – Plus Therapeutics, Inc. (the "Company"), a clinical-stage pharmaceutical company developing targeted radiotherapeutics with advanced platform technologies for central nervous system cancers, today announced that the Company's Board of Directors has approved a reverse stock split of its shares of common stock at a ratio of 1-for-25. The reverse stock split will become effective at 12:01 a.m. Eastern Time on April 2, 2026, and the Company's common stock will open for trading on The Nasdaq Capital Market on a post-split basis on April 2, 2026 under the Company's existing trading symbol, "PSTV." At such time, the Company's common stock will also commence trading with a new CUSIP number, 72941H806.

The reverse stock split is being implemented to increase the per share trading price of the Company's common stock for the purpose of ensuring a share price high enough to comply with the minimum $1.00 bid price requirement for continued listing on The Nasdaq Capital Market.

At the effective time of the reverse stock split, every twenty-five (25) shares of Plus Therapeutics common stock issued and outstanding will be combined into one (1) share of common stock issued and outstanding, with no change to the par value of $0.001 per share. This will reduce the Company's outstanding common stock from approximately 171,550,698 shares to approximately 6,862,027 shares. No fractional shares of common stock will be issued as a result of the reverse stock split and instead holders of Plus common stock will receive a cash payment in lieu of fractional shares to which they would otherwise be entitled. The shares underlying the Company's outstanding equity awards and warrants will also be adjusted accordingly. The reverse stock split affects all stockholders uniformly and will not alter any stockholder's percentage interest in the Company's common stock, except for adjustments that may result from the treatment of fractional shares.

The Company has retained its transfer agent, Broadridge Financial Services, Inc. ("Broadridge"), to act as its exchange agent for the reverse stock split. Stockholders with shares held in certificate form will receive from Broadridge instructions regarding the exchange of their certificates. Stockholders that hold shares in book-entry form or hold their shares in brokerage accounts are not required to take any action and will see the impact of the reverse stock split reflected in their accounts, subject to brokers' particular processes. Beneficial holders of Plus Therapeutics common stock are encouraged to contact their bank, broker, custodian or other nominee with questions regarding procedures for processing the reverse stock split.

**About Plus Therapeutics**

Headquartered in Houston, Texas, Plus Therapeutics, Inc. is a clinical-stage pharmaceutical company developing targeted radiotherapeutics for difficult-to-treat cancers of the central nervous system with the potential to enhance clinical outcomes. Combining image-guided local beta radiation and targeted drug delivery approaches, the Company is advancing a pipeline of product candidates with lead programs in leptomeningeal metastases (LM) and recurrent glioblastoma (GBM). The Company has built a supply chain through strategic partnerships that enable the development, manufacturing, and future potential commercialization of its products. For more information, visit https://plustherapeutics.com/.

**Cautionary Statement Regarding Forward-Looking Statements**

This press release contains statements that may be deemed "forward-looking statements" within the meaning of U.S. securities laws. All statements in this press release other than statements of historical fact are forward-looking statements. These forward-looking statements may be identified by future verbs, as well as terms such as "designed to," "will," "can," "potential," "focus," "preparing," "next steps," "possibly," and similar expressions or the negatives thereof. Such statements are based upon certain assumptions and assessments made by management in light of their experience and their perception of historical trends, current conditions, expected future developments and other factors they believe to be appropriate. These statements include, without limitation, statements regarding the implementation and proposed timing of the reverse stock split, the commencement of trading of the Company's post-split common stock, the impact of the reverse stock split on the Company's securityholders, including any adjustments that may

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**Exhibit 99.1**

result from the treatment of fractional shares, the potential for the Company to regain compliance with the minimum bid price requirement for continued listing on the Nasdaq Capital Market and the expected number of shares of common stock to be issued and outstanding following the reverse stock split.

The forward-looking statements included in this press release are subject to a number of risks and uncertainties that may cause actual results to differ materially from those discussed in such forward-looking statements. These risks and uncertainties include, but are not limited to: risks and uncertainties related to the reverse stock split having the desired effect, the Company's ability to regain compliance with Nasdaq's listing requirements, the potential de-listing of the Company's securities on Nasdaq, and additional risks described under the heading "Risk Factors" in the Company's Securities and Exchange Commission filings, including in the Company's annual and quarterly reports. There may be events in the future that the Company is unable to predict, or over which it has no control, and its business, financial condition, results of operations and prospects may change in the future. The Company assumes no responsibility to update or revise any forward-looking statements to reflect events, trends or circumstances after the date they are made unless the Company has an obligation under U.S. federal securities laws to do so.

**Investor Contact**

CORE IR

investor@plustherapeutics.com

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