Radiopharm Theranostics Ltd (ASX:RAD, OTC:RDPTF) has highlighted a head-to-head pilot study in prostate cancer which validates its development of first-in-class Terbium-161 radiotherapeutics.
The recent publication of first head-to-head data by Schaefer-Schuler et al. shows superior therapeutic index with Tb161 versus Lu177 in six metastatic castration-resistant prostate cancer patients.
This pilot study strongly supports Terbium-161 as a promising candidate for use in the radiotherapeutic targeting of advanced cancers and validates Radiopharm’s leadership in developing next-generation Tb-161 radiotherapeutics.
Highly promising isotype
Tb-161 is a highly promising isotope for targeted cancer treatment due to its unique characteristics of radiation emitted, which includes both Auger electrons and short-range beta particles. The beta radiation travels only a few millimetres and Auger electronic emission has a higher linear energy transfer that travels less than the width of a single cell.
Previously, Tb-161 has shown excellent bioequivalence presenting a biodistribution comparable to currently used radiopharmaceuticals, and its superiority to Lutetium-177 is potentially due to Auger effect increasing potency and efficacy in selectively destroying tumour cells while leaving surrounding healthy tissue largely unaffected.
Radiopharm’s highly innovative pipeline includes two Tb-161-based radiotherapeutics, RAD 402 and 502, which target advanced prostate cancer and osteosarcoma respectively. For both assets, Tb-161 will be linked to two proprietary monoclonal antibodies (RAD 402) and (RAD 502).
Through a partnership with TerThera to supply the company with Tb-161, Radiopharm remains the first public company that disclosed a secured supply of Tb-161 — a relatively scarce isotope — for the development of multiple programs.
Promise in nuclear medicine and oncology
Radiopharm Theranostics CEO and managing director Riccardo Canevari said: “Tb-161 holds remarkable promise in nuclear medicine and oncology.
“It has the strong potential to advance anti-tumour efficacy for not only primary tumours but also micrometastatic disease.
"We are delighted to continue our partnership with TerThera and hopefully bring this highly differentiated technology to eligible advanced cancer patients.”