Device Engineering

Novel technologies for implanting and protecting cell replacement therapies

We have two types of proprietary medical devices to contain, protect, and implant our cell replacement therapies. They differ based on whether they are immune-protective or allow direct vascularization. In addition, each type of device has multiple different sizes available for both preclinical and/or clinical use.

Devices for the PEC-Direct and PEC-QT product candidates are designed to allow blood vessels to directly contact the cells. The Encaptra® system for the PEC-Encap product candidate is designed to protect the implanted cells from a patient’s alloimmunity and autoimmunity, and therefore it needs to prevent graft cell contact by the immune cells of the patient.

Devices for the PEC-Direct and PEC-QT product candidates are designed to allow blood vessels to directly contact the cells.

Sentinels provide a window for clinical research

ViaCyte is using two sizes of devices for clinical trials; a larger device designed for determining a therapeutic dose of cells and a smaller clinical research device, called a “sentinel.” Sentinels are small-format cell-filled devices that are used to evaluate safety and implant viability. These units can be removed at specific time points and examined histologically to provide early insight into the progression of engraftment and maturation of the PEC-01 cells into islet cells, including insulin-producing beta cells.

Development of human cell replacement therapy requires optimization of the product candidates in patients. Evaluation in animal models provides limited information, because when the human cells are implanted in an animal, a different species, it elicits an immune response that is unlike the response that occurs when the human cells are implanted in a human patient. The sentinels provide an elegant and effective methodology for product optimization in patients.

ViaCyte’s devices are designed for implantation and cell survival and function

A key component of ViaCyte’s devices is composed of a medical-grade plastic called expanded polytetrafluoroethylene (ePTFE), which is produced by W.L. Gore & Associates (Gore). To develop leading cell encapsulation technologies, ViaCyte and Gore are working in partnership to combine Gore’s material science and implantable medical device expertise and ViaCyte’s preclinical and clinical experience with human cell replacement therapies. The combined effort is first being applied to the PEC-Encap product candidate currently under development as a potential functional cure for patients with type 1 diabetes.

The devices are manufactured from implant-grade materials specifically selected for long-term biocompatibility. All of the devices are designed to be subcutaneously implanted and allow oxygen, nutrients, proteins, and other molecules necessary for cell survival and function to reach the cells, and for insulin and other proteins secreted by the cells to leave the device and enter the blood vessels that form on the surface of the device to deliver therapeutic activity. Because the cells are contained within and remain in the devices, they allow for retrieval of the implanted cells, an important safety consideration.

In addition, ViaCyte’s devices may be suitable for use with other therapeutic agents. For example, the devices could be used to provide a platform for enzyme or hormone replacement therapies.

A cross section of the PEC-Encap product candidate.

“The combination of our decades of implantable device and materials experience, with ViaCyte’s regenerative medicine and cell therapy expertise, makes for a formidable team. Together we have an opportunity to deliver a potentially curative product for those currently suffering with type 1 diabetes and help pioneer the new field of cell replacement therapy,” said Erin Hutchinson, Business Leader, Gore PharmBIO Products. ”