225Ac-satoreotide / Ariceum Therap - LARVOL DELTA

Preclinical Evaluation of 225Ac-BPR603303, a Novel SSTR2 Antagonist–based Alpha-Emitting Radiopharmaceutical for Neuroendocrine-Derived Small Cell Lung Cancer (SNMMI 2026) - "Tumor growth, body weight changes, and survival were monitored longitudinally and compared with vehicle control and the reference agents 225Ac-BPR603100 (225Ac-DOTA-JR11) and Tarlatamab. 225Ac-BPR603303 a novel SSTR2 antagonist–based alpha-emitting radiopharmaceutical that demonstrated potent and durable antitumor efficacy in preclinical models of neuroendocrine-derived SCLC, with therapeutic activity strongly correlated with SSTR2 expression. These findings support further clinical development of 225Ac-BPR603303 for the treatment of SSTR2-positive neuroendocrine SCLC and highlight the promise of SSTR2 antagonist–based alpha therapy as a precision oncology strategy for SSTR2-positive neuroendocrine SCLC, addressing a significant unmet clinical need."

IO biomarker • Preclinical • Lung Cancer • Oncology • Small Cell Lung Cancer • Solid Tumor • DLL3 • SSTR • SSTR2

225Ac-SSO110 as next-generation SSTR2 targeting radiopharmaceutical for small cell lung cancer (AACR 2025) - "SSO110 targets a higher number of SSTR2 binding sites and shows longer tumor retention than the SSTR2 agonist DOTATATE translating into higher anti-tumor efficacy of 177Lu-SSO110 compared to 177Lu-DOTATATE. 161Tb-SSO110 demonstrated modestly better efficacy than 177Lu-SSO110, but only in the AR42J model with high and homogenous target expression. Based on promising emerging clinical data from the LuSato1 study with 177Lu-SSO110 and the outstanding preclinical activity of 225Ac-SSO110, a global phase I/II clinical study with 225Ac-SSO110 in patients with ES-SCLC or Merkel Cell Carcinoma on Immune-Checkpoint Inhibitor monotherapy is being initiated."

Lung Cancer • Merkel Cell Carcinoma • Non-melanoma Skin Cancer • Oncology • Pancreatic Cancer • Skin Cancer • Small Cell Lung Cancer • Solid Tumor • SSTR • SSTR2

Study of 225Ac-SS0110 in Subjects With ES-SCLC or MCC (SANTANA-225 ) (clinicaltrials.gov) - P1/2 | N=2 | Terminated | Sponsor: Ariceum Therapeutics GmbH | N=50 ➔ 2 | Trial completion date: Dec 2026 ➔ Dec 2025 | Recruiting ➔ Terminated | Trial primary completion date: Aug 2026 ➔ Dec 2025; Study terminated due to strategic business decisions.

Enrollment change • Trial completion date • Trial primary completion date • Trial termination • Lung Cancer • Merkel Cell Carcinoma • Non-melanoma Skin Cancer • Oncology • Skin Cancer • Small Cell Lung Cancer • Solid Tumor

Ariceum Therapeutics Doses First Patient in SANTANA-225 Phase 1/2 Clinical Trial of 225Ac-SSO110 in Patients with Extensive-Stage Small Cell Lung Cancer or Merkel Cell Carcinoma (The Manila Times) - "Initial safety data from SANTANA-225 in ES-SCLC and MCC expected in 2026."

P1/2 data • Trial status • Merkel Cell Carcinoma • Small Cell Lung Cancer

Title: Improved Tumour Targeting and Efficacy with Comparable Daughter Redistribution of 225Ac-SSO110 versus 225Ac-DOTA-TATE in a Preclinical SCLC Model; Presentation # OP-658 (GlobeNewswire) - "A second oral presentation at EANM25 showcased the superior pharmacokinetic profile of 225Ac-SSO110 versus 225Ac-DOTA-TATE, demonstrating comparable biodistribution to the internalizing agonist, alongside enhanced tumor uptake and a favorable therapeutic index....The study results demonstrate that 225Ac-SSO110’s differentiated binding profile enables superior tumor uptake and retention, compared with 225Ac-DOTA-TATE. Importantly, 225Ac-SSO110 exhibited similar retention of daughter radionuclides as the internalizing agonist 225Ac-DOTA-TATE and a more favorable therapeutic index."

