Islet transplantation with recipient Tregs or donor bone marrow
What this study tests
Trial testing donor-islet transplantation combined with recipient regulatory T cells or deceased-donor vertebral bone marrow therapy to improve immune tolerance. As of July 2026 it is listed on ClinicalTrials.gov as enrolling by invitation only — it is no longer open to unsolicited applicants.
Editorial review: .
Registry checked: 2026-09-17. Registry’s own update: 2026-06-08.
Source dates appear in the references where available; this record has no dated citation metadata.
Trial status, labels and access can change between reviews. How we review the evidence · How to read the evidence
Evidence at a glance
- Who can enter the study?
- Adults aged 18-70. Enrolling by invitation only as of July 2026, so participants are selected by the study team rather than through open recruitment. See registry for full inclusion/exclusion criteria. Registered eligibility ↗Enrollment criteria describe who may enter. They do not establish who was analyzed or the denominator for a reported result.
- Reported benefit and results
- No results posted yet. The registry lists a target enrolment of 24 and primary completion in December 2030.Read the result sources and their limitations →
- Important harms
- Read the reported results, safety discussion and original sources. A separate harms summary is not available; this does not establish safety.
- Research access and approval
- Study regions: United States. A trial listing does not establish product approval or current recruitment at a particular site. Check the study’s current entry requirements.
- What remains uncertain?
- Read the full discussion and original sources for study limitations. Planned endpoints and completion dates are not results.
Research status alone does not establish approval, clinical benefit or local availability.
Primary endpoints
- Occurrence of Grade 3 to 5 cytokine release syndrome / acute infusion reaction after Treg administration infusion reaction after Treg administration
- Occurrence of grade 4 or greater adverse events of islet transplantation
- Number of patients who receive Treg infusions (Arm1) or Donor Derived Vertebral Bone Marrow (Arm2) and islet transplantation (feasibility)
The full picture
What is being tested and why it matters
Transplanting insulin-making islet cells from a donor can restore glucose control in type 1 diabetes, but the immune system attacks the new cells — so recipients typically need ongoing anti-rejection drugs whose side effects usually outweigh the benefit for all but the most severe cases. This Phase 1 study at Stanford asks whether adding either the recipient's own regulatory T cells or bone marrow from the islet donor improves glucose control after the transplant.1
It has two arms. One infuses the recipient's own regulatory T cells (Tregs) — the immune cells whose job is to hold other immune cells back — collected by apheresis, expanded in the lab, and given back alongside the islets. The other infuses vertebral bone marrow from the same deceased donor as the islets, an approach intended to nudge the recipient's immune system toward accepting donor tissue.1
Where it stands
This is an early safety and feasibility study, not an efficacy trial. The main endpoints are whether severe cytokine release syndrome or infusion reactions occur after the Treg infusion, whether grade 4 or worse adverse events follow the islet transplant, and simply whether the combined procedure can be delivered at all. Target enrolment is 24 adults aged 18-70; the trial started in April 2024 and primary completion is not expected until December 2030. No results have been posted.1
Can you join?
Not by applying. As of July 2026 ClinicalTrials.gov lists this study as enrolling by invitation — participants are identified and approached by the study team, and it is not open to unsolicited applicants.1 If you are interested in islet transplantation, the registry entry is still worth reading for context, but this particular study is not one you can put your name forward for.
Sources
- [1]NCT05973734: Islet transplantation with recipient Tregs or donor bone marrow · Trial registry — Live-checked 27 August 2026: status ENROLLING_BY_INVITATION, enrolment 24, ages 18-70, start April 2024, primary completion December 2030.
ClinicalTrials.gov. Clinical Islet Transplantation With Apheresis, Isolation and Reintroduction of Recipient Regulatory T Cells (NCT05973734).