Tegoprubart: calcineurin-inhibitor-free islet-transplant immunosuppression
What this study tests
Donor-islet transplant study using tegoprubart as part of an immunosuppressive regimen that avoids calcineurin inhibitors. Eledon reported insulin independence in 12 initial participants in June 2026. This uncontrolled interim report does not establish superior safety, and recipients continue taking anti-rejection medicines.
Editorial review: .
Registry checked: 2026-09-17. Registry’s own update: 2026-08-11.
Most recent recorded citation date: 2026-06-08. 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 18-65 with T1D for at least five years, impaired hypoglycemia awareness and at least three unexplained severe hypoglycemic events in the prior year despite specialist care. HbA1c must be 6.5-9.5% and stimulated C-peptide below 0.3 ng/mL. Extensive transplant and immunosuppression exclusions apply. 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
- The registry lists active, not recruiting, with 70 estimated participants and no posted outcomes. In June 2026 Eledon reported all 12 initial participants insulin-independent, mean latest HbA1c about 5.4%, and median follow-up eight months (maximum 22 months). No severe post-transplant hypoglycemia, rejection or new donor-specific HLA antibodies were reported. Immunosuppression-related adverse events occurred and were generally managed by lowering mycophenolic acid. The company reported no kidney, blood-pressure or neurological toxicity signal; this uncontrolled interim report cannot establish comparative safety or exclude uncommon harms. Participants remain on immunosuppression.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. This record cites company or conference reports. Those sources may describe interim findings; their source type is shown in the source list.
Primary endpoints
- Number of participants who are insulin-independent after first and final transplant at Day 75 and Day 365
The full picture
What is being tested
Tegoprubart blocks CD40L as part of a donor-islet transplant immunosuppression regimen. The protocol also uses other anti-rejection medicines. Its goal is to avoid calcineurin inhibitors such as tacrolimus while protecting the graft; recipients still require immunosuppression.1
The registry describes a single-group Phase 1/2 study with 70 estimated participants. The 12 recipients in the June 2026 company report are an initial cohort, not the completed study.13
Interim findings and limits
Eledon reported insulin independence in all 12 initial recipients and mean latest HbA1c about 5.4%. Median follow-up was eight months, with a maximum of 22 months. No severe post-transplant hypoglycemia or rejection was reported.3
The report also describes immunosuppression-related adverse events generally managed by lowering mycophenolic acid. Absence of a reported kidney, blood-pressure or neurological toxicity signal in this cohort does not establish that the regimen is safer than standard therapy. A controlled comparison and longer follow-up would be needed to judge comparative benefit and harm.3
Sources
- [1]Safety, Tolerability, and Efficacy of Immunomodulation With a Monoclonal Antibody Against CD40L in Combination With Transplanted Islet Cells in Adults With Brittle Type 1 Diabetes · Trial registry — Active, not recruiting; estimated enrollment 70. Protocol combines tegoprubart with other immunosuppressive medicines. No registry outcomes posted as checked September 16, 2026.
ClinicalTrials.gov, NCT06305286.
- [2]
- [3]Eledon announces updated data from investigator-initiated islet transplant trial of tegoprubart in patients with type 1 diabetes at UChicago Medicine · Manufacturer · 2026-06-08
Eledon, June 8, 2026 interim update.
- [4]ADA 2026 recap: days 3 and 4 · Open-source community — Conference recap confirming the UChicago tegoprubart islet-transplant data presented at the ADA 86th Scientific Sessions - all 12 participants off external insulin, no rejection, no kidney toxicity.
- [5]CD40-CD40L Blockade: Update on Novel Investigational Therapeutics for Transplantation · Peer-reviewed study · 2023-01-01 — Review (Singh AK et al., Transplantation, 2023) establishing that CD40-CD40L blockade is costimulation blockade given chronically to transplant recipients - i.e. immunosuppression - and that first-generation anti-CD154 antibodies caused thromboembolic complications severe enough that "further use of unmodified antibodies has stopped", prompting the Fc-modified second-generation agents such as AT-1501.