Radiopharm Theranostics (RADX) reports 90% RAD101 Phase 2b imaging success
Rhea-AI Filing Summary
Radiopharm Theranostics Limited reported second interim data from its U.S. Phase 2b imaging trial of RAD101 in brain metastases. In 20 treated patients, 90% (18/20) achieved the primary endpoint of concordance between PET imaging with RAD101 and MRI, with significant and selective tumor uptake observed in brain metastases.
The first five patients with six‑month follow-up and/or biopsy data showed an encouraging trend for sensitivity and specificity, key measures of diagnostic accuracy. The company expects final data from the full 30‑patient study by June to help guide a potential pivotal trial. RAD101 has FDA Fast Track Designation for distinguishing recurrent brain metastases from treatment effects.
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Insights
Interim Phase 2b RAD101 data show high imaging concordance but remain early-stage.
Radiopharm Theranostics reported that 90% (18/20) of evaluable patients in its U.S. Phase 2b trial achieved concordance between PET imaging using RAD101 and MRI, the study’s primary endpoint. Images also showed selective uptake in brain metastases, supporting the biological targeting of fatty acid synthase.
Only five patients currently have six‑month follow-up or biopsy data, which show a positive trend for sensitivity and specificity, but the sample is still small. The trial plans 30 patients in total, and the company expects a final data readout by June, which it says will inform the design of a pivotal study.
RAD101 already holds FDA Fast Track Designation for differentiating recurrent brain metastases from treatment effects, which can help streamline future development steps. Actual regulatory and commercial outcomes will depend on the robustness of the full Phase 2b dataset and subsequent pivotal trial performance.
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 March 2026
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 March 24, 2026 titled:
“RAD101 2nd interim Ph.2b data - 90% achieve primary endpoint”
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.
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EXHIBITS
Exhibit Number |
Description | |
| 99.1 | RAD101 2nd interim Ph.2b data - 90% achieve primary endpoint |
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: March 24, 2026 | By: | /s/ Phillip Hains |
| Phillip Hains | ||
| Company Secretary | ||
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Exhibit 99.1
ASX ANNOUNCEMENT 24 March 2026 |
 |
Radiopharm Theranostics Achieves Primary Endpoint In 90% of Patients At Second Interim Analysis of RAD 101 Phase 2b Imaging Trial in Brain Metastases
90% of patients dosed with RAD 101 and evaluable at interim analysis achieved concordance with MRI imaging (the primary endpoint)
First five patients with available data from six-month follow-up and biopsy show encouraging trend for Sensitivity and Specificity (secondary objective)
Company to host webinar on March 25 at 9:00 am AEDT (Sydney, Melbourne) / Tuesday, March 24 at 6:00 pm EST (U.S.)
Sydney, Australia–24 March 2026 – 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 the second interim data from twenty patients in its U.S. Phase 2b clinical imaging trial of RAD 101 in brain metastases. RAD 101 is Radiopharm’s novel, small-molecule imaging agent targeting fatty acid synthase (FASN) and radiolabelled with Fluorine-18 for the diagnosis of suspected recurrent brain metastases from solid tumors of different origins.
The second interim analysis showed that 90% (18/20) of the patients dosed with RAD101 achieved concordance between PET imaging and MRI (the primary endpoint). The results showed significant and selective tumor uptake in the brain metastases. Images confirm metabolic activity in brain metastases compared to equivocal MRI findings.
In addition, the first five patients with evaluable six-month follow-up and/or biopsy data show a positive trend for sensitivity and specificity (the secondary objectives). Sensitivity and specificity are two of the fundamental hallmarks of any diagnostic test including in imaging. They measure an imaging test’s ability to correctly identify patients with a disease (sensitivity, true positive rate), as well as patients without the disease (specificity, true negative rate).
“The strength and consistency of these interim results further validate the potential of RAD 101 to address one of the most challenging diagnostic gaps in neuro-oncology,” said Riccardo Canevari, CEO and Managing Director of Radiopharm Theranostics. “With 90% concordance demonstrated to date and encouraging early signals in sensitivity and specificity, we are increasingly confident in RAD 101’s ability to support more accurate and timely treatment decisions for patients with brain metastases. We look forward to the final data readout from the full 30-patient study by June, which will guide our path toward a pivotal trial and, ultimately, toward bringing this important imaging agent to the clinicians and patients who need it.”
RAD 101 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.
Radiopharm Theranostics Limited
Suite 1, Level 3, 62 Lygon Street, Carlton South VIC 3053 Australia
ABN: 57 647 877 889
ASX ANNOUNCEMENT 24 March 2026 |
|
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
WEBINAR DETAILS
AUSTRALIA
Date: Wednesday 25 March 2026
Time: 9:00am AEDT
USA
Date: Tuesday 24 March 2026
Time: 6.00pm EST
Presenters:
| ● | Riccardo Canevari – CEO & Managing Director | |
| ● | Dr Dimitris Voliotis – Chief Medical Officer | |
| ● | Dr. Harshad Kulkarni – BAMF Health, Grand Rapids, MI |
Register for the webinar at the link below: https://us02web.zoom.us/webinar/register/WN_Uy9zCUEhQUaMqC1rYG5Zhw
Please submit any questions to: matt@nwrcommunications.com.au
Upon registering attendees will receive an email containing information about joining the webinar. A recording will be available at the above link soon after the conclusion of the live session, with the replay to also be made available via Radiopharm’s website and social media channels.
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.
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.
| 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
2
ASX ANNOUNCEMENT 24 March 2026 |
|
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
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FAQ
What did Radiopharm Theranostics (RADX) report about the RAD101 Phase 2b trial?
What is the primary endpoint in Radiopharm Theranostics’ RAD101 Phase 2b study?
What early sensitivity and specificity data did RAD101 show for Radiopharm Theranostics (RADX)?
How large is the ongoing RAD101 Phase 2b trial reported by Radiopharm Theranostics?
What regulatory status does RAD101 have according to Radiopharm Theranostics’ 6-K filing?
What clinical need is Radiopharm Theranostics targeting with RAD101 in brain metastases?
Filing Exhibits & Attachments
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