Amendment to Current Report (Form 8-K/A)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

(Amendment No. 1)

CURRENT REPORT

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

Date of Report (Date of earliest event reported): November 26, 2025

Actinium Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

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:

Securities registered pursuant to Section 12(b) of the Act:

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. ☐

EXPLANATORY NOTE

This Current Report on Form 8-K/A (this "Amendment") amends the Current Report on Form 8-K of Actinium Pharmaceuticals, Inc. (the "Company") filed with the U.S. Securities and Exchange Commission on November 26, 2025 (the "Original Form 8-K"). The Original Form 8-K reported the final voting results of the Company's Annual General Meeting of Shareholders held on November 26, 2025 (the "Annual Meeting"). The sole purpose of this Amendment is to disclose the Company's decision regarding how frequently it will conduct future shareholder advisory votes to approve the compensation of the Company's named executive officers ("Say-on-Pay Vote(s)") in accordance with Item 5.07(d) of Form 8-K. No other changes have been made to the Original Form 8-K.

Item 5.07 Submission of Matters to a Vote of Security Holders

As previously reported in the Original Form 8-K, in an advisory vote held at the Annual Meeting on the frequency of future Say-on-Pay Votes, the Company's shareholders expressed their preference for a Say-on-Pay Vote to be conducted every year. On March 20, 2026, the Company's board of directors considered the outcome of this advisory vote and determined that future Say-on-Pay Votes will be conducted every year. The Company's board of directors will re-evaluate this determination after the next shareholder advisory vote on the frequency of Say-on-Pay Votes (which will be at the 2031 Annual General Meeting of Shareholders, unless presented earlier).

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.