VGX Pharmaceuticals Inc. (VGX), a leading developer of DNA vaccines and therapies for HIV infection, announced that its collaborators from the University of Pennsylvania presented data showing enhanced magnitude and quality of immune responses induced by VGX's DNA vaccines with electroporation delivery compared to those induced by the recombinant Adenovirus Serotype 5 (Ad5) vector. The data was presented at the recent 16th Conference on Retroviruses and Opportunistic Infections (CROI 2009) held in Montreal, Canada.

VGX and its collaborators have previously reported that Pennvax DNA vaccines delivered with its Cellectra electroporation device induced dramatic increases in T-cell and antibody-based immune responses as well as improved control of viral replication following a simian immunodeficiency virus (SIV) challenge. The SIV model in non-human primates is considered to be the most relevant model for studying HIV infection in humans. Historically, recombinant Ad5 vector has been shown to be one of the most potent viral vectors for vaccine development.

This study was led by Professor David B. Weiner's team at the University of Pennsylvania and included collaborators from VGX and Merck. The collaborative study was the first study to directly compare a DNA plasmid-electroporation platform with a recombinant Ad5 vector in an SIV model in non-human primates. The study results showed significant enhancements in the magnitude, frequency, proliferative capacity, and polyfunctionality of the induced immune responses following DNA plasmid-electroporation vaccination compared to the Ad5 vector.

"VGX Pharmaceuticals along with our collaborators have the most active and dynamic HIV vaccine development programs in the industry," stated Dr. J. Joseph Kim, president and CEO. "We have demonstrated that our novel Pennvax HIV DNA vaccines delivered with our Cellectra electroporation device can induce significantly higher and broader T-cell responses in monkey models. We look forward to advancing studies with the aim of demonstrating the same outcome in humans."

Pennvax is an optimized DNA vaccine for HIV developed by VGX using its SynCon technology. The company's Pennvax-B (targeting HIV clade B) vaccine without electroporation delivery is currently in a phase I clinical trial sponsored by the National Institute of Allergy and Infectious Diseases' (NIAID) Division of AIDS (DAIDS) and being conducted by the HIV Vaccine Trials Network (HVTN) to evaluate the vaccine's safety and immunogenicity in healthy volunteers. The HVTN recently completed enrollment of this 120-patient study (HVTN protocol number 070). VGX and its collaborators are planning a follow-on phase I clinical trial of Pennvax-B vaccine delivered with the Cellectra electroporation device (HVTN protocol number 080).

In October 2008, VGX was awarded a $23.5 million contract by the NIAID to develop another preventative DNA vaccine candidate, Pennvax-GP (targeting HIV clades A, C, and D), in conjunction with its Cellectra electroporation technology. The Company is presently focused on optimizing the combination of the HIV vaccine candidate and electroporation delivery in pre-clinical studies.

Pennvax-B vaccine is also being tested as a therapeutic vaccine in a Phase I study conducted by investigators from the University of Pennsylvania and Drexel University. This 38-patient study is being funded by a grant from the NIAID and began enrolling patients in 4Q 2008. The investigators are planning a follow-on phase I clinical trial of Pennvax-B vaccine delivered with the Cellectra electroporation device in a therapeutic setting.

VGX Pharmaceuticals is a biopharmaceutical company with DNA vaccines and small molecule product candidates for the treatment of infectious diseases, cancer, and inflammatory diseases.