8-K

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 16, 2025

PLUS THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-34375

33-0827593

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

2710 Reed Road, Suite 160

Houston, Texas 77051

(Address of principal executive offices, with zip code)

(737) 255-7194

(Registrant’s telephone number, including area code)

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 (see General Instructions A.2. below):

☐	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:

Title of each class

Trading

Symbol(s)

Name of each exchange

on which registered

Common Stock, par value $0.001

PSTV

The Nasdaq Capital Market

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 4.01

Changes in Registrant’s Certifying Accountant.

(a) Dismissal of Independent Registered Public Accounting Firm

On July 16, 2025, the audit committee (the “Audit Committee”) of the board of directors of Plus Therapeutics, Inc. (the “Company”) dismissed BDO USA, P.C. (“BDO”) as the Company’s independent registered public accounting firm.

BDO’s audit reports on the Company’s consolidated financial statements for the fiscal years ended December 31, 2024 and December 31, 2023 did not contain an adverse opinion or a disclaimer of opinion and were not qualified or modified as to uncertainty, audit scope, or accounting principles, except that the reports included an explanatory paragraph relating to substantial doubt about the Company’s ability to continue as a going concern.

During the Company’s two most recent fiscal years and the subsequent interim period through July 16, 2025, there were no (i) disagreements as defined in Item 304(a)(1)(iv) of Regulation S-K under the Exchange Act of 1934, as amended (the “Exchange Act”) and the related instruction thereto, between the Company and BDO on any matter of accounting principles or practice, financial statement disclosure, or auditing scope of procedure, which disagreements, if not resolved to BDO’s satisfaction, would have caused BDO to make reference to the subject matter of the disagreements in connection with their reports or (ii) reportable events (as defined in Item 304(a)(1)(v) of Regulation S-K under the Exchange Act), except for the material weakness in the Company’s internal control over financial reporting as of December 31, 2023, as previously disclosed in Item 9A of the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, stemming from the conclusion that the Company’s disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act) were not effective at the reasonable assurance level due to a material weakness in the Company’s internal control over the application of appropriate accounting principles to significant and unusual grant revenue transactions as of December 31, 2023. The Audit Committee discussed this matter with BDO, and the Company has authorized BDO to respond fully to any inquiries of CBIZ CPAs P.C. (“CBIZ”) with respect to this matter.

The Company provided BDO with a copy of this current report on Form 8-K (the “Form 8-K”) prior to its filing with the U.S. Securities and Exchange Commission (the “SEC”) and requested that BDO furnish the Company with a letter addressed to the SEC stating whether BDO agrees with the statements made by the Company in this Form 8-K and, if not, stating the respects, if any, in which BDO does not agree with such statements. A copy of the letter from BDO is filed with this Form 8-K as Exhibit 16.1.

(b) Engagement of New Independent Registered Public Accounting Firm

On July 16, 2025, the Audit Committee approved the engagement of CBIZ effective immediately as the Company’s new independent registered public accounting firm to audit the Company’s consolidated financial statements for the year ending December 31, 2025.

During the Company’s two most recent fiscal years and the subsequent interim period through July 16, 2025, neither the Company, nor anyone on its behalf, consulted CBIZ regarding (A) the application of accounting principles to a specific transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Company’s financial statements, and neither a written report nor oral advice was provided to the Company by CBIZ that CBIZ concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing, or financial reporting issue, or (B) any matter that was either (i) the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-K under the Exchange Act), or (ii) a reportable event (as defined in Item 304(a)(1)(v) of Regulation S-K).

Item 9.01

Financial Statements and Exhibits.

(d) Exhibits


Exhibit Number		Description

16.1		Letter from BDO USA, P.C. to the Securities and Exchange Commission dated July 18, 2025

104		Cover Page Interactive Data file (embedded within the Inline XBRL document)

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.

Date: July 18, 2025

PLUS THERAPEUTICS, INC.

By: /s/ Marc H. Hedrick, M.D.

Marc H. Hedrick, M.D.

President and Chief Executive Officer

SEC Form 8-K filed by PLUS THERAPEUTICS Inc.