SAN DIEGO, Nov. 6 /PRNewswire-FirstCall/ -- Vical Incorporated
(Nasdaq: VICL) today announced that the Naval Medical Research Center (NMRC)
plans to conduct preclinical and Phase 1 evaluation of a dengue DNA vaccine
formulated with the company's Vaxfectin(R) adjuvant and delivered with the
Biojector(R) 2000 needle-free injection system (Bioject Medical Technologies
Inc.) (OTC Bulletin Board: BJCT). In support of the program, Vical will
manufacture the vaccine and the adjuvant under a $1.3 million contract, and
will provide regulatory and clinical expertise. Testing will be performed at
the Walter Reed Army Institute of Research (WRAIR) under sponsorship of the
U.S. Army Medical Materiel Development Activity (USAMMDA).
"Dengue is the scourge of the tropics today, just as yellow fever was
before the widespread use of an effective vaccine," said Vijay B. Samant,
President and Chief Executive Officer of Vical. "Dengue presents a serious
threat to almost half the world's population living in or traveling to endemic
regions. The U.S. government's program, intended to develop a vaccine to
protect troops being deployed to dengue-endemic regions, is among the most
advanced. The potential for a dengue DNA vaccine has been demonstrated in
animal models, and initial safety testing has been completed in humans.
Separately, we recently reported encouraging preliminary results from our
Phase 1 trial of our H5N1 pandemic influenza DNA vaccines, marking the first
time the Vaxfectin(R) adjuvant was tested in humans. We are eager to support
the application of our Vaxfectin(R) adjuvant in this important program and
hope to advance toward resolution of this significant world health problem."
NMRC scientists developed a DNA vaccine containing genes encoding the
pre-membrane (prM) and envelope (E) proteins from the dengue-1 (DEN-1) virus.
Following successful challenge testing in nonhuman primates, NMRC conducted a
Phase 1 trial of the unadjuvanted monovalent vaccine delivered with the
Biojector(R) 2000 needle-free injection system. Preliminary results indicated
that the vaccine was safe and well-tolerated at both the 1 mg low dose and 5
mg high dose tested, but even at the high dose induced only low levels of
neutralizing antibody titers in less than half of the animals. Under a
Collaborative Research and Development Agreement (CRADA) with Vical, the NMRC
developed a tetravalent dengue vaccine containing prM and E genes for all four
serotypes of dengue, and formulated with the Vaxfectin(R) adjuvant. Nonhuman
primate immunogenicity and challenge data with the tetravalent DNA vaccine,
formulated with or without the Vaxfectin(R) adjuvant and delivered by
needle-free injection using the Biojector(R) 2000, were promising.
Four of four (100%) rhesus macaques receiving the Vaxfectin(R)-formulated
vaccine developed neutralizing antibodies to all four serotypes of dengue one
month after the second injection (Day 56), and were highly protected against
challenge, exhibiting very limited viremia (group mean 0.75 days). Only one of
four (25%) macaques receiving the unformulated vaccine developed neutralizing
antibodies to all four serotypes of dengue one month after the second
injection (Day 56), and were partially protected against challenge, exhibiting
limited viremia (group mean 2.00 days). The unvaccinated control macaques did
not develop any neutralizing antibodies, and were unprotected against
challenge, exhibiting typical viremia (group mean 3.33 days). The next step in
this program will be to advance this vaccine to Phase 1 human testing.
About Dengue
Dengue virus infects up to 100 million people each year. Its impact is
magnified by the lack of effective antiviral drugs and vaccines. As many as
half a million people develop severe dengue disease each year, causing tens of
thousands of deaths, particularly where healthcare is limited.
Dengue fever can be caused by any one of four serotypes of dengue virus:
DEN-1, DEN-2, DEN-3 and DEN-4. These viruses are part of the Flavivirus
family, which includes West Nile virus and yellow fever virus. Dengue virus is
spread by mosquitoes, and is most common during the rainy seasons throughout
the world's tropical and subtropical regions. Dengue does not spread directly
from person to person. An individual infected by one serotype of dengue virus
develops lifelong immunity against that serotype, but not against other
serotypes.
