Furthermore, the combination of [<sup>225</sup>Ac]Ac-DOTA-MSC3 and ICI significantly delayed tumor growth and prolonged survival compared with PBS control (p=0.0022 and p=0.0019, respectively).<h4>Conclusion</h4>Overall, these results demonstrate first proof-of-concept of the potential of CAIX-TAT to treat hypoxic tumors by targeting CAIX-positive hypoxic tumor regions. Here, CA9 is linked to neoplasm.