Radiopharm Theranostics reports positive Phase 1 trial results

Radiopharm Theranostics (ASX:RAD) has achieved a clinical milestone, unveiling initial data from its Phase 1 "HEAT" first-in-human clinical trial.

Presented at the American Association for Cancer Research annual meeting 2026 in San Diego, the findings evaluate 177Lu-RAD202, a pioneering HER2-targeted radiopharmaceutical therapy designed to treat advanced solid tumours.

The trial’s initial cohort involved three patients with heavily pre-treated metastatic breast and urothelial cancers.

Results from the lowest dose level of 30 mCi demonstrated meaningful tumour uptake, particularly within breast cancer lesions.

The therapy was generally well tolerated; researchers reported only Grade 1–2 treatment-emergent adverse events, with no dose-limiting toxicities or treatment discontinuations observed.

Furthermore, organ-level absorbed radiation doses remained within clinically acceptable ranges, confirming a favourable safety profile for the novel compound.

Dr Dimitris Voliotis, Chief Medical Officer of Radiopharm Theranostics, described the results as an important early milestone for the company’s HER2-targeted programme.

He emphasised that the observed dosimetry supports the ongoing expansion of the study.

The Data Safety and Monitoring Committee has recently approved advancing the trial to a third cohort at a significantly higher dose of 130 mCi.

As dose escalation continues, the company anticipates observing increased antitumour activity, potentially offering a new lifeline for patients with high unmet medical needs who have exhausted traditional metastatic therapies.

At the time of reporting, Radiopharm Theranostics’ share price was $0.021.