Symptoms of classic dengue fever include high fever (up to 105 degrees F),
severe headache and/or pain behind the eyes, severe joint and muscle pain,
nausea and vomiting. A few days after fever onset, a rash often develops over
most of the body and lasts for one to two days. The rash can reappear several
days later. These symptoms typically begin within a week after infection, and
usually resolve without treatment.
Dengue hemorrhagic fever is a more serious form of disease which can
include all of the symptoms of classic dengue fever plus noticeable damage to
blood vessels and lymph vessels, bleeding from the nose and gums, and
conspicuous bruising under the skin. Dengue hemorrhagic fever can lead to
death. The most severe form of dengue disease is dengue shock syndrome, which
includes all of the symptoms of classic dengue and dengue hemorrhagic fever,
plus leaking of blood outside of blood vessels, extensive bleeding, and shock
caused by extremely low blood pressure. Dengue shock syndrome most often
occurs in children infected for a second time (with a different serotype of
dengue), and can be fatal. Dengue disease, including classic dengue, dengue
hemorrhagic fever and dengue shock syndrome, is increasing in both incidence
and severity throughout many tropical regions of the world, especially in
Africa, the Indian subcontinent, and Southeast Asia.
NMRC Dengue Focus
The Naval Medical Research Center conducts research into the many health
threats to members of the U.S. military. The Infectious Diseases Directorate
conducts research on infectious diseases that are considered to be significant
threats to deployed sailors, marines, soldiers, and airmen. The primary focus
of the Viral Diseases Division is on the development of a vaccine to prevent
dengue fever, with a major emphasis on novel vaccine technologies and
adjuvants.
About Vical
Vical researches and develops biopharmaceutical products based on its
patented DNA delivery technologies for the prevention and treatment of serious
or life-threatening diseases. Potential applications of the company's DNA
delivery technology include DNA vaccines for infectious diseases or cancer, in
which the expressed protein is an immunogen; cancer immunotherapeutics, in
which the expressed protein is an immune system stimulant; and cardiovascular
therapies, in which the expressed protein is an angiogenic growth factor. The
company is developing certain infectious disease vaccines and cancer
therapeutics internally. In addition, the company collaborates with major
pharmaceutical companies and biotechnology companies that give it access to
complementary technologies or greater resources. These strategic partnerships
provide the company with mutually beneficial opportunities to expand its
product pipeline and address significant unmet medical needs. Additional
information on Vical is available at http://www.vical.com.
This press release contains forward-looking statements subject to risks
and uncertainties that could cause actual results to differ materially from
those projected. Forward-looking statements include statements about the
NMRC's, the USAMMDA's and the WRAIR's plans for a continued development of a
DNA vaccine for dengue, and the potential effect of the company's Vaxfectin(R)
adjuvant on vaccine performance. Risks and uncertainties include whether the
NMRC, WRAIR, USAMMDA, Vical or others will continue development of the dengue
vaccine; whether USAMMDA will sponsor and the NMRC will complete preclinical
and Phase 1 testing of a tetravalent, Vaxfectin(R)-formulated DNA vaccine for
dengue; whether Vaxfectin(R) or other results in animal studies can be
duplicated in human clinical trials; whether Vaxfectin(R) will improve the
immune responses against the specific dengue vaccine targets; whether the
dengue vaccine will be effective in protecting humans against dengue infection
or disease; whether the dengue vaccine will achieve the safety and
immunogenicity endpoints in the Phase 1 trial; whether Vical or its
collaborative partners will seek or gain approval to market any product
candidates; whether Vical or its collaborative partners will succeed in
marketing any product candidates; and additional risks set forth in the
company's filings with the Securities and Exchange Commission. These forward-
looking statements represent the company's judgment as of the date of this
release. The company disclaims, however, any intent or obligation to update
these forward-looking statements.
Contact: Alan R. Engbring
(858) 646-1127
Website: www.vical.com
