An interventional study of DaRT seeds in Squamous Cell Carcinoma, Alpha Radiation and Immunocompromised, sponsored by Alpha Tau Medical LTD.. Recruiting at 11 sites in 2 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-15.
Sponsored by Alpha Tau Medical LTD. · Not applicable, Interventional, and Treatment
This is a multi-center clinical study enrolling up to 28 participants. The primary objectives are to determine the objective response rate (ORR) established by the confirmed best overall response (BOR) following intratumoral administration of DaRT - Diffusing Alpha-Emitters Radiation Therapy. Secondary objectives are to:
This study is a multicenter, single arm, open label clinical study to assess the efficacy and safety of intratumoral Alpha DaRT-224 for the treatment of of Immunocompromised Patients with Cutaneous Squamous Cell Carcinoma
The "Diffusing Alpha-emitter Radiation Therapy (DaRT)", based on the intratumoral placement of an encapsulated Radium-224 source (3.7 days half-life), is described in this study. These sources release short-lived alpha-emitting atoms into the tumor microenvironment by recoil. Alpha DaRT sources will be inserted into Cutaneous Squamous Cell Carcinoma tumors and will be removed following 14-21 days.
The The objective response rate (ORR), which is calculated as the percent of patients achieving an objective response. Best overall response using the Response Evaluation Criteria in Solid Tumors guidelines (RECIST v1.1). Best overall response is assessed starting from DaRT removal. Safety will be assessed based on the cumulative incidence rate, severity and outcome of device related Adverse Events (AEs). Classification of AEs will be done according to CTCAE v5.
627 studies on the registry are indexed under Carcinoma, Squamous Cell; 133 are open to participants now.
This study's planned enrollment of 28 is below the median of 45 across 476 interventional studies indexed under Carcinoma, Squamous Cell.
Browse Carcinoma, Squamous Cell studies →Alpha Tau Medical LTD. is the lead sponsor of 29 studies on the registry; 17 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
1. Patients with cutaneous SCC confirmed 2. Histopathological confirmation within 6 months of enrollment provided no tumor treatment occurred between the and enrollment 3. due to any primary or secondary immunodeficiencies according to v 1.1.
4. Patient able and willing to undergo multiple CT scans 5. Tumor size ≤7 cm, at the longest diameter. 6. Single lesion per subject. 7. Targeted lesion must be technically amenable for complete coverage (including margins) by the DaRT seeds. Targets will be deemed technically amenable for complete coverage if there are entry and exit vectors for placement that are not hindered by bone or major vessels or other vital organs (eg. eye) as decided by treating physician and sponsor.
8. Interstitial implant indication validated by multidisciplinary team. 9. Performance Status ≤2. 10. ≥12 months. 11. Subjects male/ female ≥18. 12. Willing and have the ability to provide signed . 13. Patients, male and female, with (including women who are menopausal for less than a year and not surgically sterilized), must practice acceptable effective methods of , such as barrier methods, condom or diaphragm with spermicide or abstinence. Birth control should be continued for 1 year after the DaRT insertion visit.
14. Women with must provide a negative pregnancy test during the screening period and up to V1, prior to the DaRT insertion procedure.
15. Blood tests values:
Exclusion Criteria:
1. Distant or nodal disease (according to the TNM staging system - N+ or M1 patients are excluded).
2. T4 disease 3. extensive PNI 4. Previously untreated cutaneous SCC 5. Mucosal SCC. 6. Inability to fully cover the entire volume with DaRT seeds 7. Inability to place DaRT seeds into tumor due to inaccessibility by presence of bones or major vessels or vital organs 8. Inability or unwillingness to undergo multiple CT scans 9. Patients receiving any of the following within 4 weeks of enrollment:
within 30 days prior to the first dose of trial treatment and while participating in the trial.
10. Longest tumor diameter >7 cm. 11. Tumor with keratoacanthoma histology. 12. Known to any component of treatment. 13. cardiovascular disease e.g., cardiac failure of class III-IV, uncontrolled coronary artery disease, cardiomyopathy, uncontrolled arrhythmia, uncontrolled hypertension, history of myocardial infarction in the last 12 months.
14. Any medical or Psychiatric illness, which in the opinion of the investigator would compromise the patient's ability to tolerate treatment and to adhere to the clinical trial protocol.
15. Serious medical comorbidities that, in the opinion of the investigator, may affect subject compliance and/or interpretation of treatment safety or effectiveness.
16. High probability of protocol non-compliance (in opinion of investigator). 17. Volunteers participating in another interventional study in the past 30 days which might conflict with the endpoints of this study or the evaluation of response or toxicity of DaRT.
18. Has a known additional that is progressing or requires active treatment. Exceptions include basal cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer.
19. Patients do not agree to use adequate (vasectomy or barrier method of birth control) prior to study entry and for 1 year after the DaRT insertion visit.
20. Breastfeeding or pregnant women 21. Tattoos scars, body jewelry (e.g., nose rings) or other identifying marks which cannot be adequately hidden on digital photos or other identifying marks which cannot be adequately hidden on digital photos
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Measurable disease
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
RECIST
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Diffusing Alpha emitters Radiation (DaRT) treatment to be delivered through radioactive sources inserted into malignant cutaneous squamous cell carcinoma of Immunocompromised Patients
Device: DaRT seeds
Diffusing Alpha emitters Radiation (DaRT) treatment to be delivered through radioactive sources inserted into malignant cutaneous squamous cell carcinoma of Immunocompromised Patients
Also known as: DaRT
objective response rate
• Assessment of the objective response rate (ORR) determined by the best overall response using the Response Evaluation Criteria in Solid Tumors (RECIST) (Version 1.1).
Time frame: From Day 14 until 52 weeks
Progression Free Survival
• Determine Progression Free Survival (PFS) up to 12 months after DaRT seed insertion.
Time frame: Up to 12 months after DaRT seed insertion
Overall Survival
• Assess Overall Survival (OS) of patients treated with DaRT up to 12 months.
Time frame: Up to 12 months after DaRT seed insertion
Local control
• Assess Local control up to 12 months after DaRT insertion.
Time frame: Up to 12 months after DaRT seed insertion
Safety Objectives
Assess the safety of the Alpha DaRT treatment, based on the cumulative incidence rate, severity and outcome of device related AEs. Classification of AEs will be done according to CTCAE v5.
Time frame: Up to 12 months following DaRT insertion
Started Jan 2026 (actual). Primary completion is estimated for Dec 2026, 11 months after the start.
Of 53 interventional studies with no phase under Carcinoma, Squamous Cell, half reached primary completion within 81 months of starting (the median), counting those still running; a quarter within 27 and three quarters within 137. This study's planned 11 months is below that.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
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Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.