Radiopharm Theranostics (ASX:RAD) has reported encouraging interim results from its ongoing Phase 2b clinical trial of RAD 101, an experimental imaging agent designed to improve the detection of recurrent brain metastases.
The announcement marks a significant step forward in addressing longstanding diagnostic challenges in neuro-oncology, where distinguishing between tumour recurrence and treatment effects remains difficult with conventional methods.
The latest analysis, based on 20 patients enrolled in the United States study, showed that 90 per cent achieved concordance between RAD 101 PET imaging and standard MRI scans, meeting the trial’s primary endpoint.
This level of agreement suggests that the agent can reliably identify active disease, and imaging results demonstrate clear, selective uptake in brain metastases. In several cases, RAD 101 was able to highlight metabolic activity where MRI findings alone had been inconclusive.
Early signals from secondary endpoints further reinforce the technology's potential clinical value. Among the first five patients with six-month follow-up or biopsy data available, researchers observed a positive trend in both sensitivity and specificity, key measures that indicate how accurately a diagnostic test can identify disease presence and absence. While the dataset remains small, the results point toward a meaningful improvement in diagnostic precision.
Chief executive Riccardo Canevari described the findings as both strong and consistent, noting that they support the broader ambition of improving decision-making for patients with brain metastases. He indicated that the company expects to complete the full 30-patient study by June, with those results guiding the next stage of development, including a potential pivotal trial aimed at regulatory approval.
RAD 101 targets fatty acid synthase, an enzyme commonly overexpressed in many solid tumours, and is labelled with Fluorine 18 to enable PET imaging. By focusing on tumour metabolism rather than structural changes alone, the agent offers a different perspective from traditional contrast-enhanced MRI, which can struggle to distinguish between active cancer and treatment-related changes in follow-up scans.
In the United States alone, more than three hundred thousand patients are diagnosed each year with cerebral metastases, and the incidence continues to rise as advances in systemic therapies extend survival. More accurate imaging could play a critical role in guiding treatment strategies and improving outcomes.