RGB-5088 autologous CiPSC-derived islet injection in T1D
What this study tests
Phase 1, single-arm study of autologous chemically reprogrammed islet cells in an estimated ten adults with T1D. Eligibility includes people with previous liver or kidney transplants; it does not require every participant to have had a transplant. The separate 2024 published case involved a recipient already taking immunosuppression and cannot establish drug-free graft survival.
Editorial review: .
Registry checked: 2026-09-17. Registry’s own update: 2025-09-15.
Most recent recorded citation date: 2025-08-18. Only explicit date metadata is included; an undated citation may be newer. This does not mean every claim was reviewed on that date.
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 18-60 with type 1 diabetes, stimulated C-peptide under 0.3 ng/mL, and at least one severe hypoglycemic event in the previous 12 months. Inclusion explicitly covers "Type 1 diabetes patients (including those who have received organ transplantation such as liver and kidney)". Type 2 diabetes is excluded. 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. The registry lists the study as recruiting (checked 15 July 2026), single-arm and open-label, with 10 participants at one site; primary completion is estimated December 2027 and study completion December 2031. The published evidence for this platform is a single patient, reported in Cell in September 2024 — insulin-independent from day 75 and still off insulin at one year — who was already on chronic systemic immunosuppression for a previous liver transplant.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: Other regions. 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
- Safety: number of participants with adverse events, from transplantation to one year
- Proportion of participants with HbA1c 6.5% or below and free of severe hypoglycemic events, from day 90 to day 365
The full picture
What is being tested
RGB-5088 is an autologous islet product: the participant's own cells are chemically reprogrammed to pluripotency (CiPSC), differentiated into islets, and transplanted back. The Phase 1 is single-arm, open-label, and enrolls 10 adults aged 18-60 with type 1 diabetes, stimulated C-peptide under 0.3 ng/mL, and at least one severe hypoglycemic event in the previous year, at Tianjin First Center Hospital.1
The eligibility line that matters
The registry's inclusion criteria read: "Type 1 diabetes patients (including those who have received organ transplantation such as liver and kidney)."1
The word “including” permits prior transplant recipients; it does not restrict enrollment to them. Such recipients generally require ongoing anti-rejection treatment. This matters when interpreting the separately published case. In Cell (September 2024), the team reported a woman with T1D who was insulin-independent from day 75 and still off insulin at one year after receiving CiPSC islets.2 She had already received a liver transplant, and the graft went into an immune system that was already being suppressed for it; a peer-reviewed review of the case states that her transplant history was what allowed the team to "leverage existing immunosuppressive therapy."3
What this trial can and cannot show
It can show that islets grown from a person's own chemically reprogrammed cells can be manufactured, engrafted under the rectus sheath, and restore glucose control — which would be a serious advance on the cell-supply problem, because it needs no donor.
The available evidence does not show that those cells survive without immunosuppression. Autologous cells solve allo-rejection; they do nothing about the autoimmunity that destroyed the person's beta cells in the first place, and a perfectly matched graft is exactly what those memory T cells were trained to attack. The available single-patient report therefore cannot establish immunosuppression-free success for this platform.
Sources
- [1]Phase I Clinical Study to Evaluate the Safety and Efficacy of RGB-5088 in Patients With Type 1 Diabetes Mellitus (NCT06731218) · Trial registry · 2025-02-17 — Checked 15 July 2026: recruiting; 10 participants; Tianjin First Center Hospital. Key inclusion criterion includes patients "who have received organ transplantation such as liver and kidney".
Hangzhou Reprogenix Bioscience. "A Single-Center, Single-Arm, Open-Label Phase I Clinical Trial Evaluating the Safety and Efficacy of RGB-5088 Islet Cell Injection in the Treatment of Type 1 Diabetes Mellitus." ClinicalTrials.gov NCT06731218. Checked 15 July 2026: recruiting, 10 participants, Tianjin First Center Hospital, start February 2025, primary completion estimated December 2027.
- [2]Transplantation of chemically induced pluripotent stem-cell-derived islets under abdominal anterior rectus sheath in a type 1 diabetes patient · Peer-reviewed study · 2024-09-25 — Wang S, Du Y, ... Deng H, Shen Z. Cell 187(22):6152-6164. Single-patient one-year result underpinning this trial.
Wang S, Du Y, Zhang B, et al. "Transplantation of chemically induced pluripotent stem-cell-derived islets under abdominal anterior rectus sheath in a type 1 diabetes patient." Cell 187(22):6152-6164 (2024).
- [3]Illuminating the future of diabetes treatment: Autologous CiPSC-derived islets take center stage · Peer-reviewed study · 2025-08-18 — "The first human trial involved a patient with a history of liver transplantation, allowing the team to leverage existing immunosuppressive therapy."
Lou Y. "Illuminating the future of diabetes treatment: Autologous CiPSC-derived islets take center stage." Cell Transplantation (2025).