Stem cell transplantation can completely cure people with severe diabetes

A cure for diabetes means a life without daily insulin injections. According to this criterion, ten out of 12 people (83%) who participated in a new clinical trial were completely cured of diabetes one year after undergoing innovative stem cell therapy.

The study used laboratory-grown pancreatic islet cells. These were injected into the liver, where they took root. Within a year, most participants no longer needed insulin injections.

One of the most notable benefits was the rapid prevention of dangerous drops in blood sugar, known as hypoglycemia. Prior to the transplant, all participants had experienced at least two episodes of severe hypoglycemia during the previous year.

After the transplant, these episodes disappeared in all participants.

These are impressive results, but what is stem cell therapy? How does it work? How is it different from other treatments? And what are the possible side effects?

What is stem cell therapy?

Stem cells are cells that can turn into almost any other type of cell. The main advantage is that scientists in the laboratory can create the right cells needed to treat the disease in the right quantity.

In the case of type 1 diabetes, the cells needed are pancreatic islets. Most of the cells in these islets produce insulin.

How does the treatment work?

The cells grown in the laboratory are injected into the body, usually into a vein in the liver, where the cells become attached. The advantage here is that insulin delivered to the liver works much better than insulin delivered under the skin, for example.

This is because the main action of insulin in correcting blood sugar levels is to suppress excessive glucose production by the liver.

In the current study, the function of the transplanted cells, a drug called XV-880, improved during the first three months. Blood glucose levels were better controlled. No severe hypoglycemia was detected, and the marker for insulin production showed improvement.

During the first year, participants were able to reduce the amount of insulin they took, until most of them stopped taking insulin injections altogether.

What are the side effects?

The biggest drawback of this new treatment is that all participants will have to take immunosuppressants for the rest of their lives. This will reduce the immune system’s ability to recognize and remove the transplanted cells.

This increases the risk of infections and certain types of cancer. This is because the immune system plays an important role in removing potentially cancerous cells.

In this new study, two participants died. Upon closer investigation, it was found that this was not related to the treatment itself. Most participants experienced stomach problems, with diarrhea being the most common side effect in 11 out of 14 people. More than half also experienced headaches and nausea.

Is this better than other treatments?

For many years, people with severe hypoglycemia have been able to receive new pancreatic islets from deceased donors. For a minority, this also leads to freedom from insulin injections in the long term.

Typically, two or three donor pancreases must be combined for a single recipient. People may also need repeat infusions within a relatively short period of time. Islet transplantation is usually limited by the number of donor cells available, which is insufficient.

This new approach provides a standardized dose of cells. The timing of the procedure is also not dependent on the death of donors.

This new study is not the first. In 2024, a 25-year-old woman with type 1 diabetes underwent a transplant of islets derived from stem cells, which also led to freedom from insulin injections.

A 59-year-old man with poorly controlled type 2 diabetes was also cured with another type of stem cell transplant.

Both of these treatments will require lifelong immunosuppression. This is undesirable for many people and may limit the use of this method.

This is driving efforts to develop treatment options that do not require immunosuppression. Attempts are being made to encapsulate transplanted cells in devices that allow insulin to pass through but not immune cells. Genetic editing techniques are also being used to hide cells from the immune system.

However, these approaches are at an earlier stage of clinical development.

When will this treatment become more widely available?

That is difficult to predict. Larger trials of XV-880 are planned. The same company had planned to test a version of its cell therapy without immunosuppression, called XV-264. However, in a small pilot study, it did not show sufficient efficacy and will not be tested further.

There is also the issue of cost. It is not yet clear how much this treatment will cost. This will affect who will be able to access advanced cell therapy methods. We also do not yet know if the transplanted cells can start to break down and when this might happen.

In this trial, the company is monitoring recipients for ten years. Initially, the observation period lasts five years, followed by a five-year extension of the study.

This gives an idea of how long we may have to wait. Despite this, recent developments give cause for cautious optimism. Perhaps in the near future, it will be possible to live without daily insulin injections.