We fact-checked the hype behind the Eledon Pharmaceuticals Type 1 diabetes treatment

Eleven adults with Type 1 diabetes have been able to stop using insulin after getting an experimental treatment.

If they stay off insulin without major side effects, that means this could be a potential cure for a disease that affects about 2 million US adults, Mandy Ford, scientific director of Atlanta’s Emory Transplant Center, told Healthcare Brew over email.

“But that is a big ‘if,’” she added.

Ford and other experts told us these updated results are promising, but there are still more questions to answer, mainly whether this insulin independence could last. That will require larger and longer studies over many years, they said.

Let’s dive in. The 11 insulin-free people are part of a pilot study at the University of Chicago. The results haven’t been peer-reviewed.

In total, 12 participants with Type 1 diabetes got transplants of pancreatic insulin-producing cells (islets). To prevent their immune systems from attacking the islet cells, they are also taking an anti-CD40L monoclonal antibody created by biotech Eledon Pharmaceuticals called tegoprubart (AT-1501), plus a daily anti-rejection pill.

Ten out of 10 participants who were more than four weeks post-treatment were able to stop taking insulin entirely so far, Eledon said in a March 16 press release. An 11th study participant later got off insulin, too, after passing that four-week threshold, Piotr Witkowski, director of the pancreas and islet transplant program at UChicago Medicine, posted on LinkedIn in early April.

This trial is exciting because it could solve a common issue following islet transplantation: transplant-related immune toxicity, Marlon Pragnell, VP of research and science at the American Diabetes Association, told Healthcare Brew over email.

Let’s back up. When scientists first published a protocol for islet transplantation in 2000, it “revolutionized” treatment and brought “a glimpse at a cure,” according to a 2023 review in the journal Cells.

But it has some issues, according to the review. (Don’t we all?) For one, patients need ongoing immunosuppressive therapy so their bodies don’t reject the transplant. Though a 20-year follow-up found the procedure and the subsequent immunosuppression were safe long term, immunosuppression can still bring a host of nasty side effects and toxicities.

Immunosuppression after a transplant is often done with a drug called tacrolimus, which evidence suggests can damage islet cells and kidneys—and, ironically, actually create diabetes symptoms.

Eledon’s investigational drug tegoprubart went head-to-head with tacrolimus in Phase 1B and Phase 2 clinical trials of kidney transplant patients and was found to provide immunosuppression without the same level of toxicities, per a March Eledon SEC filing. So far, in the current study, it has also provided enough immunosuppression to prevent transplant rejection, and there’s been “no evidence” of toxicities connected to other treatments, per Eledon’s press release.

The clock is ticking. It’s possible the patients in this trial have only ditched their insulin pumps temporarily, however.

A landmark 2006 study in the New England Journal of Medicine found 21 of 36 patients (58%) who got pancreatic islet cell transplantation were able to get off insulin at some point. Two years after their final transplant, the majority of those 21 patients (76%) needed insulin again.

The first participant in the current tegoprubart study was dosed in early 2024, with others dosed as recently as this year, so it’s not yet clear how long their insulin independence could last.

“As with any early‑phase study, the most important unknown is long‑term durability and safety. These findings will need to be confirmed in larger, multicenter trials with longer follow-up,” Pragnell said.

Eledon’s SEC filing states the company plans to “seek guidance” from the FDA this year about initiating a Phase 3 clinical trial, the next step on the path to drug approval.

Demand outpaces supply. Another concern is that even though the current trial has produced “genuinely unprecedentedly good results,” there aren’t enough islets for everyone who might want them, Allan Kirk, a transplant surgeon at Duke University, told us. Kirk is a board member of Eledon, but was not involved in this trial.

“I think for those that can gain access to an islet transplant with this drug, it’s a functional cure,” Kirk said. “But the caveat is very few people can gain access to this…The organ shortage, the islet shortage, is a critical limiter that will prevent broad-scale application of this.”

Right now, islets can only be obtained from deceased donors, but availability could increase in the future.

Biotechs like Vertex Pharmaceuticals are trying to tackle the problem by genetically engineering them.

“If you could take a generated source of islets and pair it with this, then you could actually cure every [person with diabetes] in the country. But those two things are going to have to come together. That’s a lot of work,” Kirk said.

Patient interest spikes. Despite these unresolved kinks, Type 1 diabetes patients are excited.

Laura Tremblay, clinical trial education volunteer at research and advocacy organization Breakthrough T1D, told Healthcare Brew she has never seen this much awareness and interest from patients about any other trial during her more than five years in the role.

“People are coming to me directly and saying, ‘I’ve heard about this trial,’” she said. “That has never happened to me before.”

Witkowski said in his LinkedIn post that “we only wish we could enroll and help everyone; however, due to limited funding, enrollment in the current study has been completed.” But, he added, he and other investigators are preparing to launch another study of the treatment for patients with Type 1 diabetes and kidney dysfunction.