Viacyte, a San Diego company, is pioneering a pilot project with U of Minneapolis and UBC-Vancouver, implanting heterogeneous beta cells issued from embryonic stem cells into patients’ arms:
ViaCyte’s approach is to coax stem cells, which came from a human embryo that wasn’t used for in vitro fertilization, to produce immature pancreatic cells. They are then placed in pouches that are implanted in the arms and lower backs of diabetic patients, where the cells then produce islets that are released into the bloodstream.
The company’s first product was a tightly closed pouch designed to prevent the recipients’ immune cells from entering and attacking the transplanted pancreatic cells. That would prevent patients from needing drugs to suppress their immune systems, which can be potent and cause their own severe side effects.
Bellin said this protection seems to cut the donor cells off from access to oxygen and the patients’ bloodstreams, which limits their ability to produce islets. So ViaCyte’s second product — the one the university is testing — is a pouch with small pores to increase the distribution of islets into the blood.
Patients trying this approach do need immunosuppressive drugs, Bellin said, which is why the trial is only for severe cases.
In my eyes, the requirement for immuno-suppression in the new MO makes this almost worse than the disease.
The good part, though, is that production from stem cells means you don’t need donors anymore: that is a big step forward.
I was really disappointed when Viacyte reported that they weren’t seeing vascularization around the encapsulation devices. Especially since Paul Laikind reported at a JDRF event I attended that they had seen some vascularization. I assume they saw it on a few of the study participants but not consistently. Still, it was disappointing.
I think clinical trials are still underway for the PEC-Encap, but I don’t know if they’re still recruiting. I think they’re hoping that success with the PEC-Direct will help them refine PEC-Encap. Not sure if that’s realistic or not.
I’ve been watching this company very closely, but there seems to be a bit of a catch-22. Pores too big, good vascular growth but immune kills the cells. Pores too small, protection against immune system, but little to no vascular growth. I’m curious, does anyone know if they used immune suppression in the mouse models?