6-K - RADX - Equibles

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 January 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 January 28, 2026 titled:

“Quarterly Activities/Appendix 4C Cash Flow Report”

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

Exhibit <br><br>Number	Description
99.1	Quarterly Activities/Appendix 4C Cash Flow Report

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: January 28, 2026	By:	/s/ Phillip Hains
		Phillip Hains
		Company Secretary

Exhibit99.1

ASX ANNOUNCEMENT 28 January 2026

RadiopharmTheranostics Reports Half-Year Financial Results and Business Updates

Interimresults from Phase 2b clinical trial of RAD 101 showed 92% of evaluable participants met the primary endpoint of MRI concordance in imagingstudy of patients with brain metastases

Interimdata from additional cohorts of the Phase 1 clinical trial of RAD 202 and RAD 204 in advanced solid tumors are expected in mid-2026

Cashand cash equivalents of approximately $34.52 million provide runway into 2027 to advance pipeline of high value radiotherapeutic programsthrough key clinical and regulatory milestones

Sydney, Australia – 28 January 2026 – Radiopharm Theranostics (ASX: RAD, Nasdaq: RADX, “Radiopharm” or the “Company”), a clinical-stage biopharmaceutical company focused on developing innovative oncology radiopharmaceuticals for areas of high unmet medical need, today announced financial results for the first six months of fiscal 2026 ended 31 December 2025 and provided an update on its clinical pipeline with an outline of its expected milestones for 2026.

“2025 was a year of strong execution across our pipeline, as we presented unprecedented imaging data from our RAD 101 diagnostic program, received Data Safety Monitoring Committee approval to escalate dosing in both RAD 204 and RAD 202 programs and secured clearance to advance both RV-01 and RAD 402 into Phase 1 clinical trials,” said Riccardo Canevari, CEO and Managing Director of Radiopharm Theranostics. “As we enter 2026, we remain laser-focused on advancing our radiopharmaceutical assets and taking a deliberate approach to pipeline prioritization. This year, we aim to deliver meaningful data from across multiple programs, expand treatment and diagnostic options for patients with solid tumors, and create long-term value for all stakeholders.”

Programand Business Updates

18F-RAD101– Small molecule targeting fatty acid synthase radiolabeled with Fluorine-18

RAD 101 is being evaluated in a single-arm U.S. Phase 2b clinical trial for the diagnostic performance of the molecule in 30 individuals with confirmed recurrent brain metastases from solid tumors of different origins. RAD 101 has received U.S. Food and Drug Administration (FDA) Fast Track Designation to expedite the review process and help bring the novel imaging small molecule to the over 300,000 patients diagnosed annually in the U.S. with cerebral metastases. The study is currently enrolling patients and anticipates completing enrollment in the first quarter of 2026.

●	In<br> December 2025, Radiopharm Theranostics announced interim data from the first twelve patients<br> in the Phase 2b trial of RAD 101, with 92% of evaluable patients achieving concordance with<br> MRI imaging, the primary endpoint.
●	These<br> promising interim results are in line with the Phase 2a results and, if confirmed, will trigger<br> the preparation of a multi-center, multi-country Phase 3 registrational trial.
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**Radiopharm Theranostics Limited Suite 1, Level 3, 62 Lygon Street, Carlton South VIC 3053 Australia ABN: 57 647 877 889**

ASX ANNOUNCEMENT 28 January 2026

177Lu-RAD202– Nanobody targeting HER2 radiolabeled with Lutetium 177

The Company continues to evaluate RAD 202 in the Phase 1 ‘HEAT’ clinical trial in patients with Human Epidermal Growth Factor Receptor 2 (HER2)-positive advanced solid tumors. HER2 is overexpressed in breast cancer and several other solid tumors and represents a validated target in oncology. RAD 202 has demonstrated clinical proof-of-concept with positive safety and biodistribution and was recently recommended by the Data Safety and Monitoring Committee (DSMC) to progress to the next dose level of 75mCi in the ‘HEAT’ trial.

