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): May 08, 2025

Actinium Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

Delaware	001-36374	74-2963609
(State or other jurisdiction	(Commission File Number)	(I.R.S. Employer
of incorporation)		Identification No.)

100 Park Ave., 23rd Floor,

New York, New York 10017
(Address of principal executive offices) (Zip code)

(646) 677-3870
(Registrant's telephone number, including area code)

Not applicable

(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:

☐	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 per share		ATNM		NYSE American

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) Resignation of Independent Registered Public Accounting Firm

Based on information provided by Marcum LLP (“Marcum”), on November 1, 2024, CBIZ CPAs P.C. (“CBIZ CPAs”) acquired the attest business of Marcum. On May 08, 2025, Actinium Pharmaceuticals, Inc. (the “Company”) dismissed Marcum as the Company’s independent registered public accounting firm as a result of such acquisition.

The audit report of Marcum on the Company’s consolidated financial statements as of and for the fiscal years ended December 31, 2024, and 2023 did not contain an adverse opinion or a disclaimer of opinion, and was not qualified or modified as to uncertainty, audit scope, or accounting principles.

During the fiscal years ended December 31, 2024, and 2023 and through May 08, 2025, there were no (1) “disagreements” (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) between the Company and Marcum on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure, which disagreements, if not resolved to the satisfaction of Marcum, would have caused Marcum to make reference to the subject matter of the disagreement in their reports on the financial statements for such years, or (2) “reportable events” (as described in Item 304(a)(1)(v) of Regulation S-K).

The Company has provided Marcum with a copy of the foregoing disclosures it is making in this Current Report on Form 8-K prior to its filing and requested, in accordance with applicable practices, that Marcum furnish a letter addressed to the Securities and Exchange Commission stating whether or not it agrees with the statements made herein. Attached as Exhibit 16.1 is a copy of Marcum’s letter, dated May 09, 2025, stating that it agrees with such statements.

(b) Engagement of New Independent Registered Public Accounting Firm

On May 08, 2025, with the approval of the Company’s Audit Committee, CBIZ CPAs was engaged as the Company’s new independent registered public accounting firm for the fiscal year ending December 31, 2025.

During the fiscal years ended December 31, 2024 and 2023 and through May 08, 2025, neither the Company nor anyone on its behalf consulted with CBIZ CPAs regarding (1) the application of accounting principles to a specified transaction, 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 that CBIZ CPAs concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing or financial reporting issue, or (2) any matter that was either the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) or a reportable event (as described in Item 304(a)(1)(v) of Regulation S-K).

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.		Description of Exhibit
16.1		Letter from Marcum dated May 09, 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.

	ACTINIUM PHARMACEUTICALS, INC.

Date: May 09, 2025	By:	/s/ Sandesh Seth
		Name: Sandesh Seth
		Title: Chairman and Chief Executive Officer

Actinium Pharmaceuticals, Inc. 8-K