225Ac-SSO110

225Ac-SSO110 is a **first-in-class radiopharmaceutical** that consists of the somatostatin receptor 2 (SSTR2) antagonist peptide **SSO110 (satoreotide)** labeled with the alpha-particle emitting radionuclide **Actinium-225**. It is designed for targeted radionuclide therapy of cancers that overexpress SSTR2, including small cell lung cancer (SCLC) and Merkel cell carcinoma (MCC), which are aggressive, hard-to-treat neuroendocrine tumors. SSO110 binds to more SSTR2 binding sites and has longer tumor retention than SSTR2 agonists such as DOTATATE, resulting in superior antitumor efficacy. In preclinical models, 225Ac-SSO110 showed durable tumor responses, high tumor uptake, and was well tolerated, significantly outperforming 225Ac-DOTA-TATE. The radiolabeled antagonist delivers potent alpha radiation selectively to SSTR2-positive tumors, causing DNA damage and cell death. 225Ac-SSO110 is under clinical development as part of a theranostic approach together with 68Ga-SSO120, a patient selection tracer, in the global phase 1/2 SANTANA-225 trial for SCLC and MCC[1][2][3][4][5][6][7].

Other names

satoreotideAc-SSO110Ac-SSO-110Ac-SSO 110