# EDGAR Filing Document

**Accession Number:** 0001095981
**File Stem:** 0001140361-25-028381
**Filing Date:** 2025-8
**Character Count:** 4119
**Document Hash:** ff331b3d166e2844d4489d489f46508e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001140361-25-028381.hdr.sgml**: 20250801

**ACCESSION NUMBER**: 0001140361-25-028381

**CONFORMED SUBMISSION TYPE**: DEFA14A

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20250801

**DATE AS OF CHANGE**: 20250801

**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:** DEFA14A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-34375
- **FILM NUMBER:** 251176244

**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

### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

### SCHEDULE 14A

#### Proxy Statement Pursuant to Section 14(a) of the Securities

#### Exchange Act of 1934

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Filed by the Registrant ☒

Filed by a party other than the Registrant ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ **Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))**

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material Pursuant to §240.14a-12

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![](ny20053118x1_image01.jpg)

**PLUS THERAPEUTICS, INC.**<br>

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

☒ No fee required.

☐ Fee paid previously with preliminary materials.

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

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![](ny20053118x1_image02.jpg)

#### PLUS THERAPEUTICS, INC.

#### August 1, 2025

#### SUPPLEMENT TO THE PROXY STATEMENT

#### FOR THE ANNUAL MEETING OF SHAREHOLDERS

#### TO BE HELD ON AUGUST 7, 2025

#### EXPLANATORY NOTE

This supplement (the "Supplement") to the definitive proxy statement filed by Plus Therapeutics, Inc. (the "Company") with the Securities and Exchange Commission on July 21, 2025 (the "Proxy Statement") relating to the Company's virtual annual meeting to be held at 9:00 AM, Eastern Time, on Thursday, August 7, 2025 (the "Annual Meeting") is being filed solely to correct an inadvertent error with respect to the description of the voting standard for Proposal 3 – The Reverse Stock Split Proposal (the "Reverse Stock Split Proposal").

Except as specifically supplemented by the information contained below, all information set forth in the Proxy Statement remains unchanged.

The paragraph under the heading "Required Vote" on page 48 of the Proxy Statement, which states the voting standard applicable to the Reverse Stock Split Proposal, is revised to read as follows:

#### Required Vote

The affirmative vote of a majority of all votes cast by the holders of shares of Common Stock entitled to vote will be required for approval. Abstentions and broker non-votes, if any, will have no effect on the outcome of this proposal.

The above correction has no effect on the treatment of abstentions and broker non-votes, if any, with respect to the Reverse Stock Split Proposal as described in the Proxy Statement, neither of which will have any effect on the outcome of the proposal.

This Supplement does not change the proposals to be acted upon at the Annual Meeting, which are described in the Proxy Statement. If you have already voted your shares or submitted your proxy, you do not need to take any action unless you wish to change your vote.

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