It’s hard in the cell therapy field not to get excited even with bits of seemingly encouraging news but with N=1 reports we have to be very cautious and that’s the case with news from Vertex on their 1st stem cell therapy for diabetes trial participant.
Vertex stem cell therapy for diabetes VX-880: N=1
This need for soberness came to mind with this new piece Vertex gets much-needed win with ‘extraordinary’ first patient results on potential diabetes cure in ENDPOINTS.
What’s the scoop here?
One trial participant with Type I diabetes reportedly had improved blood sugar stability after receiving a half-dose of the Vertex cellular therapy VX-880.
The man is around 90 days out from infusion with the experimental cell therapy.
As a reminder, Vertex is a large pharma company that acquired the small biotech Semma that was started by Doug Melton.
The current trial work has its foundation from Semma.
Vertex vs. ViaCyte
Where do we go from here on stem cell therapy for diabetes?
We should take it step by step.
It’s good for patients and the field that there’s competition in this space including from ViaCyte, which itself released its own similar update on 1 patient back in June.
The two companies are using somewhat similar approaches based on human pluripotent stem cells. I call this a stem cell therapy because it’s based on stem cells even though stem cells themselves are not directly used.
They each differentiate the cells in distinct ways toward the pancreatic lineage, which includes beta cells that make insulin.
I believe the intended delivery systems are somewhat different but involve capsules. ViaCyte seems far ahead on the encapsulated device front.
Interestingly the first Vertex participant was given an infusion.
“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,” said Bastiano Sanna, Ph.D., executive vice president and chief of cell and genetic therapies at Vertex.
Why an infusion to start? It’s a puzzling choice for a diabetes therapy. Do the cells engraft? Get rejected by the immune system? I guess one big advantage is it can be done quickly and simply as opposed to an encapsulated device.
Looking ahead on stem cells for diabetes
ViaCyte has had to make several adjustments in their clinical trial design over the past few years. For that reason I’d be surprised if Vertex also didn’t have to do that kind of thing too. Still it’s possible Vertex has learned from some of what ViaCyte’s experience.
I’m optimistic that a cell therapy approach of some kind will be proven safe and effective for at least helping Type I diabetes within a decade. Yes, that’s a long timeframe but these things always take way longer than you think. We’ve come a long way in the diabetes area in the last decade.
Re low-hanging fruit and CIRM, a researcher from UCSF used the term re diabetes. At the time, as I recall, he did not make it clear whether he was referring to type one or type two.
Thanks, Francisco. There is no low hanging fruit!
Hi Jeanne: Thanks for this excellent summary. The experience with the Edmonton protocol does indicate that the cadaveric cells seem to engraft, presumably in the liver, and we have seen long term success in at least a significant subset of patients, at the cost of lifelong immunosuppression. Presumably the stem cell derived cells do the same. The struggles of this group and Viacyte with encapsulation show that this, as with so many issues in stem cell science “is harder than it looks.” I was amused when,
early in the history of CIRM, a writer for a newspaper described type 1 Diabetes as “the low hanging fruit.” If only.
Hi Francisco,
I’ve also heard of other hoped-for “low hanging fruit” like using stem cells for some forms of macular degeneration. I’m still very hopeful on vision loss and with Diabetes but it’s always much harder and more time-consuming than one might wish.
Hope you are well!
Paul
Thanks. Ask Paul for my email!
I’ll send you a copy when its done…I have your email somewhere !
Thanks, Tom. I think there’s a lot of evidence of microglial activity in PD, but I haven’t yet heard anything about autoimmunity. I’ll be interested in what you find.
Jeanne
I really hope that immunosuppression will be a memory sometime soon. Awareness of the problems became clear during the pandemic.
Excellent comments Dr. Loring. I wonder though…are you sure there is no autoimmune component to Parkinson’s? we are writing a review trying to make a case for immunological aspects of PD…was curious what your position is on this
Keep up the excellent science !
Tom
Great summary Jeanne. The Edmonton Protocol is a helpful precedent in the Vertex situation, if only for unaware hypoglycemia patients.
I believe that science moves ahead in baby steps…the advances in tolerance induction procedures the need for life long immune suppression will one day be gone.
Type 1 Diabetes is a terrible disease and I congratulate all progress in this space
Type 1 diabetes is an obvious target for pluripotent stem cell-derived cell types for replacement therapy. Like Parkinson’s disease, there is a history of cell replacement therapy being successful….sometimes. The T1D treatment uses pancreatic islets harvested from cadavers, and the PD therapy used fetal tissue. Using cells derived from pluripotent stem cells (hESCs or iPSCs) is intended in these cases to make the replacement therapy safer and more reliable.
Unlike PD, T1D is an autoimmune disease. This means that even if a person were to receive islets derived from their own iPSCs (autologous), the islet cells would be attacked by the person’s immune system and killed. So immunosuppression or immunoprotection (like encapsulation) is necessary to prevent destruction of the cells.
Semma/Vertex is taking a cautious approach, starting with creating artificial islets from pluripotent stem cells and using the same delivery approach used for the cadaveric islets.
These islet-like cell clusters are presumably designed to be a similar size as genuine islets – my guess is 100-200 microns.
Size is important, because the islets are going to be injected into the hepatic portal vein, where they distribute into capillaries and get stuck. Living in the capillaries, the islets are bathed in blood and can react to blood sugar levels by releasing insulin. As long as they are the right size, they won’t block blood flow if they are too large or slip through if they are too small. Also, an aggregate of that size survives by simple diffusion of oxygen and nutrients, not requiring internal blood flow.
But the capillaries are not the normal environment for islets, so the long term survival of the stem cell-derived cells is a critical factor. That’s why I wasn’t as excited as I could be about the reported result for one patient at 90 days. I’d like to see what happens in 6 months or a year. The first question is whether patients will need additional injections at intervals, and if so, what intervals?
My second question for Vertex is: what is the composition of the aggregates? Are they only beta cells or a mixture of all of the cell types in islets? Does that matter?
A third question is the motivation for Viacyte’s approach using removable packages of artificial islets. Does Vertex have a plan for dealing with uncontrolled growth of the transplanted cells?
I am very pleased that this obvious application of pluripotent stem cells is making progress. I think having two entities in competition will drive development of a better product. We should also keep in mind that there are plenty of people with T1D and subsets of people will benefit more from one or another therapy.
Hey Jeanne,
Great points. Are any patients still getting islet transplants these days?
Paul
Immunosuppression is a damper. Hepatic artery infusion is an invasive procedure. This will a very expensive treatment.