A man living with severe type 1 diabetes who is part of a clinical trial by Vertex Pharmaceuticals appears to be have been functionally cured of the disease thanks to a new treatment involving stem cells.
Brian Shelton, aged 64, received an infusion of cells in June that “taught” the pancreas to produce insulin—something that the bodies of people with type 1 diabetes cannot do, according to the New York Times, the first to report on the revolutionary treatment in November.
People with type 1 diabetes, like Shelton, are insulin-dependent and have to give themselves injections of insulin to make up for what their body is not making.
Early data from the Vertex trial found that Shelton’s need for injected insulin decreased by 91% after he received the treatment, meaning that his body is now regulating its blood sugar levels on its own.
The outcome is significant, as Shelton had experienced several life-threatening hypoglycemic episodes (low levels of glucose in the blood, which is also called low blood sugar). These lows are common in people with severe type 1 diabetes and can have serious health consequences or even be fatal.
Between reducing the need for insulin and preventing complications, it's easy to see how the new treatment could be life-changing for people with type 1 diabetes.
“This is quite revolutionary stuff,” David Thompson, MD, the director of the Vancouver General Hospital Diabetes Centre and a clinical assistant professor of endocrinology at the University of British Columbia’s faculty of medicine who was not involved in the Vertex trial, told Verywell. “These are the first steps in a whole new field.”
The United States-based trial includes 17 people with severe type 1 diabetes and will continue for five years.
The stem cell-based treatment was developed by a team of researchers led by a Harvard University biologist named Doug Melton. The goal is to offer a cure for type 1 diabetes—it is not intended for people with other forms of the disease, such as type 2.
The hope is that people with the condition would have the treatment and then no longer need to give themselves insulin because their body would be making its own.
The treatment is thought of as a "functional cure" because it addresses the main problem that the disease causes (the body is not making insulin) rather than addressing the deeper cause (that type 1 diabetes is an autoimmune disease).
If successful, the treatment could help the 1.6 million Americans who live with type 1 diabetes.
Thompson said that treating type 1 diabetes this way involves bringing stem cells into the lab that are then “coached” into becoming beta cells—the type of cell that makes insulin in the body.
In people with type 1 diabetes, the immune system has attacked and destroyed the body's beta cells, meaning that the pancreas does not produce insulin on its own. Therefore, a person's blood sugar levels need to be controlled with injectable insulin.
According to Thompson, there are different ways to bring those cells into the body of a patient. He is also using stem cell-derived therapy to treat diabetes in his own research and recently published findings from a human phase 1/2 study.
Thompson's team is working with California-based biotechnology company ViaCyte to develop implantable devices that contain millions of cells that are derived from a stem cell. These implants are placed under the skin of the abdomen. In the Vertex study, Shelton received an infusion of cells into his liver.
Both methods have the same goal: getting a patient's body to create its own insulin and effectively cure them of type 1 diabetes.
Thompson said that his study proved the scientific principle that a stem cell-derived product can mature and function in “a normal, physiological manner"—meaning that when a person eats, the cells will make insulin, and when they are not eating, the cells will stop making insulin.
“That is very important, otherwise, you get low sugar reactions,” Thompson said. Having established that the first step is possible, Thompson added that the next is to bring more cells into the body to give a patient better control of their blood sugar levels and stop their need for insulin altogether.
Currently, the participants in the trial have been able to reduce the amount of insulin with the ViaCyte implant, but they still need small amounts.
The current stem cell-based treatment is very promising, but there are some risks. First, patients need to be on immunosuppressants, which can make them more vulnerable to infections that can be serious.
Each patient needs to weigh the risks and benefits of the treatment with their doctor. For some, it might not be worth the risk.
“Somebody who is doing very well with the current management of their type 1 diabetes and has well-controlled sugars and no complications, they may not want to take those added risks,” Thompson said.
Stem cell therapy is also quite new, and Thompson said that his team is transplanting the cells within an enclosed capsule for monitoring, which means that "if there was any sign of damage being done by these cells, like they're growing outside the capsular, for example, they will be very easy to remove."
Peter Senior, MBBS, PhD, director at the Alberta Diabetes Institute, told Verywell that most stem cell-based treatments have been focused on people with severe forms of type 1 diabetes because they are the most at-risk for serious, detrimental health outcomes, and have often experienced dangerous blood sugar levels.
According to Senior, these patients have "problems with erratic blood sugars, but that's not their only problem—they've got eye problems and kidney problems and other things like that."
Stem cell-derived treatment in humans is new, which means that it’s going to take time to prove long-term benefits. However, the potential for short-term success—as in Shelton’s case—is being seen already.
If stem cell-derived therapies prove effective over time and researchers can find a way to deliver the treatments without the need for immunosuppressants, Senior said that the candidate pool would open up.
Effectively curing someone of type 1 diabetes before the disease has progressed and caused serious health complications will help improve patients' overall quality of life.
“If I was a parent with a child with type 1 diabetes, I would want a treatment that meant they never had to worry about diabetes,” Senior said. “But it may take 40 years for us to be able to show those long-term benefits.”
People living with type 2 diabetes are not candidates for stem cell-based therapies. Type 2 diabetes differs from type 1 in an important way: the bodies of people with type 2 still make insulin, it's just that their cells have become desensitized to it.
Unlike type 1 diabetes, type 2 can be managed (and sometimes even reversed) by making diet, exercise, and other lifestyle changes, as well as using medications (like insulin) as prescribed.
Until now, the only cures for type 1 diabetes were a pancreas transplant or a transplant of the insulin-producing cells of the pancreas (islet cells) from a donor. Senior said that the problem with these options is that there’s a limited number of donors.
The risks of immunosuppressants are another factor to consider with transplants. “For those cells to survive and not be rejected as foreign, we need to use anti-rejection drugs as we would for a heart or a kidney or any other transplant,” Senior said. Like with stem cell-based therapies, those immunosuppressants—or anti-rejection drugs—come with side effects and risks.
People with severe forms of type 1 diabetes are often the people who might be considering more extreme treatments. Even if a transplant cures them of diabetes, the disease may have already progressed to the point where they have other health complications like kidney damage.
“I often say to people, you don't want to do a transplant too soon—because I don't know if it will last forever," Senior said. "But nor do I want to wait too late."
Type 1 diabetes requires people to monitor their blood sugar daily and give themselves insulin. The constant vigilance and management can be challenging even for people who have been living with the disease for many years.
“You always have the risk of unexpected high and low sugars, and you basically spend much of your waking life figuring out how to balance your insulin and your food and your exercise,” Thompson said.
Even with the most advanced treatments available, Thompson said that patients still don't get 100% “normal sugars." The treatments allow for better control and reduce the complications of diabetes, but none of them eliminate the risk.
That’s why stem cell-based therapy is exciting. According to Thompson, "it holds out the promise to be able to get a person to have normal blood sugars all the time—just like the person who didn't have diabetes—and make all those feared both short- and long-term complications a thing of the past."
While Senior is optimistic about the potential of stem cell-derived therapies, he said that the next barrier will be finding a way to eliminate the need for immunosuppressants—which remains a limiting factor in the treatment.
“We don't want to promise timelines or raise expectations that lead to disappointment later, because it's just such a cruel thing to do,” Senior said, though he added that advances in treatment have progressed further than he thought that they would five years ago. “With this most recent case…this is really, really exciting.”