Current Opinion in Immunology journal publishes Inovio's article on DNA vaccines

Inovio Pharmaceuticals, Inc. (NYSE Amex: INO), a leader in the development of therapeutic and preventive vaccines against cancers and infectious diseases, announced today that the prestigious journal Current Opinion in Immunology has published an article in its current issue entitled, "Electroporation Delivery of DNA Vaccines: Prospects for Success." The article was co-authored by Dr. Niranjan Sardesai, Inovio's Senior Vice President, Research & Development, and Dr. David Weiner, Chairman, Scientific Advisory Board, Inovio Pharmaceuticals, and Professor, Department of Pathology & Laboratory Medicine, at the University of Pennsylvania.

The article affirms that DNA vaccines are nearing the threshold of a medical leap far beyond the power of traditional vaccines, which employ 60-year-old development concepts. According to the article, "From the vaccinologists' perspective, DNA, due to its ability to combine the power of genomics with in vivo antigen expression, provides a tantalizing opportunity to easily customize vaccines through the use of molecular biology. Indeed it can be said that DNA vaccines bring to fore the strengths of molecular biology and genetic engineering to harness the potential of the immune system."  

The authors, each with more than a decade of DNA vaccine development expertise, see the unique attributes of DNA vaccines that could lead to major medical and commercial advances. "The ability to easily combine multiple plasmids or disparate gene products into a single formulation without apparent loss of potency allows the possibility to formulate multi-component vaccines targeting multiple antigens or even multiple pathogens simultaneously….. Such vaccines can be designed to increase the breadth of the immune responses and potentially increase pathogen coverage…. Approaches such as the use of synthetic consensus immunogens and mosaics – both approaches available simply in a DNA based platform – are expanding the notion of vaccine design to focus on developing 'universal' vaccines to simultaneously target multiple divergent but related strains of given pathogens."    

DNA vaccines, which use a fragment of DNA designed to produce an antigenic protein related to a particular disease, could provide the following important attributes:

• Accelerated development times
• Easy, cost effective manufacturing using well established methods
• No ability to reproduce and spread disease
• Broad, powerful immune responses, stimulating not only antibody production, as do today's vaccines, but also T-cells, which are required to kill cancerous cells or cells infected by chronic infectious diseases such as HIV and hepatitis C virus
• Preventive & therapeutic capabilities

Dr. J. Joseph Kim, Inovio's president and CEO, said: "This distinguished journal article on DNA vaccines affirms the accomplishments and potential of this field. At Inovio we are proud to be a leader in advancing novel DNA plasmid vaccines and enhanced delivery using electroporation, with vaccines for HIV, influenza and cancer all in clinical trials. We look forward to our leadership role in the coming "Decade of DNA Vaccines."

The article by Drs. Sardesai and Weiner emphasizes the progress of electroporation (EP) as the preferred DNA vaccine delivery technology. "EP mediated delivery has generated considerable enthusiasm and appears to have had a great impact in vaccine immunogenicity and efficacy by increasing antigen delivery up to a 1000 fold over naked DNA delivery alone. This increased delivery has resulted in an improved in vivo immune response magnitude as well as response rates relative to DNA delivery by direct injection alone."

Electroporation is a method to introduce macro-molecules such as nucleic acids into cells, either in vivo or in vitro, via the application of brief electric pulses to induce transient and reversible permeabilization of the cell membrane. Electroporation-based DNA delivery systems have been shown to dramatically increase cellular uptake of a DNA vaccine and resulting gene expression (i.e. production of the coded protein) and increase immune responses by 100 times or more compared to plasmid DNA delivered without other delivery enhancements.

The article also compares several DNA vaccine delivery technologies, coming to the conclusion that, "The immune responses and protection from pathogen challenge observed following DNA administration via EP in many cases are comparable or superior to other well studied vaccine platforms including viral vectors and live/attenuated/inactivated virus vaccines. Significantly, the early promise of EP delivery shown in numerous pre-clinical animal models of many different infectious diseases and cancer are now translating into equally enhanced immune responses in human clinical trials, making the prospects for this vaccine approach to impact diverse disease targets tangible."