Treatment using 225Ac-SSO110 for advanced small cell lung cancer and Merkel cell carcinoma

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)

Phase1; Phase2 Interventional Ariceum Therapeutics GmbH · NCT06939036

This study is testing a new treatment called 225Ac-SSO110 combined with standard therapies to see if it helps people with advanced small cell lung cancer and Merkel cell carcinoma.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment50 (estimated)
Ages18 Years and up
SexAll
SponsorAriceum Therapeutics GmbH Industry-sponsored
Drugs / interventionsCAR-T, radiation
Locations1 site (Miami, Florida)
Trial IDNCT06939036 on ClinicalTrials.gov

What this trial studies

This study evaluates the safety, tolerability, and preliminary effectiveness of 225Ac-SSO110 combined with standard care therapies in patients with extensive-stage small cell lung cancer and recurrent Merkel cell carcinoma. Participants will receive the investigational treatment alongside immune checkpoint inhibitors such as Atezolizumab, Durvalumab, Avelumab, or Pembrolizumab. The study aims to identify the recommended phase 2 dose and assess the antitumor activity of the treatment in patients expressing somatostatin receptor 2. The trial is designed for patients who meet specific eligibility criteria, including a positive scan for somatostatin receptor expression.

Who should consider this trial

Good fit: Ideal candidates include individuals with extensive-stage small cell lung cancer or recurrent Merkel cell carcinoma who are eligible for immune checkpoint inhibitor therapy.

Not a fit: Patients with unstable spinal cord compression or those who have received prior systemic radioligand therapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with advanced small cell lung cancer and Merkel cell carcinoma.

How similar studies have performed: Other studies have explored similar approaches using radioligand therapy, but the specific combination of 225Ac-SSO110 with standard therapies in this context is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Key Inclusion Criteria:

Signed Informed Consent Form and willing to comply with all study procedures.

Participants with ES-SCLC (defined as Stage IV per NCCN guidelines Version 1.2024) or recurrent locally advanced or metastatic MCC (per NCCN guidelines Version 1.2024) documented by histology or cytology.

Participants eligible to receive immune checkpoint inhibitor (CPI) monotherapy at the start of treatment with 225Ac-SSO110 or patients already on CPI monotherapy for 7 weeks.

ECOG performance status of 0 or 1. Life expectancy of at least 6 months.

Positive 68Ga-SSO120 scan (Investigator-assessed) during screening.

Key Exclusion Criteria:

Participants with unstable spinal cord compression.

Any previous systemic radioligand therapy or extensive radiotherapy.

Participants receiving or planned to receive consolidative chest radiation.

History of primary immunodeficiency, transplantation or CAR-T cell therapy.

Major surgical procedure except diagnostic biopsy within 28 days prior to enrolment or scheduled to have major surgery during the study.

Inadequate organ or marrow function.

Where this trial is running

Miami, Florida

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Small Cell Lung Cancer Extensive StageMerkel Cell Carcinomaactinium225Acactinium-225SSO110SSO120gallium
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.