GeoVax Labs, Inc. (OTC Bulletin Board: GOVX) On September 21, 2007, Merck & Co., Inc. announced their candidate AIDS vaccine failed to provide protection in a human study designed to test for
efficacy.
In this Merck trial involving high risk volunteers, an equal number of
people received either placebo or AIDS vaccine. The independent Data Safety
Monitoring Board recommended that the trial be stopped because it was not
reaching its efficacy endpoints.
Merck has stopped further vaccinations but will continue to follow
volunteers in the trial. The Merck trial was being carried out in
conjunction with the HIV Vaccine Trials Network (HVTN), a prestigious trial
network funded by the US National Institutes of Health.
Don Hildebrand, GeoVax's President and CEO, commented, "We, along with
the rest of the scientific community, are disappointed in the clinical
failure of Merck's HIV vaccine trial. We all share the same goal of finding
a safe and effective vaccine to address the devastation of the HIV/AIDS
epidemic. We, however, would like to take this opportunity to highlight
important differences between our vaccine technology and the technology
used in the Merck trial."
GeoVax AIDS vaccines advancing in human trials represent a
significantly different vaccine approach, vaccine composition and results
to date than the Merck vaccine.
1) Prototypes for the GeoVax vaccines were selected from a series of
trials in non-human primates for their ability to protect against the
development of AIDS when vaccinated individuals were administered an AIDS
causing virus. At each major step along the development pathway, GeoVax
vaccines providing the best protection against AIDS were moved forward.
2) GeoVax AIDS vaccines demonstrated excellent protective results in
non- human primate models, much better protective results than reported for
Merck's vaccine in similar models. GeoVax AIDS vaccines protected 22/23
non-human primates for over 3 1/2 years and 5/6 non-vaccinated controls
died of AIDS post-AIDS virus infection.
3) GeoVax AIDS vaccines are designed to elicit protective antibodies
(Ab) as well as protective T cells (white blood cells) against the AIDS
virus. The Merck vaccine stimulates only T cells for providing protection
and does not include the Env protein of HIV which is the target for
protective antibody (Ab).
4) Protective Ab has been difficult to elicit with HIV/AIDS vaccines.
GeoVax has approached this challenge by vaccinating with the natural form
of Env (HIV envelope antigens) under conditions that elicit tightly binding
Ab. GeoVax studies in non-human primates clearly show this Ab correlates
with protection.
5) GeoVax vaccines use an attenuated smallpox vaccine to provide pulses
of HIV proteins (antigen) to stimulate protective anti-AIDS vaccine
responses. Pulses of antigen from the GeoVax vaccines elicit T cell
responses that rapidly mobilize and then contract into a state called
"central memory" from which they rapidly expand to fight the appearance of
HIV.
Merck's vaccines use adenovirus instead of poxvirus vectors. Adenovirus
vectors provide more prolonged AIDS virus antigen exposure than the GeoVax
poxvirus vectors. Prolonged antigen exposure affects the state of elicited
T cells and can compromise the ability to rapidly expand in the fight
against an infection.
"The Merck study highlights the importance of clinical trials in
vaccine development," said Dr. Harriet Robinson, Chief Scientific Advisor
for GeoVax. "The volunteers who participate in these trials are Heroes of
Vaccine Development and make it possible for products that are safe and
effective to be identified and licensed for human use. GeoVax salutes the
volunteers who participated in the Merck trials and the volunteers that are
participating in the GeoVax trials. These are people who care and have
volunteered for the greater good of humanity."
GeoVax AIDS vaccines are being prepared to enter Phase 2 human trials.
These large trials will expand the safety and positive immune response data
demonstrated in the five (5) prior GeoVax AIDS vaccine trial groups. These
trials will be conducted in collaboration with the HIV Vaccine Trials
Network.
On the basis of non-human primate studies, GeoVax believes its vaccines
will be safe and protective. A rigorously conducted clinical trial in human
volunteers will be accomplished to confirm effectiveness in preventing
AIDS. With 14,000 new HIV/AIDS infections reported daily and more than 60
million people living with HIV/AIDS worldwide, the need for an effective
HIV/AIDS vaccine is extremely urgent.
The US Food and Drug Administration (FDA) has established and
oversees the regulatory guidelines for clinical trials in the United States
and requires regular reports on the progress of clinical trials. The HIV
Vaccine Trials Network provides a unifying structure for trials of
candidate HIV/AIDS vaccines.
About GeoVax Labs, Inc.
GeoVax Labs, Inc. is a biotechnology company, established to develop,
manufacture, license and commercialize human vaccines for diseases caused
by HIV-1 (Human Immunodeficiency Virus) and other infectious agents.
GeoVax's vaccine technology is protected by 20 filed patent applications
and issued patents.
GeoVax HIV/AIDS vaccines are designed to prevent development of
Acquired Immunodeficiency Disease (AIDS), caused by the virus known as
HIV-1, by vaccinating individuals prior to their infection with the AIDS
virus. GeoVax vaccine regimens employ a "prime-boost" strategy where its
DNA vaccine "primes" the immune response and is followed by administration
of the GeoVax MVA (Modified Vaccinia Virus) booster vaccination. Both
vaccines deliver over 50% of the AIDS virus components but cannot cause
AIDS. In addition, GeoVax AIDS vaccines may be effective as therapeutics
[AIDS treatments]. Studies evaluating these vaccines in already HIV/AIDS
infected individuals are being planned.
GeoVax DNA and Recombinant MVA HIV/AIDS vaccines:
-- Use DNA for priming vaccine responses and recombinant MVA to boost
vaccine responses (DNA/MVA vaccine)
-- Protected 22 of 23 (96%) non-human primates for over 3 1/2 years post-
infection with an AIDS causing virus. Five of six non-vaccinated
controls died of AIDS within the 1st year of infection. These trials
used a prototype SIV/HIV vaccine for the HIV vaccine that is being
advanced in human trials
-- Are manufactured & tested under GMP/GLP - EMEA (EU) and FDA guidelines
-- Satisfactorily completed earlier DNA HIV/AIDS vaccine Phase 1 human
trial
-- Are currently being tested in 4 Human Trials. Two started in 2006, two
in mid-07.
-- Have been safe in all tested humans
-- Are demonstrating positive immune responses in the majority of vaccine
recipients
-- Are in planning stage for a larger Phase 2 human trial in 2008
Safe Harbor Statement: All statements in this news release, not
statements of historical fact, are forward-looking statements. These
statements are based on expectations and assumptions as of the date of this
press release and are subject to numerous risks and uncertainties which
could cause actual results to differ materially from those described in the
forward-looking statements. Risks and uncertainties include, but are not
limited to, whether: GeoVax can develop and manufacture these vaccines with
the desired characteristics in a timely manner, GeoVax's vaccines will be
determined to be safe for use in humans, GeoVax's vaccines will be
effective in preventing AIDS in humans, the vaccines will receive the
regulatory approvals necessary to be licensed and marketed, GeoVax can
raise the required capital to complete development of its vaccines, there
is development of competitive products that may be more effective or easier
to use than GeoVax's products, and other factors over which GeoVax has no
control. GeoVax assumes no obligation to update these forward-looking
statements, and does not intend to do so. Certain matters discussed in this
news release are forward-looking statements involving certain risks and
uncertainties including, without limitations, risks detailed in the
Company's Securities and Exchange Commission filings and report.
GeoVax Labs, Inc.
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