Radiopharm Theranostics has announced encouraging results from its Phase 2b trial of RAD101, a Fluorine-18 labelled PET tracer that targets fatty acid synthase to detect suspected recurrent brain metastases.
In a study of thirty evaluable patients, imaging analysis showed 93 per cent concordance between MRI and RAD101 PET across all assessed lesions, meeting the trial’s primary endpoint and demonstrating substantial and selective tumour uptake.
The company reported that PET images confirmed metabolic activity in lesions that were equivocal on MRI, suggesting RAD101 could help resolve diagnostic uncertainty in follow-up surveillance after stereotactic radiosurgery.
Fourteen patients with six-month follow-up or biopsy data produced a preliminary sensitivity of 86 per cent, a secondary endpoint Radiopharm described as a strong positive trend, with specificity results expected in the fourth quarter of 2026.
Radiopharm’s chief executive Riccardo Canevari framed the findings as validation for the program and a springboard to larger trials.
He said, "The entirety of this dataset captures the strength and potential of RAD101 to address a difficult diagnostic challenge in neuro-oncology," he said, adding that the company plans to continue discussions with the U.S. Food and Drug Administration as it finalises a registrational Phase 3 study design. RAD101 already holds FDA Fast Track designation for distinguishing recurrent disease from treatment effect in brain metastases from solid tumours, and Radiopharm has secured a manufacturing and distribution partnership with Siemens Healthineers to supply 18F-labelled doses for the planned U.S. pivotal trial.
The company intends to advance RAD101 into a global Phase 3 program in the United States in the fourth quarter of 2026."
In parallel, Radiopharm released an update on RAD204, its investigational PD-L1 targeted lutetium 177 nanobody radiotherapeutic being evaluated in an ongoing Phase 1 study in patients with advanced solid tumours after progression on standard therapies.
The company said that two patients in the third dosing cohort have been treated with initial outcomes that the company described as supportive of repeated administration. Patient 1 achieved a RECIST-confirmed Partial Response with a 43 per cent reduction in target lesions after Dose 2 that was maintained through Dose 3, and the patient remained progression-free beyond seven months. Patient 2 showed an early 7 per cent reduction after the first treatment cycle and also remains on therapy.
The company said these RAD204 observations reinforce its confidence in the broader therapeutic potential of its platform. "We are excited to announce positive initial data from the first two patients treated with RAD204 in the third dosing cohort, which showed favourable tolerability and tumour reduction in target lesions with both patients remaining on treatment," said Mr Canevari. He added that the totality of the Phase 1 data is expected to inform the recommended dose for a planned Phase 2 trial and support further development of RAD204.
