Researchers at Sernova Corp, a clinical-stage regenerative medicine company located in Canada, have recently been garnering a significant amount of press coverage in response to receiving FDA approval to start a phase I/II trial testing their scalable islet cell encapsulation device, the Cell Pouch System.
This report will provide an overview of both the trial and Sernova’s Pouch System in addition to an interview with the President and CEO, Philip Toleikis, Ph.D.
Although the trial will include immunosuppression, Sernova plans to test the product without immunosuppression in a subsequent trial. If tested without immunosuppression, this will be considered a Practical Cure.
The Cell Pouch System
The Cell Pouch System, approximately the size of a business card, is implanted under the skin in a simple outpatient procedure. It is made up of materials already approved in different medical devices for permanent use in the body by the FDA and features pores (large holes) to enable tissue growth into the islets contained within the device. Because islets require oxygen to survive, it is crucial for encapsulation companies to design a device which supports vein and tissue growth.
One issue which has repeatedly presented problems for other encapsulation device companies has been fibrosis or scarring around the device once implanted. This happens when the body’s immune system recognizes the device as a foreign object and begins to attack it.
“With these devices, instead of the tissue growing into the pores of the device, it tends to form around the device and what ends up happening then is you get scar tissue forming,” Toleikis says. “We specifically developed a device that we could place under the skin that would become incorporated into the body tissue and act more as a scaffold for the tissue to grow into. In that way, we developed a highly scalable medical device that formed vascularized tissue lined chambers for putting therapeutic cells into.”
Before applying for human trials, Sernova demonstrated long-term efficacy in multiple small and large animal pre-clinical studies.
“The million-dollar question is how long are these cells going to work,”Toleikis adds. “Our animal studies have shown two things: 1) Our vascular environment under the skin is keeping cells alive long-term and 2) The quality of the cells that you put into the device really matters. Just like you do for a drug, you have release criteria that tell you that your drug is safe to use— we have release criteria for the islets and the cells that we’re putting into the cell pouch. If we put in healthy cells that are producing insulin with all the right characteristics, then those cells survive.”
The Phase I/II Trial
Sernova has stated three main goals for this trial. 1) Testing for safety, 2) Developing and testing the device-tissue environment to improve islet cell transplantation survival, and 3) Testing islet dosing and examining how the islet cells interact and vascularize inside of the cell pouch.
“The reason patients will be on immunosuppression drugs is that we are learning more about the dosing of the cells with the hope that we can achieve efficacy with a marginal dose of islets,” Toleikis says.
Although it is not the main goal of the trial, Sernova will also be measuring C-peptide, HBA1C, blood-glucose levels, as well as many other efficacy measures.
Stem Cells as an Alternative to Cadaver-Sourced Islets
Because islets are sourced from human cadavers, their supply is extremely limited.
An alternative source, as currently being developed by companies like Semma Therapeutics and ViaCyte, is stem-cell derived islets.
Stem cells have the capacity to transform into other types of specialized cells— in this case fully functioning islets. This process is called differentiation. In addition, they can also be split and multiplied to, theoretically, provide an unlimited source of cells. Another clear benefit of a stem cell product is that stem cells can be sourced from non-related donors without risk of immune attack or rejection when transplanted into the body.
Sernova is looking to partner with a stem-cell manufacturing company and plans to test their Cell Pouch System with encapsulated stem cells in the future. There is no timeline to date on when testing with stem cells will begin.
"There are multiple groups working on stem cells and stem cell devices,"Toleikis says, "and I see us all as partners in the future for better treatment for diabetes."
Researchers or companies involved in stem cell production and interested in a possible research partnership are encouraged to contact Sernova.