Exhibit 99.1
VaxGen Announces Initial Results of its
Phase III AIDS Vaccine Trial
BRISBANE, Calif. - February 24, 2003 - VaxGen, Inc. (Nasdaq: VXGN) today
announced initial results from the first of its three-year, multi-national,
randomized, double-blind, placebo-controlled Phase III trials of AIDSVAX
(rgp120) to prevent HIV infection.
The study did not show a statistically significant reduction of HIV infection
within the study population as a whole, which was the primary endpoint of the
trial. However, the study did show a statistically significant reduction of HIV
infection in certain vaccinated groups. Protection appeared to correlate with
the higher level of vaccine-induced neutralizing antibodies observed in these
groups, according to Michael Para, M.D., a principal investigator in the study.
The initial results reported in this news release are subject to additional
analysis. A more detailed analysis is expected to be presented at the Keystone
Symposia on HIV, March 29 to April 4. The full results of the trial will be
reviewed with the U.S. Food and Drug Administration (FDA) over the coming
months.
The results presented here are based on trial volunteers who received at least
the primary course of three injections of either vaccine or placebo. Recognizing
the limitations of subgroup analyses, the separate analysis of efficacy in
subgroups was pre-specified in the statistical analysis plan. The statistical
analysis plan was reviewed in advance by the FDA and its suggestions were
incorporated prior to unblinding of the data.
o The reduction of infection among the entire sample of volunteers,
including all racial groups, was 3.8% (p-value = 0.76; n = 5,009).
o There were 67% fewer HIV infections among ethnic minorities, other than
Hispanic individuals, who received vaccine compared to placebo recipients
(p-value <0.01; n = 498).
o There were 78% fewer HIV infections among black volunteers who received
vaccine compared to placebo recipients (p-value <0.02; n = 314).
Although the subgroup sample sizes were relatively small compared to the entire
study sample, the results are statistically significant. With regard to ethnic
minorities in the trial, there is less than a 1% possibility that the observed
difference in infection rates could have occurred by chance. There is less than
a 2% possibility that the observed difference in infection rates among black
volunteers could have occurred by chance. In addition to the results in those
receiving three doses, the reduction in infection in
individuals who received at least one dose of vaccine or placebo were similar
and also statistically significant. This analysis is known as "intent-to-treat".
Trial data indicate that black and Asian volunteers appeared to produce higher
levels of antibodies against HIV. White and Hispanic volunteers appeared to
develop consistently lower levels of protective antibodies following
vaccination. VaxGen intends to conduct additional analyses to confirm if there
was a direct correlation between the level of antibodies and the prevention of
infection.
"This is the first time we have specific numbers to suggest that a vaccine has
prevented HIV infection in humans," said Phillip Berman, Ph.D., VaxGen's senior
vice president of Research and Development and inventor of the vaccine. "We're
not sure yet why certain groups have a better immune response, but these
preliminary results indicate that a surface-protein vaccine that stimulates
neutralizing antibodies correlates with prevention of infection."
The results also indicate that AIDSVAX is well tolerated and has a high safety
profile. Vaccine recipients had a slightly higher rate of pain, swelling and
tenderness at the injection site compared to placebo recipients.
"We intend to continue development of this vaccine through licensure, including
additional studies as necessary, for use in groups in which the vaccine
demonstrated a significant reduction in infection," said Lance K. Gordon, Ph.D.,
chief executive officer of VaxGen. "In parallel, we will continue our work on
the vaccine to make it more broadly effective."
An independent Data and Safety Monitoring Board (DSMB) consisting of prominent
scientists, researchers, ethicists and a biostatistician oversaw the trial.
"VaxGen's conduct of this trial lived up to the highest standards of scientific
integrity," said Walter R. Dowdle, Ph.D., Chairman of the DSMB and former deputy
director of the U.S. Centers for Disease Control and Prevention (CDC). Dowdle is
one of several independent researchers who have taken part in reviewing the
trial data. The CDC participated in the statistical analysis, and the resulting
data were reviewed by Dowdle and four independent clinical researchers: Donald
Burke, M.D., from the Johns Hopkins School of Public Health; Neil Flynn, M.D.,
M.P.H. from the University of California at Davis; Donald Forthal, M.D., from
the University of California at Irvine; and Michael Para, M.D., from Ohio State
College of Medicine.
AIDSVAX is composed of a recombinant form of the protein (gp120) on the surface
of HIV and is produced in mammalian cell culture. It includes two HIV subtype B
antigens: MN and GNE8. The candidate vaccine cannot cause HIV infection since it
contains no genetic material from the virus. Made through recombinant DNA
technology, it contains non-infectious, genetically engineered proteins (rgp120)
that mimic proteins on the surface of two strains of HIV subtype B. This subtype
is prevalent in North America, Europe, Australia, Japan and Puerto Rico.
"Thanks to the dedication of thousands of trial volunteers, who are the real
heroes here, we have gained extraordinary new insight into how to prevent HIV,"
said VaxGen President and co-founder Donald P. Francis, M.D., D.Sc. "We also owe
a debt of gratitude to the investigators and their staff for their commitment to
the project. The results from this groundbreaking effort will provide new
insights into HIV and hopefully pave the way to ever more effective vaccines."
