AIDS Vaccine Advocacy Coalition Voices Disappointment in Trial Result - Applauds Merck's Leadership and Calls for Reinvigorated Effort to Design and Test AIDS Vaccines
Friday, September 21, 2007
New York, September 21, 2007 -- The AIDS
Vaccine Advocacy Coalition (AVAC) released the
following statement from Executive Director
Mitchell Warren about the announcement that
vaccinations have been discontinued in the STEP
Study, a test-of-concept trial of the MRK-Ad5
AIDS vaccine candidate developed by the Merck
Research Laboratories:
"Today's
announcement about the STEP Study is a deep
disappointment and a scientific setback for the
AIDS vaccine field. However, it must be seen
for what it is: the failure of a product to
show efficacy in a specific trial. Clinical
testing of AIDS vaccines is a scientific
process and, while this is a disappointment, it
is in no way the end of the search for an AIDS
vaccine.
"These data are certainly not
the ones that we had hoped for. The entire HIV
vaccine field, including AVAC, had been looking
to STEP and its companion Phambili trial in
South Africa, to provide initial evidence of
vaccine-related benefits. Even as the data
disappoint, we also note the success of the
STEP Study trial design in providing a swift
answer to the critical question of whether or
not the vaccine provided any benefits. A
successful clinical trial is one that produces
a scientifically accurate result. It may not be
the result you had hoped for, but it answers
questions that help the field move
forward.
"We applaud Merck's tremendous
leadership on HIV vaccine research. The company
has set an example for the field, taking on one
of the most important health technology
challenges of our time. Merck and its
collaborator, the US NIH-funded HIV Vaccine
Trials Network, have been committed, strategic
and willing to take risks at every stage of
evaluating MRK-Ad5, and they must be commended
for this. AVAC also recognizes the
contributions of the thousands of volunteers in
these trials. Their altruistic involvement
makes HIV vaccine research possible. It is
essential to build on what has been learned
here and proceed with further research as
rapidly as possible. Millions of lives are at
stake.
"In the next weeks and months the
AIDS vaccine field will need to make
carefully-considered decisions about whether to
move forward with planned trials of related
vaccine strategies, and how to proceed with the
Phambili trial, which has paused immunizations
and enrollment. AVAC is committed to working
with many other stakeholders in the AIDS
vaccine field and in other areas of AIDS
prevention research to ensure that these
discussions are thoughtful, transparent, and
clearly communicated to global
audiences.
"These results do not change
our fundamental view. Developing an AIDS
vaccine will require a series of large-scale
human trials in many different countries over a
number of years. These trials need to be
designed to produce clear results and to design
better candidates in the future. This research
must be complemented by ongoing studies of
other new biomedical prevention strategies, and
by full-scale, fully-funded implementation of
proven prevention and treatment strategies."
About the STEP
Study
An interim analysis of data
from the study, involving over 3,000 people
testing an adenovirus-based vaccine (MRK-Ad5)
developed by the Merck Research Laboratories,
showed no efficacy in protecting against new
infections or in reducing viral load in people
who received the vaccine and went on to become
infected. The study was scheduled to end in
2009. Periodic reviews of data by an
independent monitoring board are part of the
clinical trials process, and the study was
halted on the recommendation of the STEP Study
monitoring board after a regularly-scheduled
review.
There have been two previous
efficacy trials of an AIDS vaccine candidate,
called AIDSVAX. Both of these studies took more
than five years from launch to announcement of
the finding, that the candidate did not protect
against infection. The STEP Study enrolled its
first participant in December 2004, and we have
a definitive answer less than three years
later. Getting swift, precise answers about
candidates is crucial for the field. In this
sense, the STEP Study fulfilled its purpose, as
disappointing as the results may be.
One
reason for this efficiency is that both STEP
and its companion trial Phambili, which tested
the candidate in South Africa, were designed as
"test-of-concept" trials, to give an initial
answer about vaccine benefits in a relatively
abbreviated timeframe. The STEP Study met its
enrollment targets and its endpoint goals
within the timeframe specified by the trial
planners.