Type 1 diabetes patients no longer insulin-dependent after stem cell therapy

Ten out of 12 patients no longer require insulin treatment for type 1 diabetes one year after receiving stem cell-derived pancreatic islet cells.

Zimislecel (VX-880) is an allogeneic stem-cell therapy in Phase I/II clinical development. The results of the trial were presented at the 85th Scientific Sessions of the American Diabetes Association in Chicago and published in the New England Journal of Medicine. Twelve patients received a full dose of zimislecel as a single infusion, which consists of pancreatic islet cells created from healthy donor stem cells. The islet cells engrafted and started producing insulin in all patients, who were free of severe hypoglycaemic events after three months. Ten of the 12 patients no longer required regular insulin injections to maintain their blood glucose levels one year after the stem-cell transplant.

'Hypoglycaemia remains a dangerous risk for individuals with type 1 diabetes who are dependent on exogenous insulin administration,' said Professor Michael Rickels, the senior author of the study from the University of Pennsylvania Perelman School of Medicine, Philadelphia. '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 glycaemic control.'

Type 1 diabetes is a chronic autoimmune condition in which the immune system attacks the insulin-producing beta cells in the pancreatic islets, resulting in difficulties controlling blood glucose levels. Current treatment requires monitoring of the patients' glucose levels and injection of insulin. However, the narrow therapeutic range of insulin makes it difficult to keep blood glucose levels consistent, causing severe hypoglycaemia, potentially leading to conditions including vascular problems, seizures and loss of consciousness. Without timely treatment, severe hypoglycaemia may lead to coma and death.

'The results we've seen so far for restoring endogenous insulin secretion with a stem cell-derived islet therapy bring me hope and confidence for a transformative treatment option for individuals with type 1 diabetes in the not-so-distant future,' said Professor Rickels.

Cell therapies have potential for restoring the function of damaged tissues. They are usually made in a laboratory by differentiating pluripotent stem cells into the desired cell type. In this case, pancreatic islet cells were made from pluripotent stem cells and then infused into the liver. After 12 months, the transplanted islet cells appeared to respond to the patients' glucose levels and produce insulin when required.

The restoration of islet function in the patients is promising, however researchers will need to continue to follow these patients beyond the 12 months presented in this study to determine the longevity of the treatment. As with all transplantations, there is also risk involved with the immune suppression required to stop the patients' immune systems from rejecting the transplanted cells.

In addition, further studies with larger, more diverse groups of type 1 diabetes patients will be needed to prove broader efficacy.

'We are excited to complete enrolment and dosing in the Phase I/II/III programme and look forward to potential regulatory submissions next year,' said Dr Carmen Bozic, executive vice president and chief medical officer at Vertex, the company that developed the therapy.