RecruitingPhase 2NCT06552169

REgulatory T Cell Therapy to Achieve Immunosuppression REduction

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

Sponsor

Singulera Therapeutics Inc.

Enrollment

34 participants

Start Date

Jun 13, 2025

Study Type

INTERVENTIONAL

Conditions

Kidney Transplantation

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

Eligibility

Min Age: 18 YearsMax Age: 65 Years

Plain Language Summary

Simplified for easier understanding

This trial is testing whether infusing a patient's own regulatory T cells (Tregs) — specialized immune cells that prevent the immune system from overreacting — can allow kidney transplant recipients to safely reduce the amount of anti-rejection medication they take long-term. Taking fewer immunosuppressants could reduce serious side effects like infections and cancer. **You may be eligible if...** - You are 18–65 years old and receiving a kidney from a living donor - Your donor is also 18–65 years old and blood-type compatible - You have never had an organ transplant before - Your BMI is between 16 and 38 kg/m² **You may NOT be eligible if...** - You have had a previous organ transplant - You are pregnant or breastfeeding - You have significant cardiovascular disease, poorly controlled diabetes, or active cancer in the last 3 years - You have HIV, active hepatitis B or C - You have a high level of pre-existing antibodies against donor tissue (high PRA) Talk to your doctor to see if this trial is right for you.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

DRUGArm 1: SOC (mTOR + CNI)

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

BIOLOGICALArm 2A: TRACT/MONO mTOR

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.

BIOLOGICALArm 2B: TRACT/MONO CNI