Can Stem Cells Replace Daily Insulin? Understanding Islet Transplants

For people with type 1 diabetes, managing blood sugar with daily insulin injections could soon become a thing of the past. Stem cell-derived islet transplants are showing promise in restoring natural insulin production. Recent clinical trials, such as Vertex Pharmaceuticals' 2025 FORWARD study, revealed that 83% of participants achieved insulin independence within a year. Unlike conventional islet transplants, which rely on limited donor organs, lab-grown islets offer a scalable solution. Autologous therapies, using a patient’s own cells, further eliminate the need for immunosuppressive drugs, making these treatments safer and more personalized. However, challenges like high costs, limited availability, and production hurdles remain. While still experimental, these advancements suggest a future where diabetes care shifts from management to potential cure. This technology is also being explored for treating rare diseases and other chronic conditions.

How Islet Transplants Work

Islet Cells and Insulin Production

Inside the pancreas, tiny clusters called islets of Langerhans house beta cells, which play a key role in controlling blood sugar. After eating, these beta cells sense rising glucose levels and release insulin. This hormone helps muscle and fat cells absorb glucose, either using it for energy or storing it for later.

In people with type 1 diabetes, the immune system mistakenly destroys these beta cells. Without them, the body can’t produce insulin, causing blood sugar to spike dangerously high. This leads to chronic hyperglycemia and can even trigger life-threatening ketoacidosis. Since the central nervous system relies on a steady glucose supply - around 70 mg/dL at minimum - this regulation is essential for survival.

Traditional Islet Transplants: Current Challenges

Traditional islet transplants involve taking islets from a deceased donor’s pancreas and infusing them into the recipient’s liver via the portal vein. Once transplanted, the islets reconnect with blood vessels and begin producing insulin. A major milestone in this field came in June 2000 with the Edmonton Protocol, led by Dr. James Shapiro at the University of Alberta, where 44% of patients achieved insulin independence one year after the procedure.

Despite its promise, this method faces serious hurdles. The biggest issue is the limited supply of donor islets. Between 1999 and 2015, only 1,086 people worldwide received islet transplants for type 1 diabetes. A single transplant requires about 400,000 islets, often needing multiple donors to meet this demand. Additionally, recipients must take lifelong immunosuppressive drugs to prevent rejection, which increases risks for infections, kidney damage, and even cancer. These barriers mean that only about 10% of people with type 1 diabetes qualify for this procedure. To address these limitations, researchers are now focusing on stem cell-derived islets as a more scalable option.

Stem Cell-Derived Islets: A New Approach

Stem cell-derived islets present a potential game-changer by offering a laboratory-grown supply of insulin-producing cells. Unlike traditional transplants that rely on deceased donors, these islets can be produced in large quantities with consistent quality using different types of stem cells, such as human pluripotent stem cells.

"Rather than relying on cadaveric cells, pluripotent stem cells could serve as a virtually unlimited supply of insulin-producing β cells." – Endocrine Reviews

A groundbreaking study in September 2024, led by Dr. Wang at Nankai University, showcased the promise of this approach. Researchers successfully transplanted stem cell-derived islets created from a 25-year-old woman’s own adipose tissue. Before the procedure, the patient had undetectable C-peptide levels, but by day 75, she achieved complete insulin independence. Over the next 12 months, she maintained over 98% time-in-range for blood glucose levels without needing anti-rejection drugs. This autologous method - using the patient’s own cells - eliminated the need for immunosuppressive medication, hinting at a future where diabetes treatment could become more accessible and safer. This success marks an exciting step forward in stem cell-derived islet therapy.

Progress in Stem Cell-Derived Islet Therapy

Pluripotent Stem Cells and Patient-Specific Islets

Researchers are exploring two promising methods to advance stem cell-derived islet therapy. The first involves using pluripotent stem cells - either from embryonic sources or reprogrammed adult cells - to create standardized, ready-to-use islets. This approach allows for large-scale production of islets, offering an "off-the-shelf" solution that eliminates the need for organ donors.

The second method focuses on patient-specific islets, where a person's own adipose (fat) tissue is reprogrammed into chemically induced pluripotent stem cells (CiPSCs). These CiPSCs are then matured into functional islets. Unlike older techniques that relied on viral vectors to alter genetic material, this chemical reprogramming process uses small molecules, avoiding the introduction of foreign DNA. This not only enhances safety but also reduces the likelihood of immune rejection when these islets are transplanted back into the same individual. Both approaches are paving the way for rigorous clinical trials to further validate their effectiveness.

