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Kidney TransplantationPhase 2RETIRENCT06552169

REgulatory T Cell Therapy to Achieve Immunosuppression REduction

A Phase 2 study testing Arm 1: SOC (mTOR + CNI), Arm 2A: TRACT/MONO mTOR and Arm 2B: TRACT/MONO CNI in people with Kidney Transplantation, run by Singulera Therapeutics Inc. at 7 sites in 2 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The goal of this multi-national, multi-center, open-label, randomized Phase 2 trial is to determine the safety and efficacy of administering expanded regulatory T cells (TRK-001) to prevent allograft rejection in living donor renal transplant recipients. Read more about this study

Who is it for?
Ages 18 to 65 years
Conditions the study is for
Kidney Transplantation
What is being tested?
Arm 1: SOC (mTOR + CNI), Arm 2A: TRACT/MONO mTOR and Arm 2B: TRACT/MONO CNI
Type of treatment
Injection or infusion
Could I receive a placebo?
No, everyone receives an active treatment
How many people
34 participants
Where
7 sitesin 2 countries
Study dates
13 Jun 2025to Dec 2031
Phase
Phase 2
Are there results?
Not yet: the study is under way

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 to 65 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • All inclusion criteria must be met prior to randomization.
  • Males or females aged 18-65 years as of the date of informed consent who will undergo a single organ, living donor kidney transplant.
  • Donor aged 18-65 years as of the date of organ donation. A certain degree of HLA matching between the donor and the recipient is not required.
  • Blood type compatibility between recipient and donor must be established as follows.
  • Recipient A to Donor A or O; Recipient B to Donor B or O; Recipient AB to Donor A, B, AB, or O; Recipient O to Donor O.
  • No prior organ transplant of any kind.
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  • Women of childbearing potential must agree to use a medically acceptable method of contraception throughout the trial. A list of the medically acceptable methods of contraception are listed in the informed consent document.
  • Male patients must agree to use birth control following the initiation of standard-of-care immunosuppression and for a minimum of 6 months following kidney transplant.
  • Subjects (recipients) must be able to understand the consent form and give written informed consent prior to any trial procedure.
  • If donor informed consent is required by IRB/IEC, donor must be able to understand the consent form and give written informed consent prior to any trial procedure. Note: Donor informed consent is required for donors participating in the research assay collections.

