Radiopharm Theranostics (ASX:RAD) has cleared an early milestone in its bid to develop a new treatment for HER2-positive cancers, after an independent Data Safety and Monitoring Committee (DSMC) recommended that the company accelerate its Phase 1 HEAT clinical trial of its radiopharmaceutical candidate, 177Lu-RAD202.
The DSMC reviewed initial data from the first patient cohort, which received a 30mCi dose of the therapy, and found positive safety, pharmacokinetic, and biodistribution results. The committee concluded the study could continue without modification, and backed advancing directly to a higher 75mCi dose level, bypassing the originally planned 40mCi stage.
Radiopharm’s chief executive and managing director, Riccardo Canevari, said the decision was a significant step forward. “With initial dosing in June and the swift completion of the first cohort, the DSMC’s recommendation to advance to a higher dose level marks an important step toward identifying the optimal Phase 2 dose and the recognition of very encouraging initial safety signals,” he said. “Each cohort brings us closer to confirming RAD202’s safety profile and to demonstrating its potential to offer a new treatment option for patients with HER2-positive advanced solid tumours.”
The second cohort, which will receive 75mCi, is expected to begin enrolling patients in the fourth quarter of 2025. Radiopharm said it plans to share data from the first two cohorts by the end of the year.
RAD202 is a proprietary single-domain monoclonal antibody (sdAb) that targets HER2, a receptor overexpressed in breast cancer and several other solid tumours. In an earlier diagnostic study, RAD202 demonstrated clinical proof of concept in ten patients with HER2-positive breast cancer, showing encouraging safety and biodistribution signals.
Radiopharm believes the therapy could offer a novel radiotherapeutic option for patients with advanced or metastatic HER2-positive disease, an area of persistent unmet medical need despite existing targeted therapies.
The HEAT study is being conducted across clinical centres in Australia and is one of several trials underway in Radiopharm’s pipeline. The company is advancing four clinical programs, including one Phase 2 and three Phase 1 studies, spanning indications such as breast, lung, and brain cancers.
Executive chairman Paul Hopper authorised the announcement, noting that Radiopharm’s strategy is to develop a differentiated platform of radiopharmaceutical products across peptides, small molecules, and antibodies.
For Canevari, the latest DSMC recommendation validates the company’s approach. “We are encouraged by the rapid progress and strong interest in new therapeutic options for HER2-positive cancers. We remain on track to deliver initial safety data this year, moving closer to a potential breakthrough treatment for patients who urgently need more options.”