Radiopharm Theranostics Ltd 6-K, filed Nov 17, 2025
Radiopharm Theranostics Ltd (RADX)
About this 6-K
Radiopharm Theranostics Ltd filed this 6-K on November 17, 2025.
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 one announcement (the “Public Notice”) to the Australian Securities Exchange on November 17, 2025 titled:
| “RAD Announces 50% Enrollment in Phase 2b Trial of RAD101” |
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 | RAD Announces 50% Enrollment in Phase 2b Trial of RAD101 |
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 17, 2025 | By: | /s/ Phillip Hains |
| Phillip Hains | ||
| Company Secretary | ||
3
Exhibit 99.1
| ASX ANNOUNCEMENT 17 November 2025 |
 |
Radiopharm Theranostics Announces 50% Enrollment in Phase 2b Clinical Trial of RAD101 Imaging in Brain Metastases
Early patient data from Phase 2b clinical trial showed significant and selective tumor uptake in brain metastases compared to MRI
Phase 2b clinical trial expected to complete enrollment and have topline data in 1H26
Sydney, Australia – 17 November 2025 – Radiopharm Theranostics (ASX:RAD, “Radiopharm” or the “Company”), a clinical-stage biopharmaceutical company focused on developing innovative oncology radiopharmaceuticals for areas of high unmet medical need, today announced that the Phase 2b trial evaluating RAD101 imaging in brain metastases has achieved 50% patient enrollment threshold.
“Enrolling 50% of the patients in our Phase 2b study of RAD101 is a meaningful achievement for our RAD101 development program that brings us closer to demonstrating its clinical benefit in distinguishing between tumor recurrence and radiation necrosis in patients with brain metastasis following anticancer treatments, like SRS/radiation,” said Riccardo Canevari, CEO and Managing Director of Radiopharm Theranostics. “Meeting this half-way milestone, along with our continuing momentum in patient enrollment, gives us further confidence in our plans to complete enrollment and share topline results in the first half of 2026.”
RAD101 is the Company’s novel imaging small molecule that targets fatty acid synthase (FASN), a multi-enzyme protein that catalyses fatty acid synthesis and is overexpressed in many solid tumors, including Brain metastases.
Data from the first three patients showed significant and selective tumor uptake in brain metastases. Images confirmed metabolic activity in brain metastases compared to equivocal MRI findings. These promising early results are in line with the previously published Phase 2a results and, if confirmed, will trigger the preparation of a multi-center, global Phase 3 registrational trial.
In the U.S. alone, there are more than 300,000 patients diagnosed annually with cerebral metastases. The incidence of Intracranial Metastatic Disease (IMD) continues to increase, in part, due to improvements in systemic therapy resulting in a more durable control of the Primary tumor. Contrast-enhanced Magnetic Resonance Imaging (CE-MRI) is the preferred method for imaging IMD, but has limitations, particularly in follow-up surveillance scans to optimise patient care.1
RAD101 has received U.S. Food and Drug Administration (FDA) Fast Track Designation to distinguish between recurrent disease and treatment effect of brain metastases originating from solid tumors of different origin including leptomeningeal disease.
About the Phase 2 Clinical Trial of RAD101
The U.S. multicenter, open-label, single arm Phase 2b clinical trial is evaluating the diagnostic performance of 18F-RAD101 in 30 individuals with confirmed recurrent brain metastases from solid tumors of different origins. The primary objective of the study is concordance between 18F-RAD101 positive lesions and those seen in conventional imaging (MRI with gadolinium) in participants with suspected recurrent brain metastases. Secondary endpoints are accuracy, sensitivity and specificity of RAD101 in identifying tumor recurrence versus radiation necrosis in previously stereotactic radiosurgery (SRS)-treated brain metastases.
| 1 | A hybrid [18F]fluoropivalate PET-multiparametric MRI to detect and characterise brain tumour metastases based on a permissive environment for monocarboxylate transport | European Journal of Nuclear Medicine and Molecular Imaging |
Radiopharm Theranostics Limited
Suite 1, Level 3, 62 Lygon Street, Carlton South VIC 3053 Australia
ABN: 57 647 877 889
| ASX ANNOUNCEMENT 17 November 2025 |
|
About RAD101
RAD101 is the Company’s novel imaging small molecule that targets fatty acid synthase (FASN), a multi-enzyme protein that catalyses fatty acid synthesis and is overexpressed in many solid tumors, including cerebral metastasis. Targeting FASN activity may allow for the more accurate detection of cancer cells, representing a clinically relevant method for the imaging of brain metastases. Positive data from the Imperial College of London’s Phase 2a imaging trial of 18F-RAD101 in patients with brain metastases (both SRS pre-treated and treatment naïve patients) showed significant tumor uptake that was independent from the tumor of origin. The study further indicated that PET-MRI may potentially represent a non-invasive prediction of overall-survival, warranting larger studies.
About Radiopharm Theranostics
Radiopharm Theranostics is a clinical stage radiotherapeutics company
developing a world-class platform of innovative radiopharmaceutical products for diagnostic and therapeutic applications in areas of high
unmet medical need. Radiopharm is listed on ASX (RAD) and on NASDAQ (RADX). The company has a pipeline of distinct and highly differentiated
platform technologies spanning peptides, small molecules and monoclonal antibodies for use in cancer. The clinical program includes one
Phase 2 and four Phase 1 trials in a variety of solid tumor cancers including lung, breast, and brain metastases. Learn more at radiopharmtheranostics.com.
Authorised on behalf of the Radiopharm Theranostics board of directors by Chairman Paul Hopper.
For more information:
Riccardo Canevari
CEO & Managing Director
P: +1 862 309 0293
E: rc@radiopharmtheranostics.com
Anne Marie Fields
Precision AQ (Formerly Stern IR)
E: annemarie.fields@precisionaq.com
Paul Hopper
Executive Chairman
P: +61 406 671 515
E: paulhopper@lifescienceportfolio.com
Media
Matt Wright
NWR Communications
P: +61 451 896 420
E: matt@nwrcommunications.com.au
Radiopharm Theranostics
Limited
Suite 1, Level 3, 62 Lygon Street, Carlton South VIC 3053 Australia
ABN: 57 647 877 889