Ariceum Therapeutics (Ariceum), a private biotech company developing radiopharmaceutical products for the diagnosis and treatment of certain hard-to-treat cancers, today announces that it presented data on its proprietary radiolabelled peptide SS0110 (satoreotide), a first-in-class antagonist of the somatostatin receptor 2 (SSTR2), at this year’s European Association of Nuclear Medicine (EANM) Annual Conference, held in Hamburg, Germany from 19-23 October 2024.
The Top-Rated Oral Presentation (TROP) entitled ‘225Ac-SSO110 induces long-lasting anti-tumour responses in contrast to 225Ac-DOTA-TATE and 161Tb-DOTA-TATE in the treatment of SSTR2-positive tumour xenografts’, details the anti-tumour efficacy of different radiolabelled satoreotide antagonists (225Ac, 161Tb, 177Lu-labelled SSO110) versus respective DOTA-TATE agonists (225Ac- and 161Tb-labelled DOTA-TATE) in mice engrafted with SSTR2 positive xenografts of small cell lung cancer (SCLC) and pancreatic cancer using clinically relevant associated dose ranges.
Results demonstrate that 225Ac-satoreotide shows the strongest anti-tumoural effect in vivo at a low single dose when evaluating satoreotide and DOTA-TATE radiolabelled with different radionuclides. Irrespective of the radionuclides used, satoreotide demonstrated a higher pre-clinical anti-tumour efficacy when compared to DOTA-TATE which was less potent and required increased dose levels. Satoreotide was well tolerated across all dose levels and with all used radionuclides. These comparisons between satoreotide and DOTA-TATE will facilitate and guide further clinical development of satoreotide across multiple indications expressing SSTR2, such as SCLC, pancreatic cancers and Merkel Cell Carcinoma (MCC).
Previous comparisons between satoreotide and DOTA-TATE demonstrated that antagonist, 225Ac-satoreotide, is multiple times more potent than SSTR2 agonist, 225Ac-DOTA-TATE, signifying a durable complete response in standard murine xenograft models of SCLC in animal models, versus tumour growth delay.
Ariceum had previously shown at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting 2024 that 212Pb was not seen to be more potent than Lutetium or Terbium but caused more side effects and hence was not further pursued.
Manfred Rüdiger, Chief Executive Officer at Ariceum Therapeutics, said: “These results provide strong evidence for satoreotide and its potential to clinically outperform SSTR2 targeting agonists, by demonstrating significantly better efficacy in tumour growth control, up to complete tumour eradication depending on isotope used. In addition, when a single dose of 30 kBq 225Ac-satoreotide was administered, we observed high frequency of complete durable responses and 100% survival which strongly supports further clinical development for the treatment of SCLC, MCC and other cancers.”