●	Recently<br> completed dosing at the 30mCi dosing level and is moving to the next dose level of 75mCi<br> following recommendation from the DSMC.
●	Data<br> available from the first three patients in the first cohort of the study show significant<br> tumor uptake in HER2 positive tumors.
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●	RAD<br> 202 has shown a favorable safety profile with no drug-related adverse events reported.
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●	The<br> Company expects to complete enrollment in the higher dose Cohort 2 and to have data from<br> both the first and second cohorts in the first half of 2026.
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177Lu-RAD204– Nanobody targeting PD-L1 radiolabeled with Lutetium 177

RAD 204 is continuing to be evaluated in a Phase 1 study in PD-L1-driven cancers, including Non-Small Cell Lung Cancer (NSCLC), Small-Cell Lung Cancer (SCLC), Triple-negative Breast Cancer (TNBC), Cutaneous Melanoma, head and neck squamous cell carcinoma (HNSCC) and Endometrial Cancer. Previous Phase 1 imaging data of 16 NSCLC patients treated with RAD 204 demonstrated that the diagnostic compound is safe and is associated with acceptable dosimetry.

●	The<br> Company completed enrollment of the second cohort of the Phase 1 study of RAD 204 and can<br> proceed with dosing patients in the third cohort with an updated dose of 90mCi of Lu177 as<br> approved by the Data and Safety Monitoring Committee.
●	Two<br> out of three patients in the 30mCi cohort exhibited stable disease for 5.5 months in metastatic<br> NSCLC, compared to historical data of 3.5 months PFS with standard of care (SOC).
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●	Initial<br> data from the first six patients across the first two cohorts show tumor uptake in the PD-L1-positive<br> lesions, in line with published results of the previously conducted imaging study.
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●	RAD<br> 204’s safety profile is reassuring and there have been no drug-related adverse events<br> reported.
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**Radiopharm Theranostics Limited Suite 1, Level 3, 62 Lygon Street, Carlton South VIC 3053 Australia ABN: 57 647 877 889**

ASX ANNOUNCEMENT 28 January 2026

Lu177-RV01 – monoclonal antibody targeting 4Ig isoform of B7H3 radiolabeled with Lutetium 177

RV-01 (Betabart) is a monoclonal antibody targeting the 4Ig isoform of B7H3, an immune checkpoint protein that is highly expressed in tumors and not in healthy tissue. In multiple preclinical studies, RV-01 has shown tumor shrinkage and prolonged survival. This is the first radiopharmaceutical therapeutic developed by Radiopharm Ventures, a Joint Venture between Radiopharm Theranostics and the MD Anderson Cancer Center.

●	In<br> January 2026, the Company increased its ownership in Radiopharm Ventures from 75% to 87.5%<br> as the joint venture continues to show promising progress in its cancer therapeutic pipeline,<br> including the advancement of its leading B7H3 candidate and other preclinical assets.
●	In<br> July 2025, RV-01 received Investigational New Drug clearance from the FDA to initiate the<br> first-in-human Phase 1 clinical trial. The Company expects to dose the first patients in<br> the Phase 1 trial in the first quarter of 2026.
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Tb161-RAD 402 – Monoclonal antibody targeting KLK3 radiolabeled with Terbium 161

RAD 402 is a monoclonal antibody targeting Kallikrein Related Peptidase 3 (KLK3) radiolabelled with the radionuclide 161Tb for the treatment of prostate cancer. In preclinical studies, RAD 402 in mouse xenografts showed strong tumor targeting, limited bone and marrow uptake, and a hepatic excretion profile consistent with expectations for a monoclonal antibody.

