FDA Approves 225Ac-SSO110 Radiopharmaceutical Trial for Small Cell Lung Cancer Patients

Ariceum Therapeutics announced that the US FDA has cleared its investigational new drug (IND) application to commence a Phase I/II clinical trial of its proprietary radiolabelled peptide, 225Ac-SSO110 (satoreotide), in patients with small cell lung cancer (SCLC) or Merkel Cell Carcinoma (MCC).

The SANTANA-225 trial is a global, open-label Phase I/II study that will evaluate the safety, tolerability, preliminary effectiveness, and recommended Phase II dose of 225Ac-SSO110 in patients with extensive-stage SCLC or MCC receiving first-line maintenance therapy with checkpoint inhibitors. Ariceum is working with its partners and clinical sites in the US and other countries to commence recruitment of patients in Q1 2025.

“This is an important milestone, not only for Ariceum but for the whole field of targeted radionuclide cancer treatments. 225Ac-SSO110 is the first somatostatin receptor 2 (SSTR2) antagonist labelled with Actinium-225 to undergo human trials, providing the optimum combination of a long half-life α particle emitter with a long tumour retention tracer,” said  Germo Gericke, Chief Medical Officer at Ariceum Therapeutics. “Based on encouraging clinical data with 177Lu-SSO110 and very promising pre-clinical data of 225Ac-SSO110, we are very optimistic about the potential for patients with difficult to treat cancers.”

225Ac-SSO110 is being developed together with its companion patient selection tracer 68Ga-SSO120 as a ‘theranostic pair’ targeted radionuclide treatment of multiple indications expressing SSTR2, such as SCLC, MCC, and other aggressive cancers. Ariceum has recently expanded its global supply agreements for the medical radionuclides Actinium-225 (225Ac) and Lutetium-177 (177Lu), which will be used to radiolabel SSO110.