Another month, and another experimental “cure” for type 1 diabetes is in the news.
It’s good news … but don’t get too excited yet. The treatment is still in its earliest stages of testing.
It was only in October that an exciting new lab-grown islet cell transplantation treatment for type 1 diabetes made international news by showing strong results in its first patient. Now a different stem cell treatment has published results from its first phase 1/2 trial.
The new technique involves an implantable device containing pluripotent stem cells that have been engineered to grow into functioning islet cells, fully capable of secreting insulin. It is the innovation of ViaCyte, a California biotech firm that focuses on “developing novel cell replacement therapies as potential long-term diabetes treatments.” The makers hope that their technique can be further refined into a “functional cure.”
While the treatment has a lot of potential, the patients in the present study were not, in any sense, cured of type 1 diabetes.
For one thing, blood sugar results were not impressive. The patients in the study showed only modest improvements in their diabetes management results. The transplanted cells did secrete insulin, but not a lot of it, and they weren’t able to pump up their productivity in response to meals. A year after receiving the transplant, the patients had reduced their insulin usage by 20%, and spent 13% more time in-range. These are nice improvements, but they weren’t statistically significant in this small sample. And even if they can be replicated they are not approaching the results you’d expect from a “cure.”
For another, the implantable device that ViaCyte tested requires the use of immunosuppressive drugs. ViaCyte does have another similar device in the pipeline that may not need immunosuppression – it is that second device that still awaits its first significant testing that could one day represent a functional cure for type 1 diabetes.
Illustration by Diabetes Daily (Product images by ViaCyte); Studies demonstrate that transplanted PEC-01 cells producte insulin (blue), glucagon (red) and somatostatin (green).
ViaCyte is nevertheless celebrating the results of the trial, which was only designed prove that the core concept works. The implanted cells successfully grew into insulin-secreting cells and stayed safe in their implanted device for an entire year, and the device itself was tolerated well by the participants. In future experiments the company will use higher volumes of stem cells in the hopes of delivering significant blood sugar improvements.
Readers can be forgiven if they’re skeptical – many people with long-term diabetes have been hearing that a cure is “five or ten years away” since the 70’s or 80’s. When we spoke to ViaCyte in the spring, two of the clinical development leads told us that they hoped that their full “functional cure” would be available “within a decade.”
For readers eager to dive into the science, the studies of the new technique can be found in the December issues of Cell Stem Cell and Cell Reports Medicine. Cell Stem Cell also published a comment on the new technique by two diabetes researchers, who wrote that results, “despite the absence of relevant effects,” represented a landmark:
“The possibility of an unlimited supply of insulin-producing cells gives hope to people living with T1D. An era of clinical application of innovative stem-cell-derived islet replacement therapy for the treatment of diabetes has finally begun.”
The progress may seem slow, but these are undoubtedly still exciting days for people eager for news of a cure for type 1.
It was in October that a different biotech firm, Vertex, announced the results from its first significant human experiment. This procedure, named VX-880, transplants healthy new lab-grown islet cells into the body of a patient with type 1 diabetes. These cells can then sense blood glucose levels, secrete insulin in response, and send that insulin to the liver, where it is used to regulate the patient’s blood sugar.
A few weeks after the news broke, the New York Times followed up with an exclusive profile of Vertex’s lucky first patient. Although he still uses some insulin, he enjoyed a remarkable 91% reduction in daily insulin usage, and a big A1C improvement to boot. He told the Times that the treatment was “like a miracle.”
All of this recent news concerns treatments that do require the patient to take immunosuppressive drugs, so that the body does not reject the implanted cells and/or device. Those drugs can have serious side effects. Accordingly, some in the diabetes community are less than enthusiastic about these treatments, because they may involve trading one set of health issues for another. In the recent ViaCyte trial, the most significant negative side effects were related to the immunosuppressive regimen, not to the treatment itself.
A treatment that requires a whole new pharmaceutical regimen for immunosuppression won’t really count as a “cure,” but it nevertheless could be a huge improvement for many people with type 1 diabetes.
Both ViaCyte and Vertex, which seem to be on parallel paths, are working on even fancier treatments that could allow transplanted or implanted islet cells to work safely without immunosuppressive drugs. It will be years before those treatments are ready for FDA evaluation, if they ever get there. But we’ll keep watching and hoping for more progress.
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