But this part is a big deal: the cells are surviving without any immunosuppression therapy.
For anyone following cure research in T1D, that sentence alone is breathtaking.
The full results of this study with Sana Biotechnology and Uppsala University Hospital were published in the New England Journal of Medicine. For the first time in humans, gene-edited insulin-producing cells successfully avoided both transplant rejection and the autoimmune attack that defines T1D.
After decades of promising mouse studies that didn’t translate to humans, this one did.
How Islet Transplants Work & Why We Don’t All Get One
Islet transplantation isn’t new. In the early 2000s, James Shapiro helped develop the Edmonton Protocol, which transplants donor islet cells into the liver. Many people across the globe have lived insulin-free for years thanks to islet transplants.
Recently, Eledon has seen great success in a handful of people with T1D in Chicago, IL, with their islet cell transplants while using a targeted immunosuppressant administered every four weeks. But that’s the lingering problem: immunosuppression. Even with Eledon’s advanced therapy, it’s still a major caveat that would likely prevent it from becoming a worldwide cure.
Most islet cell transplant research today includes these two challenges:
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Lifelong immunosuppressive drugs
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Limited supply of islet cells from cadavers
“There just aren’t that many people for whom lifelong immunosuppression is better than lifelong insulin,” explained Steve Harr, CEO of Sana Biotechnology.
While the United States is currently fighting to make islet cell transplants more accessible with the Islet Cell Act, the Nordic countries like Sweden, Denmark, and Finland perform more islet transplants than anywhere else in the world.
Making Cells “Invisible” to the Immune System
The science behind this breakthrough comes from Sonja Schrepfer, a founding scientist at Sana Biotechnology.
Over seven years, her team identified three genetic modifications that make cells “hypoimmune” as if they are essentially wearing an invisible cloak to hide from the immune system.
In a nutshell, here’s what we know about these genetically modified cells:
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They knocked out HLA class I and II molecules, which normally trigger transplant rejection.
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But removing HLA makes cells vulnerable to “natural killer” (NK) cells.
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So they added extra layers of of CD47, a protein that signals “don’t eat me” to your immune system.
The result? Cells that can hide from both:
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Transplant rejection
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Autoimmune attack
In this proof-of-concept study, modified donor islets were transplanted into the patient’s arm muscle — not the liver like most islet cells transplants. That unique transplant location allowed researchers to monitor the cells using PET/MRI imaging. They can also retrieve the cells surgically if they need to.
Months later, without suppressing the immune system, the cells have survived, and they are functioning.
One year after transplant, the original patient’s cells are still functioning. No treatment-related serious adverse events have been reported.
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The Big Caveat: This Still Uses Cadaver Cells
For regulatory reasons in Europe, this trial used gene-modified cadaveric donor islets. Not ideal for the “big picture” cure therapy.
The real future of this gene-edited cell therapy will depend on lab-made cells to ensure there is an endless supply.
According to Harr, building a true supply of these stable gene-edited cells without tumor-forming mutations has taken years. The next step was turning those cells into pure, functioning islet cells.
Sana says it has achieved enough purity and quantity in its lab-made cell therapy product to move toward a Phase I trial and hopes to file an IND in 2026.
What Will This Cost Those of Us with T1D?
Even if the science works, getting reimbursement from your health insurance will be a tremendous hurdle to overcome. Healthcare systems are designed to pay for chronic disease management versus one-time curative therapies with big upfront costs.
And scaling this science? Even if they treated 100,000 people with type 1 diabetes per year (which would be remarkable on its own), it could take decades to actually reach everyone in the United States, let alone the millions with T1D across the globe.
Still, the patient demand is undeniable for islet cell transplants is ramping up. Breakthrough T1D recently gathered global experts to define patient-reported outcomes for cell therapy trials. What matters most?
Freedom.
After receiving an islet cell transplant, one grandmother with T1D shared that it was “the first time my daughter allowed me to be alone with my grandchild.” Another woman, diagnosed at age 3, traveled alone for the first time in 44 years.
In Canada’s Edmonton protocol program, 373 people with T1D were offered transplantation with lifelong immunosuppression. Only two people declined.
That tells you everything about the daily burden of T1D and what many of us are willing to trade for relief from the daily demands of this disease.