Clinical Trials and Current Results

These cutting-edge techniques are now being tested in clinical trials, with encouraging early results. In June 2025, Vertex Pharmaceuticals conducted a Phase 1/2 FORWARD study of zimislecel (VX-880) under the leadership of Dr. Michael Rickels. This trial involved 14 participants with type 1 diabetes, who received lab-grown islets infused into their liver's portal vein. By day 365, 10 out of 12 participants in the full-dose group achieved complete insulin independence, reflecting an 83% success rate. Additionally, all participants eliminated severe hypoglycemic events and spent over 70% of their time within the target glucose range of 70 to 180 mg/dL.

"These findings indicate the potential for a novel cellular therapy that restores endogenous insulin secretion to improve outcomes for type 1 diabetes patients who have been struggling to achieve glycemic control." – Michael Rickels, MD, MS, Professor in Diabetes and Metabolic Diseases, University of Pennsylvania Perelman School of Medicine

Autologous (patient-specific) approaches are also showing remarkable promise. In April 2024, researchers at Shanghai Changzheng Hospital treated a 59-year-old man with type 2 diabetes using islets derived from his own endoderm stem cells. After receiving 1.2 million islet equivalents, the patient stopped needing exogenous insulin by week 11. At a 113-week follow-up, his HbA1c levels dropped from 6.6% to 4.6%, which is well within the normal range for individuals without diabetes. These results highlight the potential for achieving long-term insulin independence through stem cell-derived therapies.

Addressing Immune Rejection Through New Technologies

Hypoimmunogenic Stem Cell Engineering

Immune rejection has long been a major obstacle for islet transplants, as the body's immune system often attacks foreign cells. To tackle this, scientists are using CRISPR gene-editing technology to create "invisible" stem cells that can bypass immune detection.

Here’s how it works: researchers remove the B2M gene to eliminate HLA Class I molecules, which stops CD8+ T cells from identifying and destroying the transplanted cells. They also delete the CIITA gene to lower HLA Class II expression, preventing CD4+ T cells from triggering an immune response. However, these changes can provoke NK cells to attack due to missing self signals. To counter this, scientists enhance the cells with HLA-E, HLA-G, and CD47 expression, which suppresses NK cell and macrophage activity.

In early 2025, a groundbreaking study led by Per-Ola Carlsson at Uppsala University Hospital, in collaboration with Sana Biotechnology, tested this approach in a human patient with long-standing Type 1 diabetes. They transplanted "hypoimmune platform" (HIP) islets - engineered to lack HLA Class I and II markers and overexpress CD47 - into the patient’s forearm muscle. By week 4, the patient showed glucose-responsive C-peptide secretion, and this response lasted for 12 weeks.

"Hypoimmune islets evaded T-cell, natural killer (NK)-cell, macrophage, and antibody-mediated rejection, which reflects a level of immune protection that has not been achieved thus far with partially edited or wild-type islets." – Joonyub Lee, Division of Endocrinology and Metabolism, The Catholic University of Korea

These advancements pave the way for more refined transplant methods in the future.

Mixed Immune Systems and Combined Therapies

Another promising method involves creating a "mixed immune system" by transplanting blood stem cells alongside pancreatic islets. This approach helps the recipient's immune system recognize the transplanted islets as part of the body, reducing the need for lifelong immunosuppressive drugs.

In November 2025, researchers from Stanford Medicine, led by Dr. Seung K. Kim and Preksha Bhagchandani, published their findings in the Journal of Clinical Investigation. Using a pre-transplant regimen with immune-targeting antibodies and low-dose radiation, they transplanted blood stem cells and pancreatic islets from mismatched donors into diabetic mice. The results were extraordinary: 19 out of 19 animals avoided developing Type 1 diabetes, and 9 out of 9 diabetic mice were completely cured. These mice required no insulin or immunosuppressants for six months.

"Now we know that the donated blood stem cells re-educate the recipient animal's immune system to not only accept the donated islets, but also not attack its healthy tissues." – Seung K. Kim, MD, PhD, Professor at Stanford University

This combined therapy offers a less invasive way to achieve long-term immune tolerance and improved outcomes.

Subcutaneous Implants with Vascular Support Cells

Subcutaneous and intramuscular transplant sites offer less invasive alternatives to traditional methods. However, ensuring the transplanted islets receive enough blood supply has been a persistent challenge.

Researchers at Weill Cornell Medicine have developed a solution. In January 2025, Dr. Shahin Rafii and Dr. Ge Li published a study in Science Advances showing how reprogrammed vascular endothelial cells (R-VECs) can support subcutaneous islet transplants. By co-transplanting R-VECs with human islets into immune-deficient diabetic mice, they created a robust network of blood vessels that connected to the host's circulation. This provided essential oxygen and nutrients, leading to diabetes reversal for the entire 20-week study duration. In contrast, mice receiving islets without R-VECs did not achieve the same success.

