A new clinical trial has marked a significant step towards a functional cure for type 1 diabetes (T1D), providing hope amidst a global health crisis. 

Pumping healthy islet cells from a donor pancreas into the recipient's liver, combined with an experimental anti-rejection drug, Tegoprubart, saw five T1D patients freed from insulin jabs previously needed daily to regulate their blood sugar levels. 

The findings were presented at the 2025 Congress of the Cell Transplant and Regenerative Medicine Society in Tokyo by Dr. Camillo Ricordi, who said, "These results validate decades of work to make islet transplantation safer and more widely accessible."

The success of the trial comes as global concern over diabetes escalates. The debilitating disease now affects 589 million adults globally, a significant rise from 171 million in the year 2000, according to The International Diabetes Federation. "The urgency is now," Dr. Ricordi said, noting that diabetes-related healthcare costs have topped $1 trillion and are still surging. Last year, the disease was responsible for 3.4 million deaths, or one death every nine seconds, data shows.

New drug eliminates the need for daily Insulin and toxic drugs

The life-changing trial, conducted by Piotr Witkowski, MD, Ph.D., at the University of Chicago Transplant Institute, in collaboration with the Diabetes Research Institute at the University of Miami Miller School of Medicine, tested Tegoprubart, a novel anti-rejection monoclonal antibody.

All participants were classified as having "brittle" T1D – a condition marked by severely unstable blood sugars that are poorly controlled by standard insulin, leading to frequent, dangerous episodes of high and low blood sugar. Following the hour-long islet cell infusion, all five patients stopped depending on insulin injections within weeks. The earliest treated patients have remained insulin-free for 14 months.

A key aspect of the breakthrough is the drug's ability to prevent rejection without the severe side effects associated with the traditional immunosuppressant, tacrolimus, which has been known to cause graft harm and organ toxicity.

"This is the first time we've been able to demonstrate that islet transplantation can provide lasting insulin independence without tacrolimus," said Dr. Witkowski. "Tegoprubart has shown excellent safety and tolerability."

Dr. Ricordi added that these results validate decades of work aimed at making islet transplantation a safer and more widely available biological cure for T1D.

A patient's life transformed

The first patient to undergo the procedure with the new protocol was 30-year-old Marlaina Goedel. After struggling with T1D for 25 years, a severe blood sugar drop that left her unconscious prompted her to seek help through the trial. Following her July 2025 transplant, her insulin needs steadily dropped. Within four weeks, she was instructed to stop taking insulin entirely.

"I finally have freedom from the nightly fear that I might not wake up the next morning," Goedel said, describing the end of constant monitoring and injections. Dr. Ricordi and his colleague, Dr. Norma Kenyon, who pioneered the anti-rejection strategy, later met with Goedel, marking a high point in their research.

Tegoprubart is a second-generation anti-CD40L antibody. The initial attempt at this approach, led by Dr. Ricordi and Dr. Kenyon, was halted years ago due to an unforeseen complication: life-threatening blood clots. The redesign and eventual development of the improved version, Tegoprubart, by Eledon Pharmaceuticals, Inc., addressed the past safety concerns.

The trial, initially funded by The Cure Alliance and Breakthrough T1D (formerly JDRF), is now rapidly expanding enrollment. Dr. Ricordi will serve as Principal Investigator at the University of Miami site, where the patient criteria will be broadened to include individuals with high daily insulin requirements and diabetic nephropathy – a significant expansion of access to this therapy.