# EDGAR Filing Document

**Accession Number:** 0001949257
**File Stem:** 0001213900-25-111746
**Filing Date:** 2025-11
**Character Count:** 7691
**Document Hash:** 25402de3d408e94e79739a7921b03098
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001213900-25-111746.hdr.sgml**: 20251118

**ACCESSION NUMBER**: 0001213900-25-111746

**CONFORMED SUBMISSION TYPE**: 6-K

**PUBLIC DOCUMENT COUNT**: 3

**CONFORMED PERIOD OF REPORT**: 20251118

**FILED AS OF DATE**: 20251118

**DATE AS OF CHANGE**: 20251118

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Radiopharm Theranostics Ltd
- **CENTRAL INDEX KEY:** 0001949257
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** C3
- **FISCAL YEAR END:** 0630

**FILING VALUES:**
- **FORM TYPE:** 6-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41621
- **FILM NUMBER:** 251492737

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** LEVEL 3, 62 LYGON STREET
- **CITY:** CARLTON VIC
- **PROVINCE COUNTRY:** C3
- **ZIP:** 3053
- **BUSINESS PHONE:** 61 3 9824 5254

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** LEVEL 3, 62 LYGON STREET
- **CITY:** CARLTON VIC
- **PROVINCE COUNTRY:** C3
- **ZIP:** 3053

**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

**<u>RADIOPHARM THERANOSTICS LIMITED</u>**

(Name of Registrant)

**<u>Level 3, 62 Lygon Street, Carlton South, Victoria, 3053, Australia</u>**

(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**

**<u>EXPLANATORY NOTE</u>**

Radiopharm Theranostics Limited (the "Company") published one announcement (the "Public Notice") to the Australian Securities Exchange on November 18, 2025 titled:

"RAD Approval for Phase 1 Therapeutic Trial of RAD 402"

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.

**EXHIBITS**

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| | |
|:---|:---|
| **Exhibit** <br> **Number** | **Description** |
| 99.1 | [RAD Approval for Phase 1 Therapeutic Trial of RAD 402](ea026614301ex99-1_radio.htm) |

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**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.

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| | | |
|:---|:---|:---|
|  | **RADIOPHARM THERANOSTICS LIMITED** | **RADIOPHARM THERANOSTICS LIMITED** |
| Date: November 18, 2025 | By: | /s/ Phillip Hains |
|  |  | Phillip Hains |
|  |  | Company Secretary |

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## Exhibit 99.1

**Exhibit 99.1** 

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| | |
|:---|:---|
| **ASX ANNOUNCEMENT<br> 18 NOVEMBER 2025** | ![](ex99-1_001.jpg) |

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**Radiopharm Theranostics Receives Approval to Initiate Phase 1 Therapeutic Trial of RAD 402 (KLK3-mAb with Tb161) in Advanced Prostate Cancer** 

 

*RAD 402 is a humanized IgG1 internalized by prostate cells, binding KLK3 with high affinity*

 

*Tb-161 antitumor activity driven by the dual emission of beta particles and Auger electrons* 

Sydney, Australia – 18 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 it has been granted Bellberry Human Research Ethics Committee (HREC) approval in Australia to initiate its First-In-Human (FIH) Phase 1 clinical trial of its Kallikrein Related Peptidase 3 (KLK3)-targeting radiotherapeutic, RAD 402, for the treatment of metastatic or locally advanced prostate cancer.

RAD 402 is an anti-KLK3 monoclonal antibody radiolabelled with the radionuclide 161Tb for the treatment of prostate cancer. Prostate Specific Antigen (PSA) is a widely used biomarker to detect prostate cancer and is encoded by the KLK3 gene. KLK3 is expressed in the prostate along with most adenocarcinomas of the prostate including their metastases.

Previous comprehensive preclinical proof-of-concept Biodistribution studies of RAD 402 in mouse xenografts showed strong tumour targeting, limited bone and marrow uptake, and a hepatic excretion profile consistent with expectations for a monoclonal antibody. Radiopharm has signed in 2022 a supply agreement with Terthera for the production of Tb161 and in 2025 with Cyclotek for radiolabeling RAD402 with 161Tb, supporting the initiation of the Phase 1 FiH trial of RAD 402.

"Receiving HREC approval marks a key milestone for Radiopharm and for patients in need of safer, more effective new treatments for prostate cancer," said Riccardo Canevari, CEO and Managing Director of Radiopharm Theranostics. "This clearance enables us to advance RAD 402 into our first-in-human Phase 1 clinical trial, which, to my knowledge, is the first company-sponsored therapeutic trial using 161Tb. We are highly encouraged by RAD 402's potential antitumor activity, driven by the dual emission of beta particles and Auger electrons from Tb-161. Targeting KLK3 in advanced prostate cancer represents a novel and promising mechanism of action. The strength of our preclinical data, combined with regulatory endorsement, underscores RAD 402's first-in-class potential".

**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.

**Radiopharm Theranostics Limited<br> Suite 1, Level 3, 62 Lygon Street, Carlton South VIC 3053 Australia<br> ABN: 57 647 877 889**

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| | |
|:---|:---|
| **ASX ANNOUNCEMENT<br> 18 NOVEMBER 2025** | ![](ex99-1_001.jpg) |

---

**Authorised on behalf of the Radiopharm Theranostics board of directors by Chairman Paul Hopper.**

**For more information:**

Riccardo Canevari<br> CEO & Managing Director<br> P: +1 862 309 0293<br> E: rc@radiopharmtheranostics.com

Anne Marie Fields

Precision AQ (Formerly Stern IR)

E: annemarie.fields@precisionaq.com

Paul Hopper<br> Executive Chairman<br> P: +61 406 671 515<br> E: paulhopper@lifescienceportfolio.com

<u>Media</u><br> Matt Wright<br> NWR Communications<br> P: +61 451 896 420<br> E: matt@nwrcommunications.com.au

**Radiopharm Theranostics Limited<br> Suite 1, Level 3, 62 Lygon Street, Carlton South VIC 3053 Australia<br> ABN: 57 647 877 889**