"We showed that vascularized human islets implanted into the subcutaneous tissue of mice that were immune-deficient promptly connected to the host circulation, providing immediate nutrition and oxygen, thereby enhancing the survival and function of the vulnerable islets." – Dr. Shahin Rafii, Director of the Hartman Institute for Therapeutic Organ Regeneration, Weill Cornell Medicine

Subcutaneous sites come with additional perks. They are easier to monitor and can be surgically removed if needed - advantages that liver-based transplants lack. In a 2025 clinical study, a patient achieved insulin independence within 75 days after islets were implanted beneath the abdominal anterior rectus sheath, further demonstrating the potential of this approach.

These breakthroughs in immune evasion and transplant techniques highlight the growing promise of stem cell-derived islets as a replacement for daily insulin therapy, offering hope for individuals living with diabetes.

Accessibility, Costs, and Timeline for Availability

Who Qualifies for Islet Transplants

Currently, stem cell-derived islet transplants are offered only through clinical trials, such as the Phase 3 FORWARD study. To qualify, patients must have Type 1 diabetes (T1D) with severe hypoglycemia unawareness - a condition where they cannot sense dangerously low blood sugar levels - and show no natural insulin production, typically confirmed by undetectable C-peptide levels. This condition affects about 6% of T1D patients, making them the primary focus for these trials.

Some trials also include T1D adults who have already undergone kidney transplants and are taking immunosuppressive medications. However, individuals with active infections, certain cancers, or liver disease - conditions that make lifelong immunosuppression dangerous - are excluded. These strict requirements underscore the experimental nature of this therapy while researchers work to broaden its scope.

Treatment Costs and Insurance Coverage

Since stem cell-derived islet therapy is still classified as "experimental", insurance companies generally do not cover it. For patients in future commercial settings, the cost is expected to be out-of-pocket, with advanced diabetes treatments estimated to range between $20,000 and $30,000.

For context, traditional islet transplants already cost over $100,000, excluding ongoing expenses for immunosuppressive drugs and monitoring. While clinical trials currently provide stem cell therapies at no charge, the eventual commercial price is uncertain due to the complexities of production and the therapy's classification as a drug product by the FDA.

"Without insurance, the price of stem cell therapy can be prohibitively high. In different clinics, treatments may range from $5,000 to over $30,000, depending on the complexity of the case." – Swiss Medica

Patients might be able to offset some costs using Health Savings Accounts (HSA) or Flexible Spending Accounts (FSA) if they obtain a letter of medical necessity from their doctor. Additionally, medical expenses surpassing 7.5% of Adjusted Gross Income may qualify as tax-deductible under IRS guidelines.

While these options provide some financial relief, the high cost of stem cell therapies and the challenges of scaling production remain significant barriers to widespread accessibility.

Timeline for Wider Availability and Production Challenges

The Phase 3 FORWARD study aims to complete its enrollment and dosing of around 50 participants by 2025. If the results mirror earlier successes, such as the 83% insulin independence rate observed in previous phases, regulatory approval could follow within a few years.

However, making these therapies widely available comes with challenges. Producing stem cell-derived islets at scale demands consistent manufacturing processes and specialized facilities. There’s also a limited number of interventional radiologists trained to perform the intricate infusion procedures. Transitioning to "off-the-shelf" cell lines, which don't require customization for individual patients, could help lower costs and speed up production once the therapy is approved.

"The introduction of sc-islets represents the most significant impending transformation in T1D cell therapy, promising to transition care from a model constrained by organ scarcity... to one defined by predictable supply." – Thomas Strakosch, Cell and Gene Therapy Catapult

For now, broader access is likely 3 to 5 years away for patients who meet strict eligibility criteria. Wider availability could take another 5 to 10 years, as production scales up and immune-evasion technologies advance to remove the need for immunosuppressive drugs. Expanding manufacturing capabilities will be a critical factor in making stem cell-derived therapies a practical alternative to daily insulin management.

Stem Cell Banking for Future Diabetes Treatments

How Stem Cell Banking Supports Diabetes Research

Banking stem cells at birth provides a critical resource for future regenerative therapies. Stem cells from cord blood, cord tissue, and placental tissue can be reprogrammed into induced pluripotent stem cells (iPSCs) - the same type used in groundbreaking diabetes trials to create insulin-producing islets.

Recent advancements have shown that preserved stem cells can be chemically transformed into glucose-responsive islets. These islets help achieve insulin independence and maintain over 98% time-in-range glycemic control.

