At the recent Cell and Gene conference in Carlsbad, US, two papers were presented demonstrating a new experimental stem cell treatment.
ViaCyte from San Diego is developing two versions of diabetes therapy using insulin-producing cells, grown from embryonic stem cells (ESCs). The cells are encapsulated in a device that is implanted under the skin.
One version, called PEC-Direct, periodically produces therapeutic insulin levels. This is the first time this has happened, says Paul Laikind, CEO of ViaCyte.
The results were obtained by an indirect method that determined the presence of a by-product of insulin production. However, according to Lykind, this process is not reliable enough to replace injectable insulin. ViaCyte is currently working on improving the quality of this method.
PEC-Direct is designed for the most severe cases of insulin-dependent type 1 diabetes. With this type of therapy, blood vessels grow into the device, by contacting the cells. To prevent the immune rejection reaction, patients need to take immunosuppressants.
Another product, PEC-Encap, protects cells from direct contact. Drugs to suppress immunity are not required. Nevertheless, difficulties were observed in the early stages of the experiment, since scar tissue formed around the implant.
ViaCyte has worked with partner W. L. Gore & Associates, makers of Gore-Tex and manufacturer of implant material, to solve the problem. In the process of cooperation, the company tries to reduce the likelihood of scarring
One cell, several uses
The second presentation at the Cell and Gene conference was representative by Athersys from Cleveland. Team of the company announced their multi-purpose stem cell product MultiStem. It is at a late stage of development and is aimed at treating ischemic stroke (caused by a blood clot) and is being tested for the treatment of heart attack and brain injuries.
MultiStem is a patented, ready-made universal product that can be used to treat different patients. It is obtained from the human bone marrow. Gil Van Bokkelen, chairman and CEO of Athersys, says MultiStem does not elicit an immune response.
“Stem cells secrete various proteins and other substances that reduce inflammation and promote healing”, – Van Bokkelen said. “They don’t persist, and eventually disappear from the body. This healing potential got the attention of doctors at The University of Texas Health Science Center at Houston and the Department of Defense”.
Athersys is currently planning the second phase of a MultiStem clinical trial involving patients. The aim of the study will be to temporarily reduce severe inflammation in injuries. Although stem cells are naturally present in the body, Van Bokkelen says they aren’t enough to treat serious injuries.
“It’s all about kinetics”, – he said. “In a major trauma, you’re talking about minutes or hours. You’re not talking about weeks. And so the cells simply cannot respond fast enough to be able to really have the impact that we see that we can have”.