Radiopharm Theranostics (ASX:RAD) said that data presented at the most recent European Molecular Imaging Meeting confirmed positive tumor uptake and favorable biodistribution for RAD202, according to a Monday filing with the Australian bourse.

The human epidermal growth factor receptor 2 or, HER2, is overexpressed in breast cancer as well as several other solid tumors and represents a validated target in oncology. RAD202 is a proprietary single-domain antibody that targets HER2.

The imaging data reported that gallium-68-RAD202 binds specifically to the receptor in HER2-positive xenografts, with a high tumor-to-background ratio. Imaging with it resulted in specific accumulation in the tumor and low uptake in non-target organs, except for the bladder and kidney.

The removal of a polyhistidine tag from the RAD202 nanobody, which impacts biodistribution and tumor targeting, was validated to be superior for positron emission tomography imaging due to the higher tumor-to-organ ratio.

Therapy with lutetium-177-RAD202 was well-tolerated, confirming a reduction in tumor volume, significantly prolonging survival time.

A dose escalation phase one study of lutetium-177-RAD202 is currently in the recruiting phase in Australia. It is designed to evaluate the safety and preliminary activity of the radiotherapeutic product in patients with advanced HER2-positive solid tumors.

Its shares jumped 11% on market close on Monday.