Type 1 diabetes (T1D) is an autoimmune disease in which the body destroys its own insulin-producing cells. These cells are located in the islets of Langerhans in the pancreas. Because of the immune system’s attack, little to no insulin is produced. Insulin is the hormone that regulates blood sugar levels.

The impact of T1D is still often underestimated. Despite support from modern technologies such as insulin pumps and glucose sensors, the burden of the disease remains high. It is a lifelong, serious, and potentially life-threatening condition. For most people, there is no cure and no break — someone with T1D lives 24/7 with this mental and physical strain.

At present, new treatments are not yet available for people with type 1 diabetes. Only a small group of people with type 1 diabetes and Level 3 hypos have received a treatment with stem cell–derived islet cells as part of a clinical study. This study is investigating the effectiveness and safety of the therapy in both the short and longer term. Only if the results are positive will the therapy become available on the market.

The islets of Langerhans are located in the pancreas, where they produce the essential hormone insulin. In people with type 1 diabetes, the body’s immune system attacks these islets, causing them to produce little or no insulin, which leads to high blood glucose levels. Patients therefore need to inject insulin regularly. Diabetes can cause serious complications such as blindness, kidney failure, and cardiovascular disease.

By transplanting insulin-producing cells through an islet transplantation, it is possible for patients to no longer have diabetes. This approach helps prevent the progression of diabetes-related complications, and blood glucose regulation becomes normal or much easier.

For questions about your personal treatment, we kindly refer you to your current healthcare providers.

Cure One is a new research center fully dedicated to finding a cure for type 1 diabetes. It is a joint initiative of Stichting DON and Leiden University Medical Center (LUMC), firmly embedded within existing diabetes care. Cure One brings together leading scientific research, medical expertise, and societal engagement with one shared goal: to achieve functional cure within five years for an initial group of people with type 1 diabetes — using a strategy that eliminates the need for anti-rejection medication. Leiden plays a key role in a European network focused on curing T1D.

Type 1 diabetes (T1D) is an autoimmune disease that often begins at a young age. There are many misconceptions about it — that it is “easy” to manage or even “solved” by modern technology. But for many people living with type 1 diabetes, it remains an exhausting, daily struggle.

Although extensive research is being conducted worldwide and major biotechnology companies are developing new treatments, a true cure is still out of reach for everyone with type 1 diabetes. However, recent scientific advances — in stem cell technology, gene therapy, and immune modulation — have made the goal of a cure more realistic than ever. What’s needed now is acceleration. And that’s exactly what Cure One aims to deliver.

Stichting DON is co-founder, funder, and strategic partner of Cure One. In 2025, DON is investing two million euros, with the ambition to repeat this annually. The foundation contributes strategic insight, a strong network, and promotes valorization and talent development. Through this entrepreneurial role, DON accelerates the translation of scientific research into clinical application.

At Leiden University Medical Center (LUMC), all the expertise is in place to develop and bring new treatments for type 1 diabetes into clinical practice. The hospital is a true pioneer in regenerative medicine — an approach focused not on managing symptoms, but on actually curing diseases. Over the years, researchers have gained extensive experience with stem cell technology, which they use to create new insulin-producing cells.

The LUMC is also well known for its research into the immunology of type 1 diabetes. Leading scientists have uncovered important insights into how the disease develops, providing valuable knowledge for the creation of new therapies.

Finally, LUMC is the only academic hospital in the Netherlands that performs so-called islet transplantations. Since 2007, this complex but highly impactful procedure has been carried out at the LUMC Transplant Center. This makes LUMC uniquely positioned not only to develop new treatments, but also to apply them directly in clinical care.

Cure One is led by internist-endocrinologist Eelco de Koning. His research group, together with those of Bart Roep, Arnaud Zaldumbide, Françoise Carlotti, and Marten Engelse, forms the foundation of the center’s work. In addition, the Clinical Research Unit of Internal Medicine (KRIG) is closely involved in preparing and overseeing the clinical studies that originate from the center.

Most research efforts are fragmented and funded on a project-by-project basis. Cure One brings together fundamental and clinical research in a single center, under one clear strategy — a truly unique approach.

The focus is not on knowledge for its own sake, but on real solutions for people with type 1 diabetes. By combining DON’s entrepreneurial drive with LUMC’s scientific excellence, we accelerate the journey from theory to therapy. Cure One thinks in terms of cure, not just science.

