Radiopharm Theranostics (ASX:RAD) Showcases Promising Preclinical Data on RAD202 at EMIM 2025

Highlights

• Data presented by RAD at EMIM 2025 for Imaging with 68Ga-RAD202 binds specifically to HER2-positive xenografts, showing a high tumour-to-background ratio and minimal uptake in non-target organs.
• Treatment with 177Lu-RAD202 significantly reduced tumour volume and improved survival, with fractionated dosing proving more effective than single-dose treatment.
• Findings support the ongoing Phase 1 trial of 177Lu-RAD202 in Australia, assessing safety and early efficacy in advanced HER2-positive solid tumours.

Radiopharm Theranostics Limited (ASX:RAD) has presented data at the European Molecular Imaging Meeting (EMIM 2025) with findings reinforcing the clinical potential of the therapy and imaging with 177Lu-RAD202 and 68Ga-RAD202, respectively, and validates an optimised therapeutic dosing regimen in murine models.

Data source: Company update

Results of imaging with 68Ga-RAD202

The imaging data demonstrated that 68Ga-RAD202 selectively binds to Human Epidermal Growth Factor Receptor 2 (HER2) in HER2-positive xenografts, with a high tumour-to-background ratio. Notably, modifying the RAD202 nanobody by removing the His-tag impacted its biodistribution and tumour-targeting capabilities, resulting in improved PET imaging performance due to superior tumour-to-organ ratio.

Furthermore, imaging with 68Ga-RAD202 confirmed minimal uptake in non-target organs, except for the bladder and kidneys, as anticipated.

Treatment with 177Lu-RAD202

Therapy with 177Lu-RAD202 led to a substantial reduction in tumour volume and significantly prolonged survival time, with fractionated dosing proving more effective than single-dose treatment in inhibiting tumour growth.

These findings reinforce the rationale for the ongoing Phase 1 clinical trial of 177Lu-RAD202 in Australia, aimed at evaluating safety and preliminary activity in patients with advanced HER2-positive solid tumours.

Advancing HER2-Targeted Radiotherapy

HER2, a validated target in oncology, is overexpressed in breast cancer and other solid tumours. RAD202, a proprietary single-domain antibody targeting HER2, has demonstrated the safety and biodistribution of 99mTc-RAD202 in humans in previous studies.

Recent preclinical findings have reported the therapeutic effects of 177Lu-RAD202 in HER2-positive xenografts. Together, these results provide justification for conducting First-In-Human (FIH) dose-finding studies.

RAD shares were trading 3.57% higher at AU$0.029 per share at the time of writing on 17 March 2025.