A Cure for Type 1 Diabetes May be Closer Than You ThinkNEWS | 14 October 2025This article is part of “Innovations In: Type 1 Diabetes,” an editorially independent special report that was produced with financial support from Vertex.
On one wall of endocrinologist Kevan Herold’s office hangs artwork by a girl who joined one of his type 1 diabetes trials when she was 11 years old. The girl was diagnosed with stage 2 of the disease, a status that meant her own immune system was making at least two types of antibodies that attacked the insulin-producing beta cells in her pancreas. The immune assault interfered with her ability to produce insulin, the hormone that controls blood glucose levels, says Herold, who works at Yale University. But she did not yet need insulin to treat her diabetes.
Typically people with stage 2 disease soon develop stage 3, when their blood sugar levels become so dysregulated that they need insulin. But that was before the arrival of teplizumab, a monoclonal antibody approved in late 2022 that delays the advance of the illness and may even halt it at stage 2 in some people. The girl in the trial went on the drug in about 2011. Her disease did move to stage 3—but not for almost a decade.
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“She was free of diabetes for eight to nine years. It enabled her to go to middle school, high school, graduate and so on, to grow up without diabetes,” Herold says. “Even if you develop it when you’re 21 or 22, that’s different than when you were 11, and you’ve had the opportunity to do what your peers do—not to have to think about it 24/7.” In a way, he says, “we’re kind of in the time business. We’re buying time without disease.”
Although teplizumab doesn’t work for everyone and how much it delays progression varies, it has inspired new directions in research, and a few therapies show signs of success. The progress has people in the type 1 diabetes community using a word that was rarely heard a few decades ago: “cure.”
Cure can be a charged word in medicine. “Even in people affected by diabetes, they have a difference of opinion about what a cure is,” says Alvin C. Powers, an endocrinologist at the Vanderbilt School of Medicine. As a complete remedy, he says, some people would be happy with an insulin pump with a glucose sensor that automatically detects their blood sugar levels and metes out only exactly as much insulin as they need, a goal that’s within reach now [see “The Long Journey to an Artificial Pancreas”]. “Other people say, ‘If I have to take anything, it’s not a cure,’” Powers notes. Some think of transplantation of insulin-producing cells that can permanently control glucose as a cure; still others consider real healing to be a way to stop the autoimmune attack on those cells, preserving enough so that people don’t need additional insulin.
“Ideally it’s a one-and-done, like a vaccine, so one can never get type 1 diabetes,” says Sanjoy Dutta, chief scientific officer of Breakthrough T1D, a nonprofit research and advocacy organization that’s funding efforts to find a cure for type 1 diabetes. But given the complexity and heterogeneity of the disease, that’s not likely to be what a complete remedy will look like. “Cures come in many forms, and one form is not going to work for everyone,” Dutta says.
That’s why scientists are pursuing multiple approaches. The variety and the progress suggest a remedy is possible and perhaps not even that far off. “We know that for cures, it’s a matter of when, not if,” Dutta says.
One of the biggest challenges facing doctors and patients is that type 1 diabetes involves two problems. “One, the immune system has gone rogue and is destroying [the body’s beta cells], and the second is the loss of insulin production because of the death of beta cells,” Dutta says. “So to cure or modify the disease, to slow it down or reverse it, you need something to put a check on the immune system and then protect the remaining beta cells or regrow them. I envision a world where we have to use these methods in combination to cure the disease.”
The first part of that combination, the immune therapy approach, is where teplizumab comes into play. The drug binds to a particular protein on immune system cells called T cells and reduces their ability to attack the body’s beta cells. At the same time, it promotes changes in the T cells that may pump the immune system’s brakes.
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In clinical trials that tested teplizumab in people at high risk for type 1, the drug reduced the risk of progressing to stage 3 by 59 percent overall. For those who did move to stage 3, the therapy doubled the time it took for them to get there, from a median of two years without the drug to a median of four years with it. Longer-term follow-up has found that just more than a third of patients had not progressed to stage 3 after five years. Some patients in the initial trial that started in 2011 still have not developed diabetes, says Herold, who was instrumental in developing the drug. Researchers are studying those patients, taking a close look at their biology and physiology to figure out why their bodies responded so well to the drug.
Scientists are also taking a hard look at the biology of people whose bodies didn’t respond so effectively. “If you understood the mechanisms that lead to failure over time, you might intervene with another drug that targets that specific immunological mechanism that’s gone awry,” Herold says. “That’s where a combination of drugs, or repeated treatment, would be very helpful.”
Despite the tremendous breakthrough teplizumab represents, it also has substantial disadvantages that limit its accessibility. Cost is one barrier, with a list price of just over $205,000 for a full course of the drug, although most insurance plans cover it in the U.S. It’s also available in only a handful of countries so far, so it’s not yet a global strategy. Another serious obstacle is its administration: it requires an infusion that takes at least 30 minutes, and sometimes twice that long, every day for 14 consecutive days. A patient may need to take time off from work or school, find a center with infusion capability that’s open on weekends, and have transportation to that center. Such facilities may exist only in large metropolitan areas.