At the moment, participant enrollment for ongoing studies has been paused. This means there is no longer space for new people with type 1 diabetes to receive treatment during these studies.

However, you can express your interest in taking part in future studies. To do so, send an email to cureone@lumc.nl, and we will get in touch with you.

Lead researcher and director of Cure One, Eelco de Koning, is committed to achieving a functional cure for the first group of patients within five years using a strategy that does not require anti-rejection medication. But every person with type 1 diabetes is different — there is no single solution for everyone. After that, more patient groups, more research, and more scaling will follow. It is a process, and Cure One is the first place where it truly begins.

Within five years, Cure One aims to achieve a functional cure for the first group of people with type 1 diabetes using a strategy that does not require anti-rejection medication — meaning they can live without external insulin and without the risk of medication side effects. A cure for everyone will follow, but it starts here.

We aim for a complete cure for as many people with T1D as possible, as well as the prevention of new cases. This requires multiple solutions for different patient groups. Cure One is therefore building a patent portfolio, collaborating with international partners, and creating spin-offs to scale up.

Stem cells are special cells that can replicate themselves, making them an unlimited source of new cells that can be used as medicine.

At Cure One, we use so-called pluripotent stem cells. Pluripotent means they can still develop into any type of cell in the body. By adding the right substances to the cells’ culture medium, researchers can guide pluripotent stem cells to mature into small clusters of cells (about 0.1–0.3 mm in size) that closely resemble the islets of Langerhans — the structures normally found in the pancreas where insulin-producing cells reside. These clusters, called stem cell–derived islets, are used as a new treatment for people with type 1 diabetes whose pancreatic islets have been destroyed.

Because stem cells can replicate, they may allow us to produce an unlimited number of islets in the future. These can be used to functionally cure far more people with type 1 diabetes than is currently possible using islets from donor organs.

Yes, that’s correct. It offers the prospect that, unlike islets from organ donors, many more people with type 1 diabetes could potentially be functionally cured, because pluripotent stem cells provide an essentially unlimited source of islets. Initially, as long as anti-rejection medication — which carries serious health risks — is still required, the treatment would primarily target people with severe glucose-related problems.

However, the stem cell lines also allow for small modifications to the cells’ DNA. Cure One is researching these changes, which may eventually reduce or eliminate the need for anti-rejection medication, or otherwise protect the islets from the immune system. If successful, this could make the treatment an option for much larger groups of people with type 1 diabetes.

Yes, there are risks associated with new treatments. These therapies are still experimental. The most recent study in which LUMC is participating has shown no safety issues with the cell product itself, but there is no information yet on the long-term safety of the treatment.

In addition, study participants — just like people receiving islets from organ donors — must take immunosuppressive medication for the rest of their lives to prevent the body from rejecting the islets. These medications can have potentially life-threatening side effects, especially serious infections.

The procedure to implant the islets into the liver also carries a risk of liver bleeding, estimated at around 5%.

On our website, you can read more about our research and the new treatments we are developing.

You can choose through which foundation you would like to make a donation or legacy gift. Both routes fully support Cure One.

Stichting DON — we just care for cure
The initiator and strategic partner behind Cure One. DON guides the mission, oversees the use of funds, and accelerates research in the public interest. Will you help create a future where type 1 diabetes no longer exists? Become a partner in this mission.
Donate via www.don.nl or email info@don.nl for a donation or legacy gift.

LUMC Foundation (formerly Bontius Stichting)
The official fundraising foundation of LUMC. Donations and legacies specifically intended for Cure One are used exclusively for that purpose.
Email bontiusstichting@lumc.nl or call +31 71 526 25 54 (relationship manager Juliette Kops) for a donation or legacy gift.

You help make it possible that within a few years, the first group of people with type 1 diabetes could be functionally cured using a new strategy that does not require anti-rejection medication. Donations through DON act as a leverage: they enable the acquisition of additional public funding and give Cure One and its researchers the freedom to plan ahead. In this way, you directly contribute to accelerating the cure for type 1 diabetes.

Organizations and foundations can become partners of Cure One. They can contact us at cureone@lumc.nl, and together we will explore how collaboration can accelerate the research at our center.

If you would like to contribute in another way, we are also happy to get in touch and discuss the possibilities with you.