Tribune
leads press in AidsVax coverage as scientists
doubt VaxGen results spin
The failure of
AidsVax to prevent infection with HIV - in
clinical trial results published in 2003 -
triggered an intense debate about the
controversial product and its manufacturer,
VaxGen Inc of Brisbane, California. Mail to this
website, maintained by Brian Deer, shows that existing material on a
VaxGen-AidsVax index is read by significant
numbers. This page seeks to further inform the
discussion
AIDS vaccine trial
deemed a flop
Company's stock tumbles by 47%
By Jeremy Manier
Tribune staff reporter
Published February 25, 2003
The first potential AIDS vaccine to reach
advanced human trials failed to protect most
at-risk people from the virus, the drug's
maker said Monday, though company officials
made a claim that the vaccine could offer
some benefit for blacks and Asians.
Numerous AIDS researchers said Monday there
were too few minorities in the 5,400-person
study to draw any conclusions about the
vaccine's effectiveness in those groups. The
vaccine's developer, VaxGen, agreed that the
product had no effect whatever in the 90
percent of participants who were white or
Hispanic.
"Overall what we see is the trial
failed," VaxGen President Don Francis
said Monday of his company's AIDSVAX vaccine.
The dispute over whether the vaccine might
protect blacks and Asians caps a vaccine
trial that many AIDS experts viewed as flawed
and unlikely to yield a positive result.
While Francis and other vaccine supporters
hailed the effort as the first concerted
attempt to develop an AIDS vaccine, other
researchers said the company pushed the
product to advanced trials with little
evidence it would work.
Positive spin
VaxGen focused Monday on the results in black
and Asian vaccine recipients, who had
slightly lower HIV infection rates than
subjects who received a placebo. The most
pronounced results were in the black
subgroup, where four vaccinated people were
infected, compared with nine in the group
that received no vaccine.
But Dr. Steven Wolinsky, chief of infectious
diseases at Northwestern University, said
those numbers are too low to suggest blacks
got protection.
"This is a statistical game,"
Wolinsky said. "These numbers are very
small and difficult to interpret."
Other independent experts called the results
in minorities "intriguing" and said
VaxGen's approach merits further study.
"It still falls short of what I would
call conclusive evidence that this will
work," said Dr. Donald Burke, director
of the Center for Immunization Research at
Johns Hopkins University. "But there's
enough of interest that
it deserves serious additional
attention."
Because the trial was limited to North
America and Europe, experts said it had
little relevance for HIV strains found in
Africa or Asia, where the virus is most
prevalent and spreading quickly.
One cause for doubts among some researchers
was a recent federal investigation of a
VaxGen executive on a conflict of interest
involving AIDSVAX, which spurred concerns the
company had taken its vaccine farther than
evidence warranted. In 2000 the Tribune
reported that VaxGen Vice President William
Heyward had helped approve federal funding
for AIDSVAX trial centers just before joining
the company, while he was head of the AIDS
vaccine unit at the federal Centers for
Disease Control and Prevention.
Conflict of interest
The U.S. attorney's office in Atlanta ruled
last year that Heyward was negotiating for
work with VaxGen even as he used his position
at the CDC to help approve funds for the
vaccine trial. Heyward agreed to a settlement
in which he paid the government $32,500 and
admitted he "had a financial
interest" in the vaccine decision.
"This isn't about science; it's about
corporate survival," said John Moore, an
HIV researcher at the Weill Cornell Medical
College in New York.
VaxGen stock fell by 47 percent on Monday's
news to close at $6.86 per share.
In theory, AIDSVAX should protect patients by
spurring production of antibodies that halt
infection. The antibodies are supposed to
plug up molecules that would normally attach
the virus surface to a target cell. But a
preliminary 1998 study by a team of
virologists including Wolinsky found no sign
that the vaccine produced the desired immune
response. VaxGen set a low target for
success, hoping that 30 percent effectiveness
would be enough for approval by the U.S. Food
and Drug Administration.
FDA approval
Although Monday's results showed no effect
for the overall group of 5,400 subjects,
VaxGen officials said they will look into the
feasibility of getting the FDA to approve the
vaccine for use by minorities only. The
agency has never issued such a limited
approval for one ethnic group.
"It's not likely the FDA is going to
license this based on what we've seen so
far," said Dr. Richard Novak, a
professor of infectious diseases who led the
trial at the University of Illinois at
Chicago.
Novak and several other experts said one of
the most surprising findings was VaxGen's
preliminary claim that non-white people who
escaped infection had more antibodies from
the vaccine.
"If it pans out that antibody levels
correlate with protection from infection,
that is a huge finding," Novak said.
VaxGen would not release the antibody data
Monday, saying the analysis is ongoing.
Although some experts said the results in
minorities warrant further study, Wolinsky
said the numbers are too flimsy to offer
hope. "They're confusing doing something
with doing the right thing," Wolinsky
said.
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