Who cannot join

  • The following exclusion criteria must be determined prior to randomization per SOC pre-transplant evaluation.
  • Known sensitivity or contraindication to thymoglobulin, everolimus, sirolimus, or tacrolimus or other immunosuppression medication prescribed.
  • Subjects with a positive crossmatch by virtual cross matching or complement-dependent cytotoxicity (CDC) cross matching or flow cytometry cross matching (FCXM).
  • Subjects with PRA >80% per SOC pre-transplant assessment. PRA must be repeated prior to transplant if patient receives a blood product transfusion after the initial assessment.
  • Subjects with current or historic donor specific antibodies.
  • Body Mass Index (BMI) of < 16 kg/m2 or > 38 kg/m2 per SOC pre-transplant evaluation.
Show all 38Show fewer
  • Subjects who are pregnant or nursing mothers.
  • Subjects whose life expectancy is severely limited by diseases other than renal disease, per judgement of an investigator.
  • Ongoing active drug or alcohol substance abuse, per judgement of an investigator.
  • Major ongoing psychiatric illness or recent history of noncompliance with current medical therapy, per judgement of an investigator.
  • Significant cardiovascular disease (e.g.):
  • Significant non-correctable coronary artery disease, per judgement of an investigator
  • Ejection fraction below 30% per SOC echocardiogram if an echocardiogram is performed for an individual subject as part of their pre-transplant evaluation
  • History of recent (< 12 months) myocardial infarction at time of informed consent
  • History of recent (within 3 months) vascular intervention(s) for coronary artery disease at the time of informed consent
  • Documented arrhythmias that require a pacemaker or medical therapy for control.
  • Subjects who require use of chronic anticoagulation medications. Use of anti-platelet medications will be allowed in absence of a documented arrhythmia.
  • Malignancy within 3 years, excluding non-melanoma skin cancers such as basal cell carcinoma and squamous cell carcinoma.
  • Serologic evidence of active infection with HCV, HIV or HBV per SOC pre-transplant evaluation. Historical data within three months of transplant are acceptable.
  • Subjects with a total white blood cell count < 4,000/mm3; platelet count < 50,000/mm3; triglyceride > 400 mg/dL; total cholesterol > 300 mg/dL, prothrombin time <8.4 seconds or >15.7 seconds, activated partial thromboplastin time <21.6 or > 42.3 seconds, fibrinogen <177 mg/dL or >598 mg/dL, and INR <0.64 or >1.4.
  • Subjects with underlying renal disease etiologies with high risk of disease recurrence such as primary focal segmental glomerulosclerosis and others per investigator discretion.
  • Subjects requiring the use of chronic immunosuppressive medication to control an underlying renal disease, or a disease with extrarenal manifestations (i.e., inflammatory bowel disease). Subjects requiring chronic or intermittent use of inhaled corticosteroids for respiratory conditions will be allowed.
  • Diabetic subjects with an HbA1c of >8%.
  • The following exclusion criteria must be determined prior to transplant per SOC pre-transplant evaluation.
  • Subjects with an active infection considered clinically significant by an investigator that has not resolved prior to transplant.
  • Subjects with an active infection considered clinically significant by an investigator that has not resolved prior to leukapheresis.
  • Subjects with PRA >80%, if repeated after SOC pre-transplant assessment. (PRA must be repeated prior to leukapheresis if patient receives a blood product transfusion after the initial assessment).
  • Subjects who are pregnant or nursing.
  • Subjects who received an investigational drug within 30 days prior to leukapheresis.
  • Subjects who received anti-T cell therapy within 30 days prior to leukapheresis.
  • Subjects who do not meet pre-leukapheresis clearance parameters per institutional practices or per investigator discretion.
  • Exclusion Criteria Prior to TRACT Cellular Product Infusion (Arm 2)
  • Subjects with an active infection considered clinically significant by the investigator that has not resolved prior to planned Treg infusion.
  • Subjects with a new, clinically significant medical condition that, per investigator opinion, would impact the ability to safely administer TRK-001.
  • Subjects who experience a rejection episode of the kidney graft prior to the planned Treg infusion.
  • Subjects who are pregnant or nursing. Women who are of childbearing potential must have a negative urine or serum pregnancy test before infusion of TRK-001.
  • Subjects who received an investigational drug within 30 days prior to infusion.
  • Subjects who received anti-T cell therapy within 30 days prior to infusion.

Trial locations and contacts

7 sites in 2 countries. Contact the study team or a site near you to ask about taking part.

Susan B Murray contact

+1-312-219-4670

susan.murray@singulera-tx.com

Erwin Teng contact

+886-931-392700

erwin.teng@twbio-thera.com

7 sites in 2 countries

Taiwan4 sites, 4 recruiting

  • Taichung Veterans General Hospital

    Taichung, 407219

    Cheng-Hsu Chen, MD, PhD

    Recruiting

  • National Cheng Kung University Hospital

    Tainan, 704

    Shen-Shin Chang, MD

    Not yet recruiting

  • National Taiwan University Hospital

    Taipei, 100229

    Chih-Yuan Lee, MD, PhD

    Recruiting

  • Chang Gung Medical Foundation Hospital

    Taoyuan, 333

    Huang-Yu Yang, MD, PhD

    Recruiting

Other trials in Taiwan

United States3 sites, 3 recruiting

  • Northwestern Memorial Hospital

    Chicago, Illinois, 60611

    M. Javeed Ansari, MD, MRCP

    Recruiting

  • Mayo Clinic in Arizona

    Phoenix, Arizona, 85054

    Girish Mour, M.B.B.S.

    Recruiting

  • Mayo Clinic in Minnesota

    Rochester, Minnesota, 55905

    Nikolaos Skartsis, M.D., Ph.D.

    Recruiting

Other trials in United States

About this study

Official title: The RETIRE Trial: A Randomized Phase 2 Trial of Adoptive Therapy With Treg Adoptive Cell Transfer (TRACT) To Prevent Rejection in Living Donor Kidney Transplant Recipients

The goal of this multi-national, multi-center, open-label, randomized Phase 2 trial is to determine the safety and efficacy of administering expanded regulatory T cells (TRK-001) to prevent allograft rejection in living donor renal transplant recipients.

