BLUE BELL, Pa.--(BUSINESS WIRE)--VGX Pharmaceuticals Inc. (VGX), a leading developer of DNA vaccines and
therapies for infectious diseases and cancer, announced today
preclinical results indicating that its avian influenza DNA vaccine
delivered using intramuscular or intradermal electroporation provided
100% protection of non-human primates against the H5N1 avian influenza
virus. The vaccine also provided protection against multiple unmatched
avian influenza strains. The data was published in the Journal of
Virology in a paper titled, “Electroporation
of Synthetic DNA Antigens Offers Protection in Non-Human Primates
Challenged with Highly Pathogenic Avian Influenza.” The results
support advancing this DNA vaccine candidate into human clinical studies.
The study, undertaken by VGX in collaboration with researchers at the
University of Pennsylvania, tested VGX’s avian influenza DNA vaccine
candidate, VGX-3400, delivered via electroporation in non-human primates
following previous successful challenge studies in mouse and ferret
models. This vaccine combines three SynCon™ based consensus vaccine
constructs targeting H5-influenza HA, NA, and M2e-NP antigens, but not
matched to a specific strain in either of the two main families (clade 1
and clade 2) of avian influenza. The researchers tested intramuscular
and intradermal routes of DNA vaccine delivery using the CELLECTRA®
electroporation device.
Following two immunizations, 100% of the macaques in both the
intramuscular and intradermal groups developed hemagglutination
inhibition (HAI) titers greater than 1:40 against a clade I H5N1 virus.
Antibody responses amounting to HAI titers greater than 1:40 are
classically considered sufficient to provide protection against the
influenza virus in several animal models and humans.
Notably, the vaccine also elicited robust HAI titers (greater than 1:40
in most animals) against non-matched clade 2 viruses (sub-types 2.1;
2.2; 2.3.4), suggesting the potential to address strain variations and
provide broad cross-clade protection.
While achieving potent humoral (antibody) immune responses, the vaccine
also induced significant cellular (T-cell) immune responses to each
component antigen. T-cell responses are believed to be important in
protecting from the morbidity and potential mortality associated with
influenza infection. Having cellular immune responses present to augment
incomplete or absent antibody responses could significantly impact the
toll of epidemic and pandemic influenza.
Following immunization, the animals were challenged with the
A/Vietnam/1203/04 strain. The vaccinated animals showed significant
reduction in average viral load and decreased symptoms of disease
compared to non-vaccinated controls.
“This study was the first to demonstrate that synthetic DNA vaccines
delivered with electroporation can protect non-human primates from a
highly pathogenic H5N1 avian influenza virus challenge,” stated Dr. J.
Joseph Kim, President and CEO. “We have demonstrated in multiple animal
models the ability to achieve broad immune responses and
cross-protection against multiple, unmatched avian influenza strains.
These positive results support the promising ongoing development of our
universal influenza vaccine program.”
About VGX’s Avian Influenza DNA Vaccine
The highly pathogenic avian influenza (HPAI), or "bird flu," virus is an
emerging threat that has killed millions of poultry in a growing number
of countries. Health experts are concerned that co-existence of human
and avian flu viruses (primarily sub-type H5N1) will provide an
opportunity for genetic material to be exchanged between the
species-specific viruses and possibly create a new virulent influenza
strain that is easily transmissible and lethal to humans. The pandemic
potential of bird flu highlights the need for novel vaccination
techniques that can quickly and effectively respond to emerging viral
threats and specifically address the issue of rapidly evolving strain
variations.
Using its SynCon™ technology, VGX identifies antigens and genetic
sequences that are common across a set of viral sub-types or taxonomic
groups. Combining the synthesis of optimized consensus gene constructs
to produce the identified antigens with highly efficient delivery
facilitated by electroporation, VGX aims to produce DNA-based vaccines
that are safe but have powerful preventative and/or therapeutic
capabilities against challenging infectious diseases such as avian
influenza. Pertinently, VGX’s approach facilitates rapid vaccine design
and development and has the potential to enable sufficiently robust and
broad immune responses to emerging strain variants.
VGX’s universal influenza DNA vaccine program is focused on developing a
vaccine capable of addressing both seasonal and prospective pandemic
influenza strains.
About VGX Pharmaceuticals
VGX Pharmaceuticals is a biopharmaceutical company with DNA vaccines and
small molecule product candidates for the treatment of infectious
diseases, cancer, and inflammatory diseases. The Company has entered
into a definitive merger agreement with Inovio Biomedical Corporation
(NYSE Alternext: INO). More information about VGX can be found at www.vgxp.com.
Contacts
VGX Pharmaceuticals Inc.
Kevin W. Rassas
Senior Vice-President
Tel.
267-440-4208
Fax 267-440-4242
E-mail: Rassas@vgxp.com
www.vgxp.com