State of the Cure: Cell Therapy Breakthroughs

For Ed Augustin, low blood sugar arrived without warning. During one severe episode, he became so disoriented that he wandered into the yard of a family having a party. The host mistook his hypoglycemia for intoxication and called the police. Luckily, a guest at the party recognized him and called 911. Paramedics arrived shortly after and revived him.

"I don’t feel low blood sugars – ever. I never did," Augustin said. "I’d still be talking and walking, but I was in a whole other world. People would give me juice or take me to the hospital. I don’t remember any of it.”

In August 2025, Augustin became the first recipient of an FDA-approved islet cell treatment called Lantidra, which freed him from insulin injections and high-stakes blood sugar management.

The transplant, which used islet cells from a deceased donor, was performed on a Saturday night at the University of Illinois Hospital in Chicago, and by the end of the procedure on Sunday morning, Augustin's body was producing insulin.

“You go in, and when you wake up, they’re pulling the insulin drip because your blood sugar’s already too low,” he said. “The cells are working immediately.”

Augustin will need to take lifelong immunosuppressive drugs to protect the transplant and manage a higher risk of infections, where an ordinary case could become serious. But he said it's a small price to pay to live without constant fear of low blood sugar.

“Sure, it’s great for me,” he said. “But the best part is my family, my co-workers – the people around me. No one ever has to worry about me crashing and burning.”

Recent milestones 

Augustin’s treatment marked the first non-experimental islet transplant in the U.S. In the past two years, several other major firsts in cell therapy for type 1 diabetes have been reported in major scientific journals:

• A man in Sweden received a transplant of donor islet cells and began producing insulin, without the need for immunosuppressive drugs.
• Vertex Pharmaceuticals has developed insulin-producing cells grown from stem cells, which led to the first sustained insulin production in a group of 12 people with type 1 diabetes.
• In China, a woman who had previously received a liver transplant was infused with her own reprogrammed cells, which began producing insulin.

Researchers and biotechnology companies worldwide are pursuing multiple strategies to treat, and potentially cure, type 1 diabetes. The strongest evidence of success – in people, not just in labs or animal studies – has come from transplanted islet cells from donors and insulin-producing cells from stem cells. Most of these treatments require drugs to suppress the immune system, but one patient was given donor islet cells without the need for immunosuppression.

"It's an exciting time," said Dr. Bob Gabbay, former chief scientific and medical officer at the American Diabetes Association, of recent advances in islet cell therapy. “Major hurdles we once thought might be impossible have been overcome."

A major advance

In the late 1990s, researchers at the University of Alberta in Canada developed a pioneering treatment that infused insulin-producing cells from donors into the liver of people with type 1 diabetes. The approach relied on a combination of anti-rejection drugs to suppress the immune system and became known as the Edmonton Protocol.

Gabbay said the broader shift, beginning in the 1980s, away from transplanting an entire pancreas – a far more invasive procedure – toward isolating and infusing just the insulin-producing islet cells marked a critical step toward a cure for type 1 diabetes.

“There weren’t enough pancreases, and it was major surgery with a lot of risk,” he said. “Then people realized it’s really the islet cells that matter – the insulin-producing part. It’s just a thumbnail’s worth of cells.”

The Edmonton Protocol shifted thinking in the field by showing that islet transplantation could work in real patients, not just in theory.

“The problem was that there was no good way to get enough islet cells, and the immunosuppressive therapy carried real risks,” Gabbay said. “The question was no longer ‘Does this work?’ It was ‘How do we do this better, more safely, and for more people?’”

Another hurdle cleared

In June 2025, researchers presented a major breakthrough in the effort to create an effectively unlimited supply of islet cells for transplantation. For the first time, lab-grown cells produced insulin long-term in people with type 1 diabetes.

Ten people who received Vertex's cell therapy, called zimislecel, no longer needed daily insulin after one year. Two others were producing their own insulin and spent about 70% of the time in range, though they still required some insulin.

“The real breakthrough was the potential to grow essentially unlimited numbers of these cells in the lab,” Gabbay said. “That’s what’s made this so exciting.”

