SSO-110, also known as DOTA-JR11 or satoreotide tetraxetran, is a somatostatin SST2 receptor (SSTR2) antagonist that targets a higher number of binding sites and stays longer in SSTR2-positive tumors compared to SST2 receptor agonists. It is currently in clinical development as [177Lu]Lu-SSO-110 for small-cell lung cancer (SCLC). Ariceum Therapeutics GmbH has revealed preclinical data on [177Lu]Lu-SSO-110 as well as another SSO-110-based radiopharmaceutical, [225Ac]Ac-SSO-110, which yielded better results than DOTA-TATE-conjugated isotopes.