Experimental Drug Helps Type 1 Diabetes Patients Ditch Insulin Injections Entirely

A Milestone Result That Has Doctors Paying Close Attention

For people who have lived with Type 1 diabetes for decades — tracking every meal, every blood sugar reading, every insulin dose — the idea of simply stopping injections sounds almost impossible. But that is exactly what happened in a small, early-stage clinical trial that has the medical community cautiously optimistic. Updated results from a trial of the immunosuppressive drug tegoprubart showed that all 12 participants no longer needed insulin injections following islet cell transplantation.

The study enrolled 12 adults with long-standing Type 1 diabetes and repeated hypoglycemic events, with a median diabetes duration of 33 years and a mean HbA1c of 8.0%. These were not easy cases. These were people who had spent the better part of their lives managing a relentless disease — and every single one of them achieved insulin independence.

What Makes This Trial Different

Islet cell transplantation — the process of implanting insulin-producing cells from a donor pancreas — is not a new idea. The problem has always been what comes next. Calcineurin inhibitors such as tacrolimus have traditionally played an important role in transplant medicine, yet tacrolimus can cause kidney, neurological, metabolic, and other toxicities. For islet transplantation specifically, calcineurin inhibitors may also harm the very insulin-producing cells clinicians are trying to preserve.

Tegoprubart, developed by Eledon Pharmaceuticals, takes a fundamentally different approach. It is a targeted immune therapy that, instead of broadly suppressing the immune system, blocks the specific signal that tells the body to reject transplanted tissue. Donor-derived islet cells are transplanted into the liver to restore insulin production, while tegoprubart helps protect those cells without the toxic side effects of traditional immunosuppressant drugs.

The numbers back up the theory. Among participants, roughly 3 to 5 times more transplanted islets survived and took hold versus those treated with tacrolimus. Researchers also reported no evidence of the nephrotoxicity, hypertension, or neurotoxicity commonly associated with tacrolimus-based immunosuppression in the cohort.

The Results in Plain Terms

All 12 participants achieved insulin independence, producing their own insulin and no longer requiring external insulin therapy. Each had a most recent HbA1c measurement below the clinical threshold for diabetes of 6.5%, with a cohort mean of 5.4%. To put that in perspective, their average blood sugar control went from diabetic range to essentially normal. Across the cohort, no rejection episodes or signals of graft failure were observed over a median post-transplant follow-up of 8 months and a maximum follow-up of 22 months.

Before transplantation, all enrolled participants had histories of recurrent severe hypoglycemic events. Following transplantation, researchers reported no severe hypoglycemic episodes in the cohort. For patients who had previously lived in fear of dangerous blood sugar crashes, that outcome alone is significant. Trial participant Katie Beth Hand described her experience with tegoprubart as dramatically different from what she expected. "The upside of the Tegoprubart is that I've had zero side effects from it, which is amazing," she said.

What Comes Next — and Why Caution Still Matters

These remain early results from a small, non-randomized study. The trial is listed as ongoing, with an estimated enrollment of 70 participants and study completion projected for 2029. Longer follow-up and larger studies will be essential to determine durability and safety. A key open question is whether insulin independence will last years down the road, or whether the transplanted cells will eventually falter.

A Breakthrough T1D-funded clinical trial will also give people with both Type 1 diabetes and chronic kidney disease islet transplants with tegoprubart — expanding the research into a population that faces compounding health challenges. There is no widely available cure for Type 1 diabetes yet, but 2026 is the most encouraging year the science has ever had: real patients are living without insulin after islet transplants on gentler anti-rejection drugs. The road from a 12-person pilot study to a broadly accessible treatment is long. But for millions of people who wake up every morning and reach for insulin, this trial represents the clearest signal yet that a different future may be possible.