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Optimized DNA Vaccines
DNA Vaccines
represent the newest area of R&D for VGX™ Animal Health.
However, its parent company, VGX Pharmaceuticals, has a long
standing history in this growing field. VGX’s Cofounder
Professor
David B. Weiner has been one of the most important pioneers
in the field of DNA vaccines. His original DNA vaccines research
and patents in the early 1990’s became the basis for private
biotechnology company Apollon Inc., which subsequently became
a part of Wyeth Vaccines. Dr. Weiner's DNA vaccines targeting
HIV were the first candidates to make it into clinical testing.
Dr.
J. Joseph Kim, Cofounder and CEO of VGX has been an expert
in DNA vaccines since the mid-1990’s. Dr. Kim’s
extensively published area of research was the improvement of
immune responses to DNA vaccines by utilizing various molecular
adjuvants. Drs. Kim and Weiner collaborated on over 70 biomedical
research publications in major academic journals. Through the
creation of VGX Animal Health, we are able to tap into this
wealth of expertise to bring cutting edge DNA vaccines to important
Animal Health diseases.
With such strong internal capabilities, VGX™ Animal Health
is poised to develop DNA vaccines as a new area of research
to complement and expand its current product development programs
in infectious diseases and cancer.
| VGX™ Animal health
has the key pieces of technology needed to rapidly develop
its DNA vaccine pipeline: |
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In-house
expertise that allows VGX™ Animal Health to evaluate
the gene sequences of historical, existing, as well
as emerging strains of infectious agents such as viruses.
Using computer modeling, VGX™ Animal Health is
able to rapidly develop synthetic DNA consensus (SynCon™)
gene sequences that code for the production of the most
effective immunogenic proteins possible.
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Licenses to gene
expression technology that allow the targeted gene sequences
to be expressed at high levels in the target animal
species.
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Licenses to key
manufacturing technology that allows for cost efficient
manufacturing of the plasmid based DNA vaccine platform.
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License to VGX™
Pharmaceuticals’ revolutionary gene delivery electroporation
technology known as CELLECTRA™.
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PROOF OF CONCEPT STUDIES
AND PRE-CLINICAL DATA IN ANIMAL MODELS
Avian Influenza: Mouse Challenge
Over the past 2 years, the VGX™
Animal Health team has worked with VGX Pharmaceuticals to help
validate this model, and supported significant progress in demonstrating
the efficacy of DNA vaccines. The earliest work proving the
viability of the technology is being demonstrated with a SynConTM
H5N1 Avian influenza vaccine.
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Five
groups of 10 mice each were immunized biweekly with
10µg of a single construct at weeks 0, 2 &
4 and then boosted at week 8 with 25µg of the
relevant construct.
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Animals
were then challenged with a lethal dose of a Vietnamese
strain of avian H5N1 virus and assessed for survival.
One hundred percent (100%) of animals who received the
HA DNA vaccine survived; 80% of animals receiving the
M2e-NP survived.
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Naïve
Group: 10= 0% lethality by day 9. H5 Immunized Group:
100% protection at day 17. NA, M1, M2E-NP Immunized Groups:
60%, 80%, 0% protection from disease. |
Additional work in pigs and ferrets has proven that this vaccine
was able to protect 100% of the vaccinated animals from a virulent
challenge with another strain of virus. (www.viralgenomix.com/PR_111207.html)
DNA Vaccines
DNA-based vaccines and therapeutics deliver the immunogen
or the therapeutic protein in the form of plasmid DNA encoding
the protein of interest. The body then produces the protein
of interest and elicits the appropriate immunologic response.
Vaccination with DNA has multiple potential advantages over
the present vaccine technology for a variety of infectious
diseases. DNA vaccines are easier to manufacture, can be stored
at room temperature, and have less safety concerns when delivered
to the patient. Furthermore, when compared to viral vectors,
they have the potential to more easily combine multiple antigens
in one injection that would provide protection against multiple
diseases or multiple targets from the same organism.
Over the last two decades, DNA vaccines have become a potent
means of providing immune responses or protective immunity
against viruses, bacteria and parasites in many species from
fish to primates, including humans. DNA vaccines, comprised
of plasmid DNA encoding proteins from pathogens, allergens,
and tumors, are being evaluated as prophylactic vaccines and
therapeutic treatments for infectious diseases, allergies
and cancer. The use of DNA as a means of vaccination offers
advantage in protective efficacy, cross-strain applicability,
development speed and manufacturing cost over conventional
vaccines. DNA vaccines are known to be particularly effective
in inducing killer T-cell responses which are critical to
fighting infections.
| VGX™ Animal Health
plans to exploit the early progress in human influenza
vaccines in their development program for DNA vaccines
to: |
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Swine
Influenza Virus |
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Foot and Mouth
Disease Virus
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Porcine Reproductive
and Respiratory Syndrome Virus
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Work has begun on SynCon™ vaccines
for these three diseases, and data coming out of these studies
should lay the foundation for USDA license applications in
2008-09.
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