Preclinical • Small Cell Lung Cancer

Title: SANTANA-225: A multicentre, open-label, Phase I/II study investigating the safety, tolerability, and preliminary efficacy of 225Ac-SSO110 in participants with extensive stage small cell lung cancer (ES-SCLC) or Merkel cell carcinoma (MCC) receiving Standard of Care (SoC); Presentation # OP-780 (GlobeNewswire) - "'With the SANTANA-225 initial safety readout expected in 2026 and preliminary efficacy in 2027'....This presentation, presented by Dr. Elcin Zan, Cleveland Clinic, highlighted the design of Ariceum’s SANTANA-225 Phase 1/2 clinical trial (NCT06939036) evaluating 225Ac-SSO110 for the treatment of first line (1L) maintenance ES-SCLC or 1L MCC. This global, open-label study will assess the safety, tolerability, preliminary efficacy, and recommended Phase 2 dose of 225Ac-SSO110 in patients receiving immune checkpoint inhibitor (CPI) therapy."

P1/2 data • Trial status • Merkel Cell Carcinoma • Small Cell Lung Cancer

U.S. FDA Grants Orphan Drug Designation to Ariceum Therapeutics' Proprietary Radiopharmaceutical Cancer Therapy (PRNewswire) - "Ariceum Therapeutics...announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to 225Ac-SSO110 (satoreotide) for the treatment of patients with Small Cell Lung Cancer (SCLC)....Ariceum will commence Phase I/II human clinical development of 225Ac-satoreotide under the trial name, SANTANA-225 in Q1 2025."

New P1/2 trial • Orphan drug • Small Cell Lung Cancer

ITM and Ariceum Therapeutics Enter Into Supply Agreement for Therapeutic Medical Radioisotope Actinium-225 (GlobeNewswire) - "ITM Isotope Technologies Munich SE (ITM)...and Ariceum Therapeutics (Ariceum)...announced the execution of a supply agreement for non-carrier-added (n.c.a.) Actinium-225 (Ac-225) to support the development of Ariceum’s novel targeted radiopharmaceutical therapies (RPT) pipeline, including its lead radiopharmaceutical drug, satoreotide for the treatment of aggressive, hard-to-treat cancers. Under the terms of the agreement, ITM will supply the therapeutic medical radioisotope, Ac-225, produced by Actineer Inc, ITM’s joint venture company with Canadian Nuclear Laboratories, for use in Ariceum’s Actinium-based pipeline candidates....Additional details of the supply agreement have not been disclosed."

Licensing / partnership • Solid Tumor

FDA Clears Ariceum Therapeutics' 225Ac-Satoreotide Phase I/II Clinical Study in Patients with Small Cell Lung Cancer or Merkel Cell Carcinoma (PRNewswire) - "Ariceum Therapeutics...today announced that the US Food and Drug Administration (FDA) has cleared its investigational new drug (IND) application to commence a Phase I/II clinical trial ('SANTANA-225') of its proprietary radiolabelled peptide, ²²⁵Ac-SSO110, 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 assess the safety, tolerability, preliminary efficacy and recommended Phase II dose of ²²⁵Ac-SSO110 in patients with extensive-stage SCLC or MCC who are on 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."

IND • New P1/2 trial • Merkel Cell Carcinoma • Small Cell Lung Cancer

Ariceum Therapeutics Presents Outstanding Data on its First-in-Class Radiopharmaceutical Drug 225Ac-Satoreotide at the European Association of Nuclear Medicine 2024 (PRNewswire) - "The Top-Rated Oral Presentation (TROP)...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."

Preclinical • Pancreatic Cancer • Small Cell Lung Cancer

[225Ac]Ac-SSO110 and [177Lu]Lu-SSO110 demonstrate significantly better efficacy than [225Ac]Ac-DOTA-TATE in the treatment of SST2-positive tumor xenografts (SNMMI 2024) - "Since [177Lu]Lu-SSO110 demonstrated significantly better efficacy than [177Lu]Lu-DOTA-TATE in different xenograft models, the aim of this study was to identify the optimal isotope(s) (225Ac, 212Pb, 161Tb, 177Lu) for SSO110 and how the different SSO110-based radiopharmaceuticals compare to the respective DOTA-TATE compounds. Our data highlights the potential of [225Ac]Ac-SSO110 and [177Lu]Lu-SSO110 to outperform SST2-targeting agonists that are approved or in clinical development. The superior pharmacokinetic profile of SSO110 translates into higher pre-clinical efficacy with several isotopes. The comparison of SSO110 and DOTA-TATE labelled with various isotopes will help guide clinical development of SSO110 across different SST2-expressing indications."

Clinical • Gastrointestinal Cancer • Hepatology • Lung Cancer • Oncology • Pancreatic Cancer • Renal Cell Carcinoma • Small Cell Lung Cancer • Solid Tumor • SSTR • SSTR2