Small Cell Lung Cancer Extensive StagePhase 1/2SANTANA-225NCT06939036
Study of 225Ac-SS0110 in Subjects With ES-SCLC or MCC (SANTANA-225 )
A Phase 1/2 study testing 225Ac-SSO110 + SoC, Atezolizumab and Durvalumab in people with Small Cell Lung Cancer Extensive Stage and Merkel Cell Carcinoma, run by Ariceum Therapeutics GmbH at 7 sites in 2 countries.
Trial summary
This study aims to determine safety, tolerability, recommended phase 2 dose (RP2D), and preliminary antitumor activity of 225Ac-SSO110 with standard of care (SoC) therapy in patients with somatostatin receptor 2 expressing (SSTR2+) extensive-stage small cell lung cancer (ES-SCLC) and recurrent locally advanced or… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Small Cell Lung Cancer Extensive Stage, Merkel Cell Carcinoma
- What is being tested?
- 225Ac-SSO110 + SoC, Atezolizumab and Durvalumab
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2 participants
- Where
- 7 sitesin 2 countries
- Study dates
- 1 Jul 2025to 31 Dec 2025
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
7 sites in 2 countries.
7 sites in 2 countries
United States6 sites
Virginia Cancer Specialists, PC
Fairfax, Virginia, 22031
United Theranostics
Glen Burnie, Maryland, 21061
John Theurer Cancer Center at Hackensack UMC
Hackensack, New Jersey, 07601
University of Louisville Health-Brown Cancer Center
Louisville, Kentucky, 40202
Biogenix Molecular
Miami, Florida, 33165
UPMC
Pittsburgh, Pennsylvania, 15219
About this study
Official title: 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)
This study aims to determine safety, tolerability, recommended phase 2 dose (RP2D), and preliminary antitumor activity of 225Ac-SSO110 with standard of care (SoC) therapy in patients with somatostatin receptor 2 expressing (SSTR2+) extensive-stage small cell lung cancer (ES-SCLC) and recurrent locally advanced or metastatic Merkel cell carcinoma (MCC).
- Being tested
- 225Ac-SSO110 + SoC, Atezolizumab, Durvalumab, Avelumab, Pembrolizumab
- Keywords
- actinium, 225Ac, actinium-225, SSO110, SSO120, gallium, 68Ga, gallium-68, radiopharmaceutical, MCC, Merkel Cell carinoma, ES-SCLC, Extensive Stage Small Cell Lung Cancer, radioligand, somatostatin receptor 2, JR11, sstr2-antagonist
- Medical subject headings
- Carcinoma, Merkel Cell
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
225Ac-SSO110 + SoCDrug
Dose Level -2-7
AtezolizumabDrug
Extensive Stage Small Cell Lung Cancer Checkpoint Inhibitor (SoC)
DurvalumabDrug
Extensive Stage Small Cell Lung Cancer Checkpoint Inhibitor (SoC)
AvelumabDrug
Merkel Cell Carcinoma Checkpoint Inhibitor (SoC)
PembrolizumabDrug
Merkel Cell Carcinoma Checkpoint Inhibitor (SoC)
RetifanlimabDrug
Merkel Cell Carcinoma Checkpoint Inhibitor (SoC)
| Study group | Role | What they receive |
|---|---|---|
| 225Ac-SSO110 + SoC | Experimental | Not described Receives: Drug: 225Ac-SSO110 + SoC; Drug: Atezolizumab; Drug: Durvalumab; Drug: Avelumab; Drug: Pembrolizumab; Drug: Retifanlimab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Part 1: Safety, tolerability, RP2D of 225Ac-SSO110 in combination with SoC
Identification of the DLT rate per dose level
Measured: 42 days
Part 2: Safety, tolerability, and preliminary anti-tumor activity of 225Ac-SSO110 in combination with SoC at RP2D
Rate of serious adverse events, adverse events, laboratory parameters, and other safety findings, Preliminary anti-tumor activity of 225Ac-SSO110 as assessed by progression free survival (PFS), disease control rate (DCR), best observed response (BOR), overall response rate (ORR), duration of response (DoR)
Measured: 42 days
Part 1 & 2: Safety and tolerability of 68Ga-SSO120
Rate of serious adverse events, adverse events, laboratory parameters, and other safety findings
Measured: 7 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Apr 2025
- Study start1 Jul 2025
- Primary completion31 Dec 2025
- Study completion31 Dec 2025
Why it stopped: Study terminated due to strategic business decisions.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Small Cell Lung Cancer Extensive StageStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 2 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ariceum Therapeutics GmbH
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06939036
- Sponsor's protocol ID
- SAX101
- Other IDs
- 2024-515041-42-00
- Acronym
- SANTANA-225
- Status last verified
- Apr 2025
- First submitted
- 15 Apr 2025
- Last updated
- 5 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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)
- ClinicalTrials.gov ID
- NCT06939036
- Acronym / sponsor ID
- SANTANA-225 / SAX101
- Keywords
- actinium, 225Ac, actinium-225, SSO110, SSO120, gallium, 68Ga, gallium-68
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Study terminated due to strategic business decisions.
