99mTc-RAD202

99mTc-RAD202 is a radiolabeled diagnostic agent consisting of the nanobody RAD202 conjugated with technetium-99m (99mTc), a gamma-emitting radioisotope. RAD202 is a proprietary single-domain antibody (nanobody) that specifically targets the Human Epidermal Growth Factor Receptor 2 (HER2), which is overexpressed in various solid tumors, most notably breast cancer. The primary use of 99mTc-RAD202 has been as an imaging agent to assess HER2 expression and biodistribution in patients with HER2-positive cancers. Clinical proof-of-concept studies have demonstrated its safety and favorable biodistribution profile in humans, supporting its role as a companion diagnostic for therapeutic radiopharmaceuticals based on the same nanobody platform, such as 177Lu-RAD202[1][3][4][5][6].