Fluorine F 18 GEH200521

**Semantic type:** Pharmacologic Substance

**Definition:** A radioimmunoconjugate consisting of GEH200520, a VHH nanobody targeting the human CD8 antigen on CD8-positive T-cells, labeled with the radioisotope fluorine F 18, with potential imaging activity using positron emission tomography (PET). Upon administration, fluorine F 18 GEH200521 specifically targets and binds to the CD8 antigen expressed on T-cells. This allows for visualization of the distribution of CD8+ T-cells upon imaging using PET and could be used to determine a patient's response to immune checkpoints inhibitors. CD8+ T cells are effector cells involved in the immune response against tumor cells and play a key role in the eradication of tumor cells.

**Synonyms:** - 18F-GEH200521 - 18F-labeled GEH200521 - [18F]-GEH200521