Zimislecel uses stem-cell-derived insulin-producing cells that are infused into the liver, where they can sense glucose and produce insulin. Like donor islet or pancreas transplants, the therapy currently requires immunosuppressive drugs to prevent rejection.

“Right now, this kind of therapy makes the most sense for people whose lives with diabetes are so difficult – severe hypoglycemia, repeated hospitalizations – that the risks of immunosuppression may be lower than the risks they’re already living with,” Gabbay said.

If ongoing studies continue to show the treatment is safe and effective, Vertex plans to submit the therapy to the FDA in 2026.

“It’s a new approach,” Gabbay said. “Anything brand new requires much closer scrutiny. The FDA looks closely for any signal of a problem and often asks researchers to examine those issues in much greater detail.”

The FDA has granted zimislecel fast-track review status, meaning the earliest it could become available for people with type 1 diabetes who experience severe hypoglycemia is likely 2027.

“It has to be a personal decision,” Gabbay said. “This isn’t one-size-fits-all. You’re trading one chronic condition for another form of medical management. Some people will decide that trade is absolutely worth it. Others won’t – and both decisions are completely reasonable.”

A new approach: evade and survive  

In June 2025, The New England Journal of Medicine published news of a breakthrough development. A man in Sweden with long-standing type 1 diabetes received transplanted islet cells and began producing his own insulin – without the use of immunosuppressant drugs.

The company Sana Biotechnology used a gene-editing technique called CRISPR-Cas9 to modify donor islet cells so they could evade detection and attack by the immune system.

“This approach asks: What is the immune system recognizing as foreign – and can we change that?” Gabbay said. “Can we alter the genes that code for surface receptors so the immune system doesn’t attack the cells in the first place?”

Instead of infusing the cells into the liver, as with most islet transplants, the edited donor cells were implanted into a less invasive site – the man’s forearm.

Sana is now working to apply lessons from the donor-cell trial to a new therapy in development, called SC451, which uses the same gene-editing strategy with lab-grown, stem-cell-derived insulin-producing cells. If successful, the approach could address both major hurdles at once: cell supply and immune system rejection.

Gabbay recognizes the promise – taking another step toward a cure – but takes a practical view of the challenges ahead.

“Nothing in the history of the world has ever been approved for therapy based on one person. People are different," he said. “But this was exciting because it started as a theoretical idea, and it turned out to be possible. That’s fundamentally different from saying, ‘We think it might work.’ It actually worked in a human being.”

Transforming cells from within

For decades, researchers have explored whether a person’s own cells could be reprogrammed into insulin-producing islet cells — a potential solution to the limited supply of donor tissue.

In September 2024, the journal Cell reported the first successful transplant in China of lab-grown islet cells derived from a woman’s own tissue. The team reprogrammed cells from body fat into stem cells, then guided them into functional islet cells in the lab. The cells were transplanted beneath a layer of tissue over the abdominal muscles.

Within 75 days, she no longer required insulin. Her time in range increased from roughly 43% before the transplant to nearly 98% within several months. After one year, her body was still producing insulin.

The woman was already taking anti-rejection drugs because of an earlier liver transplant. Although the cells were made from her own tissue, it remains unclear whether similar transplants could succeed without immunosuppression.

She was the first person enrolled in an ongoing exploratory clinical study, and it is not yet known whether the procedure will work in others.

“You have to be very careful about how you interpret something like this,” Gabbay said. “When someone is already on immunosuppressive therapy for another reason, you can’t assume the same outcome would happen in a typical person with type 1 diabetes. It doesn’t mean it isn’t important – it just means you can’t generalize it yet.”

Moving beyond experiments

Augustin’s experience with Lantidra illustrates some of the tradeoffs facing those considering an islet transplant today. He's had a previous transplant as part of a clinical trial – the treatment is not permanent – and the cells have a finite lifespan.

“The first time I had this done, it lasted about 12 years,” he said. “Then the cells just wore out. I went back on insulin for a few years. When the transplant team called and said, ‘We have a new way,’ I didn’t hesitate. I said yes. Now they think it could last 15 or 20 years.”

Augustin takes several pills in the morning to suppress his immune system, followed by another medication taken four times a day.

