Radiopharm picks Siemens Healthineers to support Phase III radioligand supply

Radiopharm Theranostics (ASX: RAD; Nasdaq: RADX), a Sydney-based clinical-stage radiopharmaceutical company, and Siemens Healthineers signed a clinical supply agreement under which Siemens Healthineers will manufacture and distribute Fluorine-18 (¹⁸F)-labeled RAD101 to support Radiopharm’s upcoming Phase III registrational trial in the United States. The agreement covers radiolabeling and distribution of RAD101, Radiopharm’s investigational small molecule PET imaging agent targeting fatty acid synthase (FASN), indicated for the diagnosis of suspected recurrent brain metastases from solid tumors of different origins.

Financial terms of the agreement were not disclosed. Siemens Healthineers will apply its radiolabeling manufacturing capabilities and leverage its national network of US radiopharmacies to produce and deliver ¹⁸F-labeled RAD101 doses to clinical trial sites. The geographic scope of the agreement is explicitly limited to the United States.

RAD101 targets FASN, a metabolic enzyme overexpressed across multiple solid tumor types including breast, lung, and colorectal cancers — common primary sources of brain metastases. By binding selectively to FASN-expressing tumor cells and emitting positrons detectable via PET scanning, RAD101 is designed to generate a metabolic map of active tumor burden within the brain. The clinical rationale centers on a persistent diagnostic gap: contrast-enhanced MRI, the current standard of care, lacks the metabolic specificity to reliably differentiate true tumor recurrence from treatment-related changes such as radiation necrosis or pseudoprogression. Misclassification in either direction carries material clinical consequences, either exposing patients to unnecessary retreatment or delaying intervention for genuine recurrence.

The ¹⁸F radiolabel carries a half-life of approximately 110 minutes, a property that enables centralized manufacturing and regional distribution without requiring on-site cyclotron infrastructure at each clinical site. This characteristic makes Siemens Healthineers’ established radiopharmacy network operationally well-suited to the agreement’s requirements.

The deal follows an interim analysis from Radiopharm’s Phase IIb trial of RAD101, in which 90% of dosed patients — 18 of 20 — achieved concordance between RAD101 PET imaging and MRI, the trial’s primary endpoint. The company reported significant and selective tumor uptake in brain metastases, with PET images confirming metabolic activity in lesions that appeared equivocal on MRI. Among the first five patients with evaluable six-month follow-up or biopsy data, the company reported a positive trend for sensitivity and specificity, the trial’s secondary objectives. Radiopharm has indicated it expects topline data from the Phase IIb trial in the first half of 2026, with the Phase III registrational trial initiation contingent on those results.

The FDA has granted RAD101 Fast Track Designation for distinguishing between recurrent disease and treatment effect in brain metastases originating from solid tumors of different origins, including leptomeningeal disease.