Preclinical data on Inovio’s intradermal electroporation delivery devices presented at Phacilitate Vaccine Forum

Inovio Pharmaceuticals, Inc. (NYSE Amex: INO), a leader in the development of novel therapeutic and preventive vaccines against cancers and infectious diseases, announced today the presentation of recent preclinical data using its next generation of minimally invasive intradermal (skin) electroporation delivery devices at the Phacilitate Vaccine Forum 2011 in Washington, DC. The presentation, titled "Potent cellular responses to SynCon™ DNA vaccines targeting traditional prophylactic vaccine targets," was made by Dr. Niranjan Y. Sardesai, Inovio's Sr. VP of Research and Development, and highlighted recent developments made by Inovio to improve the immune potency, usability, and tolerability of DNA vaccines delivered by electroporation.

“Potent cellular responses to SynCon™ DNA vaccines targeting traditional prophylactic vaccine targets”

The use of in vivo electroporation has focused on intramuscular (IM) delivery due to the durability of gene expression achievable from this tissue. Skin is an attractive target tissue for delivering DNA vaccines for multiple reasons: skin is the largest organ of the human body and readily accessible; it is highly immunocompetent, meaning it is the tissue most capable of developing a broad immune response to antigens; it offers the possibility of reducing invasiveness by requiring little or no penetration of the skin and avoiding stimulation of muscle tissue.

While Inovio's current IM delivery technologies are well tolerated, the company is also advancing device development to achieve various desirable attributes. Its intradermal (ID) electroporation (EP) device penetrates to no more than 3 mm, compared to intramuscular devices that go deeper. Furthermore, its minimally invasive surface electroporation (SEP) device sits on the surface of the skin and uses a virtually undetectable scratch to facilitate delivery of the vaccine. With the advancement of these devices, Inovio's aim is to make electroporation delivery amenable to mass prophylactic vaccination by decreasing dose levels, increasing tolerability of the vaccination, and increasing the breadth of viable vaccine targets.

The data highlighted by Dr. Sardesai, which relates to influenza, HIV, malaria, and smallpox antigens, demonstrates that DNA delivery with this newer generation of ID and surface electroporation devices yields levels of immunogenicity in terms of both antibody and T-cell responses and/or efficacy against a virus challenge that is comparable to intramuscular electroporation devices currently in the clinic. In particular, immune responses achieved with influenza antigens targeting H1, H3, and H5 immunogens yielded hemagglutination titers of greater than 1:40 (a level considered protective in humans) in 100% of vaccinated animals after two immunizations, with magnitudes comparable to or better than those reported from animal studies of the IM-delivered flu vaccine (VGX-3400) currently in the clinic.

Similarly, data presented from a head-to-head comparison of an ID and IM-delivered 8-component smallpox vaccine in a non-human primate challenge model showed that the monkeys vaccinated with ID EP mounted stronger antibody responses and protection against a virus challenge compared to those vaccinated via IM EP. Even more significant, the antibody titers produced by ID EP vaccination in the monkey model were comparable to those produced by the currently stock-piled but no longer manufactured Dryvax™ smallpox vaccine in the same monkey model.

The first vaccine utilizing Inovio's ID EP delivery to be tested in a human study is INO-3510, a universal H1N1 and H5N1 SynCon™ DNA vaccine. Inovio expects to initiate a Phase I clinical study of this vaccine in 2Q 2011.

Dr. Sardesai noted, "Our R&D and engineering teams are extending the boundaries of not only DNA vaccine design but also of the electroporation delivery devices that are facilitating the best-in-class immune responses we recently reported from human studies, as well as encouraging animal efficacy results. The unique design of these minimally invasive devices demonstrates our commitment to develop increasingly optimized products to better facilitate vaccine delivery and bodes well for our vaccine development activities focused on preventive targets."

Dr. J. Joseph Kim, president and CEO of Inovio Pharmaceuticals, said, "We are pleased that the excellent results obtained with our current-generation IM delivery devices continue to hold up in clinical studies as we make improvements to better serve the end-user. The preference for less invasive vaccine delivery and our demonstration of relevant vaccine responses using less-invasive Inovio devices highlights the broader potential of our vaccine platform for both therapeutic and prophylactic vaccine targets."

SOURCE Inovio Pharmaceuticals, Inc.