Radiopharm Theranostics (ASX: RAD) has received Bellberry human research ethics committee (HREC) approval in Australia for a Phase 1 first in-human (FIH) clinical trial of RAD402 for the treatment of metastatic or locally-advanced prostate cancer.
Pre-clinical proof-of-concept biodistribution studies of RAD402 in mouse xenografts showed strong tumour targeting, limited bone and marrow uptake, and a hepatic excretion profile consistent with expectations for a monoclonal antibody.
The Phase 1 FIH trial will be supported by a ++supply arrangement with Dutch radionuclide specialist TerThera++for the production of Terbium-161 (Tb-161) and an agreement with Cyclotek for radiolabelling of RAD402 with 161Tb.
Safer Cancer Treatments
Chief executive officer Riccardo Canevari said the HREC approval was a key milestone for patients in need of safer and more effective treatments for prostate cancer.
“This clearance enables us to advance our Phase 1 trial, which will be the first company-sponsored therapeutic trial using 161Tb,” he said.
“We are highly encouraged by RAD402’s potential anti-tumour activity and we believe targeting KLK3 in advanced prostate cancer represents a novel and promising mechanism of action.”
Mr Canevari said the strength of the company’s pre-clinical data, combined with the regulatory endorsement, underscored RAD402’s first-in-class potential.
Phase 2b Patient Enrolment
Radiopharm has additionally announced that a Phase 2b trial evaluating ++RAD101 imaging in brain metastases++ has achieved the 50% patient enrolment threshold.
Data from the first three patients showed significant and selective tumour uptake in brain metastases, with images confirming metabolic activity compared to equivocal MRI findings.
The positive early results – which are in line with Phase 2a results – could trigger the preparation of a multi-centre, global Phase 3 registrational trial.
“Enrolling 50% of the patients in our Phase 2b study […] brings us closer to demonstrating the clinical benefit of RAD101 in distinguishing between tumour recurrence and radiation necrosis in patients with brain metastasis following cancer treatment,” Mr Canevari said.
“Meeting this halfway milestone gives us confidence in our plans to complete enrolment and share topline results in the first half of 2026.”
RAD101 is Radiopharm’s novel imaging small molecule targeting fatty acid synthase, which is over-expressed in many solid tumours including brain metastases.
Dose Escalation Trial
In a busy period for the company, Radiopharm has also enrolled the second cohort of patients into its Phase 1 dose escalation trial of 177Lu-RAD204 in PD-L1 advanced cancers.
These include non-small cell lung cancer, small cell lung cancer, triple-negative breast cancer, cutaneous melanoma, head and neck squamous cell carcinoma, and endometrial cancer.
The open-label trial is a first-in-human study to evaluate the safety, tolerability, biodistribution, radiation dosimetry, and preliminary anti-tumour activities of 177Lu-RAD204.
It could significantly improve clinical outcomes for patients who currently face limited effective treatment options.