But the benefits go beyond replacing lost islets. Banked blood stem cells also open doors to combined therapies. For instance, research suggests that transplanting blood stem cells alongside islet cells can create a "hybrid immune system." This approach prevents the body from attacking new insulin-producing cells, eliminating the need for both insulin injections and immunosuppressive drugs.

"We need to not only replace the islets that have been lost but also reset the recipient's immune system to prevent ongoing islet cell destruction. Creating a hybrid immune system accomplishes both goals." – Seung K. Kim, MD, PhD, Stanford Medicine

This dual benefit highlights the importance of early stem cell banking as a foundation for future diabetes treatments.

Autologous Stem Cells for Personalized Medicine

Preserving a person’s own stem cells (autologous stem cells) offers a personalized path to diabetes care. Using a patient’s own cells removes the risk of immune rejection and eliminates the need for lifelong immunosuppressive medications - an advantage donor-based therapies can't match.

"The use of autologous (own) stem cells will remove the need for this [immunosuppressant] medication." – Deng Hongkui, Lead Scientist, Peking University

Families with a history of Type 1 diabetes may find stem cell banking especially relevant. Additionally, mesenchymal stem cells (MSCs) from cord tissue show promise in supporting beta cell survival and regeneration. As research progresses, these cells could lead to multiple therapeutic options for managing diabetes.

Long-Term Storage and Future Access

With stem cell-based therapies advancing quickly, long-term storage ensures access to these treatments as they become widely available. Properly cryopreserved stem cells can remain viable for decades. Typically, hematopoietic stem cells are frozen in 10% dimethyl sulfoxide (DMSO) and stored in the vapor phase of liquid nitrogen, preserving their quality for future use.

The process for accessing stored cells varies depending on the treatment. For now, participation in clinical trials is the primary way to receive stem cell-derived islet therapy. Families work with their stem cell bank to release samples to research institutions. As these therapies gain FDA approval, accessing them will become more streamlined.

Storage also supports emerging safety innovations. New technologies allow doctors to remove transplanted cells using FDA-approved antiviral drugs if complications arise, offering added security for future treatments.

With an estimated 9 million people currently living with Type 1 diabetes - a number expected to climb to as many as 17.4 million by 2040 - banking stem cells today positions families to benefit from therapies that are rapidly transitioning from experimental to standard care.

Conclusion

From understanding islet transplants to exploring stem cell therapies, recent advancements are reshaping diabetes care. Stem cell-derived islet transplants, for instance, present a potential alternative to daily insulin injections. Clinical trials, such as the 2025 FORWARD study, highlight promising results, with participants achieving glycemic control below 7% A1C and impressive rates of insulin independence [1]. Autologous stem cell therapies, which use a patient’s own cells, further reduce the risks of immune rejection and eliminate the need for immunosuppressive medications.

These developments emphasize the value of early stem cell banking. Preserving your newborn's stem cells today could provide access to future personalized therapies. Stem cells from cord blood, cord tissue, and placental tissue have the ability to generate insulin-producing islets. When stored correctly through cryopreservation, these cells remain viable for decades, offering long-term potential for medical use.

Americord Registry provides comprehensive stem cell banking services tailored to safeguard your family’s future health. With AABB accreditation, FDA-approved processing methods, and clear pricing options across multiple family plans, Americord ensures reliable storage for your child’s biological materials, preparing for their potential role in regenerative medicine.

As these therapies progress from clinical trials to standard treatments, having stem cells banked today could secure your family’s access to tomorrow’s medical breakthroughs. Stem cell-derived islet transplants are proving capable of replacing daily insulin - will your family be ready when these therapies become widely available?

[1] American Diabetes Association Press Release, 2025.

FAQs

How long can an islet transplant keep me off insulin?

Islet transplants have shown potential to help some patients manage diabetes without relying on insulin for extended periods. Many recipients remain insulin-free for up to eight years, with over half achieving this independence during that time. In exceptional cases, patients have gone more than a decade without needing insulin. While outcomes differ from person to person, ongoing progress in this field offers hope for better long-term diabetes care.

Will I need lifelong immunosuppressants after a stem cell islet transplant?

Lifelong immunosuppressants are usually necessary after a stem cell islet transplant to stop the immune system from rejecting the transplant. That said, progress in this area continues, with researchers working toward ways to minimize or even eliminate the dependency on these medications down the line.

Should I bank my baby’s cord blood for future diabetes treatments?

Banking your baby’s cord blood might be an important step toward future diabetes treatments. Stem cell-based therapies, such as islet transplants, are showing potential to reduce or even eliminate the need for daily insulin by regenerating insulin-producing cells. Although these treatments are still in development, saving cord blood today could open doors to emerging regenerative therapies down the line, offering new possibilities for managing diabetes and other health conditions.