Radiopharm Theranostics (ASX:RAD) has hit a significant milestone in its Phase 2b clinical trial evaluating RAD101, announcing that the study has now reached 50 per cent of its planned patient enrollment.
The company’s lead imaging program is being developed to help clinicians distinguish between tumour recurrence and radiation necrosis in patients with brain metastases following stereotactic radiosurgery or other anticancer treatments.
Chief Executive Officer and Managing Director Riccardo Canevari said the halfway point represents significant progress for the company’s clinical ambitions.
“Enrolling 50 per cent of the patients in our Phase 2b study of RAD101 is a meaningful achievement for our RAD101 development program that brings us closer to demonstrating its clinical benefit in distinguishing between tumour recurrence and radiation necrosis in patients with brain metastasis following anticancer treatments, like SRS/radiation,” he said. “Meeting this half-way milestone, along with our continuing momentum in patient enrollment, gives us further confidence in our plans to complete enrollment and share topline results in the first half of 2026.”
Early data from the first three patients enrolled in the study are encouraging, the company said.
According to the company, RAD101 demonstrated significant and selective uptake in brain metastases, with imaging results clearly confirming metabolic activity even where MRI scans produced equivocal findings. These observations align with outcomes previously reported in a Phase 2a study. If confirmed in the broader Phase 2b dataset, Radiopharm expects to prepare for a global, multi-centre Phase 3 registrational trial.
RAD101 is a novel imaging small molecule targeting fatty acid synthase (FASN), an enzyme overexpressed in many solid tumours, including cerebral metastases. By targeting FASN, the compound may provide clinicians with a more accurate means of differentiating between recurrent disease and treatment effects, thereby addressing a persistent challenge in post-radiation brain imaging. In the United States alone, over 300,000 patients are diagnosed with cerebral metastases each year, and traditional contrast-enhanced MRI often struggles to distinguish progression from treatment-induced tissue changes reliably.
The ongoing Phase 2b clinical trial is being conducted in the United States as a multicentre, open-label, single-arm study involving 30 participants with confirmed recurrent brain metastases from solid tumours. Its primary objective is to assess concordance between lesions detected via 18F-RAD101 PET imaging and those visible on gadolinium-enhanced MRI. Secondary endpoints include accuracy, sensitivity and specificity in distinguishing tumour recurrence from radiation necrosis in previously SRS-treated lesions.
RAD101 has already received Fast Track Designation from the U.S. Food and Drug Administration for its potential use in differentiating recurrent disease from treatment effects in brain metastases, including leptomeningeal disease.