Enrolled subjects will be randomized to one of 2 study arms:

Read more

Arm 1 subjects will receive standard of care immunosuppression

Arm 2 subjects will receive initial standard of care (SOC) immunosuppression and a single infusion of TRK-001. Three months after the transplant, Arm 2 subjects may be able to begin reducing their immunosuppression medication to a 1-drug regimen.

The primary outcome measures of trial are to evaluate several components indicating immunologic problems with the transplanted organ at 1-year post-transplant and to evaluate the ability for the study subjects given TRK-001 to wean to a 1-drug immunosuppression regimen.

All enrolled subjects will be followed for 5 years post-transplant.

Read the detailed description

This is a prospective, multi-national, multi-center, open-label, randomized Phase 2 trial to determine the safety and efficacy of administering autologous expanded regulatory T cells (TRK-001) to prevent allograft rejection in living donor renal transplant recipients.

All subjects will be followed for 5 years post-transplant, comprising of a 2-year post-transplant follow-up period and a 3-year surveillance period.

Subjects with end-stage renal disease undergoing a living donor kidney transplant will be enrolled into the trial as follows:

Arm 1 SOC: Standard of care immunosuppression (N=14)

Arm 2 TRACT/MONO: TRK-001 and initial SOC immunosuppression weaned to monotherapy (N=20)

At Month 3 post-transplant, Arm 2 subjects will be further randomized prior to weaning to either mTOR or CNI monotherapy as follows:

Arm 2A: TRACT/MONO mTOR (N=10) or Arm 2B: TRACT/MONO CNI (N=10)

Being tested
Arm 1: SOC (mTOR + CNI), Arm 2A: TRACT/MONO mTOR, Arm 2B: TRACT/MONO CNI
Keywords
Regulatory T cells, Treg adoptive cell transfer (TRACT), Kidney Transplantation, Graft Rejection, Autologous cell therapy, End stage renal disease, Prevention of organ transplant rejection, Tregs, Reduced immunosuppression
Medical subject headings
Kidney Failure, Chronic

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Arm 1: SOC (mTOR + CNI)Drug

    Also called sirolimus or everolimus + tacrolimus

    Subjects randomized to Arm 1 will remain on standard dual-immunosuppression therapy (CNI and mTOR) throughout the trial.

  • Arm 2A: TRACT/MONO mTORBiological

    Also called TRK-001 + sirolimus or everolimus

    All subjects will be prescribed standard of care (SOC) immunosuppressive agents. Subjects randomized to Arm 2 will be maintained on the prescribed SOC immunosuppression (tacrolimus + sirolimus or everolimus) and have a single intravenous infusion of autologous, expanded Tregs (TRK-001) at Day +53 to +67 post-transplant. At Month 3 post-transplant, Arm 2 subjects will be further randomized to receive either:

    • Arm 2A: mTOR monotherapy or
    • Arm 2B: CNI monotherapy.

    These subjects will transition to the assigned 1-drug immunosuppression regimen beginning at Month 3 post-transplant. Weaning must be completed by 12 months post-transplant.

    Subjects in Arm 2 will undergo leukapheresis to collect peripheral blood mononuclear cells required for the cellular product.

  • Arm 2B: TRACT/MONO CNIBiological

    Also called TRK-001 + tacrolimus

    All subjects will be prescribed standard of care (SOC) immunosuppressive agents. Subjects randomized to Arm 2 will be maintained on the prescribed SOC immunosuppression (tacrolimus + sirolimus or everolimus) and have a single intravenous infusion of autologous, expanded Tregs (TRK-001) at Day +53 to +67 post-transplant. At Month 3 post-transplant, Arm 2 subjects will be further randomized to receive either:

    • Arm 2A: mTOR monotherapy or
    • Arm 2B: CNI monotherapy.

    These subjects will transition to the assigned 1-drug immunosuppression regimen beginning at Month 3 post-transplant. Weaning must be completed by 12 months post-transplant.

