This transcript has been edited for clarity.
Recently, my patients have been asking me if there’s a new cure for people with type 1 diabetes. This has been in the news and it was a front-page story in The New York Times. So, Is it true? In a word, no. But we are part of the way there, which is much closer than we were 6 months ago.
The way I think about it, to cure type 1 diabetes, we need two things: We need a ready supply of islet cells so that we can give people without islet cells new islet cells that can make insulin. We need immune tolerance to these islet cells so we don’t need to give people immunosuppression.
Recently, two companies, ViaCyte and Vertex, have been able to show that stem cell–derived cells can become functional beta cells when infused into humans. Although it requires immunosuppression for these cells to work, it still solved part of the problem. It’s showing us that we can have a supply of stem cells that will turn into islet cells that can help cure type 1 diabetes.
For full disclosure, I have worked as an unpaid consultant to ViaCyte and I have received honoraria for consulting for Vertex. As such, I’m only going to discuss what is in the public domain provided through company-created press releases.
Let’s talk about Vertex. Vertex released the results of their first patient to receive these stem cell–derived differentiated islet cells. This is a phase 1/2 clinical trial, and the compound is called VX880. This was developed by Dr Doug Melton at Harvard. The first patient to receive this treatment was a man in his 50s. He’s had 40 years of type 1 diabetes and has had recurrent episodes of severe, level 3 hypoglycemia.
He was given half a dose of VX880 plus immune suppression. Within 90 days, he responded. His insulin dose was reduced from 34 to 3 units, and his C-peptide response, showing that these beta cells were working, was markedly improved on a mixed meal tolerance test. His A1c fell from 8.6% to 7.2%, and he became free of these life-threatening episodes of severe hypoglycemia.
This worked in the first patient. Now, obviously, we need to go forth and do this in many other patients, and this trial is ongoing. Vertex published two articles on stem cell–derived therapy in two different journals, Cell Stem Cell and Cell Reports Medicine.
The Cell Reports Medicine paper reported on 17 patients who were implanted with ViaCyte’s PEC-Direct devices, which are subcutaneous pouches. In the pouches are stem cell–derived pancreatic cells, and these pancreatic cells turn into functioning islet cells. In these 17 individuals, they saw the development of positive C-peptide levels, which basically shows that they’re making insulin. They saw this as early as 6 months after this was implanted in some of their patients.
These initial data suggest that pancreatic endoderm cells can be differentiated into a renewable source of insulin-producing pancreatic islet cells.
The second paper, which was in Cell Stem Cell, reported on the 15 patients who were treated at the trial’s largest participating site, the University of British Columbia and Vancouver Coastal Health in Canada. They showed at these two sites that 6 months after implantation, the cells had, again, matured into insulin-producing islet cells. They saw a rise in C-peptide levels after patients ate a meal, and this was indicative of functional insulin production from these islet cells.
Patients spent 13% more time in target glucose range, and some were able to reduce the amount of their injected insulin. With these ViaCyte pouches, immunosuppression is still required.
Again, this is part of the way to curing type 1 diabetes. The next step is to make beta cells that don’t require immunosuppression to function. Many companies are working on this. To mention one, CRISPR Therapeutics has partnered with ViaCyte to develop a novel beta cell replacement therapy.
CRISPR is a gene-editing platform, so basically they’re attempting to create an allogeneic gene-edited, immune-evasive stem cell–derived therapy for the treatment of people with type 1 diabetes. The first clinical trial with this will be done in Canada and should be starting soon.
Have we cured type 1 diabetes? No, but we are advancing in terms of our treatments for type 1 diabetes, and I think we’re closer than we ever have been to making it much easier for people to live with type 1 diabetes. The development of these new therapeutic approaches is incredibly exciting, and I think in the next few years we’ll learn newer, novel, and better ways for helping our patients with type 1 diabetes.
This has been Dr Anne Peters for Medscape. Thank you.