About the AIDSVAX B/B Phase III Trial
VaxGen's randomized, double-blind, placebo-controlled Phase III trial was
designed in consultation with the FDA to test AIDSVAX B/B for safety and
protective efficacy against the sexual transmission of HIV. The study volunteers
included 5,108 men who have sex with men and 309 at-risk women, all of whom were
meant to be HIV negative when they joined the trial. During the 36-month trial,
a total of seven injections were administered at months 0, 1, 6, 12, 18, 24 and
30. The ratio of vaccine to placebo recipients was 2:1.
The trial was conducted in the United States, Canada, Puerto Rico and the
Netherlands. Trial volunteers received regular counseling to avoid risks that
could lead to HIV infection and were advised to assume that they may have
received a placebo and that the vaccine might not be effective. A separate CDC
study indicated that volunteers did not increase their risk behavior, and
VaxGen's preliminary analysis of the trial data indicates that risk behavior was
reduced in both the placebo and vaccine groups.
"If licensed, this vaccine could be an important tool to help prevent HIV
infection, but it should not be considered a substitute for other risk-reducing
practices," Dowdle said. "HIV prevention programs will continue to be very
important."
VaxGen is nearing completion of its Phase III trial in Thailand, testing a
formulation of AIDSVAX designed to protect against HIV subtypes B and E, and
expects to announce results of that trial in the second half of 2003. Subtype E
is prevalent in Southeast and East Asia and the Central African Republic. Unlike
the AIDSVAX B/B trial, which tested the vaccine against sexual transmission of
the virus, the trial in Thailand is testing the vaccine against infection
acquired by injection drug use.
VaxGen is also in an early stage of developing a vaccine against HIV subtype C,
prevalent in Sub-Saharan Africa, India and China. The company is committed to
developing increasingly effective formulations of AIDSVAX that target all HIV
subtypes.
AIDSVAX B/B Trial Statistics
Number of volunteers to complete three immunizations: 5,009
Placebo recipients: 1,679
AIDSVAX B/B recipients: 3,330
White volunteers: 4,185
Hispanic volunteers: 326
Non-white volunteers (Black, Asian, Other): 498
Black volunteers: 314
Annual study infection rate 2.7%
Approximate Efficacy (after at least 3 primary doses)
All volunteers: 3.8% (p-value = 0.76; confidence interval: -23% to 24%)
Non-white volunteers: 67% (p-value < 0.01; confidence interval: 30% to 84%)
Black volunteers: 78% (p-value < 0.02; confidence interval: 29% to 93%)
Conference Call and Webcast
VaxGen will host a conference call and webcast today, Monday, February 24, 2003,
at 9:00 a.m. EST (14:00 GMT) to discuss the results of its Phase III AIDS
Vaccine Trial. Participants are asked to dial in 10 minutes before the start of
the call. The following phone numbers will provide access to the conference
call, the replay of which will be available through February 28, 2003.
WHEN: Monday, Feb. 24, 2003
9 a.m. EST (14:00 GMT)
WHERE: Live Call: Domestic: 888-937-5291
International: 212-271-4646
No passcode required
Replay: Domestic: 800-428-6051
International: 973-709-2089
Passcode: 286715
The replay will be available for five business days following the
call.
Webcast: Accessed via any one of three web sites:
www.vaxgen.com
www.kaisernetwork.org
www.companyboardroom.com ( insert Ticker: VXGN)
About VaxGen
VaxGen is focused on the commercial development of biologic products for the
prevention and treatment of human infectious diseases and is currently
developing vaccines against HIV/AIDS, anthrax and smallpox. Additionally, VaxGen
is the largest shareholder of Celltrion, Inc., a joint venture created to
provide large-scale manufacturing services, principally for products produced in
mammalian cell culture, including AIDSVAX. VaxGen is located in Brisbane, Calif.
For more information, please visit the company's web site at: www.vaxgen.com.
AIDSVAX(R) is a registered trademark of VaxGen.
VaxGen was co-founded by Donald Francis, M.D., D.Sc., and Robert Nowinski, Ph.D.
Francis leads the clinical development of the vaccine, and Dr. Nowinski, who
retired from VaxGen in 2001, was the company's entrepreneur, financing the
company at its origin and key early stages. AIDSVAX was invented by Phillip
Berman, Ph.D., head of VaxGen's research and development.
This press release contains "forward-looking statements" within the meaning of
the federal securities laws. These forward-looking statements include without
limitation, statements regarding the outcome of any further analysis of the
clinical data from this AIDSVAX trial, the timing and progress of completion of
development efforts for AIDSVAX, the need for additional clinical trials to
support licensure of AIDSVAX, the timing or ultimate outcome of FDA approval of
AIDSVAX in racial subgroups or more broadly, and the timing and progress of the
Company's second Phase III clinical trial in Thailand. These statements are
subject to risks and uncertainties that could cause actual results and events to
differ materially from those anticipated. Reference should be made to VaxGen's
Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission
on November 14, 2002, under the heading "Risk Factors" and to VaxGen's Annual
Report on Form 10-K, filed with the Securities and Exchange Commission on April
1, 2002, under the heading "Business" for a more detailed description of such
factors. Readers are cautioned not to place undue reliance on these
forward-looking statements that speak only as of the date of this release.
VaxGen undertakes no obligation to update publicly any forward-looking
statements to reflect new information, events, or circumstances after the date
of this release except as required by law.
Contact: VaxGen Media/Investor Relations
Domestic: 1-877-682-9436 (1-877-6VAXGEN)
International: 1-202-266-3325