Stem Cells Could Help Diabetics Produce Their Own Insulin
/By Pat Anson, PNN Editor
With insulin prices soaring out-of-reach for many U.S. patients, there’s hope on the horizon for people with Type 1 diabetes. Researchers are making significant progress in developing stem cell therapies that could restore their ability to produce their own insulin.
Interim findings from two early stage clinical trials, published today in the journals Cell Stem Cell and Cell Reports Medicine, show that pancreatic endoderm cells derived from human pluripotent stem cells (PSCs) began producing insulin in diabetic patients within months of being implanted in a tiny device under the skin.
While the amount of insulin secreted by the cells was not enough to cure Type 1 diabetes, they were sufficient enough to reduce the insulin requirements of some patients by as much as 20% and increase the amount of time spent in their targeted blood glucose range. Both studies showed that the stem cells can survive up to 59 weeks after implantation.
"A landmark has been set. The possibility of an unlimited supply of insulin-producing cells gives hope to people living with type 1 diabetes," says Eelco de Koning, MD, of Leiden University Medical Center in the Netherlands, who co-authored a commentary published in Cell Stem Cell. "Despite the absence of relevant clinical effects, this study will remain an important milestone for the field of human PSC-derived cell replacement therapies as it is one of the first to report cell survival and functionality one year after transplantation."
There are a number of caveats here. Less than three dozen patients participated in the Phase 1/2 studies, the outcomes were highly variable, and there were no control groups to compare the results with. The implanted stem cells were also derived from donors – meaning the patients had to take immunosuppressive drugs to prevent their bodies from rejecting the implants, leaving them vulnerable to infections. At least two patients experienced serious adverse events associated with having their immune systems suppressed.
Researchers still need to determine at what stage the stem cells are optimal for transplantation and the best place to implant them. It is also not clear how long the cells remain effective and whether the need for immunosuppressive therapy can be eliminated.
But the studies demonstrate that stem cells can mimic the insulin-producing pancreas cells that diabetics lack.
“A landmark has been set. The possibility of an unlimited supply of insulin-producing cells gives hope to people living with type 1 diabetes.”
"The clinical road to wide implementation of stem cell-derived islet replacement therapy for type 1 diabetes is likely to be long and winding,” de Koning says. "But an era of clinical application of innovative stem-cell based islet replacement therapy for the treatment of diabetes has finally begun."
About 460 million people worldwide have diabetes mellitus, a disorder in which the body does not produce enough insulin, causing blood sugar (glucose) levels to be abnormally high. In Type 1 diabetes, the body’s immune system attacks the insulin producing cells of the pancreas. Left untreated, diabetes damages blood vessels and significantly raises the risk of stroke, heart attack and diabetic neuropathy.
Diet, exercise and regular insulin injections can help control Type 1 diabetes. But with insulin selling for about $300 a vial in the United States – 10 times more than in other developed countries -- some diabetics have rationed or even stopped taking the life-saving injections.
Another encouraging stem cell study -- involving just one patient -- was recently reported by Vertex Pharmaceuticals. A chronically ill man with Type 1 diabetes who has been taking insulin injections for decades – up to 34 units per day – began producing his own insulin after being injected with an experimental stem cell product called VX-880.
As a test, researchers only injected him with about half the targeted amount of VX-880, but within 90 days the man had reduced his need for insulin injections by 91 percent.
“These results from the first patient treated with VX-880 are unprecedented. What makes these results truly remarkable is that they were achieved with treatment at half the target dose,” Bastiano Sanna, PhD, Executive Vice President of Vertex, said in a statement. “While still early, these results support the continued progression of our VX-880 clinical studies, as well as future studies using our encapsulated islet cells, which hold the potential to be used without the need for immunosuppression.”
Vertex plans to expand the study to eventually include up to 17 patients, at multiple sites in the U.S. and Canada.
