Ariceum Therapeutics (Ariceum), a private biotech company developing radiopharmaceutical products for the diagnosis and treatment of certain hard-to-treat cancers, is pleased to announce that the first patient has been dosed with its first-in-class lead molecule, satoreotide, targeting extensive stage small cell lung cancer (ES-SCLC), at the Murdoch University Health Center in Perth, Australia.

Ariceum has successfully initiated its multicentre, open label Phase Ib study which will investigate the safety and tolerability of the ‘theranostic pair’ of somatostatin receptor antagonist 68Ga-Satoreotide Trizoxetan (SSO120) and 177Lu-satoreotide tetraxetan (SSO110) in patients with ES-SCLC. The main objective of the study is to establish a recommended Phase 2 dose and schedule.

‘Theranostics’ is the approach of using two paired drugs – the first, a diagnostic agent to identify cells which exhibit a particular biomarker; and the second, a therapeutic drug, to act on those cells. Both the diagnostic agent and therapeutic drug contain Ariceum’s proprietary peptide satoreotide, a first-in-class and best-in-class antagonist of the somatostatin receptor 2 (SST2), a cell surface protein often overexpressed in certain cancers including small cell lung cancer (SCLC).

The study, entitled LuSato-1 study, includes patients with ES-SCLC who will each receive an infusion containing the diagnostic imaging agent, somatostatin receptor antagonist before undergoing a positron emission tomography (PET) scan. This will determine if a patient’s tumours express the SST2. Patients identified with confirmed SST2 expression will receive escalating doses of satoreotide, in addition to the immunotherapy atezolizumab, a PD-L1 checkpoint inhibitor, during the maintenance phase of their treatment until a recommended phase 2 dose can be defined. Additional patients may be enrolled in an expansion cohort. Further details on the study can be found on Australian Clinical Trials, under identifier Ariceum SSO11O-01.

Manfred Rüdiger, PhD, Chief Executive Officer of Ariceum Therapeutics, said: “The initiation of this Phase Ib study is an important milestone reached by the Company in close collaboration with our partners in Australia and Europe. We believe that our lead targeted systemic radiopharmaceutical product satoreotide has the potential to demonstrate positive results in patients with extensive stage small cell lung cancer. Theranostics holds great hope as a highly targeted form of cancer therapy, using a ‘search and destroy’ approach to seek out tumours while sparing healthy tissue.”

Germo Gericke, Chief Medical Officer of Ariceum Therapeutics, said: “Although immune checkpoint blockade has improved the treatment of ES-SCLC, disease recurrence often occurs early in the maintenance phase. Adding targeted radiotherapy with satoreotide to immune checkpoint blockade in the maintenance setting holds the promise to improve the therapeutic effect of the maintenance therapy.”

An Abstract on the LuSato-1 study will be presented at the European Association of Nuclear Medicine Congress 2023 (EANM 2023) in Vienna, Austria, on 10th September 2023. Presentation details below.