“People ask me about the anti-rejection drugs,” he said. “At first, the doctors watch you very closely – blood tests every week. They constantly adjust the pills so you don’t reject the cells. But once it levels out, it just becomes part of your routine. For me, the side effects are minimal.”

Since the therapy relies on islet cells from donors and requires lifelong immunosuppressive drugs, Lantidra is only being done at the University of Illinois Hospital in Chicago and is approved only for the small number of people whose diabetes is especially dangerous and difficult to manage.

“Every treatment has its pluses and minuses," Gabbay said. "Immunosuppressive therapy doesn’t selectively turn off just the part of the immune system attacking the transplanted cells – it suppresses the entire immune system. That means people are more prone to infections, and infections that might be minor for others can be serious.”

Augustin's treatment is the result of years of research showing that islet transplants could sustainably and safely produce insulin in people. 

At the 2024 ADA conference, researchers reported results from two Lantidra studies involving 30 adults with impaired awareness of hypoglycemia. About two-thirds no longer needed insulin one year after their final transplant, and a similar number had near-normal glucose levels. Severe hypoglycemia was eliminated.

Longer follow-up showed that many participants maintained good glucose levels for years, suggesting transplanted islet cells can function well over time with consistent immunosuppression.

“For me, the tradeoff is absolutely worth it,” Augustin said. “I’m not taking shots. I’m not crashing. I’m not scaring my family anymore. Now I wake up, get in my car, and drive. I don’t have to check my blood sugar first.”

His daughter Jill recalled during childhood frequently seeing paramedics at their home. She was skeptical about whether Ed's first transplant would solve the problem. But when it worked, the change was unmistakable. 

“It was incredible just seeing how happy it made him,” she said. “Even little things, like the first time he took a shower and didn’t have to worry about his pump. Those were things he never thought would happen for him.”

And then when the first transplant eventually ran its course, the uncertainty returned.

“You don’t realize how much you’re always on edge until that fear is gone,” she said. “By then, we knew what the difference was – what the transplant gave him back. It’s life-changing, not just for him, but for everyone around him.”

The road ahead

A series of breakthroughs has shifted the conversation about cell therapy for type 1 diabetes from theoretical to possible. University researchers and biotechnology firms are working to make these therapies feasible for many people with type 1 diabetes. And they are increasingly solving longstanding problems around the supply and survival of insulin-producing cells.

Over the past two years, studies have shown that stem cells can be grown into insulin-producing cells. Although recipients typically require immunosuppressant drugs, the results suggest these cells can produce insulin sustainably and meaningfully improve blood sugar levels.

While studies show that stem-cell–derived islets can function in humans, manufacturing them at large scale remains a challenge. Producing billions of high-quality cells safely – under strict regulatory standards – is a complex process, and companies are still refining production methods.

Techniques are also under development to protect transplanted cells from immune attack. So far, only one published case has shown donor islet cells successfully protected using Sana’s CRISPR-Cas9 gene-editing technique. A second benefit of this approach is that the cells were implanted in the forearm – a potentially simpler approach than infusing them into the liver, which has been standard practice since the Edmonton Protocol of the late 1990s.

The downside is that costs are likely to be very high for these treatments. Lantidra – currently the only FDA-approved islet cell therapy in the United States – costs roughly $300,000, though it is covered by insurance for eligible patients. Some argue the costs could be another barrier unless therapies are broadly covered by government insurance, as dialysis is in the United States.

Despite significant challenges, the success of cell-based therapy in human trials suggests the approach is increasingly likely to become a practical treatment for type 1 diabetes, Gabbay said.

“That’s what has shifted in my mind,” he said. “It’s not if, it’s when. We don’t know when. But we know it can be done, because it has been done.”

Learn more about type 1 research here:

• Diabetes Challenges, the Search for a Cure, and How to Help
• Pathways to Stop Type 1 Diabetes: A Look Forward
• Join Type 1 Diabetes Clinical Trials
• How Do People With Type 1 Diabetes Monitor Beta Cell Function?
• From Uncertainty to Empowerment: The Journey in Type 1 Screening