Radiopharm Theranostics' (ASX:RAD) second interim analysis from its phase 2b clinical imaging trial of RAD 101 in brain metastases showed that 90% of patients achieved concordance between positron emission tomography imaging and magnetic resonance imaging (MRI) for detecting brain metastases, achieving the primary endpoint, according to a Tuesday filing with the Australian bourse.

RAD 101 is the company's small-molecule imaging agent targeting fatty acid synthase and radiolabeled with Fluorine-18 for the diagnosis of suspected recurrent brain metastases from various solid tumors, the filing said.

The results indicated "significant" and selective tumor uptake in brain metastases, with images confirming metabolic activity compared with equivocal MRI scans.

Additionally, the first five patients with evaluable six-month follow-up and biopsy data in the trial indicated a positive trend for sensitivity and specificity, per the filing.