Delivery System
Encapsulated Cell Therapy Platform
To circumvent the relatively short half-lives of therapeutic protein drugs and provide a steady-state therapeutic and safe concentration following single intraocular application, a novel cell-therapy technology has been developed and advanced into human clinical studies by Neurotech Pharmaceuticals. Encapsulated Cell Technology (ECT) potentially mitigates the risk associated with repeated intraocular injections or drugs, sub-retinal injections required of gene therapy and bypasses the restrictions of conventional allogeneic cellular transplantation by supplying an immunoisolated microenvironment optimized for cell survival and consistent drug delivery based on the target indication and cell type.
Encapsulated Cell Technology (ECT)
Compared to other forms of intraocular drug delivery, ECT affords the ability to control the dose of drug delivered to the eye at a constant rate over an extended period of years for chronic, degenerative ocular diseases. Combined with our proprietary cell line, ECT has evolved to the point of providing long-term implant survival, safety and therapeutic efficacy demonstrated in humans.
In combination with robust device design and attention to manufacturing quality, the hardiness of the encapsulated, proprietary cell line has proven to be a foundation of the NT-501 product shown to slow the loss of visual photoreceptors in macular telangiectasia as well as prevention of ganglion cell death in glaucoma, each with direct benefits in the design of future products targeting a wide range of untreated or undertreated ocular diseases.
Long-Term Intraocular Drug Delivery
The ECT platform technology has been optimized to deliver a therapeutic protein from engineered human mammalian cells for greater than 2 years, with near zero-order kinetics as demonstrated in Neurotech’s ophthalmic human clinical programs targeting Dry AMD and RP (Kauper et al., 2012). The environment of the vitreous is one of low nutrients and high oxygen tension, factors that would normally preclude this site from cell-based delivery. Cellular encapsulation technology is designed to permit therapeutic cells to survive in diseased conditions and to replace or assist the function of the failing target cells or tissue.
There are several distinct advantages to ECT. Foremost, it offers the potential for any gene encoding a therapeutic protein to be engineered into a cell and therefore has a broad range of applications. In addition, the therapeutic protein is freshly synthesized and released in situ; thus, a relatively small amount of the protein is needed to achieve a therapeutic effect in comparison to pulsatile dosing. Stable, endogenous secretion of the protein assures that the availability of the protein at the target site is not only continuous but also long-term. Furthermore, the output of an ECT implant can be controlled to achieve the optimal dose for treatment. Finally, treatment by ECT can be terminated if necessary, by simply retrieving the implant. Thus, ECT is a potentially effective means of long-term delivery of proteins and polypeptides to the retina.