All 12 Tegoprubart Recipients Off External Insulin Following Islet Implant in Pilot Study

All 12 patients treated with tegoprubart following islet cell transplant for type 1 diabetes (T1D) in Eledon’s investigator-initiated trial have successfully discontinued external insulin, according to new data.1

Presented at the American Diabetes Association (ADA) Scientific Sessions 2026 in New Orleans, Louisiana, by Piotr Witkowski, MD, PhD, associate professor of surgery in the Transplantation Institute and director of the Pancreatic and Islet Transplant Program at the University of Chicago, these data reflect a potentially groundbreaking shift in islet transplantation strategy.1

“These data are very reassuring, and I attribute this to the mechanism of action and the fact that this is provided intravenously on a regular basis,” Witkowski told HCPLive in an exclusive interview. “Our patients did not skip any doses, and they tolerated treatment very well, and because they tolerate it so well, they don’t hesitate to continue. They really appreciate the outcome because they have the clear benefit of not taking insulin again.”

Tegoprubart is a humanized monoclonal antibody that selectively inhibits CD40 ligand (CD40L). This ligand is a co-stimulatory molecule involved in the activation of T cells. Tegoprubart is simultaneously being investigated for xenotransplantation, liver and kidney allograft transplantation, and amyotrophic lateral sclerosis.2

This investigator-initiated pilot study investigated a total of 12 adult patients, all of whom had long-standing T1D. These patients had a median T1D duration of around 33 years and a mean HbA1c of roughly 8% prior to transplantation. Their median body mass index (BMI) was 25.1 kg/m2 with a range of 19.4-29.9 kg/m2. Median daily baseline insulin was 47.5 U, with a range of 35-90 U.3

Prior to transplantation, patients began induction therapy with daily thymoglobulin 1.5 mg/kg and solumedrol 1 mg/kg. The day before transplantation, patients received tegoprubart 20 mg/kg as a 1-hour infusion, with repeat doses occurring on days 0, 1, 3, 7, 14, 21, and 28. These repeat doses were then lengthened to 3-week intervals. Patients also received etanercept 50 mg on day 0, with 25 mg administered on days 3, 7, and 10. Mycophenolic acid 720 mg was administered twice daily following induction.3

Witkowski and colleagues noted rapid improvement in glycemic control after transplantation, with stable islet graft function observed across the cohort. All 12 patients were successfully removed from insulin therapy with no rejection episodes and no de novo donor-specific HLA antibodies. Additionally, among the included patients, roughly 3-5 times more transplanted islets survived and took hold versus those treated with tacrolimus, a common immunosuppressant. The team also recorded no kidney or nerve damage and no high blood pressure, all common side effects of tacrolimus.4

“Seeing these exciting results, Eledon has committed to continue clinical trials and to organize and begin the next steps of clinical testing of tegoprubart,” Witkowski said. “The problem is that all of this transplantation, and the procedure itself, hasn’t been made available to patients. So, in parallel to the trials, we are working on adjusting the regulations, allowing cadaveric islet transplantation, to be reimbursable in the US.”

Editors’ Note: Witkowski reports no relevant disclosures.

References

1. Witkowski P. Anti-CD40L to Induce Graft Survival and Function in Islet Allotransplantation. Presented at the American Diabetes Association (ADA) Scientific Sessions 2026, New Orleans, LA. June 5-8, 2026.

2. Brooks A. Tegoprubart Enables Insulin Independence in Type 1 Diabetes Islet Transplantation Study. HCPLive. March 16, 2026. Accessed March 24, 2026. https://www.hcplive.com/view/tegoprubart-enables-insulin-independence-in-type-1-diabetes-islet-transplant-study

3. Williams L. Tegoprubart islet transplantation achieves insulin independence in type 1 diabetes. Springer Medicine. June 19, 2026. Accessed July 10, 2026. https://www.springermedicine.com/type-1-diabetes/ada-2026/tegoprubart-islet-transplantation-insulin-independence-t1d/52747112

4. Herrick B. All 12 Clinical Trial Participants Off External Insulin: New Data on Tegoprubart Continues to Impress. Breakthrough T1D. June 7, 2026. Accessed July 10, 2026. https://www.breakthrought1d.org/news-and-updates/tegoprubart-islet-transplant-all-participants-off-external-insulin/