Radiopharm Theranostics Ltd. has entered into an expanded agreement with Terthera BV under which Terthera will supply Radiopharm with Terbium-161 (Tb-161). The Tb-161 isotope will be linked to a proprietary monoclonal antibody to form RAD-402, a radiotherapeutic that is being developed by Radiopharm to target KLK3 expression.