    Subjects in Arm 2 will undergo leukapheresis to collect peripheral blood mononuclear cells required for the cellular product.

Study groups in NCT06552169
Study groupRoleWhat they receive
Arm 1: Standard of Care (SOC)Active comparatorArm 1: SOC-Subjects randomized to Arm 1 will be followed on the prescribed 2-drug SOC immunosuppression throughout the trial. The study allowed SOC regimen is tacrolimus + sirolimus or everolimus.
Receives: Drug: Arm 1: SOC (mTOR + CNI)
Arm 2A: TRACT/MONO mTORExperimentalArm 2: TRACT/MONO- At the beginning of the trial, subjects randomized to Arm 2 will be maintained on the prescribed 2-drug SOC immunosuppression and have a single infusion of expanded Tregs (TRK-001) at Day +53 to +67 following living donor kidney transplantation. At Month 3 post-transplant, Arm 2 TRACT/MONO subjects will be further randomized to either Arm 2A: TRACT/MONO mTOR or Arm 2B: TRACT/MONO CNI. Subjects randomized to Arm 2A: TRACT/MONO mTOR who have a normal biopsy and no de novo donor specific antibodies at Month 3 will begin weaning of tacrolimus and will remain on a 1-drug regimen with either everolimus or sirolimus until the end of the trial.
Receives: Biological: Arm 2A: TRACT/MONO mTOR
Arm 2B: TRACT/MONO CNIExperimentalArm 2: TRACT/MONO- At the beginning of the trial, subjects randomized to Arm 2 will be maintained on the prescribed 2-drug SOC immunosuppression and have a single infusion of expanded Tregs (TRK-001) at Day +53 to +67 following living donor kidney transplantation. At Month 3 post-transplant, Arm 2 TRACT/MONO subjects will be further randomized to either Arm 2A: TRACT/MONO mTOR or Arm 2B: TRACT/MONO CNI. Subjects randomized to Arm 2B: TRACT/MONO CNI who have a normal biopsy and no de novo donor specific antibodies at Month 3 will begin weaning of the mTOR medication and will remain on a 1-drug regimen with low dose tacrolimus until the end of the trial.
Receives: Biological: Arm 2B: TRACT/MONO CNI

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Development of de novo donor-specific antibodies

    A primary outcome measure for this study is to evaluate a composite endpoint of immunologic events against the allograft, where a failure is defined as patient-experienced immunologic events including the development of de novo donor-specific antibodies.

    Measured: Month 12 Post-transplant

  2. Biopsy-proven acute rejection

    A primary outcome measure for this study is to evaluate a composite endpoint of immunologic events against the allograft, where a failure is defined as patient-experienced immunologic events including biopsy-proven acute rejection.

    Measured: Month 12 Post-transplant

  3. Biopsy-proven subclinical rejection

    A primary outcome measure for this study is to evaluate a composite endpoint of immunologic events against the allograft, where a failure is defined as patient-experienced immunologic events including biopsy-proven subclinical rejection.

    Measured: Month 12 Post-transplant

  4. Development of significant (2+) interstitial fibrosis/tubular atrophy

    A primary outcome measure for this study is to evaluate a composite endpoint of immunologic events against the allograft, where a failure is defined as patient-experienced immunologic events including the development of significant (2+) interstitial fibrosis/tubular atrophy.

    Measured: Month 12 Post-transplant

  5. Successful taper to monotherapy (Arm 2)

    A primary outcome measure for this study is to evaluate the ability for Arm 2 subjects to successfully taper to monotherapy by one-year post-transplant.

    Measured: Month 12 Post-transplant

Secondary outcomes (15)

  1. Successful maintenance of monotherapy (Arm 2)

    A secondary outcome measure for this study is to evaluate the ability for Arm 2 subjects to successfully maintain monotherapy through two-years post-transplant.

    Measured: Month 24 Post-transplant

  2. Development of de novo donor-specific antibodies

    A secondary outcome measure for this study is to evaluate overall and composite component-specific time to immunologic failure where a failure is defined as patient-experienced immunologic events including the development of de novo donor-specific antibodies.

