Breakthrough in Diabetes Treatment: Lab-Grown Cells Restore Insulin Production

In a promising advancement for diabetes treatment, a recent clinical trial has demonstrated the potential of lab-grown cells to restore insulin production in individuals suffering from severe type 1 diabetes. The study, published in the esteemed *New England Journal of Medicine* in June 2025, explored an innovative therapy known as zimislecel, which involves the infusion of stem cell-derived islet cells into the liver of patients who have endured long-standing type 1 diabetes.

Type 1 diabetes is characterized by the immune system's attack on the pancreas's islet cells, which are responsible for insulin production. Without these cells, patients depend on external insulin, often facing challenges in managing blood sugar levels. Current treatments, including insulin pumps and continuous glucose monitors, while beneficial, fail to replicate the natural function of a healthy pancreas, leaving many patients with uncontrolled blood sugar levels.

The clinical trial involved 12 participants, all of whom had been diagnosed with type 1 diabetes for over two decades and had no detectable insulin production. Following the infusion of zimislecel, a remarkable transformation was noted: within 90 days, all participants began producing C-peptide, a biomarker for insulin production, with levels increasing significantly by day 365. Notably, blood sugar control improved markedly; prior to treatment, none of the participants had an HbA1c level below 7%, yet four months post-infusion, all maintained levels below this threshold.

According to Dr. Nihal Thomas, Professor of Endocrinology and Head of the Centre for Stem Cell Research at Christian Medical College, Vellore, the results are encouraging. “In the group studied, the response is very encouraging, with clear signs that insulin production and cell function were preserved for a meaningful period of time,” Dr. Thomas stated. Ten participants ceased needing insulin altogether, while the remaining two required significantly less.

The trial's design included an immunosuppressive regimen to prevent the body from rejecting the transplanted cells, although some participants experienced manageable side effects, such as headaches and gastrointestinal issues. The authors noted that while two patient deaths occurred during the trial, neither was directly linked to zimislecel.

As the research progresses, phase 3 trials have already been initiated, involving 50 participants from various countries who will be monitored for five years. This ongoing research is crucial, considering the estimated 2.2 million children with type 1 diabetes in India alone, as reported by global estimates. Despite initiatives aimed at improving diabetes care access, advanced technologies remain largely unattainable for many.

Dr. Thomas emphasizes that while the findings mark a significant step forward, key concerns regarding the therapy's cost and the implications of long-term immunosuppression remain. “This study marks a promising step forward in a field that has seen remarkably slow progress over the last 70 years,” he concluded. As the landscape of diabetes treatment evolves, the potential to restore natural insulin production could transform lives and reduce the burden of this chronic disease.