[6-K] Radiopharm Theranostics Ltd Current Report (Foreign Issuer)

Rhea-AI Filing Summary

Radiopharm Theranostics Limited furnished a Form 6-K to provide U.S. investors with information simultaneously released on the Australian Securities Exchange. The company attached two announcements dated November 19, 2025: an “Initial Director’s Interest Notice” and a release titled “Life Sciences Leader Bruce Goodwin Appointed to Board.”

The filing explains that these materials are being furnished, not filed, under U.S. securities laws and will only be incorporated into other U.S. filings if specifically referenced.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER

THE SECURITIES EXCHANGE ACT OF 1934

For the Month of November 2025

Commission File Number: 001-41621

RADIOPHARM THERANOSTICS LIMITED

(Name of Registrant)

Level 3, 62 Lygon Street, Carlton South, Victoria, 3053, Australia

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒       Form 40-F ☐

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes ☐       No ☒

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82-

RADIOPHARM THERANOSTICS LIMITED

EXPLANATORY NOTE

Radiopharm Theranostics Limited (the “Company”) published two announcements (the “Public Notice”) to the Australian Securities Exchange on November 19, 2025 titled:

“Initial Director’s Interest Notice”

“Life Sciences Leader Bruce Goodwin Appointed to Board”

A copy of the Public Notice is attached as an exhibit to this report on Form 6-K.

This report on Form 6-K (including the exhibit hereto) shall not be deemed to be “filed” for purposes of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and shall not be incorporated by reference into any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such filing.

1

EXHIBITS

Exhibit Number		Description
99.1		Initial Director’s Interest Notice
99.2		Life Sciences Leader Bruce Goodwin Appointed to Board

2

SIGNATURE

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, thereunto duly authorized.

	RADIOPHARM THERANOSTICS LIMITED
Date: November 19, 2025	By:	/s/ Phillip Hains
		Phillip Hains
		Company Secretary

3

FAQ

What did Radiopharm Theranostics (RADX) report in this Form 6-K?

Radiopharm Theranostics furnished a Form 6-K to provide copies of two announcements released to the Australian Securities Exchange: an “Initial Director’s Interest Notice” and “Life Sciences Leader Bruce Goodwin Appointed to Board” dated November 19, 2025.

What announcements are attached to Radiopharm Theranostics’ November 2025 Form 6-K?

The Form 6-K includes as exhibits an Initial Director’s Interest Notice (Exhibit 99.1) and an announcement titled “Life Sciences Leader Bruce Goodwin Appointed to Board” (Exhibit 99.2).

Is the information in this Radiopharm Theranostics (RADX) Form 6-K considered filed under the Exchange Act?

The company states that this Form 6-K, including its exhibits, shall not be deemed to be “filed” for purposes of the U.S. Securities Exchange Act of 1934 and will not be incorporated into Securities Act filings unless expressly referenced.

Which market received the original announcements covered by this Radiopharm Theranostics Form 6-K?

Radiopharm Theranostics explains that it published the announcements to the Australian Securities Exchange on November 19, 2025, and is furnishing them to U.S. investors via this Form 6-K.

Who signed the Radiopharm Theranostics (RADX) November 2025 Form 6-K?

The Form 6-K was signed on behalf of Radiopharm Theranostics Limited by Phillip Hains, identified as Company Secretary, dated November 19, 2025.

What are the exhibit numbers in this Radiopharm Theranostics Form 6-K?

The filing lists Exhibit 99.1 as the Initial Director’s Interest Notice and Exhibit 99.2 as “Life Sciences Leader Bruce Goodwin Appointed to Board.”