immune response that causes the body to try to reject transplants as foreign invaders.
Two approaches under investigation involve coating the transplanted cells in a capsule that protects them from the immune system, experts note.
These capsules would allow nutrients and oxygen to come in and feed the cells, but prevent larger immune system cells from attacking the transplants, Dutta and Kudva share.
Unfortunately, a clinical trial by the pharmaceutical company ViaCyte involving fully encapsulated cells planted just under the skin did not prove successful, Kudva says.
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A second approach by ViaCyte using partially encapsulated cells also didn’t go well, Kudva adds. Insulin production didn’t become strong enough to provide benefit to the patients, who also needed immune-suppressing drugs to protect their now-vulnerable transplants.
“If you read the two papers, they did very little in terms of changing people’s insulin and changing people’s life,” Kudva said of the ViaCyte trials.
Companies haven’t given up on the capsule approach, however.
ViaCyte continues to tinker with its method, and Vertex has said that it plans to file an application with federal regulators this year to test its own encapsulated implant.
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But ViaCyte is investigating a third way to protect the stem cell transplants — gene editing that would help the new beta cells evade detection by the immune system.
“You take the insulin-producing beta cells and you tinker with about seven, eight or nine genes,” Dutta shares. “Tinkering with the genes will not compromise insulin production in any way, but it will render the cells cloaked or camouflaged from the immune system. You cheat the immune system to think these cells are not foreign.”
ViaCyte plans to start a clinical trial of a gene-edited stem cell therapy for type 1 diabetes by the end of the year, according to a statement from Aaron Kowalski, chief executive officer of JDRF.
It is “feverishly” supporting all three approaches to a cure, Dutta says.
“We have significant funding in the third bucket of gene editing and gene modification, because that’s where the future lies,” he adds. “Which one will get to the finish line first, we don’t know. Which one will be the safest, we don’t know. Which one will be attainable for adult humans, we don’t know.”
It could be at least three to four years — maybe longer — before enough is known about the first-generation stem cell therapy to know whether it works long-term, much less make it available to the public, Kudva says.
“It’s going to be some years before we know where we are with this work, honestly speaking,” he concludes. “The first [patient] is good, but it was one. We have to do more. It’s going to take a little while here before we actually know.”
