The grant will allow the company, Polyplus-transfection, to finance GMP production of its lead in vivo-jetPEI reagent to promote its use in gene therapy. According to the firm, the reagent is the only synthetic alternative to traditional viral methods of gene delivery currently available on the market. The synthetic molecule used in the gene delivery product is polyethylenimine (PEI), a cationic linear polymer with a number of properties making it an effective gene delivery molecule, and already recognised as a highly successful reagent for in vivo delivery of nucleic acids. PEI is a stable molecule with a very simple chemical structure and is very robust, able to last for up to three years in solution at room temperature without affecting performance. The in vivo-jetPEI delivery reagent works by condensing nucleic acids into small nanoparticles of 50nm that remain stable for several hours. These nanoparticles are small enough to diffuse into tissues and enter cells by endocytosis, where in vivo-jetPEI facilitates the release of the enclosed DNA into the cell, and results in the desired therapeutic effect through expression of the gene. Aside from the fact that the company foresees this technique as a cheaper alternative to traditional gene therapy techniques, the in vivo-jetPEI technology offers several advantages over the viral approach to gene delivery, which uses deactivated viruses. One of the major benefits is the fact that while admittedly not being as effective as viral vectors, the technique does not cause an inflammatory immune response, a common problem when using viruses which prevents their repeated use in patients. The elimination of this barrier to repeated use of gene delivery could prove a significant point in the favour of the synthetic molecule-based delivery system. In addition to this, the company has carried out numerous tests in a range of animal species which have illustrated a number of possible administration methods from topical applications or injections to nebulisation and transdermal patches. The much needed grant, awarded by France's Muscular Dystrophy Association, allows Polyplus to move from non-GMP production to GMP compliance, a key factor in widening the use of the in vivo-jetPEI technique. The company believes this extra cash injection will help accelerate the use of in vivo-jetPEI in gene therapy clinical trials, and it is currently being used as a delivery vector for cancer therapy in human clinical trials. The firm also told in-PharmaTechnologist that the system is currently being investigated in two Phase I clinical trials, but was unable to disclose any further details about the studies. Although currently primarily used for R&D in gene delivery using animal models, the in vivo-jetPEI non-viral gene delivery method could also be applied as part of therapeutic treatment for cancer.