- Enrolment
- 2 participants (actual)
- Lead sponsor
- Ariceum Therapeutics GmbHIndustry (pharma, biotech, devices)
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- 31 Dec 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 22 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to determine safety, tolerability, recommended phase 2 dose (RP2D), and preliminary antitumor activity of 225Ac-SSO110 with standard of care (SoC) therapy in patients with somatostatin receptor 2 expressing (SSTR2+) extensive-stage small cell lung cancer (ES-SCLC) and recurrent locally advanced or metastatic Merkel cell carcinoma (MCC).
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| 225Ac-SSO110 + SoC | Experimental | Drug: 225Ac-SSO110 + SoC, Drug: Atezolizumab, Drug: Durvalumab, Drug: Avelumab, Drug: Pembrolizumab, Drug: Retifanlimab |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- 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 (6 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 225Ac-SSO110 + SoCDose Level -2-7 | Drug | 225Ac-SSO110 + SoC |
| AtezolizumabExtensive Stage Small Cell Lung Cancer Checkpoint Inhibitor (SoC) | Drug | 225Ac-SSO110 + SoC |
| DurvalumabExtensive Stage Small Cell Lung Cancer Checkpoint Inhibitor (SoC) | Drug | 225Ac-SSO110 + SoC |
| AvelumabMerkel Cell Carcinoma Checkpoint Inhibitor (SoC) | Drug | 225Ac-SSO110 + SoC |
| PembrolizumabMerkel Cell Carcinoma Checkpoint Inhibitor (SoC) | Drug | 225Ac-SSO110 + SoC |
| RetifanlimabMerkel Cell Carcinoma Checkpoint Inhibitor (SoC) | Drug | 225Ac-SSO110 + SoC |
Primary outcome
Part 1: Safety, tolerability, RP2D of 225Ac-SSO110 in combination with SoC
Time frame: 42 days
Identification of the DLT rate per dose level
Part 2: Safety, tolerability, and preliminary anti-tumor activity of 225Ac-SSO110 in combination with SoC at RP2D
Time frame: 42 days
Rate of serious adverse events, adverse events, laboratory parameters, and other safety findings, Preliminary anti-tumor activity of 225Ac-SSO110 as assessed by progression free survival (PFS), disease control rate (DCR), best observed response (BOR), overall response rate (ORR), duration of response (DoR)
Part 1 & 2: Safety and tolerability of 68Ga-SSO120
Time frame: 7 days
Rate of serious adverse events, adverse events, laboratory parameters, and other safety findings
Results and safety
The study was stopped early (reason given: Study terminated due to strategic business decisions.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Feb 2026.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
7 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing 225Ac-SSO110 + SoC, Atezolizumab and Durvalumab in people with Small Cell Lung Cancer Extensive Stage and Merkel Cell Carcinoma, run by Ariceum Therapeutics GmbH at 7 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 5 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in United States, Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: Study terminated due to strategic business decisions.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Part 1: Safety, tolerability, RP2D of 225Ac-SSO110 in combination with SoC (time frame: 42 days). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Feb 2026.