An investigational stem cell-derived therapy for people with type 1 diabetes, developed by the Boston-based company Vertex Pharmaceuticals, has been shown to be effective at restoring insulin production in the first person to receive the therapy, according to a recent announcement from the company.
The new therapy, known as VX-880, involves infusing fully functional pancreatic islet cells — derived from human stem cells, rather than taken from an actual pancreas — into a person with type 1 diabetes. The recipient must also take drugs that suppress the immune system’s attack on these new cells, since they come from outside the body and are seen by the immune system as foreign invaders. In someone with type 1 diabetes, the pancreas no longer has enough fully functional islet cells to produce insulin — the hormone that allows the body to use glucose (sugar) from the blood as energy for cells. Without insulin, blood glucose levels build up and cells cannot get enough energy — eventually leading to death unless insulin from outside the body is injected (or infused using an insulin pump).
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Treatment well tolerated
For the first person who received VX-880, the trial investigators used only half of the target dose as a safety precaution. The treatment resulted in successful engraftment — meaning that the new islet cells took hold in a major blood vessel and began to produce insulin. The recipient quickly showed improvement in a few areas, including fasting and stimulated (food-induced) C-peptide — a measure of insulin production by the pancreas — along with overall glucose control including A1C (a measure of long-term blood glucose control) and external insulin needed. The treatment was also well tolerated, without any serious side effects.
“What makes these results truly remarkable is that they were achieved with treatment at half the target dose,” said Bastiano Sanna, PhD, executive vice president and chief of cell and genetic therapies at Vertex. “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.”
The company’s encapsulated islet cells are another investigational treatment that would eliminate the need to take drugs that suppress the immune system in the recipient. That’s because the cells are protected by a membrane that shields them from the immune system, allowing them to be implanted in the recipient’s abdomen. This treatment has not yet been tested in humans.
For the latest trial of VX-880, the recipient had had type 1 diabetes for about 40 years and experienced five severe episodes of hypoglycemia (low blood glucose) in the year before receiving VX-880. Before receiving the new treatment, the recipient needed to take 34 units of insulin per day and had undetectable levels of C-peptide — indicating that their pancreas produced no insulin at all. After 90 days, the picture was very different when it came to insulin production. Fasting C-peptide increased from undetectable to 280 pmol/L, and peak stimulated C-peptide increased to 560 pmol/L. The need for external insulin dropped to 2.9 units per day — a decrease of 91%. At the same time, A1C dropped from 8.6% before the treatment to 7.2%.
Based on these results, Vertex plans to continue testing VX-880 at multiple sites across the United States. It is also continuing with studies of its encapsulated islet cell program, which the company hopes will let it apply for investigational new drug (IND) status for this program in 2022. Official IND status is needed before a new drug can be studied in humans.