A Phase 1/2 interventional study of Allogeneic thyTreg 5.000.000 and Allogeneic thyTreg 10.000.000 in Systemic Inflammatory Response Syndrome, sponsored by Hospital General Universitario Gregorio Marañon. Recruiting at 1 site in Spain. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-09-18.
Sponsored by Hospital General Universitario Gregorio Marañon · Phase 1/2, Interventional, and Treatment
The investigators developed a GMP protocol to isolate Treg cells from thymic tissue (thyTreg). The thyTreg cells are being evaluated in a Phase I/II clinical trial to evaluate the safety and efficacy of the adoptive transfer of autologous thyTreg to prevent rejection in heart transplant children (NCT04924491), with preliminary results indicating the feasibility and safety of the therapy.
In addition, thyTreg cells have shown low immunogenicity in the pre-clinical setting, indicating that allogeneic use of these thyTreg cells (allo-thyTreg) would have a low risk of adverse effects. These thyTreg cells could inhibit an excessive inflammation in SARS-CoV-2 infection, or ameliorate the immunological affection underlying Acute respiratory distress syndrome, improving life-threatening manifestations, restoring immune balance, and protecting affected tissues.
This clinical trial is an open-label Sequential Parallel Group Phase I/II study to evaluate the safety and efficacy of allogeneic thymus derived Tregs (thyTreg) (thyTreg) in controlling the immune dysregulation associated with SARS-CoV-2 infection and/or Acute Respiratory Distress Syndrome.
The immune system is the body's defense system against pathogens and other harmful agents, but it is also responsible for transplant rejection or autoimmune diseases. Another scenario of disproportionate immune response is the Immune Hyperactivation, an exaggerated systemic inflammatory response such as that caused by respiratory infections like COVID-19, a major cause of acute respiratory distress syndrome (ARDS) in critically ill patients.
The standard treatment to prevent these immune responses is the use of immunosuppressive and immunomodulatory therapy, which produces a pleotropic inhibition on the immune system and have a high cost. However, a widespread feeling among the scientific community is that only re-educating immune system to promote immune tolerance will decline the harmful immune responses without prejudice to the functional integrity of the immune system.
In the context of severe COVID-19 and ARDS, it has been shown that an alteration in the frequency and functionality of Tregs. In addition, it has been described that the increased oxygen therapy requirements is not due to the viral effect, but to the triggered immune hyperinflammation that can lead to multi-organ failure and death. Therefore, although the adoptive transfer of Treg is a promising cell therapy for the treatment of this type of disease, the characteristics of the patients make it unfeasible to obtain enough Treg from the patient to produce a therapeutic dose and, if achieved, the quality of these cells does not allow a prolonged therapeutic effect to be obtained over time.
Tregs are a subset of CD4+ T cells with suppressive function that maintain the immune system balance. Adoptive Treg cell therapy has shown efficacy in a variety of immune-mediated diseases in preclinical and clinical studies. To date, most of the clinical trials employing Treg cell therapy have been limited due to a small Treg numbers obtained (Treg cells represent less than 10% of CD4+ T cells) and the low quality of infused Treg (in terms of purity, survival, and suppressor capacity).
The investigators have developed an innovative Treg manufacturing protocol, that overcome the existing difficulties by employing a new source of cells, which is the thymic tissue routinely removed and discarded in paediatric cardiac surgeries. The protocol allows to produce massive amounts of thymus derived Treg cells (thyTreg), with improved survival, high suppressive capacity and suitable for therapeutic use.
The study will evaluate escalating doses of thyTreg administrated as a single IV dose. The study will include up to 2 cohorts of 4 to 8 subjects per each arm (control group and thyTreg group) followed for a total of 24 months. All subjects will receive standard of care treatment for COVID-19 or ARDS, including dexamethasone and other approved therapies from institutional guidelines.
195 studies on the registry are indexed under Systemic Inflammatory Response Syndrome; 24 are open to participants now.
This study's planned enrollment of 24 is below the median of 76 across 98 interventional studies indexed under Systemic Inflammatory Response Syndrome.
Browse Systemic Inflammatory Response Syndrome studies →Hospital General Universitario Gregorio Marañon is the lead sponsor of 60 studies on the registry; 7 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.
Patient with clinical, radiological, gasometric and immunological criteria defined as:
Exclusion Criteria:
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
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.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (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.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
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.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Allogeneic thyTreg 5.000.000
Biological: Allogeneic thyTreg 5.000.000
Standard of care
Allogeneic thyTreg 10.000.000
Biological: Allogeneic thyTreg 10.000.000
Standard of care
Treg lymphocytic cells, differentiated, allogeneic, of thymic tissue, expanded and stimulated with Interleukin (IL-) 2 (thyTreg)
Also known as: Allogeneic thyTreg cells
Treg lymphocytic cells, differentiated, allogeneic, of thymic tissue, expanded and stimulated with Interleukin (IL-) 2 (thyTreg)
Also known as: Allogeneic thyTreg cells
1. Incidence of infusion-related adverse events (safety) by type, frequency, severity, and causality
Time frame: 24 months
Length of intensive care unit stay
Time frame: 24 months
Oxygenation improvement as assessed using PaO2/FiO2 and/or SaO2/FiO2
Time frame: 24 months
Change in clinical status as assessed using Sequential Organ Failure Assessment Score
Time frame: 24 months
Change in clinical status as assessed using Acute Physiology and Chronic Health disease Classification System (APACHE) III
Time frame: 24 months
Change in clinical status as assessed using Barthel score
Time frame: 24 months
Change in myocardial function as measured by mitral and tricuspid regurgitation using doppler echocardiography
Time frame: 24 months
Change in myocardial function as measured by mitral and tissue mitral doppler using doppler echocardiography
Time frame: 24 months
Change in myocardial function as measured by tricuspid and tissue tricuspid using doppler echocardiography
Time frame: 24 months
Change in SARS-CoV-2 positivity or etiology of ARDS assessed using diagnostics test
Time frame: 24 months
Change From Baseline in ferritin parameter
Time frame: 24 months
Change From Baseline in interleukin 6 (IL-6)
Time frame: 24 months
Change From Baseline in C-Reactive Protein (PCR)
Time frame: 24 months
Change From Baseline in Treg cells number in peripheral blood
Time frame: 24 months
Number of T cells, B cells, NK cells, monocytes, dendritic cells, and granulocytes in peripheral blood
Time frame: 24 months
Change From Baseline in cytokines levels of interferon gamma, tumor necrosis factor alpha and interleukins (IL-6 and IL-10).
Time frame: 24 months
Overall patient survival rate at 24 months
Time frame: 24 months
Started Jun 2023 (actual). Primary completion is estimated for Dec 2027, 54 months after the start.
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Systemic Inflammatory Response Syndrome →
Hospital General Universitario Gregorio Marañon