# EDGAR Filing Document

**Accession Number:** 0001095981
**File Stem:** 0001140361-26-012353
**Filing Date:** 2026-3
**Character Count:** 4926
**Document Hash:** d3fff8f6993853d9062b2dc27a0c3ffa
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001140361-26-012353.hdr.sgml**: 20260331

**ACCESSION NUMBER**: 0001140361-26-012353

**CONFORMED SUBMISSION TYPE**: DEFA14A

**PUBLIC DOCUMENT COUNT**: 4

**FILED AS OF DATE**: 20260331

**DATE AS OF CHANGE**: 20260331

**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:** 26822454

**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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**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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Your Vote Counts! PLUS THERAPEUTICS, INC. C/O BROADRIDGE P.O. BOX 1342 BRENTWOOD, NY 11717 PLUS THERAPEUTICS, INC. 2026 Annual Meeting Vote by May 13, 2026 11:59 PM ET You invested in PLUS THERAPEUTICS, INC. and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the stockholder meeting to be held on May 14, 2026. Get informed before you vote View the Proxy Statement and the 2025 Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 30, 2026. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. Vote Virtually at the Meeting\* May 14, 2026 9:00 a.m. Eastern Time Virtually at: www.virtualshareholdermeeting.com/PSTV2026 \*Please check the meeting materials for any special requirements for meeting attendance. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V90026-P50350

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Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Delivery Settings". 1. Elect six (6) members of our board of directors for a one-(1) year term, to hold office until our Annual Meeting of Stockholders in 2027 and until their successors are duly elected and qualified, or until their earlier death, resignation or removal; For Nominees: Howard Clowes 04) Marc H. Hedrick, M.D. An Van Es-Johansson, MD 05) Ronald A. Andrews Richard J. Hawkins 06) Kyle Guse, Esq., MBA 2. Ratification of the appointment of CBIZ P.C. as our independent registered public accounting firm for the 2026 fiscal year; For 3. Provide a non-binding advisory vote on the compensation of our named executive officers; and For 4. Proposal to Approve the Sixth Amendment and Restatement of the 2020 Stock Incentive Plan. For NOTE: In addition to the above, we may transact such other business as may be properly brought before the meeting or any adjournment or postponement thereof. Voting Items Board Recommends V90027-P50350

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