“From a health system perspective, there are real barriers to propping up these programs. From a patient perspective it’s not only disruptive, but it causes a lot of barriers for patients who are underserved,” says Shivani Agarwal, an endocrinologist at Montefiore Medical Center in New York City. “They can barely kind of make ends meet, they have multiple jobs to get to, and they don’t have all the resources to be able to even get to their normal doctor appointments.”
Agarwal says that for her patients the demanding methods of taking the drug are bigger problems than costs or insurance. “As soon as I mention how it’s administered, they say, ‘Oh, no, never mind, I can’t do that,’” she says. “As we are developing more of these therapies, my sincere hope is that there is some cognizance of the patient” and what they are up against.
The protocol for giving new drugs is generally based on evidence seen in animal models and then in human trials, says Mattias Wieloch, a cardiologist and medical head of the type 1 diabetes program in North America at Sanofi, the company that manufactures teplizumab as Tzield. He says there are centers in the U.S. experimenting with shorter hybrid regimens, and although the company still advises adhering to the label, he and his colleagues are aware of the barriers.
“Being first-in-class is not a honeymoon,” Wieloch says. “There are hurdles like this, and there are not answers to all the questions.”
Still, the fact that an approved therapy can now delay the disease’s progression has added momentum to the quest for other therapies to thwart type 1 diabetes. “The approval of one drug made all the difference in the world,” Herold says. There hasn’t been another drug with such an impact on the disease since the discovery of insulin, he says.
Some other therapies that act on the immune system have also demonstrated progress. For example, baricitinib, an oral drug currently approved for rheumatoid arthritis, showed promise for preserving beta cell function in a phase 2 trial of people with newly diagnosed type 1 diabetes. Essentially the drug safeguards healthy beta cells by blocking overstimulation of the immune system. And the immune-modulating drug GAD-Alum, currently in a phase 3 trial for people with newly diagnosed type 1 diabetes and a particular genetic marker, attempts to preserve beta cells by reprogramming the immune system to ignore an enzyme that would otherwise prompt it to attack beta cells. Multiple other monoclonal antibodies, both being tested in clinical trials and already approved for various conditions, are in trials to see whether they can slow the disease’s advance.
Cell therapies are the other new approach to slowing or reversing type 1 diabetes. These treatments aim to create a renewable source of beta cells or to help maintain existing beta cells by shielding them from the immune system or enabling them to evade it. The therapies can stimulate the expansion of the population of a person’s remaining beta cells before the immune system has destroyed all of them. The treatments may also involve transplanting beta cells into someone.
For transplants, scientists are pursuing multiple sources of beta cells, including ones from a deceased donor and ones grown from other cells in a patient’s own body. Researchers are also transplanting donor stem cells. Stem cells are immature cells that have the ability to turn into insulin-producing beta cells and to produce more cells like themselves.
For example, researchers in China published findings in 2024 in which a female patient’s stem cells were taken from her body, chemically induced to differentiate into insulin-producing cells in the laboratory, and then reimplanted in her body. Though successful, this is not a scalable approach for the global population of people affected by this disease, Dutta says.
“We will need to be able to provide sustainable insulin independence for one adult individual and then multiply that nine million times” for all those living with the disease across the globe, he says.
To meet that nine-million-person challenge, BreakthroughT1D is funding research into renewable sources of beta cells, Dutta says. The drug Zimislecel (formerly known as VX-880) from Vertex Pharmaceuticals helps to grow collections of pancreatic cells, called islets, from donor stem cells. These islets include beta cells and can be infused into a patient to restore their ability to produce their own insulin. In a small study of a dozen patients published this past summer, 83 percent no longer needed to take insulin a year after the transplant. But they needed to take immune-suppressing drugs to prevent transplant rejection.
And that’s a big problem. After all, people need their immune systems to fight off other diseases, from cancer to the yearly flu. “The one thing we can’t do is substitute chronic immune suppression for diabetes progression,” Herold says. “The risk of a lifetime of immune suppression is too great.”
An alternative, selective immunotherapy, which targets specific cells or pathways, has milder side effects and leaves the person less vulnerable to other diseases. The monoclonal antibody drug tegoprubart attempts to do this by blocking a pathway used by immune cells to communicate and organize an attack against the transplanted beta cells. This protects the beta cells yet preserves the immune system’s overall ability to defend the body.
Other provocative strategies involve hiding transplanted cells from the immune system by editing the genes of those cells to make them invisible to the immune system—immune cells look for very specific proteins coded for by these genes, and small edits make such proteins undetectable. Sana Biotechnology recently demonstrated the gene-editing approach by transplanting donor islets of beta cells into a patient after genetically modifying the cells to evade the immune system. Three months later the patient’s immune system had not attacked the transplanted cells, which had begun producing insulin. CRISPR Therapeutics is pursuing a similar gene-editing approach with a therapy called CTX211.
Several of these therapies are in advanced human trials, and others are entering more preliminary studies. The approval and success of teplizumab can, researchers say, provide a way to buy time for people with type 1 diabetes until the next breakthrough. “The people we treat tomorrow ... could potentially benefit from the next treatment and then maybe the next treatment,” Wieloch says. “For the first time, we not only have an approved drug, but we might be able to buy some time to bridge to future treatments.”
And sooner rather than later, researchers in the field say, that bridge will lead—no matter how you define the word—to cures.Author: Jeanna Bryner. Tara Haelle. Source