    Measured: To Month 60 Post-transplant

  3. Biopsy-proven acute rejection

    A secondary outcome measure for this study is to evaluate overall and composite component-specific time to immunologic failure where a failure is defined as patient-experienced immunologic events including biopsy-proven acute rejection.

    Measured: To Month 60 Post-transplant

  4. Biopsy-proven subclinical rejection

    A secondary outcome measure for this study is to evaluate overall and composite component-specific time to immunologic failure where a failure is defined as patient-experienced immunologic events including biopsy-proven subclinical rejection.

    Measured: To Month 60 Post-transplant

  5. Development of significant (2+) interstitial fibrosis/tubular atrophy

    A secondary outcome measure for this study is to evaluate overall and composite component-specific time to immunologic failure where a failure is defined as patient-experienced immunologic events including the development of significant (2+) interstitial fibrosis/tubular atrophy.

    Measured: To Month 60 Post-transplant

  6. Graft loss

    A secondary outcome measure for the study is the incidence and timing of clinical outcomes, including graft loss. Graft loss is defined as 56 consecutive days of hemodialysis or re-transplantation.

    Measured: To Month 60 Post-transplant

  7. Malignancy

    A secondary outcome measure for the study is the incidence and timing of clinical outcomes, including malignancy.

    Measured: To Month 60 Post-transplant

  8. Infections

    A secondary outcome measure for the study is the incidence and timing of clinical outcomes, including infections (bacterial, viral, fungal).

    Measured: To Month 60 Post-transplant

  9. Metabolic anomalies

    A secondary outcome measure for the study is the incidence and timing of clinical outcomes, including metabolic anomalies (e.g., diabetes mellitus, metabolic syndrome, hyperthyroidism, hypothyroidism).

    Measured: To Month 60 Post-transplant

  10. Biopsy-proven acute rejection

    A secondary outcome measure for the study is to evaluate the incidence and timing of a composite endpoint of immunologic events against the allograft, where a failure is defined as patient-experienced immunologic event, including biopsy-proven acute rejection.

    Measured: To Month 24 Post-transplant

  11. Graft loss

    A secondary outcome measure for the study is to evaluate the incidence and timing of a composite endpoint of immunologic events against the allograft, where a failure is defined as patient-experienced immunologic event, including graft loss. Graft loss is defined as 56 consecutive days of hemodialysis or re-transplantation.

    Measured: To Month 24 Post-transplant

  12. Death (all cause)

    A secondary outcome measure for the study is to evaluate the incidence and timing of a composite endpoint of immunologic events against the allograft, where a failure is defined as patient- experienced immunologic event, including all cause death.

    Measured: To Month 24 Post-transplant

  13. Quality of Life Measures by using KDQOL-SF

    The KDQOL-SF is an assessment tool designed for individuals with kidney disease to measure the impact of kidney disease and its treatment on a patient's quality of life.

    Measured: To Month 60 Post-transplant

  14. Quality of Life Measures by using EQ-5D-5L

    The EQ-5D-5L is a standardized measurement tool to evaluate health status. The questionnaire has a descriptive section and a visual analog scale.

    Measured: To Month 60 Post-transplant

  15. Safety- Adverse Events

    Incidence of adverse events

    Measured: To Month 60 Post-transplant

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted13 Aug 2024
  2. Study start13 Jun 2025
  3. Primary completionDec 2027 (estimated)
  4. Study completionDec 2031 (estimated)

Resources

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 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
34 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06552169
Sponsor's protocol ID
TRACT-KD-101
Acronym
RETIRE
Status last verified
Apr 2026
First submitted
26 Jul 2024
Last updated
27 Apr 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Undecided

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Arm 1: SOC (mTOR + CNI), Arm 2A: TRACT/MONO mTOR and Arm 2B: TRACT/MONO CNI in people with Kidney Transplantation, run by Singulera Therapeutics Inc. 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 10 inclusion and 38 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: looking for participants now, as of the sponsor's last update on 27 Apr 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 Taiwan, United States. 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 phase mean?

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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Susan B Murray (+1-312-219-4670, susan.murray@singulera-tx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Development of de novo donor-specific antibodies (time frame: Month 12 Post-transplant). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06552169.

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 27 Apr 2026.

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