●	In<br> November 2025, RAD 402 was granted Bellberry Human Research Ethics Committee approval in<br> Australia to initiate a First-In-Human (FIH) Phase 1 clinical trial of RAD 402 for the treatment<br> of metastatic or locally advanced prostate cancer.
●	The<br> Company anticipates initiating a Phase 1 trial of RAD 402 in adults with metastatic or locally<br> advanced prostate cancer in Q1 2026.
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Ga68-RAD301– Peptide targeting αvB-integrin radiolabeled with Gallium 68

RAD 301 is being evaluated in a Phase 1 imaging trial in patients with Pancreatic Ductal Adenocarcinoma (PDAC). The αvB-integrin is a cellular marker for tumor invasion and metastatic growth, which correlates with decreased survival in several carcinomas, particularly pancreatic. RAD 301 has previously received Orphan Drug Designation (ODD) from the FDA and data from the Phase 1 trial is supportive of the Company’s decision to move to a Phase 2 imaging trial in patients with loco-regional pancreatic cancer.

●	Enrollment<br> in the Phase 1 imaging trial in metastatic pancreatic cancer continues, having dosed 8 patients<br> out of 9, with the last patient expected in Q1 2026.
●	Initial<br> data from the first six patients demonstrated confirmed safety and significant uptake in<br> the AvB6 positive lesions.
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The unmet medical need in the earlier stage of disease and the larger disease prevalence compared to the patient population of the current Phase 1 trial have influenced the decision to evaluate RAD 301 in loco-regional pancreatic cancer.

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

ASX ANNOUNCEMENT 28 January 2026

FinancialUpdate

The following is a summary of the Appendix 4C Cash Flow Report:

●	The<br> half-year closing cash balance was $34.52 million, a rise from $29.12 million at the close<br> of the year-end balance.
●	Net<br> cash outflows from operating activities for the 6 months ended 31 December 2025 totaled $22.67<br> million.
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●	In<br> October 2025, Radiopharm Theranostics announced that it had received firm commitments from<br> international and Australian institutional and industry investors to raise approximately<br> $35 million by way of private placement.
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In compliance with Listing Rule 4.7C, payments to related parties and their associates, as detailed in item 6.1 of Appendix 4C, encompass remuneration for director fees to executive and non-executive directors, conducted in the ordinary course of business at commercial rates, excluding reimbursements for out-of-pocket expenses.

AboutRadiopharm 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.

Authorizedon behalf of the Radiopharm Theranostics Board of Directors by Executive Chairman Paul Hopper.

Formore information:

Investors:

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

Media:

Matt Wright

NWR Communications

P: +61 451 896 420

E: matt@nwrcommunications.com.au

FollowRadiopharm Theranostics:

Website – https://radiopharmtheranostics.com/

X – https://x.com/TeamRadiopharm

LinkedIn – https://www.linkedin.com/company/radiopharm-theranostics/

InvestorHub – https://investorhub.radiopharmtheranostics.com/

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

ASX ANNOUNCEMENT 28 January 2026

Appendix4C

Quarterlycash flow report for entities subject to Listing Rule 4.7B

Name of entity
Radiopharm Theranostics Limited
ABN	Quarter ended (“current quarter”)
57 647 877 889	31 December 2025

Consolidated statement of cash flows
1.	Cash flows from operating activities
1.1	Receipts from customers
1.2	Payments for
	research and development	)	)
	product manufacturing and operating costs
	advertising and marketing	)	)
	leased assets
	staff costs	)	)
	administration and corporate costs	)	)
1.3	Dividends received (see note 3)
1.4	Interest received
1.5	Interest and other costs of finance paid
1.6	Income taxes paid
1.7	Government grants and tax incentives
1.8	Other – GST refunded
1.9	Net cash from/(used in) operating activities	)	)
2.	Cash flows from investing activities
2.1	Payments to acquire or for:
	(a) entities
	businesses
	property, plant and equipment
	investments
	intellectual property
	other non-current assets
2.2	Proceeds from disposal of:
	(a) entities
	businesses
	property, plant and equipment
	investments
	intellectual property
	other non-current assets
2.3	Cash flows from loans to other entities
2.4	Dividends received (see note 3)
2.5	Other - payments of license fee liabilities	)	)
2.6	Net cash from/(used in) investing activities	)	)